Science Interviews

Interview

Wed, 21st Aug 2013

New batteries for renewable energy farms

Cullen Buie, MIT

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At the moment, there isa big debate going on about the fact that the UK needs more energy, can't decide where to get it from. One of the options is solar panels and wind turbines which offer really low carbon ways to generate power, but they only work when the sun shines or the wind blows. To make sure we’ve got power 24 hours a day, we need a way to store the energy that they generate and until now, this has been really expensive. However, writing in the journal Nature Communications this week, scientists from the Massachusetts Institute of Technology think that they’ve found a new and really cheap form of battery based on bromine solution. Dominic Ford spoke to Cullen Buie all about his idea.

 

Cullen - So, the great thing about this battery is that it gets the performance of systems with a membrane, but it eliminates the cost of the membrane. So, this is the next we have to no membrane which is one of the most expensive components of the cell.

Dominic - So, what's this membrane doing in the battery?

Cullen - So, the membrane is in the battery to separate the reactants. So you have reactions happening either side of the system and so, you need to separate those reactions or else they would happen spontaneously and you wouldn’t be able to get any useful energy from it. What we propose is a membraneless hydrogen bromine batteries.  So, batteries are typically characterised by their chemistry. We have this hydrogen bromine chemistry which actually isn’t new. This chemistry has been around and known since maybe the ‘70s and people have been excited about it because of the cheap and abundant reacting materials, and the potential for high efficiency. The problem is that it’s very difficult to design a membrane that will last for the thousand of cycles and that is low cost. So, it’s been limited by largely the materials because this hydrogen bromine battery makes hydrobromic acid which is difficult to work with for some membrane materials. Conversely, maybe 10 years ago, a research group at Harvard invented these membraneless systems. So, they were the first to propose eliminating membranes altogether and using fluid mechanics in order to keep your reactants separate. The issue there was that they used chemistries that- they didn’t produce a lot of power. So, it was interesting, but for the most part, the industry has disregarded these cells because they never produce enough power or energy in order to make them practically viable. So, what we’ve done is taken these two technologies which have kind of been sitting on the shelf effectively and put them together. And by putting them together, we get a hydrogen bromine system that now eliminates its issues with the membrane. And so, by eliminating the physical structure, we eliminate one entire component and all of its associated costs and complexity.

Dominic - Now, you're using bromine. Why is that so especially cheap?

Cullen - So, bromine is all over the world. It’s in saltwater. So, any place where you have a large body of saltwater, you're effectively, as a by-product of harvesting other things from saltwater, you get a lot of bromine.

Dominic - I know you're invisaging this battery for use with renewable energy generation. Why is it so important with renewable energy farms to have these large batteries?

Cullen - You have no control over when the sun is shining. Demand varies throughout the day. So, if you could couple storage with these intermittent sources like solar and wind, you can store the energy when it’s not being used and then sell it back to the grid when it is being used.

Dominic - When I think of new battery technologies, I think of cell phones and iPads, and so on. How do the needs of renewable energy farms compare to what you need for say, a cell phone?

Cullen - They're much more cost restrictive. So, the battery in your cell phone or in your laptop is probably at least 10 times more expensive than what you would like to see for something that’s going to go grid scale.

Dominic - I guess I find that quite surprising actually because you think if you're building a huge wind farm say, you’ve got a lot of infrastructure there.  You're pouring concrete for these windmills. I would’ve thought the cost of the battery on the back of that would be relatively slight cost.

Cullen - Our prevailing battery technologies are still very expensive. They use a lot of precious metals. They use things that are difficult to contain or control. And so, when you talk about that large scale, it’s difficult to make it scale and make it affordable.

Dominic - Is lifetime also an issue here? I mean, I'm thinking, if you're building something in the remote desert to harness solar power or you're building an offshore wind farm presumably you don’t want to be replacing those batteries every few months off the back of that renewable energy farm.

Cullen - Yeah, you nailed it right on the head. Lifetime is absolutely an issue. You want thousands of cycles, maybe 10,000 cycles. So, you mentioned batteries before.  How long does your battery actually operate? Maybe you get a year or two and then after 2 years, you notice all of a sudden, it can't hold any kind of charge. That would be unacceptable for something like a grid scale application.

Dominic - And the other problem that we have with cell phone batteries is the memory effect where if you're only ever half discharging it, then it doesn’t tend to hold its full charge any longer. That I guess is also something you’ve got to avoid in these batteries that are being charged when the sun shines and discharged when it’s cloudy.

Cullen - Yeah, you'd like to minimise all those effects, so it’s a very challenging problem. What we presented is just one more way and the novelty in this one is that we’ve eliminated one of the more costly components in the battery.

Dominic - How long do you think it would take to get this from the lab into the field? I mean, if you're saving a lot od money, if this is very cheap then presumably, the energy companies would be very keen to use this as soon as possible.

Cullen - I would say, 5 to 7 years. We’re talking about developing a new battery, a new type of battery.  New batteries don’t come out very often and part of the reason is, battery development is hard.

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Excellent technology, with serious economic consequences.

The problem with unreliable energy sources is that if they account for more than about 10% of the maximum grid capacity, they make the entire system uneconomic. If the wind blew at rated speed for 90% of the time, you would need 10% of your reliable sources to be switched off for 90% of the time in order to cover the gaps. This might be tolerable, but idle machines need space and maintenance, so they represent a financial loss (and the wind generally only blows at 10% of rated speed). Above 10% of unreliables, it is difficult  to persuade anyone to invest in conventional plant: big nukes and clean coal take a long time to fire up, small ones are expensive; gas plant costs less to install but is at the mercy of suppliers on the other side of the world; and whilst oil can be stockpiled, it is horrendously expensive to run. The sensible investment is in nuclear and big coal plant, but the prospect of at least 20% overcapacity or underutilisation will not attract shareholders.

So rather than impose levies on conventional power in order to subsidise unreliables, government should require windfarmers and the like to subsidise conventional standby plant, or require them to install at least 5 days' storage capacity at rated power, and insist that the store is full before allowing them to supply the grid directly.  alancalverd, Wed, 28th Aug 2013

But look how terribly dangerous nuclear power is probably as many as 100 people have died as a result of nuclear mishaps since 1940 syhprum, Wed, 28th Aug 2013

My goodness! That's almost a whole day's toll of coal miners, or ten minutes at Aberfan.

Now you could argue that wind electricity hasn't killed many people to date, but that is taking a very short-term view of windmills, which have been killing people on and off for thousands of years. And ignoring the lifecritical nature of a continuous electricity supply in the modern world.  alancalverd, Wed, 28th Aug 2013

Many of the "wind farms" are being built in places that get quite regular wind such as at the coast, or the Columbia gorge, although undoubtedly it varies somewhat with weather. 

Building a battery system with several megawatt-days, or gigawatt-days capacity, as well as high peak power flow, and low losses is undoubtedly expensive, as well as replacement expenses.  Some UPS type batteries may last over a decade, but only with occasional power drains.

It is my belief that hydroelectric power plants need to be redesigned to have a portion of the generation with quick reacting grid buffers.  While one might not want to vary the dam output from 0% to 100%, one could certainly fairly rapidly vary the flow by 10% or 20% or so.

In some cases, the reservoirs are back to back as on the Columbia River, or paired as the Lookout Point / Dexter Reservoir pairs in which the upper reservoir could go through huge production surges with little environmental impact.

In designing a "grid", one should consider each energy resource for its strengths and weaknesses.

Solar: Strong diurnal patterns.  Also affected by seasons and clouds.  Perhaps helped by an East/West or North/South power grid, but long distance grid links are also expensive.  Unused power is "wasted".

Wind:  Variable, 24 hrs/day.  Unused power is "wasted"

Nuclear, I believe power output can be varied somewhat on a diurnal basis, but to a large part slow reacting.  Also, one has to plan on shutdowns and recharge cycles.

Coal/Steam, also slow reacting, but can vary with diurnal usage.  UNUSED POWER IS CONSERVED.

Internal Combustion fuels including biogas, can be quick reacting, Unused power is conserved, depending on supply and storage.

Hydroelectric.  Generally seasonal.  Should have a couple of days partial storage capacity depending on the design, but certainly must use 100% of the water supply.  I believe many plants are designed to be slow reacting, but that isn't necessarily a requirement.  They should be able to be designed to be quick reacting, at least in part, especially if designed to buffer water flow.

Tides.  Diurnal, no storage capacity beyond perhaps a few hours.

Underwater Ocean Currents.  Are these fairly constant?  No Storage.

Anyway, it is my thought that rather than investing in expensive batteries, to design the grid to utilize the natural capabilities of each power generation system. 

Any use of fossil fuels should be incorporated only to buffer other systems considering essentially infinite storage capacity of the fossil fuels, and expense of the fuels. CliffordK, Wed, 28th Aug 2013

The big problem with wind is that power output depends on the cube of the wind speed, so a windmill with a nominal rating of 100 kW at its optimum wind speed tends to produce less than 15 kW averaged over a year, even in the best UK onshore locations. Offshore you can get about 20% of rated power but the maintenance costs are ridiculous. You can't make it go much faster than its optimum because the blade speed is limited to the speed of sound at the tip, so if you use big wings to squeeze the last drop out of a gentle breeze, you have to feather it in a gale (drag force increases with v^2, so you need to minimise the angle of attack to prevent damage), and a small fan will only produce useful power on the few days when it gets really windy.

All the best UK locations have been taken, so future wind plant is unlikely to exceed 10% of its rated capacity.  And even if we covered the entire country with windmills, we couldn't generate all the power we need (less than 30% of our energy consumption is electricity).   

Windmills are very effective where you can use power opportunistically. Grinding corn is possibly the only large scale example.

Scottish Hydro have already built pretty much everything that might possibly be economic for hydroelectricity in the UK.

Tidal power is hugely attractive in theory, and has been for the last 150 years or so. But only three large plants have ever been built because there really aren't many suitable locations.

My vote is for biofuel, and an 80% reduction in energy use. alancalverd, Wed, 28th Aug 2013

Storage of electricity has always been problematic. Liquid and gaseous/liquified fuels store much more densely and safely (because the atmosphere is a vast, omnipresent "free" repository of the other energy-producing ingredient: oxygen; it also doubles as a toxic waste dump - it's a pity we have to breathe the stuff!).

For solar-thermal generators, molten-salt thermal storage seems more promising than lithium-ion electric batteries. The thermal storage can shift generation capacity from the daytime (when the sun shines best) into the evening peak, when solar heating is fairly ineffective.

Most of the discussion so far has been about "Supply-Side" energy management, where you manage how much power is produced from different sources, and when.

However, an equally important aspect is "Demand-Side" management, where you manage how and when energy is consumed.

In some countries, there is a long history of using off-peak electricity for hot water and slab heating. The electricity company signals when it is to turn on and off, typically using tones on the power line to select one of dozens or hundreds of "channels". If power is short that night, they can leave it on for less time.

New buildings are often built from better insulating materials (less air conditioning load), are pre-configured so the power consumption in office blocks is reduced at night and weekends, and can often sense when rooms are unoccupied and turn off the lights

Extending this to other applications like air conditioning, dishwashers, clothes dryers etc is effectively a problem in communication, computing and economics.

In the end, what we spend on electricity is a tradeoff with what we spend on health, communication, transport, entertainment, food, etc. You only really discover how much you value something when it stops for a while...
evan_au, Wed, 28th Aug 2013

Another thing to consider.
Most of the "developed world" is based on grid power.

An alternative is distributed off-grid power.  In a sense, it is inefficient because excess power is wasted, and it can be difficult to plan for peak needs. 

However, there are some advantages such as lower line losses, and it shifts the storage needs from the producer to the consumers.  The consumer also becomes much more aware of actual power usage.

Anyway, one might consider encouraging distributed generation/storage in cases where the "grid" is unavailable such as the developing world, new developments, and places where the grid suffers massive failures such as after Hurricane Katrina. CliffordK, Wed, 28th Aug 2013

Using primary electricity for space heating is insane. It is the most expensive and most flexible form of energy we have, and really shouldn't be squandered. A properly insulated and correctly sited new build, even in the British Isles and the northern US states, doesn't require any space heating at all. A school in Chester, built some 50 years ago with airspaced double glazing, has never used space heating, and modern insulators are a lot better.

Right now I'm converting a 150-year-old stable  block into domestic accommodation. Despite having all-north-facing picture windows, and being shaded by trees on the south so negligible solar input, we calculate that an airsource heat pump will provide all the hot water and space heating for a 120 square meter single storey building - possibly the worst case starting specification for a single elderly occupant - for around £1.50 per day. With a family of four, it shouldn't need any space heating at all.

I never understood why commuter trains are heated in winter. You stand on the platform in the snow, wearing several layers of clothing, then cram into a small space with lots of other people, take off your coat, and sweat. Why not turn the heating off keep your coat on for the journey?   

Grid power actually accounts for very little of our energy needs. What matters is that it is instantly available at all times, and extremely flexible - hence the electricity grid, and with rather less flexibility, the gas grid.  I guess the most common example of distributed off-grid energy is road fuel. Reliable old technology, no problem dealing with peak demand, and no waste! And the consumer is acutely aware of power usage. Indeed that is true in any case where you have to pay for it, surely? alancalverd, Thu, 29th Aug 2013



"In 1979 the Danish government unveiled the “Heat Supply Law for Denmark,” dividing the country into regions that would be supplied with domestically produced natural gas, and those that would be supplied with CHP produced district heating. Furthermore, the government created an “obligation to connect law” which required citizens to connect to district heating or natural gas if it was available, and outlawed the use of electric heating for new building construction. This acted as a reinforcing loop - creating a strong domestic demand for the new Danish gas, and also for the continued expansion of district heating"- Source: Danish Energy Agency, 2010

And why not here? peppercorn, Thu, 29th Aug 2013

Creeping socialism, dammit. alancalverd, Thu, 29th Aug 2013

Here, rainfall is strongly seasonal.  And, thus river flow also is seasonal.  Thus, more hydroelectric energy is generated during the winter.    Therefore, there are actually benefits of using electric heating when there is more electricity being generated.

However, I agree it is ludicrous to keep the house at 70° year around.  Let it get a bit warmer in the summer and save on the AC bill, and a bit cooler in the winter. 

Much more could be done to incorporate geothermal heating/cooling in home design. CliffordK, Fri, 30th Aug 2013

In Quebec, the provincial hydroelectricity agency prices electricity so cheaply everyone uses it to heat their houses. The government then declares a loss which is made up by billions in equalization payments from the rest of Canada. No creeping socialism there, it's rampant. grizelda, Sun, 1st Sep 2013



I don't we should confuse mismanagement with socialism (of whatever flavour).

However, it would seem a great shame in places where hydroelectric is seasonal, that there may turn out to be far too little incentive to improve the housing stock to make it thermally efficient.  This outcome has not exactly been uncommon over the years in a 'free market' economy either; power has been cheap (relatively speaking) for a very long time. peppercorn, Mon, 2nd Sep 2013

Talking of socialism...

The Chinese government have identified the batteries in electric cars as being the perfect reservoir for the country's electrical storage requirements.  Imagine a whole population of electric vehicles with maybe a third of them plugged in and charging from the grid at any moment. Some of them will be pretty close to being fully charged and so they can be used to buffer the supply. Presumably you'd get some financial inducement to leave your car plugged in as much as possible.

Seems like an interesting idea. FunkyWorm, Wed, 4th Sep 2013

Yes,
Plug-In cars may serve as a power reservoir, unless you are planning on a trip that requires a 100% charge, and find your car is only 75% charged.

Battery life is also affected by depth of discharge and the number of cycles.  So, extra power cycles during the day may adversely affect one's car battery life, and having the batteries partly charged when one expects them to be fully charged could be bad.

On the other hand, some power companies are charging different rates depending on the time of day, so it may make sense to use a smart charger to recharge after midnight when the rates are lowest.  CliffordK, Wed, 4th Sep 2013

Well yes obviously renewable energy can provide 24-hour power with an energy store back-up but there's no need to re-invent the wheel here folks.

Pumped-storage hydroelectricity
http://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity
works well to back-up intermittent wind turbine power, if you build enough energy storage capacity to service your electricity grid's needs when the wind isn't blowing much.

The more difficult question, which I now have an answer for all you naked scientists to check my figures and peer-review for me please is -

How much nameplate or maximum wind power generation capacity in GigaWatts (GW) and pumped-storage hydro-electricity energy storage capacity in GigaWatt-hours (GWh) ONLY would it take to provide all the electrical power needs for the UK grid, 24-hours a day, 7 days a week?

My estimate for the UK grid's requirements is -

Wind Turbine maximum power 290GW
Pumped-storage hydro energy capacity 1400GWh

That's a LOT more of both needed than we have installed already.

Today in the UK we have about 12GW of wind power installed.

So I estimate we'd need a factor of 290/12 = 24 times more wind turbine power than we have today.

Today in the UK we have about 27GWh of pumped-storage hydro installed.

So I estimate we'd need a factor of 1400/27 = 52 times more pumped-storage hydro than we have today.

I initially worked out figures for the energy requirements of Scotland only, or a peak demand of 6GW or 11.4% of the UK peak power demand of 52.5GW.

Scotland Electricity Generation – my plan for 2020
https://scottishscientist.wordpress.com/2015/03/08/scotland-electricity-generation-my-plan-for-2020/



I've created a spreadsheet model to determine how much wind power and pumped-storage hydro energy capacity would be required for Scottish needs.

So remember to multiply the figures in my diagrams by 52.5/6 or 8.75 to get the appropriate numbers for the UK.

Modelling of wind and pumped-storage power
https://scottishscientist.wordpress.com/2015/04/03/scientific-computer-modelling-of-wind-pumped-storage-hydro/


Click for full size image - https://scottishscientist.files.wordpress.com/2015/04/windpumpedstorage_june.jpg


Click for full size image - https://scottishscientist.files.wordpress.com/2015/04/windpumpedstorage_january_b1.jpg

My cost estimate for Scotland was £50 billion for wind turbines and pumped-storage not counting grid infrastructure upgrades.

So say maybe £480 billion for the UK.

The annual government budget for the UK is something over £700 billion so a project of the size of £480 billion or the cost of 40 channel tunnels would clearly take a number of years to afford and to build.

So renewables-only electricity generation is indeed possible but it is not cheap and it is not easy, if my figures are anything like correct.

Scottish Scientist, Wed, 8th Apr 2015

Present UK grid capacity is about 80 GW. It is sensible to plan for 100 GW in the foreseeable future.

Nameplate capacity of a windfarm is of no importance: what matters is actual mean performance. Currently it is about 30% of rated capacity and is unlikely to improve as all the best sites have, of course, already been taken. So the current input from wind is about 4 GW averaged over the entire year.

http://www.gridwatch.templar.co.uk  shows today's wind contribution to be 0.68 GW as I write, about 1.9% of present consumption. The amount is likely to decrease in the next 3 hours as he sun goes down, and this will coincide with rising demand for rush-hour trains and domestic cooking. Today is fairly typical of the hottest and coldest days in the UK, which are the days when there is maximum demand and no wind. These anticyclonic conditions can last up to 14 days at a time, so if you want to rely entirely on wind you need at least 14 days' storage capacity, and 100% overcapacity in your generating system so that you can recharge the batteries when the wind blows, whilst continuing to supply the immediate load.

If you can site the storage units next to the windmills, that's entirely sensible and indeed should be a planning condition for every windmill. Unfortunately you probably can't do so for offshore windmills, and would create a huge visual nightmare and an additional maintenance problem if you did so for onshore wind. So you probably need to site your storage units somewhere near the distribution stations. Problem is that you now need to double the power capacity of the grid cables so they can carry both the demand current and the recharging current. You need to factor that cost into your calculation. 

Present pumped storage capacity is 30 GWh, installed on the best available sites. 14 days' storage is almost 27,000 GWh. Given the very small amount of ground above 1000ft amsl in the UK, I suspect that this cannot be achieved without substantial damage to upland farming. Remember that a PSU needs two ponds, one at the top of the hill and one at the bottom. And of course the pump/generators need to have the same running capacity as the maximum grid demand.

Thus, if you are prepared to flood  most of the Highlands and Snowdonia, you need to install 300 GW of windmills to meet peak demand, plus 300 GW to recharge the storage units, plus 100 GW of pump/generators, plus 100 GW of additional grid cabling and switchgear. 

The cost of doing so is left as an exercise for the reader, but I think you will find nuclear power a lot cheaper, more reliable, and less environmentally damaging. alancalverd, Wed, 8th Apr 2015

Hi Alan and thanks for your feedback.


Data statistics show a trend of decreasing maximum power demand.

Wikipedia
http://en.wikipedia.org/wiki/National_Grid_(Great_Britain)#Network_size
2005/6 63GW

Digest of UK Energy Statistics
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/337649/chapter_5.pdf
Table 5.9 page 143

2009 60,231 MW
2010 60,893 MW
2011 57,086 MW
2012 57,490 MW
2013 53,420 MW

Gridwatch
23/01/2014 17:30:03 52477 MW

I am no expert but my guess would be the energy trend is caused by the deindustrialization of the UK with our previous heavy industry being done in China increasingly?

So I don't foresee a need for 100GW total capacity on present trends.

Also I don't see an urgent need to build additional renewable reserves since it would be acceptable at least initially to use other types of capacity - such as biomass fuel burning or even fossil-fuel burning power stations as a reserve.

For the academic interest in looking at the figures, to calculate a capacity where peak demand = 70% of total capacity including reserves.

52.5 GW / 0.7 for a 75GW total renewable capacity.

maximum wind power + reserve = 290GW / 0.7 = 414 GW
pumped-storage hydro + reserve = 1400 GW / 0.7 = 2000 GWh




I've taken all those factors into account in my modelling. Did you not even notice that I recommend installing 290GW of wind turbines which makes peak demand of 52.5GW only 18% of installed nameplate wind turbine capacity?

My model has been tested on real gridwatch data for 2014 and the more cost effective solution is not "14 days' of storage capacity" but only a bit more than 1 day of storage and more wind power.

Alan you are doing what I was doing before I did the numerical modelling using real demand and wind power data from gridwatch -  guessing and going on hunches.

There's no substitute for running a computer model on real data and plotting graphs to prove your solution works. I did that. My solution works, I think. Certainly you are not disproving my model by quoting your hunch that 14 days storage is needed. No it's not.



Pumped-storage can be built in a very low profile way. Admittedly 52 times more pumped-storage than we have now, would have a higher profile but nothing like the profile of the existing wind turbines we have never mind the 24 times more we'll need.


Well I've just not factored the cost of grid into my cost estimates, sorry.



Already remembered, thanks.


290GW of wind turbines. Only more if we opt for a wind turbine reserve.


No peak demand is 52.5 GW so I only need 52.5 GW of hydro-generators. The same 52.5 GW for pumps is plenty too and has no problem in filling the reservoirs from empty in a little over a day.


The additional grid infrastructure is needed to connect up all the new turbines which can be supplying up to 290GW of power, but not all to the pumped-storage and demand. Anything in surplus above 2 x peak demand needs new grid for export only or to power-to-gas to generate hydrogen for the gas grid.


Aside from the grid costs which are complicated to calculate and depend on the length of new grid between plants whose location is not yet known, I've already estimated costs of about £480 billion for 290GW of wind turbine and 1400GWh of pumped-storage.

Well thanks again for your feedback Alan!
Scottish Scientist, Wed, 8th Apr 2015

1400 GWh (5.04x1015 J) of pumped hydro storage would be quite an engineering feat!

Even assuming 100% efficiency (not a terrible approximation) you would have to have about 1010 m3 (1013 kg) of water pumped up 50 meters. That volume is slightly larger than the average volume of Loch Ness, which is the largest Loch in Scotland (7.4 km3 = 7.4x109 m3)*.

Perhaps we could use an elevation of 300 meters (the height of the Shard, in London) and only 1.67x109 m3 of water (somewhere between the size of Loch Tay and Loch Morar)*.

On the other hand, 1400 GWh of electrochemical energy could be stored in 1.4x105 m3 of zinc metal (and the air needed to react with it). Not a small volume, certainly, but four or five orders of magnitude smaller than for pumped hydro.

*Loch volumes found here: http://en.wikipedia.org/wiki/List_of_lochs_of_Scotland chiralSPO, Wed, 8th Apr 2015

Hi chiralSPO and thanks for your feedback.


Check.
1400 GWh = 1.4TWh = 58.33 GW-days


This is 1960s technology. Technically, it is very easy to do and not such a big a job either. £37 billion or 3 channel tunnels' worth of work.

Now the wind turbines are more work. 290GW with 12GW installed already leaves 278GW to build and install and at £1.6 billion per GigaWatt (on land) that comes to £445 billion worth of turbines or 37 channel tunnels' worth.

So the wind turbines are far more of an engineering feat.


David JC MacKay in his book "Sustainable Energy - Without the Hot Air" considers finding sites for 1200GWh and reckons it would be tough.
http://www.withouthotair.com/c26/page_192.shtml

David cleverly managed to think of not putting all the water at one site though which makes it a lot less tough.

300 metres of head is typical for pumped-storage though 500 metres is possible too.
http://www.withouthotair.com/c26/page_191.shtml

The pumped-storage hydro scheme at the Cortes-La Muela, Spain hydroelectric power plant has a head of 524m and impounds a water of volume of 23Hm3 = 23 x 106m3 with a mass of 23 x 109Kg.


https://www.youtube.com/watch?v=No1itubcd4Q

Which represents a stored energy maximum of mgh = 23 x 109 x 9.81 x 523 = 1.18 x 1014J or 32.8 GWh. A similar amount of energy is planned by the SSE for their pumped-storage hydro scheme for Coire Glas, Scotland.
http://sse.com/whatwedo/ourprojectsandassets/renewables/CoireGlas/

So only 1400/32.8 = 43 Cortes-La Muelas or 1400/30 47 Coire Glases. I should point out that unlike Cortes La Muela which is pretty much maxed out, the site at Coire Glas - if the design was maxed out in the same fashion - could host a much bigger reservoir there - not 1400 GWh certainly - but 1/3rd of that possibly.

So if three sites like Coire Glas could site our needs for pumped-storage, I don't think it is as tough as David MacKay claims.

Time for the tough to get going.


Well pumped-storage hydro is the method of choice for electricity grid energy storage.

Thanks again for your feedback chiralSPO!



Scottish Scientist, Wed, 8th Apr 2015



and that, I think, is the fatal flaw in all proposals for wind power. During a winter anticyclone, the whole of the UK (and most of Europe) can be covered by a high pressure zone with average winds of 5 kt or less, for at least a week at a time. "More wind power" won't deliver any power when there's no wind! You need to consider a supply that, in effect, can go to zero for several days at a time, and when it recovers, you need to supply all the present demand plus enough power to recharge your storage system before the next shutdown. Thus your installed primary generating capacity needs to be about 6 times average demand, plus 1 x peak demand for the pumped storage units. Ignoring the cost of building the storage ponds and extra grid capacity, this means that you have to install 7 times the present generating capacity in order to meet present demand from renewables instead of fossil and nuclear generators. 

Saying that is frankly ignoring the weight of the elephant. As I understand it, current biomass generators in the UK are net negative - the energy required to transport and process the fuel is more than they produce - and any "reserve" station has to recoup its costs from unplanned and intermittent running, which makes even gas an uneconomic investment. And it's intellectually dishonest! You can't start off with a plan for 100% renewables and then say "plus a bit of coal in case it goes wrong".

My preference would be to reinstate low-pressure gasholders and use wind power to generate hydrogen which we distribute through the existing gas grid. And before the usual smartasses tell us about the difficulties and dangers of hydrogen, let me remind them that until 1963, the gas grid contained 50% hydrogen: the dangerous stuff was 10% carbon monoxide. alancalverd, Wed, 8th Apr 2015



and that, I think, is the fatal flaw in all proposals for wind power.
No testing my model on a whole year of real world demand and wind power data demonstrates there's no fatal flaw.


Well I tested my model on all the data from 2014, including the winter months.

Actually, as this graph of the January modelling shows, there was no such shortage of wind in January 2014.


Click for full size image - https://scottishscientist.files.wordpress.com/2015/04/windpumpedstorage_january_b1.jpg

The biggest lull in the wind in 2014 was pointed to on this "Idiocy of Renewables" webpage.

"92 Continuous Days of LoLo Wind - That's EverSoLo Electricity from Wind Turbines!"
http://idiocyofrenewables.blogspot.co.uk/2014/10/92-continuous-days-of-lolo-wind-thats.html

To cope with this difficult time, I had to fine tune my solution, but it does work as this graph for June 2014 shows.


Click for full size image - https://scottishscientist.files.wordpress.com/2015/04/windpumpedstorage_june.jpg

But instead of pointing to real data which illustrates a wind condition, you simply wave your hands in a data-free way. That's not scientific Alan.

I admit I have not tested my model on data from all years. Maybe there is data set from Gridwatch which will break my model and force me to increase the wind GW or pumped-storage GWh, but you certainly have not pointed to such a specific data set, have you?

You have not done the scientific thing which the author of the "Idiocy of Renewables" did when he quoted hard data to make his point.

You know Alan, I love a challenge. I really do. If you can point to the data of a very low wind spell in the UK from Gridwatch, I'd be delighted to test out my model on it.


is frankly ignoring the weight of the elephant. As I understand it, current biomass generators in the UK are net negative - the energy required to transport and process the fuel is more than they produce
Really? Got some evidence for that? Mankind has long used wood as fuel so maybe they knew something you don't?


Well the grid can hire power plants to stay on stand-by and pay a premium for emergency power and make reserve stations profitable.


If I had to resort to fossil fuel, gas would be the choice because a) it is a faster start up and b) renewable-generated hydrogen from power-to-gas can be added to the fuel mix.

My plan for Scotland recommends converting the last coal power station in Scotland at Longannet to burn biomass fuel.

I do offer a 100%-renewable 24-hours a day, 7-days a week electricity generation plan but it is much tougher to guarantee 52 weeks a year.

If that's as intellectually dishonest as the "teetotal" man who has one glass of sherry at Christmas, well I can live with that.


Yes, my plan generates surplus wind power at times of up 60% of maximum wind power. This can be used to produce hydrogen in power-to-gas for injection into the gas grid.

However, it is not as efficient to re-generate electricity from power-to-gas hydrogen as it is from pumped-storage hydro, so we need the pumped-storage as I have described for more efficient energy storage.
Scottish Scientist, Thu, 9th Apr 2015



As you say, we have 12 GW installed windpower in the UK.

According to Gridwatch, today is the seventh consecutive day with wind power at less than 2GW. In fact the running average is less than 1 GW for the past week.

I think you - or at least your customers - will find 24 hours' storage rather inadequate, even in a mild spring.

I am reminded of the statistician who, on learning that the average depth of the Thames is 3 feet, drowned whilst walking from Chelsea to Battersea. alancalverd, Thu, 9th Apr 2015



As you say, we have 12 GW installed windpower in the UK.
Yes.


Be aware that Gridwatch data for wind power is not what is served from the full 12 GW installed in the UK, but for only just over 50%. So Gridwatch's maximum wind power data reading in 2014 was only 6835 MW on 2014-12-09 19:50:02.

To check this, visit the Gridwatch website http://www.gridwatch.templar.co.uk/
and hover your mouse above the wind power dial and a context pop-up text bubble appears which says ..


Which also means the demand data is slightly lower than it really is too but that can be discounted for present purposes.



As I say, I love a challenge and the low wind period just now is such a challenge, so I've run it through my model - normalised for a case study of the UK this time - and here's the results.


Click for full size image - https://scottishscientist.files.wordpress.com/2015/04/windpumpedstorage_april2015.jpg

So there would still be some water left at this time in the 1400 GWh reservoirs with 290 GW installed wind power, but it is running low admittedly, so we'll have to wait to see if the wind can pick up to save the day or whether I will need to rethink my 1400 GWh / 290 GW recommendation.


Remember I have tested these the equivalent of these 1400 GWh / 290 GW specifications (normalised for the case study of Scotland) on the spring of 2014 and it worked.

As you can see for this period in early April 2015, the design specifications of 1400 GWh / 290 GW have managed this period of low wind (so far) for longer than 24 hours of low wind.

This is because 1400GWh is 58.33 GW-days but the daily average of power demand is less than the peak demand of 52.5GW. Demand from April 1 to 9 2015 has varied between a minimum of  25649 MW and a maximum of 43069 MW.


He should have gone to spec-savers.  Scottish Scientist, Thu, 9th Apr 2015

This is the 8th consecutive day with wind below 2 GW - your storage system is looking a bit marginal.

However, having addressed the elephant in the room, it is a good time to look at a couple of diplodoci.

Diplodocus 1. Electricity accounts for less than 25% of UK energy consumption. Practically all the rest is direct burning of fossil fuels. So if you replaced all electricity generation with wind, we would still be emitting at least 75% of current carbon dioxide levels, and society would grind to a halt when the oil runs out. If you want to run everything on unreliables, you will need at least 4 times as much generating distribution and storage capacity as your current best estimate, plus an unimaginable capital expenditure on electric transport and heating. As that expenditure will be mandatory, it will have to come from government or the windmill builders. Fat chance.

Diplodocus 2. We use electricity because it is cheapish and reliable. Given that you will need to install at least 3 times overcapacity (possibly 7 times on my assumptions) plus storage facilities in order to approach current levels of reliability, what is the anticipated future unit cost? You need to take into account a 10 - 15 year life for outdoor electromechanical equipment, a sensible rate of return on capital, maintenance costs (I usually estimate 50 - 100% of capital cost over 10 years for a guaranteed uptime maintenance contract. Equipment installed indoors at ground level is a lot cheaper to maintain.), and the cost of supporting the interim use of reliable sources.

The problem is that you are looking at it from an idealistic Scottish perspective. The more practical Irish saying is: If I was going to Cork, I wouldnt start from Dublin. Alas we are, metaphorically, in Dublin. And riding a diplodocus or two.
alancalverd, Fri, 10th Apr 2015


I demonstrated with a graph how my plan coped with your challenge but still you nit-pick.


Well what is the real problem? Fossil fuels "running out" or "warming the globe"?


The 25% of energy use for transport would need 2 times as much (more because of rush hours by trains and trams but less because electric motors are more efficient than combustion engines) but the 50% of heating energy doesn't need proportionally more electrical power because we can use the surplus power at windy times for hydrogen generation from power-to-gas and electrical storage heaters using off-peak electricity. Also heat pumps and geothermal heating provide proportionally more heat energy than electrical power consumed.


We can imagine and estimate the expenditure but none of it is "mandatory". We could just let the globe warm up.


I've recommended nameplate maximum wind power = 5.5 times peak demand.

The figures I gave were very clear - for Scotland 33GW/6GW = 5.5, for UK 290GW/52.5GW = 5.5

I'm not sure where you get "3" or "7" from?


I anticipated a total cost in my first post.



It all depends on how quickly, over how many years, the country decided to spend those vast amounts of money and how it was funded.  There's no requirement to fund any of it by additions to fuel bills.



Well it would have to be built to last because £480 billion extra is not an amount of money which Britain could afford to spend on electricity bills every 10 to 15 years. Maintenance costs would have to be much less than the capital investment otherwise it's not affordable.


Much is favourable in Scotland for renewable energy - the geography is ideal for both wind and pumped-storage - so Scotland could serve as a testing ground for a renewables-only energy strategy, for Britain, Europe and the world to test out solutions.

If we can't afford to do renewables-only in Scotland, chances are it won't be affordable anywhere.

HEY 'APOSTROPHES' ARE ALLOWED AGAIN! 
Scottish Scientist, Fri, 10th Apr 2015



Fine. But average demand for the last 8 days has been over 30 GW so you needed 240 GW-days to supply it. I don't think a 300% shortfall (and the wind is only just now picking up to 3 GW) is "nitpicking"!



We're not far apart here. 3 is the absolute minimum required to meet average demand, assuming that all future windfarms have the same average load factor as at present. Thus is unlikely as the best sites are already occupied. You need twice that capacity in order to meet demand whilst you are recharging your storage facilities, hence 6. Your storage facilities must also be capable of meeting peak demand, hence 7. But given the high failure rate of windmills (see below) you will need a continuous build program to replace them all every 10 years or so, so the figure is probably nearer 8 times.     



Perfectly correct and exactly wrong! Scotland is enormously favoured - perfect geography and climate, with very low populaton density. It is a rubbish model for England - flat, prone to long periods of zero wind, high population density - and virtually irrelevant to the rest of the world. Anywhere windier tends to be unpopulated except for the coast of Iceland, where steam comes out of the ground anyway. Anywhere with higher mountains and more rain already has signficant hydroelectricity.

Not much to test, really. You can't change weather or geography, or do much about demand distribution. Physics is well understood. Which just leaves economics:http://www.ref.org.uk/press-releases/281-wearnandntearnhitsnwindnfarmnoutputnandneconomicnlifetime



Compared with 45-plus years for nuclear and coal plant, this isn't an attractive investment.

There is a solution, but wind isn't it. alancalverd, Fri, 10th Apr 2015



Fine. But average demand for the last 8 days has been over 30 GW so you needed 240 GW-days to supply it. I don't think a 300% shortfall (and the wind is only just now picking up to 3 GW) is "nitpicking"!
It seems nitpicking when you don't acknowledge the graph I posted shows acceptable performance for the data available when I downloaded it which was up to the 9th April.



As I say, I love a challenge and the low wind period just now is such a challenge, so I've run it through my model - normalised for a case study of the UK this time - and here's the results.


Click for full size image - https://scottishscientist.files.wordpress.com/2015/04/windpumpedstorage_april2015.jpg

So there would still be some water left at this time in the 1400 GWh reservoirs with 290 GW installed wind power, but it is running low admittedly, so we'll have to wait to see if the wind can pick up to save the day or whether I will need to rethink my 1400 GWh / 290 GW recommendation.


Remember I have tested these the equivalent of these 1400 GWh / 290 GW specifications (normalised for the case study of Scotland) on the spring of 2014 and it worked.

As you can see for this period in early April 2015, the design specifications of 1400 GWh / 290 GW have managed this period of low wind (so far) for longer than 24 hours of low wind.

This is because 1400GWh is 58.33 GW-days but the daily average of power demand is less than the peak demand of 52.5GW. Demand from April 1 to 9 2015 has varied between a minimum of  25649 MW and a maximum of 43069 MW.





We're not far apart here.

We're as far apart as Hans Solo and Luke Skywalker.





You are "dusting crops" with your hand-waving guess-timates but I've got my "precise calculations" and "co-ordinates from the navi-computer" from my spreadsheet model.




Perfectly correct and exactly wrong! Scotland is enormously favoured - perfect geography and climate, with very low populaton density. It is a rubbish model for England - flat, prone to long periods of zero wind, high population density - and virtually irrelevant to the rest of the world. Anywhere windier tends to be unpopulated except for the coast of Iceland, where steam comes out of the ground anyway. Anywhere with higher mountains and more rain already has signficant hydroelectricity.

Not much to test, really. You can't change weather or geography, or do much about demand distribution. Physics is well understood. Which just leaves economics:http://www.ref.org.uk/press-releases/281-wearnandntearnhitsnwindnfarmnoutputnandneconomicnlifetime

Scotland is more of a "rubbish model" for somewhere such as Holland where it is even flatter than England. Scotland could still offer pumped-storage hydro facilities for surplus wind power generated in flat parts of Europe like Holland though.

My point was not that Scotland is the same as elsewhere but that all the key components of a renewables-only energy strategy could be developed, perfected and implemented there. It has the geography and it also has at least the beginnings of the engineers and engineering infrastructure required. It's an excellent place to host the engineering side of a renewables-only international effort.

Scotland is not the only such place in the world but the Scottish government has been keen to promote renewables - we have 5GW of wind power installed already - and I'm sure this is an area of industry where Scots would like to co-operate with others throughout the UK and internationally.



Compared with 45-plus years for nuclear and coal plant, this isn't an attractive investment.
Not at 10 to 15 years at £1.6 billion per gigawatt, admittedly. Nevertheless, the UK has 12GW already invested in wind turbines so the technology has advantages over the other renewables which the government has been promoting. Wind still looks like the best of the renewables.

Also, it may well be possible to drive costs down. Either new designs for turbines giving more power per pound and longer service-life or mass production techniques to reduce costs per turbine of much the same design.

Considering the size of the investment required, it makes a lot of sense to see what can be done to get costs down.


Backed-up with pumped-storage, maybe wind is a solution.

I don't think coal or fossil fuels can be made climate-friendly by carbon capture and storage (CCS) because CCS is vulnerable to black-market dumping of carbon dioxide which will defeat the climate change aim.

Nuclear has excellent prospects for portable power. I have a vision of helicopters big enough or nuclear reactors small enough to be flown anywhere in the world to provide power for the initial development of a location. Or a nuclear-powered ground vehicle, producing energy or fuel to power civil engineering machines - rail-track laying, road-building, runway making, port-construction. Enough to get conventional development established somewhere undeveloped, then the portable nuclear moves on to elsewhere in the wilderness where the going is too tough for fast progress because of power shortages.

So I'm all for nuclear where it offers unique advantages. But nuclear for grid power, I'm not convinced has a future though. Too risky - as Fukushima, Chernobyl, Dounreay shows. If you don't need to take the risk of nuclear - and with renewables, we don't - why take the risk?

Scottish Scientist, Fri, 10th Apr 2015



In 2014 Spain got 27% of its energy from wind power (21%) and the solar. According to you, nothing over 10% is possible. Spain are increasing this up to 40%.

Coal and nuclear? Are you blooding kidding?

Nuclear is very, very, very heavily subsidised (about 12p per kWh or more in liability insurance).

As for 'clean coal' what drugs are you on? The piles of toxic sludge that are the end product of burning coal are the lie to that, and there's the huge CO2 pollution. You'd have to be a complete idiot to build new coal power stations. Natural gas is much better, but even that...



Um. No.

The way it actually works is that the electricity gets a 'spot price' on the electricity market, and this determines what the electricity is sold at. In some grids, the price of electricity can actually go negative over short periods. The market mostly sorts itself out, people don't install generators if they don't think they will make money; and note that the subsidies on wind are very small right now; pennies per kWh.



It's not the deaths it's the economic disruption. Note that we haven't had the worst possible nuclear accident. For example with Fukushima, if the wind had been different, it would have dumped nuclear fallout over Tokyo. There was a possibility that they would have had to evacuate Tokyo...

Try to imagine what that would have been like. My brain is too small to imagine it, and I think yours is too. wolfekeeper, Fri, 10th Apr 2015



Fine. But average demand for the last 8 days has been over 30 GW so you needed 240 GW-days to supply it. I don't think a 300% shortfall (and the wind is only just now picking up to 3 GW) is "nitpicking"!
It seems nitpicking when you don't acknowledge the graph I posted shows acceptable performance for the data available when I downloaded it which was up to the 9th April.

Your graph appears to show 60 GW of wind power on 7 April. Gridwatch put the figure at about 1.5 GW. Does a discrepancy of 4000% count as nitpicking?




As long as I have to subsidise your product when I use it, pay an additional subsidy when it is not required, and fire up a coal station when the wind doesn't blow, wind power is one hell of a good investment. But if you eliminate the crooks politicians, insist on adequate storage and grid capacity, and leave it to the market, it isn't.

The fact that the government has been promoting anything is no measure of its rationality. There are three reasons why a politician does anything: because the EU tells him to, because it will improve his chances of re-election, or because his brother-in-law will make a profit.



It probably will anyway. Massive climate change predates homo sapiens, and it was warmer 500 years ago than now. Or maybe it will cool down. Nothing we can do to prevent it, but we could spend a bit of time and effort mitigating its effect, which will be disastrous either way. Chucking money at windmill manufacturers won't prevent mass migration as world agriculture fails to meet demand. alancalverd, Fri, 10th Apr 2015



Fine. But average demand for the last 8 days has been over 30 GW so you needed 240 GW-days to supply it. I don't think a 300% shortfall (and the wind is only just now picking up to 3 GW) is "nitpicking"!
It seems nitpicking when you don't acknowledge the graph I posted shows acceptable performance for the data available when I downloaded it which was up to the 9th April.

Your graph appears to show 60 GW of wind power on 7 April.
My graph is the result from a computer simulation of what wind power the UK would generate if the UK had installed 290GW of maximum wind power rather than just the 12GW we have installed just now.

So the grey line plots gridwatch data for wind power multiplied by a normalisation factor to indicate what wind power would have been produced had we 290 GW's worth of wind turbines installed. Understand?

Imagine 7 April is Groundhog Day but what Phil Connors (Bill Murray) does different this time is he installs 290 GW of wind turbines and 1400 GWh of pumped-storage hydro.



Well I told you to be aware about Gridwatch wind power data. Remember?



As you say, we have 12 GW installed windpower in the UK.
Yes.


Be aware that Gridwatch data for wind power is not what is served from the full 12 GW installed in the UK, but for only just over 50%. So Gridwatch's maximum wind power data reading in 2014 was only 6835 MW on 2014-12-09 19:50:02.

To check this, visit the Gridwatch website http://www.gridwatch.templar.co.uk/
and hover your mouse above the wind power dial and a context pop-up text bubble appears which says ..


Which means a Gridwatch wind data item of "about 1.5 GW" corresponds to a real UK wind power generation of something a bit less than 3 GW.



The exact normalisation factor used in the simulation is 4243%. That is worked out as 290000 / 6835.

290000 MW is the 290 GW maximum wind power installed being modelled and 6835 MW is the maximum wind power data item from Gridwatch wind power on 2014-12-09 19:50:02

So the model plots 42 times the wind power data Gridwatch records but only 290/12 or 24 times the actual wind power currently installed.

So you were only nitpicking about the days plotted, when there is no way I could have plotted data that was not available at the time.

It seems you have not before now begun to examine what values are being plotted.

So maybe less nitpicking on the days plotted and more attention to the detail of what is being plotted might be appropriate.



As long as I have to subsidise your product when I use it, pay an additional subsidy when it is not required, and fire up a coal station when the wind doesn't blow, wind power is one hell of a good investment. But if you eliminate the crooks politicians, insist on adequate storage and grid capacity, and leave it to the market, it isn't.
Well the energy market was never going to find its way to renewable energy on its own. It needed incentives. Either that or nationalisation.


And the greatest of these is "because it will improve his chances of re-election" 



It probably will anyway. Massive climate change predates homo sapiens, and it was warmer 500 years ago than now. Or maybe it will cool down. Nothing we can do to prevent it, but we could spend a bit of time and effort mitigating its effect, which will be disastrous either way.
Disastrous which "either way"? Warmer or colder? Preventing or not preventing? Mitigating or not mitigating?

It seems to me if we can prevent it getting a lot warmer that's likely to prevent a disaster.

If we can't prevent it getting a lot warmer, it seems to me mitigating it - by say moving to settle the cooler polar regions, building sea walls to keep out rising sea levels, growing crops on floating man-made islands towed to where it is cooler, putting up orbiting sun-reflectors - that could all help to prevent a disaster.


Well it may just help a lot with that too.
Scottish Scientist, Fri, 10th Apr 2015



Yes.

A bit colder and crops fail in Russia, western Europe and North America. A bit warmer and crops fail in southern Asia. Either way you will be looking at mass starvation or mass migration. We may be lucky as the warming seems to have slowed down a bit, but it hasn't reached a historic maximum yet. Unfortunately the human population has, and continues to rise, so life is becoming more marginal each day.

You might try to increase crop yields with artificial fertilisers, but it's already the case that about 20% of the mass of humans is derived from the Haber-Bosch process, which consumes vast quantities of fossil fuel (about 5% of all natural gas, currently) and ultimately damages the environment through nitrate runoff. Even if we ignore those elephants, a small change in rainfall distribution will be disastrous.

In summary: wind-generated electricity on a large scale creates more problems than it solves and is not affordable as a significant replacement for conventional generation; electricity is in any case not the key energy source for sustaining human life or lifestyle; and a climate-led disaster is pretty well inevitable. 

One question intrigues me: the "unmetered" wind power contribution. I can't imagine anyone giving away expensively-generated electricity, so my guess is that the unmetered capacity is individual windmills supplying fully-off-grid installations. Thus whilst they might be said to be reducing (or rather, eliminating) demand, you can't factor them against the actual metered demand on the grid.  I'd appreciate some elucidation here.  alancalverd, Fri, 10th Apr 2015



That's great if you work night shifts. Unfortunately most people use their cars during daylight. I guess you could have two cars, but as it takes as much energy to make a conventional car as it uses during its lifetime, and rather more to make an electric car, you're still screwed by the laws of physics. alancalverd, Fri, 10th Apr 2015

Not on today's grid it doesn't. Solar panels mean that the fossil fuel production goes down during the day, and the car pulls it back up at night. So the net carbon footprint is zero, or negative, even if you're not putting the electricity directly into the car.

And suitable pricing would help. You should be able to be charging your car with the electricity you're generating, even if you're not at home. It's all the same grid. There's no reason that couldn't be sorted out.
wolfekeeper, Sat, 11th Apr 2015



Yes.

A bit colder and crops fail in Russia, western Europe and North America. A bit warmer and crops fail in southern Asia. Either way you will be looking at mass starvation or mass migration. We may be lucky as the warming seems to have slowed down a bit, but it hasn't reached a historic maximum yet.
Even at our unluckiest, global warming couldn't speed up faster than the speed of modern civilisation to focus on the warming, slow it down or find another solution to any problems arising.

I wouldn't describe mass migration as necessarily being a "disaster" per se. One could describe the movement of Homo Sapiens out of Africa as a mass migration that happened over 200,000 years. Out-of-Africa was not exactly a disaster, except perhaps for the Neanderthals and maybe the previous top predators who had to make way for man.

The colonisation of the Americas was a mass migration. Again not a disaster, except perhaps for indigenous civilisations, such as they were.

You say "mass migration" like it is a bad thing. It doesn't have to be.


Now human population is something which can rise and fall at an astonishing rate compared to global temperature changes. However population rise can also be a solution, if the populations are well led and productive.


All such bridges have been crossed when we got to them. So shall it be.



I can see you are a rainfall gauge "half-empty" kind of guy. 


Well the affordability of £480 billion for the UK - or proportional sums for other countries - is questionable certainly. It would be wise not to put all our eggs in that basket until such time as the figures look more affordable. Nevertheless putting some eggs in that basket would be wise.


I didn't factor in non-metered demand into my calculations. That was ignored or discounted as irrelevant. The system I designed and modelled was to supply the metered demand only and it does that, perfectly so far.
Scottish Scientist, Sat, 11th Apr 2015

A lot of the 'unmetered' wind and (more so) solar is actually on the grid, and metered, but there's no real-time monitoring of them, so the graphs don't include them. Basically the individual installations are too small.

Nevertheless they do subtly appear on the graphs, but as a reduction in demand. The national grid do model them by using met-office data. wolfekeeper, Sat, 11th Apr 2015



20 years after the Kyoto Protocol, nothing has been done. In fact, if the warmists are to be believed, things are getting worse. I don't share your faith in human altruism. 

The gradual dispersal of a few humans into unoccupied hunting grounds cannot be compared with the movement of 150,000,000 Bangladeshis when the sea level rises and the crops fail for 3 consecutive years.

Hardly mass migration. The population of Tennessee, for instance, has grown "internally" by a factor of 200 since independence, and of the entire USA by a factor of 100 in just over 200 years. And as with the African diaspora, the spread has been onto largely unpopulated but very fertile land. There's not a lot left.

Your peaceful solution to a 5 cm sea level rise in Bangladesh would be welcome.


You are halfway to the solution. We could live very well and entirely sustainably with about one tenth of the present population. If we reproduce at half the replacement level, we would reach that state in 100 years at no cost - in fact a considerable saving of effort and money. I shudder at the idea of "well led": Great Leaders like Stalin, Mao, Hitler and Thatcher were a disaster.


All such bridges have been crossed when we got to them. So shall it be. What an appalling strategy! Everyone involved in such activities, from Caesar to Montgomery, regarded the planning of bridges and crossings to be absolutely essential to progress. There's an old saw about "the skilled pilot uses his skill to foresee and avoid situations that will place demands on his skill".



I can see you are a rainfall gauge "half-empty" kind of guy.  Well spotted. Actually I'm a pilot who notices "tanks half empty" before the fires go out.



Hold on there, pardner! You insist that present wind supply is twice what Gridwatch displays, but present demand is only the metered demand. You can't have it both ways! alancalverd, Sat, 11th Apr 2015



20 years after the Kyoto Protocol, nothing has been done. In fact, if the warmists are to be believed, things are getting worse. I don't share your faith in human altruism.
Civilisation has accomplished a lot in 20 years, including installation of renewable energy electricity generators. You, I and the warmists are 20 years older. For us as individuals things can always get worse, of course.

The gradual dispersal of a few humans into unoccupied hunting grounds cannot be compared with the movement of 150,000,000 Bangladeshis when the sea level rises and the crops fail for 3 consecutive years.

Hardly mass migration. The population of Tennessee, for instance, has grown "internally" by a factor of 200 since independence, and of the entire USA by a factor of 100 in just over 200 years. And as with the African diaspora, the spread has been onto largely unpopulated but very fertile land. There's not a lot left.
There's a lot of infertile land left world-wide to be made fertile by appropriate civil engineering works. There's also a lot of ocean left to be floated upon.

Your peaceful solution to a 5 cm sea level rise in Bangladesh would be welcome.
Raise the land by 5cm. Raise the sea walls by 5cm. If my first guess is not appropriate there will be plenty of time for the people of Bangladesh to come up with better solutions.

You are halfway to the solution. We could live very well and entirely sustainably with about one tenth of the present population. If we reproduce at half the replacement level, we would reach that state in 100 years at no cost - in fact a considerable saving of effort and money.
There's no need to seek to reduce the population. More people means more effort and money is available.


The bad leaders make my point that the quality of leadership makes a difference.


All such bridges have been crossed when we got to them. So shall it be. What an appalling strategy! Everyone involved in such activities, from Caesar to Montgomery, regarded the planning of bridges and crossings to be absolutely essential to progress. There's an old saw about "the skilled pilot uses his skill to foresee and avoid situations that will place demands on his skill".
Well I've managed to cross my own bridges perfectly well thank you. I don't claim to cross everyone else's bridges for them but trust them to do so for themselves but offer my help if needed.


I can see you are a rainfall gauge "half-empty" kind of guy.  Well spotted. Actually I'm a pilot who notices "tanks half empty" before the fires go out.
So you fly a fire-fighting airplane, do you? I always think there is more sense in dry lands subject to fires in allowing or insisting that people clear fire-breaks around their houses and that authorities do the same for roads so as to keep people safe enough but otherwise just let forests and scrub land burn. I'd rather employ fire-fighters in helicopters to go rescue people in danger than to employ them putting out forest, bush etc. fires.



Hold on there, pardner! You insist that present wind supply is twice what Gridwatch displays, but present demand is only the metered demand. You can't have it both ways!

I've not claimed either the unmetered demand or unmetered wind is "not present". I've simply ignored both unmetered demand and unmetered wind power as not relevant to my calculations, my recommended solution or the success of my solution. I'd be recommending 290GW even if unmetered demand and unmetered wind was 1000 times what it is, even if it was all the rest of the demand and the wind power in the world, even if it was demand and wind power in strange new worlds, new civilisations, to which we have not yet boldly gone.

My plan is to meet the metered UK demand with 290GW and 1400GWh and so far, so good. Scottish Scientist, Sat, 11th Apr 2015

The only thing I disagree with in the model is that you're assuming only wind and pumped storage.

In the real world we have solar coming up. It's running behind wind because it's more expensive than it, and much more expensive than burning dinosaurs... but it's starting to be cheaper than metered electricity from the grid. When that happens the price of the metered electricity from the grid will start to go up; more of the electricity will be peaking electricity. This will push installation of solar ever harder, because it's cheaper to the end user, and the grid will get greener.

Also, wind and solar are anti-correlated.

During the summer, the wind is relatively low, but solar goes up. Vice versa in the winter.

And then there's electric cars. Electric cars are a drop in the bucket right now. But the lifetime cost of electric cars is becoming cheaper than petrol cars. We're more or less at the cusp. When we cross the cusp a LOT of people are going to start buying. Sure, they're not good for everyone, but 99% of most people's journeys can be done with them (some people-notably sales people-need hybrids or diesels or other cars). But the vast majority of other people are better off with electric cars. So we're probably going to suddenly see a jump; large percentages of new cars will electric.

I mean, right now, there's about 2 million new cars sold each year in the UK. If even half a million electric cars were sold, after two years, there would be one million cars. If they were connected to the grid through inverters, then they could potentially supply the entire electricity demand for about half an hour (not that they would, but the point is that it's a *substantial* resource.)

So, electric cars; the pumped storage stuff may not be needed.

The fundamental point is that the more you add different types of sources and other storage to the mix, the more the variations even out. So the full 290 GW may not be needed; that gives on average maybe 70 GW or a little less, but to the extent other sources provide power, this can be reduced.
wolfekeeper, Sat, 11th Apr 2015



I was very surprised recently when a colleague decided to replace his petrol car by a hybrid car, on economic grounds. Part of this was the observation that the hybrid has a higher resale value than a petrol car of the same age. I always thought that they carried a significant cost premium.

A move from petrol to hybrids brings a significant reduction in dinosaur consumption*, provided you don't use the airconditioning too much.

A major takeup of all-electric cars (and smartphones and smart watches) depends on further advances in battery technology; unfortunately, this is an area of technology which is not progressing particularly quickly.

* OK, according to current theories, most carbon-based fossil fuels come from the Carboniferous period, which predates the dinosaurs. evan_au, Sat, 11th Apr 2015


No, that's false. The main problem that is stopping people buying the cars right now, is purchase price, but the cost of the battery (which is the primary cost item) is dropping 8% year on year due to economies of scale. The limited range is rarely the issue that people think it would be (some people really do regularly do long distances and they would be better off with a hybrid or a diesel.) The UK has a pretty good charging infrastructure now and it's likely to further improve.
wolfekeeper, Sat, 11th Apr 2015

Thank you for your feedback wolfekeeper.


Well what is it about my model that you agree with then?


Which very strongly suggests to me that I should extend my model to include power from solar as well.



Which makes me disappointed indeed that the Gridwatch site, http://www.gridwatch.templar.co.uk/ from where I downloaded the demand and wind power data http://www.gridwatch.templar.co.uk/download.php does not include any data relating to solar power. 

Does anyone know where data for solar-generated MW with time for the UK can be found? I mean like how much every 5 minutes like Gridwatch -

How Gridwatch data is downloaded, in a format that can be uploaded by a spreadsheet ...


- or how much every hour would be excellent too, but how much every week is no good for simulating how it interacts with wind intermittency. Daily values might be of marginal interest.

Anyone? Who knows where UK solar-generation data can be had? Come on! Speak up! 


The Scottish government has approved a plan to build a pumped-storage hydro scheme at Coire Glas, Scotland, proposed by the SSE, http://sse.com/whatwedo/ourprojectsandassets/renewables/CoireGlas/

but, frustratingly, has not been given financial incentives from UK policy.
I'm not the only Scot who is pointing this glaring omission out.

"Scottish Renewables – Pumped Storage – Position Paper"
http://www.scottishrenewables.com/media/uploads/140529_scottish_renewables_pumped_storage_position_paper.pdf

So I really need to accuse UK Secretary of State for Energy and Climate Change Ed Davey, and the UK government of Cameron & Clegg for really failing Scotland and Britain very badly on pumped-storage hydro. 

I can't really in any way agree with any kind of statement which lets that lot of rubbish UK politicians off the hook for not incentivizing or bankrolling the urgently-needed pumped-storage hydro.

If I am to be expected to discuss electric cars for energy storage, it needs to be after said politicians have been thoroughly named, shamed and turfed out of office, a better government is elected and all planned pumped-storage hydro plans are fully funded and going ahead to construction.


A very interesting fundamental point and if I can source solar generation data with time, I'll see what I can do to extend my model to investigate it.

Thanks again for your feedback wolfekeeper. 
Scottish Scientist, Sat, 11th Apr 2015

National grid do a far g(r)eekier version:

http://www.bmreports.com/bsp/bsp_home.htm

From there I managed to find this:

https://www2.bmreports.com/bmrs/?q=actgenration/actualorestimated

That might only be today's though, I didn't look at it too carefully, but if you hunt around you might find more.

edit: no you can select any day over a wide range and get the data. wolfekeeper, Sat, 11th Apr 2015


Great find wolfekeeper! 
Even the guy from gridwatch didn't seem to know about any solar data available. I will investigate further later and report back but the BM Reports site seems to be unresponsive right now. Scottish Scientist, Sat, 11th Apr 2015

I imagine the solar figures are estimates based on weather and PV installation data: the national grid need a model of it to improve their demand estimates.
wolfekeeper, Sat, 11th Apr 2015



It's not an omission. It's called "preparing for independence". For as long as SNP policy is to appropriate UK-owned energy sources and sell the product to the remainder of the Kingdom, you will have to fund your own capital projects.   


Reading Motorway Services has parking space for about 600 cars and 100 trucks, with two recharging points. OK for "early adopters" (I've never seen either charging point occupied!) but a long way short of providing an adequate replacement for liquid fuels. And as I am sure SS will agree, if you replace all road transport with electric vehicles, you will need to double your entire grid capacity: generation, distribution and storage. No problem, as long as the cost only falls on the users of electric vehicles (why  not? Petrol companies are not charities and not subsidised by the taxpayer - the entire extraction, refinement and distribution system is paid for by the user, who also pays 120% tax to support "alternatives"!) alancalverd, Sun, 12th Apr 2015


"Actual Or Estimated Wind And Solar Power Generation (B1630)"


You can select the year back to "1999" but get "No results" for selected dates earlier than about Christmas holidays 2014. The data doesn't look reliable. Highly corrupt or random data in places.

There's also "solar" data included here -
"Actual Aggregated Generation Per Type (B1620)"
https://www2.bmreports.com/bmrs/?q=actgenration/actualaggregated


The guy from Gridwatch says "that is estimated and its not real time. ..Its the guess for a days worth".

I asked him if he knew where to find solar data but he didn't offer much hope.


Hmmm.




It's not an omission. It's called "preparing for independence". For as long as SNP policy is to appropriate UK-owned energy sources and sell the product to the remainder of the Kingdom, you will have to fund your own capital projects.

Well we can still co-operate on joint projects even if Scotland goes independent, as per the Channel Tunnel which was a British - French venture, as was Concorde, as is Airbus. The fact that the UK and France are independent countries didn't stop us co-operating on a joint ventures for mutual benefit.

So let's co-operate, as Britons, but also as Europeans.

I was thinking, if we are needing to use solar then let's do it right.


"Solar power in the United Kingdom"
http://en.wikipedia.org/wiki/Solar_power_in_the_United_Kingdom

What Europe needs is a whole lot of mass-arrays of solar photo-voltaic panels somewhere near the south of Spain, either on land, or if the Spanish need their land for growing grapes or whatever, how about on artificial floating islands somewhere off Gibraltar?

Maybe north Africa wants in too? There's a lot of sun in Morocco across the Gibraltar Strait. Maybe Morocco would like to sign a 50- or 100-year lease to the European Union for some land in Morocco to put solar photovoltaic arrays on? We could make it worth their while. Guarantee the deal by deploying a European military force to guard our solar PV arrays and the interconnector carrying the power back to Europe.

So the Mediterranean or thereabouts for solar, everywhere for wind, Scotland for pumped-storage hydro.

If we pull together as Europeans, we can take advantage of the best renewable resources and share the spoils amongst us all. Everyone wins if we co-operate. If we retreat into our bunkers, everybody loses.

We need to be co-operating and national independence should be not be viewed as "a barrier" to co-operation on joint projects for mutual benefit. The multi-national companies have figured that out years ago so here and now we all also need the independent national public sectors to remember the benefits of working together, right?

Scottish Scientist, Sun, 12th Apr 2015


Reading Motorway Services has parking space for about 600 cars and 100 trucks, with two recharging points. OK for "early adopters" (I've never seen either charging point occupied!) but a long way short of providing an adequate replacement for liquid fuels.

Right.... so you've never seen either of them occupied, but you "know" that it's not adequate? Do you have these 'intuitions' often???


Right.... it's a 'funny' thing, none of the electric car adopters have reported their electricity bill doubling. It's almost like you're talking bullshit, but you would never do that, right?

Electric cars do, on average 25 miles per day. They use 0.15-0.25kWh per mile. So let's take the upper of those two figures. That's about 6.25kWh/day.

Let's further assume that all of the cars in the UK become electric. There's 35 million cars in the UK.

So that's 6.25 * 35,000,000 * 365 = 79 billion kWh.

Meanwhile the UK grids output in (say) 2012 was 375 TWh.

If you divide one by the other you get 21%; most of which would be done at night, when the grid is quiet, and that's assuming worst case 0.25 kWh per mile. More normally electric cars get more like 0.15 kWh/mile.

So nothing like doubling.

And that's going to take a decade or two to achieve.

Meanwhile, people are installing solar panels... currently at a faster rate than they're buying electric cars.

A 1kW (peak) solar panel in London makes very roughly 3kWh of electricity per day, on average. That's about 5 square metres. The car uses 4kWh.
wolfekeeper, Sun, 12th Apr 2015

Part of the problem for electric car users is the distance between filling stations. If you take the M25 and M4 from South Mimms to Reading, it's "only" 50 miles, with no service stations in between. The next station westwards is a further 20 miles, out of reach for most hybrids on "battery only" and marginal for medium 100% electrics. So if we have 500 electric cars parked at either station (not unusual) we will need 500 charging points, not 2. If you have slowmoving traffic in winter you can expect to find a fair number of automotive corpses around the motorways.

Yes, electric transport is great for urban use. I am all in favour of electric taxis, trolleybuses, trams and underground trains, but quoting "average daily mileage" does not make the electric car practicable for intercity use, or desirable in town. alancalverd, Sun, 12th Apr 2015


Everything you're saying is such complete and utter bullshit.

If you have a hybrid, do you want me to draw you a picture? They have a hole for petrol? You see the word 'hybrid' means hybrid electric-fossil fuel engine, and you can put fuel in it, or you can charge it from the wall. It's MAGIC.

And the economics of fast chargers is bloody simple, even for you. Each charger cost about US$60,000, about £40,000:

http://cleantechnica.com/2014/05/03/ev-charging-station-infrastructure-costs/

So if you charge (say) £40 for a recharge, then to repay for the charger infrastructure costs in a year each charger has to charge £40,000/£40 = 1000 cars per year = ~3 cars per day. After that, it's gravy. Of course you could charge less, say £20, and take longer to repay the loan, but the economics are simple; if you have cars queueing, add more chargers, unless you're a complete moron they make you money. (n.b. they're not charging at the moment, that's not a permanent thing, and they are already in some parts of America).

So if they really need 500 fast chargers, they would be ecstatic, they're making money.

edit: so what you're saying is that they may have to make multistory car parks, with fast chargers, so they can make EVEN MORE MONEY. Oh dear, they will be so sad. wolfekeeper, Sun, 12th Apr 2015

No need for a drawing, thanks. I first drew a hybrid car (actually it was a bus) 60 years ago and would very much like to own one, preferably with a gas turbine rather than a reciprocating engine as prime mover.

But this thread is about the replacement of fossil fuels by wind, not just better ways of using them.

The engineering of recharging stations isn't a problem. All you need to do is deliver an additional 20MW to every motorway service station. There are just over 100, so using your figures for a charging point and assuming there is adequate grid capacity and every station is within 30 m of an 11 kV supply, we need an infrastructure investment of about £1.5 - 2bn for the motorways alone. Probably the same again for A roads and again for city stations.

This leads to a chicken and egg problem. Even if I could afford the cost and inconveniece of an electric car, I couldn't go anywhere with it until there were enough charging points along the way, and it would be difficult to persuade anyone to invest £2bn in the hope that everyone will buy an electric car the next day. I think you would be looking at about 10 years for 50% market penetration. That sort of investment requires government intervention (not guarantees - they just end up with a tax bill and no product) and a nationalised electricity supply. I'm all in favour of that, but it doesn't seem very likely to happen in the UK.

alancalverd, Sun, 12th Apr 2015

I have no idea why you think the government would need to pay for this.

At the service station, they get money from the punters, and they use this to pay for the equipment.

If it costs them more, they charge more. They have (pretty much) a captive audience, and the equipment has a long life- they can probably easily borrow money for this, it's capital investment, and the users effectively pay them to build it.

It's self financing. It's money that would otherwise have gone to pay for petrol, often in another countries, instead it's spent on jobs within the UK.

On the contrary, the government could tax it, just like they tax petrol. wolfekeeper, Sun, 12th Apr 2015

The revenue argument is clear, but how are you going to raise £3billion capital for a venture that depends on everyone else buying an electric car before your hardware is obsolete? Market penetration (outside of the urban weekend ecowarrior clique) will be poor until the recharge network is complete.

Just try it! Private venture capital expects a 20% return in the second year of investment. Banks expect to see 50% equity funding for a new venture and are unlikely to lend at less than 10% in the foreseeable future. So you install £3billion capital equipment in, say , a year, then have to repay at least £300,000,000 in year 2 (half capital repayment, half interest, on the £1.5bn you borrowed). But how many people will have bought electric cars in the first year?

As I pointed out earlier, incremental growth (say 2 recharge points per station) is fairly easy to accomplish, but at some stage you are going to have to bite the bullet and undertake a massive refit to bring 20MW to each service station. If you are too slow, people will complain about having to wait for hours to recharge, if you are too quick you won't realise the expected (or required) return on investment.

Be sure the government will find a way to tax it, whatever you do, because whilst personal transport is obviously essential for politicians, it's an undeserved luxury for the plebs who vote for them. I'd prefer it if the grid were run as a profitable national asset, with a 20 year planning horizon. But I don't see any rightwing government nationalising the grid, or any leftwing government promoting private transport. And whilst businessmen can work with 20 or 50 year plans, politicians can't.

Any thoughts about electric HGVs? Obviously feasible, but what recharging facilities can you offer?    alancalverd, Sun, 12th Apr 2015

Look, none of this is rocket science; apparently it is for you, but I think everyone else reading this thread will understand that there's no fundamental problem, and I haven't even mentioned that you can order backup generators up to 250 megawatts, off-the-shelf items, to power recharging points during peak time if you're a bit shy on grid connection. The electricity itself is not even the expensive bit, it's installing the plug-in points, and as I say, they're self financing; and it's good to have a backup generator anyway, in case the grid goes down.

Really, this is not hard. wolfekeeper, Sun, 12th Apr 2015



I look forward to your becoming the first UK electric car billionaire. alancalverd, Mon, 13th Apr 2015

No, but buying shares in services stations might be profitable. wolfekeeper, Mon, 13th Apr 2015

Chicken! This is, apparently, a self-financing no-brainer, led by an acknowledged expert. You should be selling shares, not buying them! alancalverd, Tue, 14th Apr 2015


Check.
1400 GWh = 1.4TWh = 58.33 GW-days


This is 1960s technology. Technically, it is very easy to do and not such a big a job either. £37 billion or 3 channel tunnels' worth of work.

Now the wind turbines are more work. 290GW with 12GW installed already leaves 278GW to build and install and at £1.6 billion per GigaWatt (on land) that comes to £445 billion worth of turbines or 37 channel tunnels' worth.

So the wind turbines are far more of an engineering feat.


David JC MacKay in his book "Sustainable Energy - Without the Hot Air" considers finding sites for 1200GWh and reckons it would be tough.
http://www.withouthotair.com/c26/page_192.shtml

David cleverly managed to think of not putting all the water at one site though which makes it a lot less tough.

300 metres of head is typical for pumped-storage though 500 metres is possible too.
http://www.withouthotair.com/c26/page_191.shtml

The pumped-storage hydro scheme at the Cortes-La Muela, Spain hydroelectric power plant has a head of 524m and impounds a water of volume of 23Hm3 = 23 x 106m3 with a mass of 23 x 109Kg.


https://www.youtube.com/watch?v=No1itubcd4Q

Which represents a stored energy maximum of mgh = 23 x 109 x 9.81 x 523 = 1.18 x 1014J or 32.8 GWh. A similar amount of energy is planned by the SSE for their pumped-storage hydro scheme for Coire Glas, Scotland.
http://sse.com/whatwedo/ourprojectsandassets/renewables/CoireGlas/

So only 1400/32.8 = 43 Cortes-La Muelas or 1400/30 47 Coire Glases. I should point out that unlike Cortes La Muela which is pretty much maxed out, the site at Coire Glas - if the design was maxed out in the same fashion - could host a much bigger reservoir there - not 1400 GWh certainly - but 1/3rd of that possibly.

So if three sites like Coire Glas could site our needs for pumped-storage, I don't think it is as tough as David MacKay claims.

Time for the tough to get going.


Well pumped-storage hydro is the method of choice for electricity grid energy storage.

Thanks again for your feedback chiralSPO!


Intro please ...

Billy Ocean - When the Going Gets Tough, the Tough Get Going - https://www.youtube.com/watch?v=-n3sUWR4FV4



Click for a larger image - https://scottishscientist.files.wordpress.com/2015/04/strathdearn_pumped-storage.jpg

The map shows how and where the biggest-ever pumped-storage hydro-scheme could be built – Strathdearn in the Scottish Highlands.

The scheme requires a massive dam about 300 metres high and 2,000 metres long to impound billions of metres-cubed of water in the upper glen of the River Findhorn. The surface elevation of the reservoir so impounded would be as much as 650 metres when full and the surface area would be as much as 40 square-kilometres.

There would need to be two pumping stations at different locations – one by the sea at Inverness which pumps sea-water uphill via a pressurised pipe to 350 metres of elevation to a water well head which feeds an unpressurised canal in which water flows to and from the other pumping station at the base of the dam which pumps water up into the reservoir impounded by the dam.

The potential energy which could be stored by such a scheme is colossal – thousands of Gigawatt-hours – a minimum of 100 GigaWatt-days, perhaps 200 GW-days or more.

This represents enough energy-storage capacity to serve all of Britain’s electrical grid storage needs for backing-up and balancing intermittent renewable-energy electricity generators, such as wind turbines and solar photovoltaic arrays for the foreseeable future.

The geography of Scotland is ideal for siting pumped-storage hydro schemes to serve a European energy network infrastructure, with benefits for Scots, Britons and Europeans alike.
Scottish Scientist, Wed, 15th Apr 2015



David,

I’m honoured to welcome your first comment on my blog – the first of many I hope. Your book – “Sustainable Energy – without the hot air” by David JC MacKay
http://www.withouthotair.com/
is the 2nd-most quoted reference source (after Wikipedia) in the online discussions I have been party to regarding renewable energy, especially your Chapter 26 “Fluctuations and storage”
http://www.withouthotair.com/c26/page_186.shtml
in the context of pumped-storage hydro.

I rushed this post out in the early hours of this morning because I am keen to share my design concept at the earliest opportunity regardless that many key details of my proposal remain unspecified in the post at this time (15 April 2015). I intend to update this post on my own initiative and in answer to comments such as yours.

The most important missing detail in the first draft of this post is (was) any estimate for the power capacity. Whilst we may agree that power capacity should be in proportion to the energy storage capacity, we may differ on precisely what constant of proportionality to recommend.

On page 189 of your book,
http://www.withouthotair.com/c26/page_189.shtml
you recommend storage capacity equivalent to 5 days of average power. Attempting to follow the guidance in your book, from an energy storage capacity of 100 GW-days, would not your book’s recommendation for power capacity be the peak power equivalent of 20 GW average power (1.6 x 20 = 32 GW peak power) or for 200 GW-days energy storage then the peak power equivalent of 40 GW average power (1.6 x 40 GW = 64 GW peak power), which is a lot more than “a few GW”?

Peak-power is the more relevant nameplate specification for a pumped-storage hydro-scheme because pumps and turbines must be able to handle peak power, not only average power.

In my blog post “Modelling of wind and pumped-storage power”
https://scottishscientist.wordpress.com/2015/04/03/scientific-computer-modelling-of-wind-pumped-storage-hydro/
I modelled a smaller constant of proportionality for energy storage capacity of only 1.11 peak-demand-days (equivalent to 1.6 x 1.11 = 1.77 average power-days), with satisfactory results. So, as of now, I’m recommending only “1.77 days” equivalently compared to your “5 days”, a constant of proportionality of about a third of yours.

Accordingly, I’d recommend for 100 GW-days, a nameplate peak power capacity of 100 / 1.11 = 90 GW, and for 200 GW-days, 180 GW. As you can see this is considerably in excess of UK peak demand of 60 GW, opening up the possibility to provide grid energy storage services to Europe as well.

Those figures had to be discussed first before turning to the requirements for water flow through the pumps, the pipe and the canal because all of the features of the hydro scheme must be scaled appropriately.

The required flow rate of water can be calculated, as you know, from the head and the power capacity and the empirical Manning formula
http://en.wikipedia.org/wiki/Manning_formula
may be used to design the cross-sectional area of a canal to achieve the required flow rate.

So to get to your question David, yes there would indeed be problems in maintaining the required flow along the canal to maintain the head – at both ends because flow is in both directions – but a holding pool at either end, however large, would not solve those problems. Only a canal of a sufficient cross section with additional design features as required could hope to do so.

I’ve not done any estimates for the required minimum cross section of the canal as yet but that’s of interest certainly.

Once again, David, I must tell you how ‘fair chuffed’ I am that you commented on my post!
Scottish Scientist, Wed, 15th Apr 2015

You think you could get planning permission for that massive salt-water tank? There are better technologies on the way which will wipe out the point of it before it could be built. David Cooper, Wed, 15th Apr 2015

The scale of this 64 GW dam project can best be appreciated by comparison with the Hoover Dam with a peak output of 1.4GW, and Drax power station (4GW). The largest hydroelectric station in the UK is 0.3GW at present. Admittedly these are fairly historic structures, so a fair comparison would be with the 22 GW Three Gorges Dam



except that both Hoover and Three Gorges are freshwater systems. Having overcome the minor technical problem of pumping seawater back and forth, raised enough money to build a power station three times larger than any other on the planet, and installed a distribution system to carry the entire national demand to and from one station instead of 600 with sufficient redundancy, you may find just the teensiest hint of concern from the occasional treehugger!

I think it is an inspiring project, which should be started immediately and funded entirely by the windpower industry. As the Hoover Dam was completed in 5 years and the Three Gorges in 12, it should be possible to complete this project before wind generation exceeds 20% of grid capacity - the point at which grid stability would be seriously compromised. The only pity is that it is in the wrong place:



but you can't have everything! alancalverd, Wed, 15th Apr 2015

Mere scale is virtually never a reason not to do something. You should look at stuff like cost per person, and the timescale over which it would be built instead. wolfekeeper, Fri, 17th Apr 2015

Scale is important because this project requires capital input. There is obviously no physical reason why it can't be done but the practicality is that you need enough money up front to start the work, with a sufficient promise that it will be funded to completion. Failing that, a project will run into the sand as lack of continuing funding means delay, which increases costs and makes further funding less attractive. 

Whilst Scottish independence remains a serious possibility, it won't be funded by the UK government, so the money has to be raised either by private investors or by taxing the Scots for long enough to build up the required capital reserve (and not spending it on something else, which politicians are bound to do). 

So, let's have some cost estimates, please! alancalverd, Fri, 17th Apr 2015

I’ve updated my post to include more detailed estimates for the reservoir volume, maximum flow rate, energy storage and power capacity.

The volume of water impounded by the dam - about 4.4 billion metres-cubed of water.

The maximum potential energy which could be stored – about 6800 Gigawatt-hours – or 280 Gigawatt-days.

To fill or empty the reservoir in a day would require a flow rate of  51,000 metres-cubed per second, the equivalent of the discharge flow from the Congo River, only surpassed by the Amazon!

When nearly empty and powering only the lower turbines by the sea, then about 132 GW could be produced. When nearly full and the upper turbines at the base of the dam fully powered too then about 264 GW could be produced.

I’ve also used the Manning formula to estimate a canal size to cope with the maximum flow rate.

Canal

The empirical Manning formula relates the properties, such as volume rate, gradient, velocity and depth of a one-directional steady-state water flow in a canal.



Click to view a larger image - https://scottishscientist.files.wordpress.com/2015/04/manning_power_canal_200.jpg

For 2-way flow, the canal must support the gradient in both directions and contain the stationary water at a height to allow for efficient starting and stopping of the flow.



Click to view a larger image - https://scottishscientist.files.wordpress.com/2015/04/2-way_power_canal1.jpg

The “2-way Power Canal” diagram charts from a spreadsheet model for a 51,000 m3/s flow how the width of the water surface in a 45-degree V-shaped canal varies with the designed maximum flow velocity. The lines graphed are

• Moving width – from simple geometry, for a constant volume flow, the faster the flow velocity, the narrower the water surface width

• Static width – the width of the surface of the stationary water with enough height and gravitational potential energy to convert to the kinetic energy of the flow velocity

• 30km 2-way wider by – using the Manning formula, the hydraulic slope can be calculated and therefore how much higher and deeper the water must begin at one end of a 30km long canal to have sufficient depth at the end of the canal and therefore by how much wider the canal must be

• Canal width – adding the 30km-2-way-wider-by value to the static-width determines the maximum design width of the water surface.

The equation thus derived,

y = 2 √ ( 51000/x) + 0.1529 x2 + x8/3/40

where y is the maximum surface water width in the canal and x is the designed maximum flow velocity

predicts a minimum value for the canal width of about 170 metres (plus whatever additional above the waterline freeboard width is added to complete the design of the canal) at a design maximum flow velocity between 10 and 11 metres per second.

Guinness World Records states that the widest canal in the world is the Cape Cod Canal which is “only” 165 metres wide.

So the canal, too, would be the biggest ever!


Well the SSE got planning permission for their plans for a pumped-storage hydro-scheme at Coire Glas.

BBC: "Scottish government approves £800m Lochaber hydro scheme" - http://www.bbc.co.uk/news/uk-scotland-highlands-islands-25365786

Admittedly, the SSE plan is only for a 30GWh reservoir and mine is some 226 times bigger.


Well the "long-life" electrical battery has been such a favourite topic for marketing hyperbole for so many decades that scientists are naturally sceptical of any such new claims.


I've increased the estimate for the storage capacity up from "200 GW-days or more" to "280 GW-days", so even assuming David MacKay's very conservative requirements for 5-days of average power that estimate goes up to 280/5 x 1.6 = 90 GW.



The population density of the Highlands of Scotland is 9 people /km2. The scheme could be easily contained within 4 squares each of 10km x 10 km. So tops only 400km2 x 9 = 3600 people might be displaced (with generous compensation I trust).


The Okinawa pumped-storage hydro scheme uses the sea as a lower reservoir.
http://en.wikipedia.org/wiki/Okinawa_Yanbaru_Seawater_Pumped_Storage_Power_Station



Even the SSE has not raised the £800 million for their 226 times smaller scheme, so the 226 x £0.8 billion = £180 billion for this scheme is a big ask.


It all adds to the cost, for sure.


We can easily plant more trees than we have to uproot for this scheme.


No for this, I was thinking some of the European Central Bank quantitative easing money would come in handy.
http://www.bbc.co.uk/news/business-30933515
The ECB has only created 60 billion Euros because, after all, governments don't tend to trust bankers all that much these days but for a sound investment like this, with overwhelming benefits for Europe's renewable energy goals, perhaps the ECB can be persuaded to chip-in a good deal more than 60 billion Euros. Then of course the UK can chip-in with some Q.E. or deficit-spending likewise.

It's a big ask but it is worth it.


Well this scheme's full power output from 130 GW up to 230 GW of power available is 20% of 650 GW to 1150 GW or 20% of the entire generation capacity of Europe.
http://www.eia.gov/cfapps/ipdbproject/IEDIndex3.cfm?tid=2&pid=2&aid=7



but you can't have everything!

Direct current is more efficient for long distance power transmission.
http://en.wikipedia.org/wiki/High-voltage_direct_current


Agreed.


I think the way to build this is not all at once but first to build part of the sea-side scheme, using a length of canal as an upper reservoir.

Get a system working for Scottish 2020 renewables-only needs then once the team which has done that has a working scheme in place, hopefully the investment to complete the rest of the sea-side scheme and the reservoir and dam-base pumps would become available.

That way at least we'd have working pumped-storage to show for any investment if the money ran out before final completion.



8 GW / 8.5 GW-days - £5.4 billion (Scottish needs demonstrator project, using about 20km of canal as the upper reservoir)
264 GW / 280 GW-days- £180 billion
Scottish Scientist, Fri, 17th Apr 2015


Well the "long-life" electrical battery has been such a favourite topic for marketing hyperbole for so many decades that scientists are naturally sceptical of any such new claims.


I was thinking about two things: nuclear fusion power stations, and battery storage optimised not for power to weight ratio but for low cost bulk storage (there are promising noises coming from people working on that). Both of these will be in place before you can build your monster.

What is certain is that your giant fish tank would meet with enormous opposition for a variety of obvious reasons. You're talking about a dam 300m high and 2km long - an earthquake of 6 on the Richter scale is not an impossibility in that location, so I wouldn't want to live downhill from there. David Cooper, Fri, 17th Apr 2015

The production of concrete generates 410 kg of CO2 per m3.

A dam is roughly triangular in section with base width equal to its height, so we are looking at a carbon footprint of 37 million tonnes of carbon dioxide for the dam, plus probably twice as much to line the canal. plus whatever it takes to get the concrete to site. I guess at least 150 megatonnes. How much wind energy is required to offset this?

Remember that this project doesn't generate any energy, it merely stores energy generated elswhwere, so there's no "carbon offset" involved.

Nuclear power has the lowest carbon footprint of all energy sources, at about 4 gram per kWh so you would need 37,500 GWh of additional free wind energy to repay the carbon cost of building the project. Except that wind actually has a higher carbon footprint than nuclear, so if you wanted to reduce the overall carbon emission of the electricity grid you would do better to replace all the fossil plant with nuclear: no storage problem, no additional land requirement, and no additional transmission grid capacity.

But the SNP is pledged to a non-nuclear Scotland! alancalverd, Sat, 18th Apr 2015

I agree that nuclear power is an excellent, low carbon energy source that should be taken better advantage of. However, that doesn't get you completely away from the energy storage problem. Nuclear plants have a very constant output, that can only be modulated a little bit, and quite slowly (as far as I know). While this can be used to provide a large portion of the base load, it is ill-adapted to the variability in consumer demand for electricity. Energy storage technology is still required for peak shaving and peak shifting, if you don't want to have some gas- or coal-fired powerplants that get cycled on and off as needed... chiralSPO, Sat, 18th Apr 2015

We could get rid of a lot of the sudden peaks in energy demand by getting rid of soap operas. David Cooper, Sat, 18th Apr 2015

There is certainly a place for pumped energy storage in an all-nuclear system, but as the ramp-up time for a nuke is a matter of minutes (the trick is never to shut the reactor down completely, and baseload is about half peak in the UK), you don't need to store the entire grid demand for 5 days, just half the demand for an hour or two. This was the philosophy behind Dinorwig, and it works very well. 

As I recall, the largest peak demand was during the Queen's coronation. as the procession left the Abbey, the entire nation switched the kettle on and went for a pee. alancalverd, Sun, 19th Apr 2015

Nuclear is a non starter; renewables are growing far faster and that's not changing any time soon.

Although nuclear reactors can and are built to load follow, running a nuclear reactor at partial power makes it even less economic; the cost of the electricity is inversely proportional to its production.

Indeed that's why Dinorwig was built, it looked like they would need a whole bunch of pumped storage because the plan was to produce lots of nuclear power plants and they didn't want to have to make them load follow; in the end nuclear got scaled wayyyy back.

Apart from the huge economic risks of a major meltdown, nuclear power also has the waste problems, which have never really had any good solutions, only least bad ones; which still weren't very good.
wolfekeeper, Sun, 19th Apr 2015

At the moment I can't remember who to attribute this to, but there is a quote or saying out there along the lines of:

"I am a firm believer that nuclear fusion will ultimately be the only source of power used by the people of Earth--after all, we already have the reactor!"


In all seriousness, with the exception of radioactive materials and geothermal power, all of our energy is originally solar. We just need to develop more efficient ways of capturing, storing and distributing that energy, and we would have access to an almost unlimited  supply of energy (several orders of magnitude more than our current demands.) chiralSPO, Sun, 19th Apr 2015



Plants do it very well, and you can eat them too. The problem is that there are too many people. But that problem can be solved by simply doing nothing - make fewer people. Alas, however, there is no profit to be made by such a simple solution, and a world with a small population of well-fed, contented people would have no need of priests, politicians, and other parasites, so it won't happen because people are individually clever but collectively stupid. alancalverd, Sun, 19th Apr 2015

Plants are actually not that good at photosynthesis; their conversion efficiency for solar energy to plant energy is only about 1-3% or so, whereas solar panels are ~15-45% or more. Some of that is probably because they need the energy for metabolism; but the end result is the same; they suck for what we as humans want from them. wolfekeeper, Sun, 19th Apr 2015

Canal lining and boulder trap



To maximise the water flow velocity, canals are lined to slow erosion. Concrete is one lining material often used to allow for the highest water flow velocities, though engineering guidelines commonly recommend designing for significantly slower maximum flow velocities than 10 m/s, even with concrete lining.

Designing for a slower maximum flow velocity requires a wider canal to maintain the maximum volume flow rate and is expensive in construction costs.

Water flowing at 10 m/s has the power to drag large – in excess of 10 tonnes – boulders along the bottom of a canal with the potential of eroding even concrete, so I suggest that the bottom 6 metres width of the lining, (3 m either side of the corner of the V) may be specially armoured with an even tougher lining material than concrete and/or include bottom transverse barriers of 2 metres depth to impede the flow along the corner of the V and trap boulders, smaller stones and gravel, in which case the water flow is more precisely modelled for Manning formula calculations as a trapezoidal canal with a bed width equal to the 4 metre width of the top of bottom transverse barrier (“boulder trap”) and a 2-metre smaller depth from the top of the boulder trap to the water surface.

Main Dam


Click to view a larger image -  https://scottishscientist.files.wordpress.com/2015/04/strathdearndam.jpg

The image shows the location of the main dam at latitude 57°15’16.2″N, decimal 57.254501°, longitude 4°05’25.8″W, decimal -4.090506°.

Click to view location on Google Maps -

NOPE - MY LINK TO GOOGLE MAPS IS BEING BLACKLISTED
but I've got a work-around via tinyurl
http://tinyurl.com/StrathdearmDamGoogleMaps

Assuming the dam would be twice as wide as its height below the dam top elevation of 650 metres, the superficial volume is estimated at 80 million cubic metres, not including the subterranean dam foundations which would be built on the bedrock after clearing away the fluvial sediment.


Well the "long-life" electrical battery has been such a favourite topic for marketing hyperbole for so many decades that scientists are naturally sceptical of any such new claims.


I was thinking about two things: nuclear fusion power stations,
So impractical as to not even be worth discussing. In my opinion, that will never be in place. I regret that Prof Brian Cox has been allowed air time on the BBC to mislead popular science viewers about this topic. Well I suppose he is more entertaining than a lot of the other rubbish on the box, but still - there's no substitute for practical applied science.



Well we've heard promising noises for decades about this. I'm not getting my hopes up.


It should be possible to build a dam as strong as the surrounding mountains, to withstand any earthquake which the mountains endure.

Admittedly, for people living near such big dams, repeated minor earthquakes arising from reservoir induced seismicity
http://en.wikipedia.org/wiki/Induced_seismicity#Artificial_lakes
may cause fear and alarm, at least until such time as the locals get used to it.


I would place that configuration on the experimental side of the experimental-versus-conservative design boundary for dam footprints, which I would place at the ratio of base width equal to twice its height, which is how I've drawn my dam's footprint in my above diagram.

The issue is blast waves normal to the dam wall - with the 
"width = 2 x height"
or wider configurations, the normal shock is directed into the ground, harmlessly and foiling any sabotage of the dam.

Any narrower than w=2h and the normal shock wave reaches the opposite dam wall above the ground which can fail in tension as the shock wave is reflected from opposite wall, as was demonstrated in the WW2 Dam Busters raid.




You appear to have assumed a dam volume of 90 million cubic metres, which is closer to my estimate than expected because
a) the dam is effectively smaller near its edges because the geography is higher
b) my 80 million cubic metres doesn't include dam foundations so the total including foundations could easily exceed your 90 million cubic metres.


Well I can't agree with this estimate. What did you assume for the canal length, lining area and thickness?

If the depth of the canal water is 88 metres and ignoring any freeboard above the waterline.

Length of lining of canal up the 45 degree slope = √( 2 x 88 x 88) = one slope 124.45 m
Two slopes = 248.9 call that 249m
Canal length 30km = 30,000 metres
Lining area = 30,000 x 249 = 7.47 x 10^6 m^2

Volume of lining per metre thickness is about 7.5 million metres cubed

So even if the lining were 1 metre thick - more than it needs to be I think - that would only be 7.5 million metres cubed, less than 1/10th of the dam volume.

Yet you estimate the canal needs twice the concrete for the dam. Why? Does the canal lining have to be 20 metres thick? Or has one of us got our sums wrong?


Plus fuel for the construction equipment and explosives to blast rock.


Really?



Well it is your figure so you work it out. This link
http://www.electricityinfo.org/co2emissions.php
suggests that the average CO2 emission is 470g/kWh of electricity generated.

I'll work out how much CO2 my dam will save if used as part of a renewable-only generation system for the equivalent peak-power of 264 GW which equates to an average power capacity of 264/1.6 = 165GW

Annual CO2-free energy produced is 165 x 24 x 365 = 1.445 x 10^6 GW-hours = 1,445 TerraWatt-hours = 1.445 PetaWatt-Hours (PW-hours)

CO2 emissions 470g/kWh
= 470Kg/MWh
= 470 tonnes / GWh

So that's an annual CO2 saving of 470 x 1.445 x 10^6 tonnes CO2 = 679 million tonnes CO2



This pumped-storage hydro scheme would allow intermittent renewables to supply power 24/7 so it should get part of the credit for the carbon dioxide not emitted.


What is the carbon footprint of Chernobyl or Fukushima and who is wasting time counting that when the radiation poisoning footprint of a nuclear disaster is what matters most anyway?


I favour retention of the British nuclear deterrent on the Clyde.


Scottish Scientist, Mon, 20th Apr 2015

maybe build a solar highway/belt around the equator? floating kind? jccc, Mon, 20th Apr 2015



But (a) you state we only need an average of about 60 GW and (b) wind currently produces rather less than one third of its peak capacity - and the best sites have already been used.

Note that your dam won't save (i.e. generate or reduce the need for) electricity, only embarrassment. 


http://nextbigfuture.com/2011/03/deaths-per-twh-by-energy-source.html


So if we add hydropower storage to wind, it's altogether about 6 times more dangerous than nuclear. alancalverd, Mon, 20th Apr 2015



But (a) you state we only need an average of about 60 GW and (b) wind currently produces rather less than one third of its peak capacity - and the best sites have already been used.


That may or may not be the case, but in any case there's something called 'repowering' where you replace wind turbines with bigger ones.


This is a systems question.

The system as whole certainly does generate electricity and not embarassment, and the dam is part of that system. 



So if we add hydropower storage to wind, it's altogether about 6 times more dangerous than nuclear.

Yes, these are still very small numbers, whereas nuclear power is plausibly more than a billion times more potentially economically destructive in the worst conceivable accident. At one point in Fukushima, they were wondering whether they were going to have to evacuate the whole of Tokyo FFS.

Estimates I've seen are that Ukraine is spending about 5% of its GDP on Chernobyl-related work, to this day.

So, the upside with nuclear power is that your lights work. The downside is that you potentially have to evacuate, lose your job, your house, your pets die chained to a railing until they starve to death, while you go and live in some hell-hole evacuation centre, as happened in Japan.

Thanks... but no thanks. wolfekeeper, Tue, 21st Apr 2015



Ah yes, Fukushima. 16,000 civilians killed by a tsunami that destroyed an entire county, and one power station worker voluntarily received a lethal dose of radiation. My point exactly: water is dangerous, people are irrational. Apart, it seems, from our French neighbours who generate almost 80% of their electricity from nukes with remarkably few cases of hysteria.

Chernobyl wasn't an accident. It was a deliberate experiment to override the safety systems and ignore the operating manual "to see what happens" - which was all in the textbooks anyway.
alancalverd, Tue, 21st Apr 2015

Back to square one: it's 21 April, and so far only 4.5 days this unexceptional month with wind sufficient to generate 2 GW - the running mean is less than 10% of capacity. Time, I think, to review the statistics: as I suggested a few pages back, you need at least 14 days' storage at mean demand if you are going to use electricity as a reliable power source.

Interestingly, governments get upset and start putting emergency schemes into play when at-plant fossil fuel reserves fall below 5 days' worth. One can't help feeling that they know something about it. alancalverd, Tue, 21st Apr 2015

Careful here.

The measured wind output is 0.77 GW. That's about 1.5GW, because half is unmetered. This is coming from 12 GW of nameplate wind power.

Meanwhile Scottish Scientist called for 290GW of nameplate wind power.

So, if we had 290GW we would be getting 290/12 * 1.5 = 37 GW of power right now.

Demand is... about 33 GW (adding 0.77 to allow for the unmetered wind power).

So yes, it would be working perfectly fine right now.


And there's blazing sunshine here. By the time a system like Scottish Scientist's would be up, how many GW of solar power will be on the grid? How many GWh of electric car batteries?

Consider: it's getting to summer. In summer, you get more sunshine and less wind.
wolfekeeper, Tue, 21st Apr 2015

You can't assume that metered demand is being met by unmetered input - that would be ridiculously generous of the suppliers, and anyway, as Gridwatch states, unmetered supply is already shown as a reduction in demand, so you mustn't double-count it! Furthermore it is generally the case that unmetered wind is small power for local consumption and therefore will not contribute significantly more to the grid as large windfarms are built to absorb your taxes.

Thus using conventional arithmetic, if we had 290 GW of installed wind power  right now, we would be getting  290/12 =  24.16 GW from the wind and about 10 GW from SS's reservoir. 

Except that the 100 GW-day reservoir would by now be empty, so we are going to be about 20 GW short of demand by 8 pm. No problem: just shut down half of the country, and reintroduce Victorian Values, the Paleolithic Diet, and all the other trendy non-electric goodies from the past. alancalverd, Tue, 21st Apr 2015

I didn't double count it, I added it to both the demand AND the generation sides of the equation, and doing that is quite valid.

Yes, they're individually small, but there's a lot of them.

In fact my calculation is pessimistic; some of the wind will be not grid connected, in which case it won't be reducing the grid demand; so the calculated demand would appear higher, not lower than it should be in my calculation.

All I'm really assuming is that the wind power production is representative of the unmetered production. Given that weather systems tend to cover the country, that's not an unreasonable assumption.
wolfekeeper, Tue, 21st Apr 2015



You really want to have your cake and eat it! Every watt of car battery is another load on the grid, so if you want to replace road vehicles with electric ones, you will need 580 GW of installed wind power and twice the storage capacity that SS is proposing. Plus, of course, twice the grid carrying capacity and a whole lot of infrastructure to deliver the juice to the cars.

And that will still leave you with 50% of current UK fossil fuel consumption for heating, cooking and direct use in industry.... alancalverd, Tue, 21st Apr 2015

We already explained to you that you that average daily mileage of cars is only 20-30 miles, and that that only needs 5 kWh per car, per day. Meanwhile the minimum electric car has a 25 kWh battery...

Please try to not repeat falsehoods that we have already pointed out. I know you don't really care about facts and truth, but it gets boring. wolfekeeper, Tue, 21st Apr 2015

According to HM Government (or at least the Department of Energy and Climate Change), 36% of current UK energy use is for transport. If I am repeating falsehoods, they come with great authority.

If you look at domestic fuel bills you will find that the average consumption is around 50% electricity and 50% gas, oil or coal. Pretty much the same over all industries, though as UK manufacturing declines, the trend is toward more electricity and less primary heat. But then the supply companies are probably lying too.

One of the many problems with the windmill lobby is a fixation with electricity. It only accounts for a about a third of UK energy consumption, and worldwide, a lot less. Trouble is that you can't use a windmill to make anything else, so it's a very expensive fix for a small part of the problem, and replaces a cheap, reliable fuel with an expensive, unreliable one. Which is a pity. I'd love to have a wind generator, and I'd be delighted if the whole UK could be run on wind,  but it just won't do the job on the required scale.  alancalverd, Tue, 21st Apr 2015

As we have already pointed out to you, but you have pointedly 'forgotten', again, windmills and solar panels are not heat engines and the solar/wind/battery/electric motor power system is much, much, much more energy efficient than going the antiquated heat engine route.

Even with heating, it's much more energy efficient to use electrical power and run air or water source heat pumps than to use fossil fuel energy directly for heating.

So instead of using 36% of the UK's energy on transportation, try ~10% using electricity. wolfekeeper, Tue, 21st Apr 2015



True, but vehicle aerodynamics takes no account of the power source. If you need 100 kW to shift load x at speed y with engine A, you will still need 100 kW with engine B. There is admittedly something to gain by using regenerative braking but in the words of Ettore Bugatti, "my cars are designed to go, not to stop".

And given that the energy required to make a petrol-engined car is about the same as the energy it consumes in its lifetime, how does the lifetime energy balance work out for an electric car? alancalverd, Thu, 23rd Apr 2015



Perhaps surprisingly, the equator is not the ideal location for solar power, for two reasons
- the insolation (amount of sunshine) is higher where the air is drier than the equator which gets a lot of rainfall
- the equator is hotter and photo-voltaic panels are less efficient when hot

So those two reasons explain why parts of the Himalayas and the Andes which are sunny and cold are optimal sites for PV panels. Land nearer the tropics than the equator looks to be better for solar power than land nearer the equator than the tropics.

"So nearer the equator" is not always better depending on where you start from, but starting from Scotland or Britain, most places nearer the equator are better for solar power than we are here.

Most surprisingly, according to the Atlas of Solar Power, even Antarctica (during the southern hemisphere's summer presumably) is a good spot for PV panels!

Atlas of Solar Power from Photo-Voltaic Panels


Click to view a larger image - https://scottishscientist.files.wordpress.com/2015/04/photo-voltaic-atlas.jpg



Yes indeed, as I already suggested, mounting PV panels on artificial floating islands is a good idea. Looking at the Atlas of Solar Power, there looks to be a good place to float PV-panel platforms off the west coast of north Africa, between the Canary Islands and Cape Verde. 



Scottish Scientist, Thu, 23rd Apr 2015



True, but vehicle aerodynamics takes no account of the power source. If you need 100 kW to shift load x at speed y with engine A, you will still need 100 kW with engine B. There is admittedly something to gain by using regenerative braking but in the words of Ettore Bugatti, "my cars are designed to go, not to stop".

Irrelevant. A petrol car burns about 500kW or more of primary energy to get that power, and that's ignoring the energy needed to make that petrol, which is substantial, whereas the electric car is the equivalent of ~130 kW.

It seems to be significantly better, particularly if you're using solar or wind for the source of energy. They take more energy to build, but use a LOT less in operation.

Whereas virtually all of the lifecycle analyses being done right now, pretty much assume that power is more or less only being generated using fossil plants, and even they show a net win; but that isn't even what we're talking about here, we're talking about a true green grid. wolfekeeper, Thu, 23rd Apr 2015

SS, you are so beautiful, as your science! jccc, Thu, 23rd Apr 2015

Presumably with 290 GW of peak wind, you'd have spare energy a lot of the time. I mean the standard capacity factor is about 25-35%, so you'd be averaging more power than you actually need- it's sized for the periods when the wind is a bit anemic. So at 25% CF, that's 72GW average, whereas the normal demand is 35-55.

But that's actually probably good; things like electric cars don't usually care as much about having to have power every single day; you could potentially just set the minimum charging point for what you need day-to-day, and if there's spare electricity going because it's particularly windy, it would charge it up further and save money; also electric water heaters could be switched on. wolfekeeper, Thu, 23rd Apr 2015




I entered this discussion with a guesstimate that an installed capacity of 6 times average demand and 5 days' storage would do the trick, but events have shown otherwise,. My apologies.

So far this month, 20 out of 24 days the capacity factor of wind has been less than 10%, and for the last 2 days, zero. The mean capacity factor for the last 24 days has been about 14% and tomorrow isn't looking any better. So in order not to lose too many lives, destroy too much food, bring industry to a halt, or generally inconvenience the population, it seems on current evidence that you need at least to install at least 7 times average demand and one month's storage capacity.

And that's just to meet the present need for electricity. If you want a wholly wind-powered economy you will need a generating capacity of 20 times present electrical demand, and a month's storage capacity at 150GW, otherwise people will surely die or find themselves stranded far from home.

But here's a trick - sell electricity on a live market. When supply is low, prices are high. That will regulate demand and ensure that it is always exactly matched to supply. Because there is no significant lag between supply and consumption, and consumption can be monitored at every point of use, the unit price can be varied every second or less. The poor will have to learn to make choices instead of profligately cooking and keeping warm at the same time, and they will have to trade in their huge plasma screen TVs for neater LED models (everyone knows that the poor have ENORMOUS televisions - the Daily Mail says so). My private patients will continue to enjoy the fruits of their crimes, whilst honest peasants will be told that the waiting list for radiotherapy is due to factors beyond human control, not politics or incompetence.    alancalverd, Fri, 24th Apr 2015

On floating platforms, solar power, power-to-gas and energy storage ...

Off-shore wind-turbines generate electricity, as we all know. Now I’ll explain how off-shore solar and hydrogen can power our electricity too.

Solar at sea is easy. Simply mount photovoltaic panels on platforms isolated on their own or in the wide-open spaces between the off-shore wind turbines. Mount PV-panels high and dry but be sure to mount them below the height of the rotors of the wind turbines so as not to interfere with the wind flow.

Deep Sea Hydrogen Storage


Floating platforms can generate electricity from wind, sun or hydrogen gas, which can be stored in inflatable gas bags in deep sea water.

The diagram shows how hydrogen gas can be used to store energy from renewable-energy platforms floating at sea by sending any surplus wind and solar electrical power down a sub-sea cable to power underwater high-pressure electrolysis to make compressed hydrogen to store in underwater inflatable gas-bags.

Deeper seas are better because the water pressure is proportional to the depth allowing the hydrogen to be compressed more densely, so that more hydrogen and more energy can be stored in an inflatable gas-bag.

Later, when there is a lull in the wind or when it is dark, the hydrogen can be piped from the gas-bag up to the platform on the surface to fuel gas-fired turbine generators or hydrogen fuel cells to generate electricity on-demand in all weather conditions.

Deeper seas, which are better for storing hydrogen in, can be found from an atlas of the oceans, such as this one.

Sea Atlas - https://scottishscientist.files.wordpress.com/2015/04/6004-050-e076d00f.gif

Looking at a close-up of the map for the area of sea closest to Scotland, Britain and Western Europe –



Click to view a larger image - https://scottishscientist.files.wordpress.com/2015/04/seas_euro_n_africa-200.jpg

– this shows that deep sea water most suitable for hydrogen storage is not to be found around the coast of the British Isles but depths greater than 4,000 metres can be found in vast areas of the Atlantic beginning a few hundred miles to the south-west in the Bay of Biscay.

So one area of sea which looks suitable for both solar and hydrogen powered electricity generation appears to be just to the west and south-west of the Canary Islands and to the north of the Cape Verde Islands. Whether this area is near enough to western Europe to be the best choice to supply western Europe considering the additional costs of longer interconnection cables remains to be estimated.
Scottish Scientist, Fri, 24th Apr 2015


No:

https://twitter.com/ElectricMixUK/status/591194830824411136

0.37 GW out of 6 GW metered.

With 290 GW that's equivalent to 17 GW, about half the demand.

Previous day was 0.75 out of 6 GW metered:

https://twitter.com/ElectricMixUK/status/590832433391673344

That's equivalent to 36 GW, which is pretty much the average demand that day.

Previous day to that was:

https://twitter.com/ElectricMixUK/status/590470039096156160

That's equivalent, to all of the demand: 38.7 GW

After that, I got bored. But whatever else, that's not zero production; it's most of the UK demand supplied by wind, per Scottish Scientist's plan.

Anyway, so... yup... you're full of sh1t, again, sorry. wolfekeeper, Fri, 24th Apr 2015



Very sensible idea. Worth also investigating the use of the existing UK gas grid to store and distribute low-pressure hydrogen or manufactured methane, thus obviating the need for an electricity store, major construction works or any novel generating plant: use the gas to run the existing gas power stations when the wind fails, just as now.

http://www.technologyreview.com/news/510066/audi-to-make-fuel-using-solar-power/

Existing petrol-engined road vehicles can run on methane with very little conversion, or you could synthesise higher hydrocarbons for better energy density: pure synthetic diesel produces less NOx than biodiesel. And of course methane is already the preferred source of domestic and industrial heating in the UK, whilst hydrogen and oxygen are extremely useful industrial gases. 

This approach might actually make wind power economically viable and socially useful. alancalverd, Fri, 24th Apr 2015

"The UK has reached the limit on hydro" (paraphrased) said Andrew Neil questioning the parties' energy and climate change spokespersons on the BBC's Daily Politics, first broadcast on 20th April and rebroadcasted earlier today on BBC Parliament.

What Mr Neil meant is that even it would be nice to build more hydro-electric schemes to provide renewable power when the wind is not blowing (sun is not shining etc), regrettably there are no more suitable sites to build more hydro schemes in the UK.

Actually, I have a plan to build a new massive pumped-storage hydro scheme in Scotland which could keep the UK's lights on 24/7, in a 100% renewable energy way.

World’s biggest-ever pumped-storage hydro-scheme, for Scotland?
https://scottishscientist.wordpress.com/2015/04/15/worlds-biggest-ever-pumped-storage-hydro-scheme-for-scotland/

So Andrew Neil was wrong. The orthodoxy about "the UK has reached the limit on hydro" is wrong.

Scottish Scientist, Sat, 25th Apr 2015


I'm certain that the rest of us in this forum would very much appreciate it if you'd stop using such a disrespectful tone with Alan. He's an intelligent, knowledgeable person whom many of us in the forum respect and admire. We don't like to see him insulted like this. Please stop. PmbPhy, Sat, 25th Apr 2015



How big is this gas-bag ?, and how deep will it be under the sea ? .
Do flexible materials exist to make such a bag which can withstand the buoyancy forces ?


http://en.wikipedia.org/wiki/Lifting_bag RD, Sat, 25th Apr 2015

It needn't be a balloon. A steel can will do quite nicely, and it doesn't need to be very deep under the ocean: the domestic gas supply pressure is only a meter of water gauge or less. The deeper it is, the more efficient, but large steel cans are very cheap and easy to make. alancalverd, Sat, 25th Apr 2015



Scottish Scientist was suggesting storing the hydrogen at depth (~100m)



Building a heavy-duty "gasometer" made of steel, on the sea-floor, 100m below the surface of the salty-sea, sounds very-expensive and impractical to me : It will be bigger than a military submarine , and they cost over a billion dollars each. RD, Sat, 25th Apr 2015

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