How can renewable energy farms provide 24-hour power?

  • 148 Replies
  • 75951 Views

0 Members and 1 Guest are viewing this topic.

*

Offline thedoc

  • Forum Admin
  • Administrator
  • Sr. Member
  • *****
  • 513
    • View Profile
Renewable energy farms can only produce power when the sun shines or the wind blows, but new cheaper batteries allow them to store energy.
Read a transcript of the interview by clicking here

or [chapter podcast=1000467 track=13.08.22/Naked_Scientists_Show_13.08.22_1001224.mp3] Listen to it now[/chapter] or [download as MP3]
« Last Edit: 27/08/2013 14:04:01 by _system »

*

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • 4902
  • life is too short to drink instant coffee
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #1 on: 28/08/2013 10:13:03 »
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.   
helping to stem the tide of ignorance

*

Online syhprum

  • Neilep Level Member
  • ******
  • 3925
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #2 on: 28/08/2013 13:18:13 »
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

*

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • 4902
  • life is too short to drink instant coffee
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #3 on: 28/08/2013 15:09:54 »
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.   
helping to stem the tide of ignorance

*

Offline CliffordK

  • Neilep Level Member
  • ******
  • 6321
  • Site Moderator
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #4 on: 28/08/2013 19:04:16 »
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.
« Last Edit: 28/08/2013 19:13:14 by CliffordK »

*

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • 4902
  • life is too short to drink instant coffee
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #5 on: 28/08/2013 19:52:33 »
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.
helping to stem the tide of ignorance

*

Offline evan_au

  • Neilep Level Member
  • ******
  • 4312
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #6 on: 28/08/2013 22:30:01 »
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...
« Last Edit: 28/08/2013 22:38:44 by evan_au »

*

Offline CliffordK

  • Neilep Level Member
  • ******
  • 6321
  • Site Moderator
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #7 on: 28/08/2013 22:46:07 »
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.

*

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • 4902
  • life is too short to drink instant coffee
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #8 on: 29/08/2013 08:10:13 »
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?
helping to stem the tide of ignorance

*

Offline peppercorn

  • Neilep Level Member
  • ******
  • 1466
    • View Profile
    • solar
Re: How can renewable energy farms provide 24-hour power?
« Reply #9 on: 29/08/2013 14:03:07 »
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.

"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?

*

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • 4902
  • life is too short to drink instant coffee
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #10 on: 29/08/2013 18:45:31 »
Creeping socialism, dammit.
helping to stem the tide of ignorance

*

Offline CliffordK

  • Neilep Level Member
  • ******
  • 6321
  • Site Moderator
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #11 on: 30/08/2013 15:43:10 »
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.

*

Offline grizelda

  • Hero Member
  • *****
  • 740
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #12 on: 01/09/2013 18:41:39 »
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.

*

Offline peppercorn

  • Neilep Level Member
  • ******
  • 1466
    • View Profile
    • solar
Re: How can renewable energy farms provide 24-hour power?
« Reply #13 on: 02/09/2013 12:30:36 »
No creeping socialism there, it's rampant.

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.

*

Offline FunkyWorm

  • Jr. Member
  • **
  • 21
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #14 on: 04/09/2013 11:13:17 »
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.

*

Offline CliffordK

  • Neilep Level Member
  • ******
  • 6321
  • Site Moderator
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #15 on: 04/09/2013 11:28:19 »
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. 

*

Offline Scottish Scientist

  • Jr. Member
  • **
  • 36
  • Independent Scientific Adviser for Scotland
    • View Profile
    • Scottish Scientist Wordpress Blog
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 [nofollow]
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/ [nofollow]



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/ [nofollow]


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


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

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.

« Last Edit: 08/04/2015 19:22:06 by Scottish Scientist »

*

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • 4902
  • life is too short to drink instant coffee
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #17 on: 08/04/2015 17:13:32 »
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.
« Last Edit: 08/04/2015 17:17:56 by alancalverd »
helping to stem the tide of ignorance

*

Offline Scottish Scientist

  • Jr. Member
  • **
  • 36
  • Independent Scientific Adviser for Scotland
    • View Profile
    • Scottish Scientist Wordpress Blog
Re: How can renewable energy farms provide 24-hour power?
« Reply #18 on: 08/04/2015 18:48:23 »
Hi Alan and thanks for your feedback.

Present UK grid capacity is about 80 GW. It is sensible to plan for 100 GW in the foreseeable future.
Data statistics show a trend of decreasing maximum power demand.

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

Digest of UK Energy Statistics
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/337649/chapter_5.pdf [nofollow]
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


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 [nofollow]  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.

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.

Thus, if you are prepared to flood  most of the Highlands and Snowdonia,

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.


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.
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.

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


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.
Already remembered, thanks.

you need to install 300 GW of windmills to meet peak demand, 
290GW of wind turbines. Only more if we opt for a wind turbine reserve.

  plus 300 GW to recharge the storage units, plus 100 GW of pump/generators,
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.

  plus 100 GW of additional grid cabling and switchgear.   
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.

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.
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!
« Last Edit: 25/04/2015 19:18:55 by Scottish Scientist »

*

Online chiralSPO

  • Global Moderator
  • Neilep Level Member
  • *****
  • 1932
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #19 on: 08/04/2015 20:24:28 »
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

*

Offline Scottish Scientist

  • Jr. Member
  • **
  • 36
  • Independent Scientific Adviser for Scotland
    • View Profile
    • Scottish Scientist Wordpress Blog
Re: How can renewable energy farms provide 24-hour power?
« Reply #20 on: 08/04/2015 22:46:23 »
Hi chiralSPO and thanks for your feedback.

1400 GWh (5.04x1015 J)
Check.
1400 GWh = 1.4TWh = 58.33 GW-days

of pumped hydro storage would be quite an engineering feat!
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.

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)*.
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 [nofollow]

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 [nofollow]

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 [nofollow]

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/ [nofollow]

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.
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.

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

Thanks again for your feedback chiralSPO!


 
« Last Edit: 08/04/2015 23:20:24 by Scottish Scientist »

*

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • 4902
  • life is too short to drink instant coffee
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #21 on: 09/04/2015 00:13:39 »
Quote
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.

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
Quote
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.
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.
helping to stem the tide of ignorance

*

Offline Scottish Scientist

  • Jr. Member
  • **
  • 36
  • Independent Scientific Adviser for Scotland
    • View Profile
    • Scottish Scientist Wordpress Blog
Re: How can renewable energy farms provide 24-hour power?
« Reply #22 on: 09/04/2015 01:33:29 »
Quote
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.

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.

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.
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 [nofollow]

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 [nofollow]

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 [nofollow]

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.


Saying that
Quote
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.
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?

- and any "reserve" station has to recoup its costs from unplanned and intermittent running, which makes even gas an uneconomic investment.
Well the grid can hire power plants to stay on stand-by and pay a premium for emergency power and make reserve stations profitable.

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".
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.

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.
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.
« Last Edit: 09/04/2015 01:42:54 by Scottish Scientist »

*

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • 4902
  • life is too short to drink instant coffee
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #23 on: 09/04/2015 08:23:25 »
Quote
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.

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.
« Last Edit: 09/04/2015 08:26:04 by alancalverd »
helping to stem the tide of ignorance

*

Offline Scottish Scientist

  • Jr. Member
  • **
  • 36
  • Independent Scientific Adviser for Scotland
    • View Profile
    • Scottish Scientist Wordpress Blog
Re: How can renewable energy farms provide 24-hour power?
« Reply #24 on: 09/04/2015 11:59:12 »
Quote
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.

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

According to Gridwatch,
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/ [nofollow]
and hover your mouse above the wind power dial and a context pop-up text bubble appears which says ..
Quote
Wind: This is the total contributed by metered wind farms. Wind power contributes another about 50% from embedded (or unmetered) wind turbines that shows only as a drop in demand.

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

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.

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 [nofollow]

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.

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

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.
He should have gone to spec-savers.  [:)]
« Last Edit: 09/04/2015 12:19:35 by Scottish Scientist »

*

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • 4902
  • life is too short to drink instant coffee
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #25 on: 10/04/2015 09:09:57 »
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.
« Last Edit: 10/04/2015 10:50:46 by alancalverd »
helping to stem the tide of ignorance

*

Offline Scottish Scientist

  • Jr. Member
  • **
  • 36
  • Independent Scientific Adviser for Scotland
    • View Profile
    • Scottish Scientist Wordpress Blog
Re: How can renewable energy farms provide 24-hour power?
« Reply #26 on: 10/04/2015 15:09:06 »
This is the 8th consecutive day with wind below 2 GW - your storage system is looking a bit marginal.
I demonstrated with a graph how my plan coped with your challenge but still you nit-pick. [|)]


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

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,
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.

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

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)
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?

plus storage facilities in order to approach current levels of reliability, what is the anticipated future unit cost?
I anticipated a total cost in my first post.

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.

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.


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.
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.

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.
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!  [:)]
« Last Edit: 10/04/2015 16:16:04 by Scottish Scientist »

*

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • 4902
  • life is too short to drink instant coffee
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #27 on: 10/04/2015 17:46:34 »
Quote
This is because 1400GWh is 58.33 GW-days

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"!

Quote
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?


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.     

Quote
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.

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

Quote
The Renewable Energy Foundation [1] today published a new study, The Performance of Wind Farms in the United Kingdom and Denmark,[2] showing that the economic life of onshore wind turbines is between 10 and 15 years, not the 20 to 25 years projected by the wind industry itself, and used for government projections. 

The work has been conducted by one of the UK’s leading energy & environmental economists, Professor Gordon Hughes of the University of Edinburgh[3], and has been anonymously peer-reviewed.  This groundbreaking study applies rigorous statistical analysis to years of actual wind farm performance data from wind farms in both the UK and in Denmark.

The results show that after allowing for variations in wind speed and site characteristics the average load factor of wind farms declines substantially as they get older, probably due to wear and tear. By 10 years of age the contribution of an average UK wind farm to meeting electricity demand has declined by a third. 

This decline in performance means that it is rarely economic to operate wind farms for more than 12 to 15 years.  After this period they must be replaced with new machines, a finding that has profound consequences for investors and government alike. 

Specifically, investors expecting a return on their investment over 20-25 years will be disappointed.  Policymakers expecting wind farms built before 2010 to be contributing towards CO2 targets in 2020 or later must allow for the likelihood that the total investment required to meet these targets will be much larger than previous forecasts have suggested.  As a consequence, the lifetime cost per unit (MWh) of electricity generated by wind power will be considerably higher than official estimates.

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.
« Last Edit: 10/04/2015 17:56:38 by alancalverd »
helping to stem the tide of ignorance

*

Offline Scottish Scientist

  • Jr. Member
  • **
  • 36
  • Independent Scientific Adviser for Scotland
    • View Profile
    • Scottish Scientist Wordpress Blog
Re: How can renewable energy farms provide 24-hour power?
« Reply #28 on: 10/04/2015 19:41:40 »
Quote
This is because 1400GWh is 58.33 GW-days

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.

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.

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 [nofollow]

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.

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


Quote
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?


We're not far apart here.

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

Quote
Obi-Wan: How long before you can make the jump to light speed?

Han Solo: It'll take a few moments to get the coordinates from the navi-computer.

[the ship begins to rock violently as lasers hit it]

Luke: Are you kidding? At the rate they're gaining...?

Han Solo: Traveling through hyperspace ain't like dusting crops, boy! Without precise calculations we could fly right through a star, or bounce too close to a supernova and that'd end your trip real quick, wouldn't it.

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.

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.


Quote
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.

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 [nofollow]

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.


Quote
The Renewable Energy Foundation [1] today published a new study, The Performance of Wind Farms in the United Kingdom and Denmark,[2] showing that the economic life of onshore wind turbines is between 10 and 15 years, not the 20 to 25 years projected by the wind industry itself, and used for government projections. 

The work has been conducted by one of the UK’s leading energy & environmental economists, Professor Gordon Hughes of the University of Edinburgh[3], and has been anonymously peer-reviewed.  This groundbreaking study applies rigorous statistical analysis to years of actual wind farm performance data from wind farms in both the UK and in Denmark.

The results show that after allowing for variations in wind speed and site characteristics the average load factor of wind farms declines substantially as they get older, probably due to wear and tear. By 10 years of age the contribution of an average UK wind farm to meeting electricity demand has declined by a third. 

This decline in performance means that it is rarely economic to operate wind farms for more than 12 to 15 years.  After this period they must be replaced with new machines, a finding that has profound consequences for investors and government alike. 

Specifically, investors expecting a return on their investment over 20-25 years will be disappointed.  Policymakers expecting wind farms built before 2010 to be contributing towards CO2 targets in 2020 or later must allow for the likelihood that the total investment required to meet these targets will be much larger than previous forecasts have suggested.  As a consequence, the lifetime cost per unit (MWh) of electricity generated by wind power will be considerably higher than official estimates.

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.

There is a solution, but wind isn't it.
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?

« Last Edit: 10/04/2015 20:11:44 by Scottish Scientist »

*

Offline wolfekeeper

  • Neilep Level Member
  • ******
  • 1093
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #29 on: 10/04/2015 20:01:40 »
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.

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...

Quote
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.

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.

But look how terribly dangerous nuclear power is probably as many as 100 people have died as a result of nuclear mishaps since 1940

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.

*

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • 4902
  • life is too short to drink instant coffee
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #30 on: 10/04/2015 20:40:41 »
Quote
This is because 1400GWh is 58.33 GW-days

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?


Quote
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.

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.

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

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.
« Last Edit: 10/04/2015 20:58:33 by alancalverd »
helping to stem the tide of ignorance

*

Offline Scottish Scientist

  • Jr. Member
  • **
  • 36
  • Independent Scientific Adviser for Scotland
    • View Profile
    • Scottish Scientist Wordpress Blog
Re: How can renewable energy farms provide 24-hour power?
« Reply #31 on: 10/04/2015 22:18:18 »
Quote
This is because 1400GWh is 58.33 GW-days

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.


Gridwatch put the figure at about 1.5 GW.
Well I told you to be aware about Gridwatch wind power data. Remember?

Quote
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.

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

According to Gridwatch,
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/ [nofollow]
and hover your mouse above the wind power dial and a context pop-up text bubble appears which says ..
Quote
Wind: This is the total contributed by metered wind farms. Wind power contributes another about 50% from embedded (or unmetered) wind turbines that shows only as a drop in demand.

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.


Does a discrepancy of 4000% count as nitpicking?
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.

Quote
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.

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.

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

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

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.

Chucking money at windmill manufacturers won't prevent mass migration as world agriculture fails to meet demand.
Well it may just help a lot with that too.
« Last Edit: 10/04/2015 22:22:18 by Scottish Scientist »

*

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • 4902
  • life is too short to drink instant coffee
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #32 on: 11/04/2015 00:40:01 »
Quote
Disastrous which "either way"? Warmer or colder?

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. 
helping to stem the tide of ignorance

*

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • 4902
  • life is too short to drink instant coffee
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #33 on: 11/04/2015 00:44:36 »
It's perfectly possible to power an electric car your normal mileage using the electricity from a domestic roof PV. You need just 5kWh generation per day to get the average car mileage.

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.
helping to stem the tide of ignorance

*

Offline wolfekeeper

  • Neilep Level Member
  • ******
  • 1093
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #34 on: 11/04/2015 01:48:28 »
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.

*

Offline Scottish Scientist

  • Jr. Member
  • **
  • 36
  • Independent Scientific Adviser for Scotland
    • View Profile
    • Scottish Scientist Wordpress Blog
Re: How can renewable energy farms provide 24-hour power?
« Reply #35 on: 11/04/2015 02:08:09 »
Quote
Disastrous which "either way"? Warmer or colder?

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.

Unfortunately the human population has, and continues to rise, so life is becoming more marginal each day.
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.

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


Even if we ignore those elephants, a small change in rainfall distribution will be disastrous.
I can see you are a rainfall gauge "half-empty" kind of guy.   [8D]

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.
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.

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.
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.
« Last Edit: 11/04/2015 02:14:03 by Scottish Scientist »

*

Offline wolfekeeper

  • Neilep Level Member
  • ******
  • 1093
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #36 on: 11/04/2015 02:21:25 »
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.

*

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • 4902
  • life is too short to drink instant coffee
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #37 on: 11/04/2015 09:42:12 »

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.

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. 

Quote
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 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.

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

Quote
You say "mass migration" like it is a bad thing. It doesn't have to be.
Your peaceful solution to a 5 cm sea level rise in Bangladesh would be welcome.


Quote
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.
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.

Quote
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.
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".


Quote
Even if we ignore those elephants, a small change in rainfall distribution will be disastrous.
I can see you are a rainfall gauge "half-empty" kind of guy.   [8D]
Well spotted. Actually I'm a pilot who notices "tanks half empty" before the fires go out.

Quote
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.

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!
« Last Edit: 11/04/2015 10:11:50 by alancalverd »
helping to stem the tide of ignorance

*

Offline Scottish Scientist

  • Jr. Member
  • **
  • 36
  • Independent Scientific Adviser for Scotland
    • View Profile
    • Scottish Scientist Wordpress Blog
Re: How can renewable energy farms provide 24-hour power?
« Reply #38 on: 11/04/2015 11:30:04 »

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.

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.

Quote
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 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.

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

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

Quote
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.
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.

I shudder at the idea of "well led": Great Leaders like Stalin, Mao, Hitler and Thatcher were a disaster.
The bad leaders make my point that the quality of leadership makes a difference.

Quote
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.
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.

Quote
Even if we ignore those elephants, a small change in rainfall distribution will be disastrous.
I can see you are a rainfall gauge "half-empty" kind of guy.   [8D]
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.

Quote
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.

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.
« Last Edit: 11/04/2015 11:56:08 by Scottish Scientist »

*

Offline wolfekeeper

  • Neilep Level Member
  • ******
  • 1093
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #39 on: 11/04/2015 15:32:11 »
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.

*

Offline evan_au

  • Neilep Level Member
  • ******
  • 4312
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #40 on: 11/04/2015 17:17:31 »
Quote from: alancalverd
an unimaginable capital expenditure on electric transport
Quote from: wolfekeeper
the lifetime cost of electric cars is becoming cheaper than petrol cars
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.

*

Offline wolfekeeper

  • Neilep Level Member
  • ******
  • 1093
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #41 on: 11/04/2015 17:32:32 »
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.
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.

*

Offline Scottish Scientist

  • Jr. Member
  • **
  • 36
  • Independent Scientific Adviser for Scotland
    • View Profile
    • Scottish Scientist Wordpress Blog
Re: How can renewable energy farms provide 24-hour power?
« Reply #42 on: 11/04/2015 20:59:30 »
Thank you for your feedback wolfekeeper.

The only thing I disagree with in the model is that you're assuming only wind and pumped storage.
Well what is it about my model that you agree with then?

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

Quote
Solar power in the United Kingdom
"In 2014, the almost 650,000 solar installations had a total capacity of over 5,000 MW of solar power."
http://en.wikipedia.org/wiki/Solar_power_in_the_United_Kingdom [nofollow]

Which makes me disappointed indeed that the Gridwatch site, http://www.gridwatch.templar.co.uk/ [nofollow] from where I downloaded the demand and wind power data http://www.gridwatch.templar.co.uk/download.php [nofollow] 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 ...
Quote
id, timestamp, demand, wind
403446, 2015-04-01 00:05:03, 26774, 5590
403447, 2015-04-01 00:10:02, 26993, 5571
403448, 2015-04-01 00:15:02, 27252, 5566

- 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!  [?]

So, electric cars; the pumped storage stuff may not be needed.
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/ [nofollow]

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 [nofollow]

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.

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.
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.  [:)]
« Last Edit: 11/04/2015 21:46:28 by Scottish Scientist »

*

Offline wolfekeeper

  • Neilep Level Member
  • ******
  • 1093
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #43 on: 11/04/2015 23:13:47 »
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.
« Last Edit: 11/04/2015 23:18:49 by wolfekeeper »

*

Offline Scottish Scientist

  • Jr. Member
  • **
  • 36
  • Independent Scientific Adviser for Scotland
    • View Profile
    • Scottish Scientist Wordpress Blog
Re: How can renewable energy farms provide 24-hour power?
« Reply #44 on: 11/04/2015 23:36:27 »
National grid do a far g(r)eekier version:

http://www.bmreports.com/bsp/bsp_home.htm [nofollow]

From there I managed to find this:

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

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.
Great find wolfekeeper!  [8]
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.

*

Offline wolfekeeper

  • Neilep Level Member
  • ******
  • 1093
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #45 on: 12/04/2015 00:23:55 »
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.

*

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • 4902
  • life is too short to drink instant coffee
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #46 on: 12/04/2015 07:54:33 »
Quote
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.

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.   

Quote
The UK has a pretty good charging infrastructure now and it's likely to further improve.
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"!)
helping to stem the tide of ignorance

*

Offline Scottish Scientist

  • Jr. Member
  • **
  • 36
  • Independent Scientific Adviser for Scotland
    • View Profile
    • Scottish Scientist Wordpress Blog
Re: How can renewable energy farms provide 24-hour power?
« Reply #47 on: 12/04/2015 10:50:40 »
National grid do a far g(r)eekier version:

http://www.bmreports.com/bsp/bsp_home.htm [nofollow]

From there I managed to find this:

https://www2.bmreports.com/bmrs/?q=actgenration/actualorestimated [nofollow]
"Actual Or Estimated Wind And Solar Power Generation (B1630)"

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.
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 [nofollow]

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.
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.

Quote
It doesn't exist. I've been looking for years. Its all small scale stuff and no one knows until people send in their bills how much it has generated.  Or how much fraud is going on.

How can you collect real-time data from a million rooftop solar panels? Even if you could,. how could you tell if it was really solar energy or someone driving an inverter from next doors supply, or from a diesel generator?

You can guess at how much is being generated by looking at the midday dip in the 'demand' figures. But its only a guess.
Hmmm. [:-\]


Quote
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/ [nofollow]

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

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 [nofollow]

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. [O8)]

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?

« Last Edit: 12/04/2015 12:14:21 by Scottish Scientist »

*

Offline wolfekeeper

  • Neilep Level Member
  • ******
  • 1093
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #48 on: 12/04/2015 13:58:18 »
Quote
The UK has a pretty good charging infrastructure now and it's likely to further improve.
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???

Quote
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"!)
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.
« Last Edit: 12/04/2015 14:12:47 by wolfekeeper »

*

Offline alancalverd

  • Global Moderator
  • Neilep Level Member
  • *****
  • 4902
  • life is too short to drink instant coffee
    • View Profile
Re: How can renewable energy farms provide 24-hour power?
« Reply #49 on: 12/04/2015 14:42:34 »
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.
helping to stem the tide of ignorance