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Author Topic: How can renewable energy farms provide 24-hour power?  (Read 74404 times)

Offline alancalverd

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Re: How can renewable energy farms provide 24-hour power?
« Reply #125 on: 27/04/2015 17:29:00 »

Everyone loves a bargain Alan and wind power can offer very cheap rate electricity at windy times.


It's a sad fact that only the wealthy can afford a bargain. I would like to have an electric car for nipping out to the shops, but I only have the capital for one car so it has to be the one that will also do 300 miles at 70 mph without stopping, so I can get to work and back on the same day - not some time in the distant future when we have 20-second charging points all over the country, but tomorrow. I would like to buy bulk electricity for a storage heater but having just spent a fortune on an underfloor heat pump system, I can't adapt to that brave new world without destroying half the house. Fortunately I can afford to buy heating oil (for the other half!) in bulk when it's cheap, but the poor never seem able to fill a big tank, or to buy a whole case of wine  (I pay 25% less than someone who can only afford a bottle at a time). And so it goes on. Sure, rip out your 50 gallon hot water tank and replace it with an intelligent offpeak 200 gallon unit - it will only cost you £1000 and you will save £100 per year: try that on a pensioner!

And if we all started using offpeak electricity, wouldn't that just create a new peak, or at least even out demand?  The offpeak boom was in the 1950s and 60s when common sense ruled and the trend was to build more nuclear power stations, which work best when feeding a constant load at 90% capacity, so you could match load to supply over the long term by pricing. With wind it's the other way around - you have to use the stuff when it's available or get involved in expensive storage schemes.   

Seriously, I think your hydrogen store is a runner, because it can be introduced gradually and with no significant change in infrastructure or consumer hardware (changing from town gas to methane just involved changing the final jets on cookers and furnaces) but pumped water is a nonstarter in the big race.
 

Offline wolfekeeper

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Re: How can renewable energy farms provide 24-hour power?
« Reply #126 on: 28/04/2015 15:38:02 »
It's a sad fact that I don't have a car that can go at 150 mph for 300 miles without stopping.

When will this conspiracy against poor people like me end??? When?
 

Offline alancalverd

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Re: How can renewable energy farms provide 24-hour power?
« Reply #127 on: 28/04/2015 15:50:08 »
It's a sad fact that I don't have a car that can go at 150 mph for 300 miles without stopping.

That's why I use an aeroplane. Or, if I'm in a real hurry, a telephone.

Quote
When will this conspiracy against poor people like me end??? When?

When we have ground the last peasant into the dust and rid the world of poverty by the simple expedient of ridding it of poor people, of course. Really, why do the working class ask such stupid questions? Qu'ils mangeant de brioche, mon ami.
 

Offline Scottish Scientist

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Re: How can renewable energy farms provide 24-hour power?
« Reply #128 on: 28/04/2015 18:12:03 »

Deep Sea Hydrogen Storage


Very sensible idea.
Thanks Alan.  :)

Worth also investigating the use of the existing UK gas grid to store and distribute low-pressure hydrogen or manufactured methane,
Methane is harder to make from power-to-gas but easier to pipe into the existing gas grid with no conversion issues.

thus obviating the need for an electricity store,
Well hydrogen needs storing somewhere too.

Also pumped-storage hydro offers a higher energy efficiency energy store. You lose at least half of the energy converting to hydrogen then back to electricity. So a power-to-gas only energy store would not be the most efficient in the long run.

So I recommend what's most appropriate where and when
  • pumped-storage hydro for land storage up to a limit of 1.11 peak-electricity-demand-days for the intermittent renewables,
  • power-to-gas and gas-storage for surplus power after the pumped-storage hydro reservoirs have been topped up
  • undersea hydrogen stores for off-shore when there's no or less demand for electricity from land than is being generated

major construction works or any novel generating plant: use the gas to run the existing gas power stations when the wind fails, just as now.
But for renewables-only generation, even using gas-energy-stores only, we'd need to build more novel gas-fired power stations. There's not enough gas-fired plant to provide the full electricity demand as yet. We'd also need either lots of hydrogen to methane conversion plant and / or additional hydrogen storage. Hydrogen is not a zero-build option.

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

Existing petrol-engined road vehicles can run on methane with very little conversion, or you could synthesise higher hydrocarbons for better energy density: pure synthetic diesel produces less NOx than biodiesel. And of course methane is already the preferred source of domestic and industrial heating in the UK, whilst hydrogen and oxygen are extremely useful industrial gases.
I'm not sure if it is worth collecting the oxygen from the undersea electrolysis situation. I had in mind the option of just letting the oxygen gas bubble away.

One reason to store the oxygen would be to increase the efficiency and reduce the nitrogen oxide combustion by-products of hydrogen-fired generators. Whether that advantage is worth the cost of collecting the oxygen, I'm not sure.

Be aware that for undersea electrolysis in order to produce oxygen as the anode gas, a custom electrolyte solution will have to be used. If you try electrolysing sea water directly you get chlorine gas off at the anode, which is not so easy to dispose of and can be poisonous.

So the technique will be to separate the custom more-concentrated electrolyte solution from the sea water by a semi-permeable membrane and allow pure water to pass through it by osmosis from the relatively dilute sea water.

It's worth pointing out that whereas we might describe this process as undersea "high-pressure" electrolysis, it is only so, "high-pressure", because of the ambient high-pressure resulting from being under water at depth.

So there's no high-pressure-vessel containment required for the electrolyte solution - as is required for high-pressure electrolysis which operates on the surface - and so undersea, a semi-permeable membrane is all that is required to keep the electrolyte solution contained.

This approach might actually make wind power economically viable and socially useful.
Hmm. I still think we need to build more pumped-storage hydro for best results.
« Last Edit: 28/04/2015 21:09:37 by Scottish Scientist »
 

Offline alancalverd

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Re: How can renewable energy farms provide 24-hour power?
« Reply #129 on: 28/04/2015 23:01:54 »
Hydrogen storage isn't a problem, or at least it has been solved, used and abandoned in living memory (mine!). The oldfashioned town "gasometers" contained 50% hydrogen at final delivery pressure, above ground in water tanks, and worked for well over 100 years.

Rather than electrolyse seawater, my preference would be to bring the electricity ashore (as is already done, so no new technology required) and electrolyse fresh water inside the gasometer, either using "high pressure" electrolysis at the bottom of a lake or near-atmospheric pressure in a river or pond.

Gas-fired power stations already supply about half the UK demand, and are much cheaper and easier to build than coal or nuclear. The principal reason that gas has not taken over completely from coal is the rising cost of gas, so I don't foresee any great problem in expanding the gas-to-electric capability if electrolytic hydrogen becomes as cheap as wind enthusiasts would have us believe.

Thermal inefficiency isn't a problem either.We already tolerate a 50% energy loss in converting fossil or biofuel to electricity, but as I have pointed out a few times above, electricity is not the most important energy source anyway: we burn 70% of our fossil fuel either for direct heat or for transport, and hydrogen or synthetic liquid fuel would be perfectly acceptable in these roles, with minimal modifications to the burners, as distinct from ripping out industrial furnaces wholesale and replacing them with electric ones.

The organic growth of a wind-to-hydrogen economy is the least disruptive path to sustainable, secure, zero-carbon energy for the UK - it's the next best thing to Icelandic geothermal power, without the attendant earthquakes and volcanic deserts.     
 

Offline wolfekeeper

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Re: How can renewable energy farms provide 24-hour power?
« Reply #130 on: 28/04/2015 23:41:43 »
I forget whether I already posted this:


(basically Texas has shed-loads of wind)
« Last Edit: 28/04/2015 23:46:03 by wolfekeeper »
 

Offline wolfekeeper

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Re: How can renewable energy farms provide 24-hour power?
« Reply #131 on: 01/05/2015 22:10:44 »
Interesting and related news from Elon Musk.

So he's selling 10kWh of battery for around $3500.

That's an average of $350 for 1kWh. If the batteries last 10 years, and they get cycled once a day; that's 3650 cycles, i.e. 9.6 c = ~ 6p for storage. The current cost difference on economy 7 is about 10p. So it's cheaper to buy all of your electricity at night and use it during the day storing it in these batteries.

Now, you might say- oh well, the economy 7 will smooth out then, because everyone will buy the batteries and then there won't be such a big price differential. This isn't actually a bad thing, because the day price will go down even if you haven't got a battery.

But this also misses the point that as more wind comes into the network, the natural variations in supply can be eaten up by the batteries also; the suppliers just need to create a new super 'economy' rate that is related to the wind supply.

edit: reading the small print, the 7kWh battery is suitable for daily cycling, and costs $3000 and is guaranteed for 10 years. So that's $428/kWh. So that's 11.7c per kWh; which is still 7p/kWh average per day.

edit2: OK, so it's only 92% efficient, so that makes it 8.1p/kWh.
« Last Edit: 01/05/2015 23:13:35 by wolfekeeper »
 

Offline alancalverd

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Re: How can renewable energy farms provide 24-hour power?
« Reply #132 on: 02/05/2015 12:21:36 »

10 kWh will run a house for most of a day, so it's a sensible starting point.

Lead-acid traction batteries cost about $30 per kWh, generally last about 5 years, and are easy to maintain and recycle. Why pay more? 

All modern domestic appliances work on 50 or 60 Hz AC, so in addition to the battery you will need a charger/inverter unless you want to completely re-equip your house. Add another £2000 and at least £500 installation charge to estimate the payback period.
« Last Edit: 02/05/2015 12:37:06 by alancalverd »
 

Offline Scottish Scientist

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Undersea hydrogen storage for energy store
« Reply #133 on: 02/05/2015 14:48:39 »
... Deep Sea Hydrogen Storage ...

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


http://en.wikipedia.org/wiki/Lifting_bag [nofollow]

The biggest air-lifting bags available to buy now off-the-shelf hold a volume of 50 metres-cubed and they have a diameter of 5 metres and a height of 7.5 metres.



Presumably they could be custom-made much bigger for storing hydrogen but are not yet available to buy off-the-shelf because any bigger would not be useful for air-lifting bag purposes.

In any case, it will always be possible to increase the volume by rigging multiple gas-bags together as shown in this diagram.


As for depth, as I mentioned earlier

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

the deeper the better because the density of hydrogen increases with depth, as per these graphs.


Click to view a larger image - https://scottishscientist.files.wordpress.com/2015/04/densityofhydrogenwithdepth.jpg [nofollow]

Consider how many 50 m3 gas-bags we'd need to store the energy required to provide 1 MW of electrical power for 1 day - a useful amount of back-up energy to store to serve one floating platform.

1 MW for 1 day = 1 MJ/s x 60 x 60 x 24 = 86.4 GJ of electrical energy which can be generated from 86.4/e GJ of hydrogen energy of combustion where "e" is the efficiency of the hydrogen-to-power generator and can vary from 30% to 60% depending on the complexity and expense of the generator.

The combustion energy from 1 gram of hydrogen is 143 kJ.

So the mass of hydrogen with 86.4/e GJ of energy is
mass = 86.4 x 109 J / (143 x 103 J/gram x e)
mass = 604/e Kg of hydrogen to provide 1 MW of power for 1 day

Consider three scenarios - 50 m3 gas-bags floating on the surface, at 200 metres depth and at 2000 metres depth.

Surface
Surface density of hydrogen 0.1g/L
Volume = 604,000g / (0.1g/L x e) = 6,040,000/e L = 6040/e m3
= 121/e x 50 m3 gas-bags
for efficiency of 30% that's 121/0.3 = 403 x 50m3 gas-bags  [V]

200m
200m density of hydrogen 1.8g/L
Volume = 604,000g / (1.8g/L x e) - 335/e m3 = 6.7/e x 50 m3 gas-bags
for efficiency of 30% that's 6.7/0.3 = 23 x 50m3 gas-bags  :-\

2000m
2000m density of hydrogen 16 g/L
V = 604,000g / (16 g/L x e ) = 37.75/e m3 = 0.755/e x 50 m3 gas-bags
for efficiency of 30% that's only 0.755/0.3 = 3 x 50 m3 gas-bags  :)

So the advantage of depth in reducing the volume and therefore the number of gas-bags required to store a given mass and energy content of hydrogen is clear.

How deep you actually want to put the bags depends on -

a) the depths available of the sea where floating platforms can be operating at - consult a sea depths map, like the ones I posted earlier

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

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

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



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

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

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

- and how deep you actually want to put the gas-bags depends on -

b) how deep the high pressure electrolyser can be made to work. High-pressure electrolysers can be made to work (in pressure vessels on the surface) at pressures corresponding to the pressures at depths of 1000 metres (about 100 bar) but higher pressures maybe up to 300 bar may be possible (corresponding to a depth of 3000 metres).

Since, as far as I know, the electrolysers required for this application have neither been designed, prototyped nor tested experimentally at sea depths, it is impossible at this stage to say with any certainty or proof at what precise sea depth high pressure electrolysers can be made to work, at all, or economically.

There seems to be an opportunity from this concept but only speculative answers to certain questions can be given at this time.
« Last Edit: 02/05/2015 17:48:46 by Scottish Scientist »
 

Offline wolfekeeper

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Re: How can renewable energy farms provide 24-hour power?
« Reply #134 on: 02/05/2015 18:59:30 »

10 kWh will run a house for most of a day, so it's a sensible starting point.

Lead-acid traction batteries cost about $30 per kWh, generally last about 5 years, and are easy to maintain and recycle. Why pay more? 
Because they only last 5 years, because they can only be discharged halfway, because they're not very efficient, and because $30/kWh is highly over optimistic?
 

Offline RD

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Re: How can renewable energy farms provide 24-hour power?
« Reply #135 on: 02/05/2015 19:25:50 »
2000m
2000m density of hydrogen 16 g/L
V = 604,000g / (16 g/L x e ) = 37.75/e m3 = 0.755/e x 50 m3 gas-bags
for efficiency of 30% that's only 0.755/0.3 = 3 x 50 m3 gas-bags  :)

What does 4000*m of [copper] underwater power-cable cost ?, and how much does 4km of power-cable weigh ? , ( weight will have a bearing on the size of the floating-platform necessary ).

Divers can only work at 200m , so if it's 2000m forget about maintenance.
Putting stuff in 2km of water is what people do if they never want to see it again.
 [ the Titanic is at 3.8 km ].


[*Two 2km power-cables according to your diagram ,
 and 2 or3 anchor cable$ also each 2km long ].
« Last Edit: 02/05/2015 19:42:33 by RD »
 

Offline alancalverd

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Re: How can renewable energy farms provide 24-hour power?
« Reply #136 on: 03/05/2015 21:22:39 »
Rather than work 2000 m below the sea, Why not compress hydrogen to 200 atmospheres in standard industrial bottles? It's already available off the shelf and used in huge quantities every day.

Bring the electricity ashore, electrolyse fresh water, and use the existing gas grid to store and distribute energy as previously.

Audi announced this week that they are now running a car on synthetic hydrocarbon fuel made from atmospheric CO2 and electrolytic hydrogen - LPG and liquid fuels are a lot more convenient and require very little conversion of existing vehicles.

As for the notion of siting windmills in a circle, the reason it isn't done is because half of them will then be in downwind of the other half, regardless of the wind direction.

Optimum siting is obviously in a line perpendicular to the prevailing wind. In the UK the wind rose generally has two maxima, one southwest and the other, rather smaller, northwest, so a staggered phalanx works pretty well.   
« Last Edit: 04/05/2015 11:33:00 by alancalverd »
 

Offline wolfekeeper

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Re: How can renewable energy farms provide 24-hour power?
« Reply #137 on: 30/10/2015 16:13:45 »
Looks like organic flow batteries are going to start to be available from 2017.

http://www.greentechmedia.com/articles/read/harvards-organic-flow-battery-under-development-in-europe

The previous estimates I've seen were that the chemicals for storing a kWh cost about $30; the current chemistries appear to be able to handle 5000 reuses; which is about $0.006 per kWh of usage.

If this is successful, it would appear to be a total game changer.
 

Offline alancalverd

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Re: How can renewable energy farms provide 24-hour power?
« Reply #138 on: 30/10/2015 16:33:39 »
http://www.greentechmedia.com/articles/read/harvards-organic-flow-battery-under-development-in-europe

Quote
First, the company plans to attack the domestic storage market with systems of 5- to 20-kilowatt-hours, designed to hold around four hours of electricity.
Some elementary physics missing here.

Quote
He also cites the fact that quinones are natural, organic products that present little or no health risk.
Bullshit
Quote
http://pubs.acs.org/doi/abs/10.1021/tx9902082Quinones represent a class of toxicological intermediates which can create a variety of hazardous effects in vivo, including acute cytotoxicity, immunotoxicity, and carcinogenesis.

So, apart from some duff science and a few barefaced lies, it seems like a good idea!
 

Offline chiralSPO

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Re: How can renewable energy farms provide 24-hour power?
« Reply #139 on: 30/10/2015 16:58:29 »
Looks like organic flow batteries are going to start to be available from 2017.

http://www.greentechmedia.com/articles/read/harvards-organic-flow-battery-under-development-in-europe

The previous estimates I've seen were that the chemicals for storing a kWh cost about $30; the current chemistries appear to be able to handle 5000 reuses; which is about $0.006 per kWh of usage.

If this is successful, it would appear to be a total game changer.

I am familiar with this from the primary literature, it's nice to see that the tech is going from academia to application, though I'm not sure that quinone-based flow batteries are ultimately the most exciting development. Flow batteries can store effectively unlimited amounts of energy (as big as you want the electrolyte reservoirs to be), which is nice, but both the energy density and power density are quite low compared to other energy storage methods. Flow batteries will be very useful for some applications, but I don't think it will be a "total game changer."

Also, there is no reason to say that quinones are benign! Sure there are natural quinones (like those involved in photosynthesis, and what bombardier beetles blast their enemies with, and the myriad cytotoxic quinones deployed by bacteria in their perpetual chemical warfare)...
 

Offline wolfekeeper

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Re: How can renewable energy farms provide 24-hour power?
« Reply #140 on: 30/10/2015 22:21:05 »
In the context of this thread, for storing renewable energy, it's primarily a question of cost. If it costs £0.1 per kWh that is stored, then it's unlikely to be widely deployed as representing a large percentage of our power, whereas at ~£0.01 per kWh, it becomes more or less a no brainer.

I believe the quinones they're planning to use are believed to be relatively benign; they're chemically closer to photosynthesis quinones. The real nasty with previous versions was the hydrobromic acid, but they've replaced it with potassium hydroxide; which is clearly corrosive, but probably wouldn't form WWI-style gas attack if a premises caught fire.
« Last Edit: 30/10/2015 22:25:26 by wolfekeeper »
 
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Offline wolfekeeper

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Re: How can renewable energy farms provide 24-hour power?
« Reply #141 on: 19/11/2015 18:19:50 »
In the context of the organic flow battery, taking Scottish Scientist's estimate of a requirement for 1400 GWh of storage, then we can calculate the cost for the batteries.

The estimate I saw before for the batteries was that the chemicals cost around $30/kWh of capacity. On top of that we would need tankage and pumps, and power converters. But for a first cut, let's just convert that nominatively to £30/kWh, as a start.

So we need 1400e9/1e3 = 1400 million kWh of storage, which at £30 per kWh = £42 billion for equipment that should last 20 years.

If we assume the money was borrowed for this at (say) 10% APR, I make that an average yearly cost of ~£70 per person. Which probably sounds like quite a lot. But this is deceptive.

Most of that is indirect charges, since much of the electricity is used in industry, and really overall the battery only adds a penny per kWh that is stored and then sold- and maybe about half of the power/energy would be used directly without storage. Additionally, wind power is a penny or so cheaper than nuclear, and wind power backed up with battery is flexible power- it's both baseload and peaking power; whereas nuclear power is really only baseload power, it gets more expensive when used to load follow, and it avoids any need for peaking plants.
 

Offline highvoltpower

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Re: How can renewable energy farms provide 24-hour power?
« Reply #142 on: 22/04/2016 07:25:43 »
Nighttime energy demands is much lower than the day and we are wasting a great deal of energy from nuclear power plant and coal that’s difficult rapidly to power up. Wind power is cheapest source of renewable energy, but now a day’s challenge to deal with periodic movement of wind speed. Single wind farm will swing greatly, the variations in the total output from number of wind farms originally distributed in different wind systems.
 

Offline Robcat

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Re: How can renewable energy farms provide 24-hour power?
« Reply #143 on: 24/04/2016 12:24:16 »
selected
100 since 1940 wow
Having spent 7 years of my life in nuclear I, m still alive but your 100 is missing some 5 noughts minimum
Or was that a joke?
 

Offline Robcat

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Re: How can renewable energy farms provide 24-hour power?
« Reply #144 on: 24/04/2016 12:34:42 »
If you want really good reading matter, see if you can find a small book by Fred Hoyle in the 1960s/70s
It's called "Energy or Extinction"
It answers all your questions and put into KWHr all out uses of energy from fuel to food etc.
To the young. Fred Hoyle was a great informer.

Although times have changed,    guess the annual energy usage in KWHr of Americans, British and Indians on average before you read this book.
See how  wave power compares with wind turbines etc.

It's really essential reading.
Rob
 

Offline alancalverd

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Re: How can renewable energy farms provide 24-hour power?
« Reply #145 on: 24/04/2016 15:00:21 »
we are wasting a great deal of energy from nuclear power plant and coal that’s difficult rapidly to power up
Very little is wasted - where and how would you dump it? The trick is to supply as much base load and predicted demand as possible from nuclear and big coal stations, using gas and small coal to supply short-term additional demand. In fact demand doesn't change abruptly as it is diversified among some 60,000,000 users. The problem arises when more than 20% of capacity is unreliable and generally unavailable when most needed - on the hottest and coldest days, when there is no wind.
 

Offline wolfekeeper

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Re: How can renewable energy farms provide 24-hour power?
« Reply #146 on: 24/04/2016 16:10:29 »
Demand changes fairly quickly on the UK grid due to the wide availability of electric kettles. They actually have to have people in the grid control centre watching TV so they know when to kick in extra power.

Peak demand on the UK grid is actually in the winter, not the summer, and happens when wind is at its strongest.

See:

http://gridwatch.templar.co.uk/

Coal is being killed off now, even wind power often beats power production, the grid is mostly gas at the moment. Nuclear is chugging along, but I don't see it growing.

Worldwide, renewables are being installed and the net effect is that fossil plants are being retired; because renewables are cheaper.

Scottish scientist's plan of installing salt water pumped storage seems to be quite promising, particularly if there's a lot of solar in the grid, the electricity should be super cheap and reliable.

Solar panels are getting ridiculously cheap now; they're well under £0.5/W, and still getting cheaper. A 1kW panel produces about 900 kWh per year in the UK, and produces power more cheaply than the grid can, so a grid tied solar panel is a win for the consumer, and over the life of the panel ridiculously cheap.
 

Offline alancalverd

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Re: How can renewable energy farms provide 24-hour power?
« Reply #147 on: 24/04/2016 16:25:41 »
Worth a careful look at the Gridwatch graphs. In recent weeks and months, demand has (as always) generally been highest when wind output was lowest. This is because UK winter weather is dominated by warm Atlantic lows, that bring high winds but mild temperatures, and cold Arctic highs that bring low temperatures and negligible wind speed.

The "electric kettle problem" hasn't really raised its head since 2 June 1953 when there was a hiatus in the BBC transmission of the Coronation and everyone had a cuppa and used the toilet - all the water pumps started at the same time. Thus warned, the CEGB managed to avoid significant power cuts after the 1966 World Cup Final but were caught unawares on 2 June 1979, a day of major national celebration.
 

Offline wolfekeeper

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Re: How can renewable energy farms provide 24-hour power?
« Reply #148 on: 24/04/2016 19:58:49 »
Worth a careful look at the Gridwatch graphs. In recent weeks and months, demand has (as always) generally been highest when wind output was lowest. This is because UK winter weather is dominated by warm Atlantic lows, that bring high winds but mild temperatures, and cold Arctic highs that bring low temperatures and negligible wind speed.
A pretty story, but I am not seeing any such trend in the data.
Quote
The "electric kettle problem" hasn't really raised its head since 2 June 1953 when there was a hiatus in the BBC transmission of the Coronation and everyone had a cuppa and used the toilet - all the water pumps started at the same time. Thus warned, the CEGB managed to avoid significant power cuts after the 1966 World Cup Final but were caught unawares on 2 June 1979, a day of major national celebration.
Only because they watch this like a hawk and kick in Dinorwig when they need to; the idea that "In fact demand doesn't change abruptly as it is diversified among some 60,000,000 users." is clearly false.
 

The Naked Scientists Forum

Re: How can renewable energy farms provide 24-hour power?
« Reply #148 on: 24/04/2016 19:58:49 »

 

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