PowerSwitch from coal

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adam2
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Post by adam2 »

Yes it is PARTLY due to the virus reducing electricity consumption, but coal burning was on a downward trend before the virus.

Some coal burning will be unavoidable during the coming winter, but I expect it to be less than in previous years.

I expect that the winter after the next winter will see a further reduction in coal burning.
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Post by vtsnowedin »

How many Megawatts of new renewables have to be installed to totally replace the remaining coal facilities?
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adam2
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Post by adam2 »

vtsnowedin wrote:How many Megawatts of new renewables have to be installed to totally replace the remaining coal facilities?
I don't believe that there is a simple answer to that, no question of saying XXMw.

Neither solar nor wind power can be the complete answer as solar contributes nothing during the winter evening peak, and in calm weather wind contributes only slightly.

Hydropower is most useful, but all the best sites are already in use.
Pumped storage helps but is limited by geography.
Battery storage helps, but only at present on a small scale.
Demand side control and preferential tariffs will help in the future.
Wood pellets and other biofuels contribute about 3Gw, and being steam plant assists with stability.
International interconnectors help.
But for decades I expect that the main non-renewable input will be natural gas, with light oil as a reserve.
I expect coal to decline markedly and cease in not many years. It is very carbon intensive, and not ideal for load following. A lot of coal burning plant is near the end of its life and no more will be built.
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BritDownUnder
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Post by BritDownUnder »

adam2 wrote:
vtsnowedin wrote:How many Megawatts of new renewables have to be installed to totally replace the remaining coal facilities?
I don't believe that there is a simple answer to that, no question of saying XXMw.

Neither solar nor wind power can be the complete answer as solar contributes nothing during the winter evening peak, and in calm weather wind contributes only slightly.

Hydropower is most useful, but all the best sites are already in use.
Pumped storage helps but is limited by geography.
Battery storage helps, but only at present on a small scale.
Demand side control and preferential tariffs will help in the future.
Wood pellets and other biofuels contribute about 3Gw, and being steam plant assists with stability.
International interconnectors help.
But for decades I expect that the main non-renewable input will be natural gas, with light oil as a reserve.
I expect coal to decline markedly and cease in not many years. It is very carbon intensive, and not ideal for load following. A lot of coal burning plant is near the end of its life and no more will be built.
It's just unfashionable to burn coal these days.

To replace generation capacity one has to consider the so called capacity factor of a particular type of generation, e.g. coal, nuclear, gas, solar or wind. A good description of it is here on wikipedia.

Replacing a fossil fuelled, higher capacity factor source of generation which is available on demand with a renewable, lower capacity factor and internittent generation will require much higher MW of generation than was being replaced. For instance to replace nuclear generation with a near 100% capacity factor with wind generation of 30% capacity factor would in theory need 3.33x the MW of generation of wind generation. So to replace 1000MW of nuclear you would need 3333MW of wind.
However you would still not be home and dry as you would have to have some kind of storage to store excess wind generation and then to discharge when the wind is not blowing. The storage capacity may need to last from hours to potentially months.

Bear in mind that storage can take many forms such as batteries, pumped hydro, flywheels and even thermal storage. Another form of virtual storage is to defer the use of electricity by demand response, i.e. by using power when it is plentiful such as heating your hot water at night or by pumping water and then by not using electrical equipment at times of energy shortage. I would imagine that most of these are already being done.

Personally I think the UK will struggle to find enough storage on its own. I think they will have to rely heavily on Norway and Iceland for their hydro storage. Unfortunately other countries such as Denmark, Netherlands and Germany also have the same ideas.

I expect that the UK will also have to use estuaries as pumped storage to store energy by means of some kind of tidal barrages and possibly hydrogen or high temperature thermal storage. Biomass power stations may also be needed to provide some emergency on-demand power when needed and a completely carbon neutral generation is required.
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Post by vtsnowedin »

Considering all of the above I see the future is bright for the latest generation of batteries both at substations and in parked EVs attached to smart meters. Consider that they would charge these batteries when solar and wind were in surplus so worth maybe a penny a KWH and draw it down when needed then worth 15 cents per KWH making an income for the battery bank of $0.14/KWH cycled through it. Such batteries are not sensitive to geography and can be anywhere in the grid convenient not just at wind or solar generation sites. All of the other power storage methods have location and practicality issues that put the battery bank in the lead. Imagine getting the permits to flood an estuary on a controlled basis that interferes with the local wildlife and dependent fish stocks.
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Post by BritDownUnder »

vtsnowedin wrote:Considering all of the above I see the future is bright for the latest generation of batteries both at substations and in parked EVs attached to smart meters. Consider that they would charge these batteries when solar and wind were in surplus so worth maybe a penny a KWH and draw it down when needed then worth 15 cents per KWH making an income for the battery bank of $0.14/KWH cycled through it. Such batteries are not sensitive to geography and can be anywhere in the grid convenient not just at wind or solar generation sites. All of the other power storage methods have location and practicality issues that put the battery bank in the lead. Imagine getting the permits to flood an estuary on a controlled basis that interferes with the local wildlife and dependent fish stocks.
I think you forgot the capital cost of the batteries which these days may not be too much if the batteries are sold at close to manufacturing costs.

I got a quote for a 5kWh capacity storage battery for my house. It was AU$10,000 so a cost of about US$1000 per kWh. The battery was warrantied for 10 years or 10,000 charge or discharge cycles. This means that the battery will cost you about US$0.10 per cycle (of 10,000 total) per kWh stored.
I would hope that your utility would be a better price negotiator than I was (I just told then it was too expensive and not financially viable and then ignored their calls) but if they were not then they would have to sell the battery output power for 10 cents more than they pay more it to recover the capital cost of the battery. I expect that a utility would get a better deal and the price differential would be much less than I have indicated.

On utility scale battery storage. The UK uses about 1 TWh of electricity per day. If they wanted to store half of this, for example, solar generated and
half stored for overnight usage this would require 500,000,000 kWh of battery storage at a cost of US$50,000,000,000 or 50 billion dollars at best price and not allowing for the inverters cost.

I have read that a 1 kWh LiIon battery contains about 10 to 100 grams of lithium so you would need between 5 and 50 million tonnes of lithium to make these batteries. World annual lithium production is about 100,000 tonnes per annum.

I suspect that utility batteries will remain rather 'niche' for the time being.
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Post by vtsnowedin »

BritDownUnder wrote:
vtsnowedin wrote:Considering all of the above I see the future is bright for the latest generation of batteries both at substations and in parked EVs attached to smart meters. Consider that they would charge these batteries when solar and wind were in surplus so worth maybe a penny a KWH and draw it down when needed then worth 15 cents per KWH making an income for the battery bank of $0.14/KWH cycled through it. Such batteries are not sensitive to geography and can be anywhere in the grid convenient not just at wind or solar generation sites. All of the other power storage methods have location and practicality issues that put the battery bank in the lead. Imagine getting the permits to flood an estuary on a controlled basis that interferes with the local wildlife and dependent fish stocks.
I think you forgot the capital cost of the batteries which these days may not be too much if the batteries are sold at close to manufacturing costs.

I got a quote for a 5kWh capacity storage battery for my house. It was AU$10,000 so a cost of about US$1000 per kWh. The battery was warrantied for 10 years or 10,000 charge or discharge cycles. This means that the battery will cost you about US$0.10 per cycle (of 10,000 total) per kWh stored.
I would hope that your utility would be a better price negotiator than I was (I just told then it was too expensive and not financially viable and then ignored their calls) but if they were not then they would have to sell the battery output power for 10 cents more than they pay more it to recover the capital cost of the battery. I expect that a utility would get a better deal and the price differential would be much less than I have indicated.

On utility scale battery storage. The UK uses about 1 TWh of electricity per day. If they wanted to store half of this, for example, solar generated and
half stored for overnight usage this would require 500,000,000 kWh of battery storage at a cost of US$50,000,000,000 or 50 billion dollars at best price and not allowing for the inverters cost.

I have read that a 1 kWh LiIon battery contains about 10 to 100 grams of lithium so you would need between 5 and 50 million tonnes of lithium to make these batteries. World annual lithium production is about 100,000 tonnes per annum.

I suspect that utility batteries will remain rather 'niche' for the time being.
No I did not forget the capital costs. Using your figure of 10cents / cycle my estimate of 14 cents covers cost with a 4 cent profit on that activity. Your real life numbers are interesting as I was just using my local costs which have a low of $0.02 USD for wholesale hydro Quebec power to My retail cost of $0.21/KWH from my rural co-op utility. They do not yet do peak power pricing here but at one time had different summer and winter rates and had programs to have timers on water heaters to keep them off during peak hours so future innovations of pricing structures are certainly possible. As to the lithium supply increased demand will of course increase price and then supply and the utilities would not try to build out a 50% capacity all at once but would bring it on gradually building enough to meet the then current shortfall of peak power storage.
Rather then being niche items I think battery storage especially EV cars and substation renewable storage will be a strong growth industry for this entire decade.
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Post by BritDownUnder »

I think I have a 1000 fold error in my maths. Maybe only 5,000 to 50,000 tonnes of lithium per year which is a bit more possible. I just don't see batteries being used for all storage when it is not always necessary to store electricity as electricity but rather more in the form its end use will be.

Heat is a logical storage in homes for short terms of less than a week which is about what the cycles in max to min wind power may last or to cover a few cloudy days. The best numbers I can find are that domestic electricity in the UK is 65% used for heating so maybe a heat store is better than a battery for water and space heating. Just have a bigger hot water tank operating at 90 C. I will use the following website instead of my failing maths which claims a one tonne tank of water will store 81kWh heating water from 20 C to 90 C. Even at the best battery price that would still be US$8,100 for an equivalent 81 kWh battery and probably a lot more since a Tesla battery (13kWh) is around US$7,000 these days. I am fairly sure you could get a hot water tank for around $1000 in that size.

Also in your case would it not be better to use Quebec Hydro's lakes as the energy storage and not the battery unless Quebec Hydro have a desperate need to keep their hydro stations operating evenly all the time.

As for using estuaries for energy storage, yes it would be devastating for the animal life no doubt about it. It may be better than a human die off however. I think will be less NIMBYism regarding estuaries than beautiful mountain valleys.
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Post by vtsnowedin »

Yes point of use storage is cheaper but you can't put that stored heat (or cool) back into the grid when needed. A 75 gallon water heater lists for $1850USD and I haven't got any hits on 265 /1MT tanks but I'm sure they have them in institutional and industrial applications but they will cost well above $1000.
People are going to buy the electric vehicles anyway so having them connected to a smart grid while parked will be the cheapest source of stored energy. The hydro from Quebec is base load power and you would not want to try to fine tune the turbines minute by minute to adjust to relatively small variations out at the end of the grid.
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Post by kenneal - lagger »

BritDownUnder wrote:.........I have read that a 1 kWh LiIon battery contains about 10 to 100 grams of lithium so you would need between 5 and 50 million tonnes of lithium to make these batteries. World annual lithium production is about 100,000 tonnes per annum...................
Why use lithium for a static battery when weight is not a problem as it would be on a car?
Last edited by kenneal - lagger on Fri Jun 12, 2020 2:47 pm, edited 1 time in total.
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Post by kenneal - lagger »

The vast majority of UK houses need to be properly insulated before they go over to electric heating. That will drop the heating requirement by about 80%. That energy requirement will then be at least halved as those houses go over to heat pumps to supply the heat at an average Coefficient of Performance of 2 (that may be a conservative estimate). The electricity storage requirement for domestic use can be vastly reduced on this basis to about 10% of current energy use.

This will be unlikely to happen as the nation's Big Six energy suppliers wouldn't allow the government to do it. The Prostitute State getting in the way again.
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Post by BritDownUnder »

kenneal - lagger wrote:The vast majority of UK houses need to be properly insulated before they go over to electric heating. That will drop the heating requirement by about 80%. That energy requirement will then be at least halved as those houses go over to heat pumps to supply the heat at an average Coefficient of Performance of 2 (that may be a conservative estimate). The electricity storage requirement for domestic use can be vastly reduced on this basis to about 10% of current energy use.

This will be unlikely to happen as the nation's Big Six energy suppliers wouldn't allow the government to do it. The Prostitute State getting in the way again.
From what I understand the space heating fraction for a typical house is about 30% and hot water is about the same. I am not sure that all houses could be insulated that well and not sure if there is enough money (even printed money may not suffice) or labour to do that in a timely manner. Perhaps shredded worthless money could be used as insulation? I once suggested a power station run on shredded commissioning test documents and not gas as the test documents seemed to be more abundant.

On a more serious note on a not very serious evening I think it may be more difficult to get hot water down to 20% of present energy requirement. I know that in Australia there are heat pump hot water heaters but their lifetime is somewhat limited and they are far more expensive, complex and prone to breakdown than their simple resistance heating competition. Some heat from hot water could possibly be recovered or run through an underfloor slab to dissipate the final heat usefully.

I would also think that in times of national togetherness the least wise thing to do might be to worsen your trade deficit by investing in far eastern manufactured AC units if the UK could supply underfloor heating or super large hot water tanks with resistance heating and British made radiators.
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Post by vtsnowedin »

kenneal - lagger wrote:
BritDownUnder wrote:.........I have read that a 1 kWh LiIon battery contains about 10 to 100 grams of lithium so you would need between 5 and 50 million tonnes of lithium to make these batteries. World annual lithium production is about 100,000 tonnes per annum...................
Why use lithium for a static battery when weight is not a problem as it would be on a car?
That would come down to total lifetime costs. Can the lithium battery last long enough to outlast two or three lead acid batteries?
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Post by kenneal - lagger »

I'm still using a set of lead acid batteries after over ten years.
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Post by BritDownUnder »

You are both right about the batteries. using LiIon batteries for static storage is not very clever. I hope that a sodium or aluminium battery (still theoretical) is used instead that maybe heavier and bulkier but that does not really matter. It would be better if batteries were made of more abundant materials such as Iron, Sodium or Aluminium. I also think that the lithium ion behaves in an unusual way (more like a proton than a metal ion) that makes it unique for batteries.

As for your lead acids lasting 10 years did they do an 80% cycle every day for that time?
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