EdwinSm wrote:I know this is not the silver bullet, but it might work out to be a small part of a diverse approach to energy storage.
The article says that the company building admits it is too small (at 5MW), but it is a trial facility and the idea needs to be scaled up to be worthwhile:
The world's largest cold energy storage plant is being commissioned at a site near Manchester.
The cryogenic energy facility stores power from renewables or off-peak generation by chilling air into liquid form.
When the liquid air warms up it expands and can drive a turbine to make electricity.
The 5MW plant near Manchester can power up to 5,000 homes for around three hours.
http://www.bbc.com/news/science-environment-37902773
I don't "get" this in terms of timing and efficiency.
Per the article, the liquid air needs to be stored at -190 degrees Celcius or colder. So, you either have to spend a lot of resource on building a super-efficient "thermos" to keep the liquid air at least that cold and/or use a lot of energy to keep it that cold (i.e. lots of waste).
So this sounds really expensive. If we know one thing about energy, it's that costs matter.
Since this is about the intermittency of green sources, the problem I see is those are highly unpredictable. So while you wait to need it (maybe for weeks in some cases), you have this super cold tank to keep super cold.
At least for pumped hydro (which the article talked about this being a substitute for, where pumped hydro would be inconvenient), I get it. You pump the water uphill, and it sits there until you are ready to let it run downhill and turn a turbine. There will be small losses from evaporation, but it could generally sit weeks or even months with relatively minor losses, if the storage tank is fairly deep compared to the surface area.
OTOH, given some of the other ideas in this space like keeping a giant flywheel spinning very rapidly (which also sounds expensive, wasteful, and potentially quite dangerous) -- as long as there were some VERY ROBUST safety features so if the cooling breaks down, loses power, etc., the gas (air) produced as the liquid warms can be reliably released without incident, at least perhaps it could be very reliable and safe.
Given the track record of the perma-doomer blogs, I wouldn't bet a fast crash doomer's money on their predictions.