To Store Renewable Energy, Try Freezing Air

Re:To Store Renewable Energy, Try Freezing Air by timoth3y on Wednesday January 08, 2020 @10:33PM (#21998326)

Efficiency needs to be viewed with target storage times in mind. For example, the reason batteries are not used for seasonal storage is not just because of their cost, but the fact that they lose their charge pretty quickly. They are 90%+ efficient in the short term, but that drops pretty quickly.

On the other hand, something like pumped hydro is less efficient and takes longer to bring online, but can store the energy for months or even years.

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Re:To Store Renewable Energy, Try Freezing Air by fyfy18 on Wednesday January 08, 2020 @11:13PM (#21998507)

> takes longer to bring online

For anyone wondering how long that is, the largest pumped hydro plant in the UK can be at full capacity in 16 seconds from standby, or 75 seconds from cold.

https://en.m.wikipedia.org/wiki/Dinorwig_Power_Station

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Re:To Store Renewable Energy, Try Freezing Air by dTal on Thursday January 09, 2020 @06:44AM (#22000368)

Note that "standby" is burning power to keep the turbines spinning without flow, so that they don't have to accelerate when the stopcocks are opened. Dinorwig's purpose is smoothing demand spikes, so its 75% roundtrip efficiency is acceptable and its duty cycle somewhat predictable, but it must be a tricky optimization problem to maximize efficiency while never failing to meet the load.

(Interesting side note - when I took a tour of Dinorwig some years back, the guide said that when the facility was built it rarely needed to run more than 1 turbine - now they routinely fire up all 6. At some point it will run out of capacity...)

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Re:To Store Renewable Energy, Try Freezing Air by wbl on Thursday January 09, 2020 @08:32AM (#22000994)

Dont forget the person who watches the telly to know when to turn it on. https://www.google.com/url?sa=t&source=web&rct=j&url=https:/...

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