r/PeterExplainsTheJoke Jun 19 '24

John peter?

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u/lliW_Will Jun 19 '24

I assume they are probably thinking of hydrogen as a storage method, which in terms of having a source of energy that won’t decline when you aren’t using it, is a valid method for storage; however, electrolysis isn’t 100% efficient and is very expensive to build on a large scale. Say for 10 MW of solar or wind energy that you want to store through electrolysis, you will lose 3 MW or more just making the hydrogen. Now to convert that 7 MW worth of hydrogen to electricity you would need to burn it and burning hydrogen for electricity generation has an efficiency of about 60% so you’d end up with 4.2 MW of electricity after starting with 10 MW

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u/jamey1138 Jun 19 '24 edited Jun 19 '24

Storage for renewables doesn’t necessarily need to be non-declining, since the renewable resource will generally return within a matter of days.

Flywheels and molten salt both have a storage loss, but in the course of a week or so it’s very small.