> An exercise to the reader, calculate the space and materials required to replace the average norwegian hydro reservoir with batteries.

Solution: I can't compute the space and materials, but can estimate the cost.

Norway has 1240 storage reservoirs with a total capacity of 87 TWh [1], which yields an average of 70 GWh/reservoir.

Last year, in China, a 16 GWh battery storage plant received an average bid price of $US66.3/KWh [2]. From this we can compute that a 70 GWh plant should cost $US4.65 billion.

A bit on the high side, but can battery prices fall by another order of magnitude? Then again, this is for replicating one reservoir. Replicating 1240 would be a 5 trillion dollar endeavor.

[1] https://energifaktanorge.no/en/norsk-energiforsyning/kraftpr...

[2] https://reneweconomy.com.au/mind-blowing-battery-cell-prices...