Comment by blaze33

If it works it could reduce the electricity price in the evenings and mornings.

Now if I take the french grid example that I know best, for the past 7 days the usual spot price is around 100 to 150€/MWh but between 9am to 6 pm it is greatly reduced due to solar production, frequently down to 0 like today (current heatwave, lots of sun). And today between 1 and 3pm we had up to 5GW of solar production being curtailed. That is on top of the nuclear plants already reducing their output by up to 8GW around noon to accommodate solar power. Hydraulic storage was also running but tops at ~3GW.

That is to say there's already unused energy during the day, in theory, if you had a MWh battery you could have charged it for free today (sometimes even been paid to do so) and earned 100€ a few hours later.

One thing I see coming (albeit slowly) is EV cars phasing out IC engines, that once plugged on the grid with their big batteries could be a good distributed storage solution: they recharge during the day whenever the price is low and smooth out the expensive peaks when possible.