iljah's comments

According to Finnish version (https://yle.fi/a/74-20203091) ATH was hit several times with largest average over 15 minutes of 15.6 GW starting at 5 pm on thursday. Dividing that by population from Wikipedia gives approximately 2.7 kW / person.

https://yle.fi/a/74-20203419 gives a breakdown of ATH production over same period (14.3 GW): 5.8 wind, 4.2 nuclear, 2.3 heat+electricity, 1.8 hydro, 0.3 other.

This energy storage system near Helsinki, Finland operated by Helen (https://en.wikipedia.org/wiki/Helen_Oy) might be interesting for HN readers. Some facts from previous article (https://www.helen.fi/en/news/2020/mustikkamaa), not sure which one would've been better in url field: District heat is stored in two rock caverns in Mustikkamaa. The temperature of the water in the caverns varies between 50 and 90 °C. The effective volume of the cavern storage facility is 260000 cubic metres and energy capacity about 11500 MWh. The charging and discharging capacity is 120 MW. The discharging or charging of the heat caverns at full power takes four days. The rock caverns will decrease Helen’s carbon dioxide emissions by 21000 tonnes per year. The stored heat can be used for balancing demand peaks and that way cutting fossil heat production, for example, in cold winter days.