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Finnish City Inaugurates 1 MW/100 MWh Sand Battery

(cleantechnica.com)
190 points erwinmatijsen | 1 comments | 03 Sep 25 06:00 UTC | HN request time: 0.207s | source
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haspok ◴[03 Sep 25 11:49 UTC] No.45114642[source]▶
This is not a battery, this is thermal storage. No electricity is stored or generated. (Unlike liquid-metal batteries, for example, which are actual battery storage.)
replies(2): >>45114908 #>>45114922 #
1. alkonaut ◴[03 Sep 25 12:30 UTC] No.45114922[source]▶
No one is claiming it is storing electricity. I think people who use imperial (BTU) units for heat but SI units for electric power some times get confused by what power really is and what a battery is.

Something that stores _energy_ is a battery. Not necessarily electric energy. You can absolutely have a battery with mechanical energy (wound up springs), a battery with kinetic energy (a weight in a shaft) a battery with nuclear energy (Thermal reactor in a satellite), a battery with thermal energy (silo full of very hot sand) or a battery with chemical energy such as a Li-ion battery.

This stores 100 MWh heat energy, so it is a battery.

From wikipedia:

> Energy storage is the capture of energy produced at one time for use at a later time to reduce imbalances between energy demand and energy production. A device that stores energy is generally called an accumulator or battery.