5 ms·

> The battery is charged overnight when the electricity prices are lower. Sounds like the battery is charged via electricity.

• automatic6131 4y ago
  But missing the crucial second half, releases electricity on discharge.
  • tomrod 4y ago
    It's not a chemical battery, which releases energy as electricity, but electricity can certainly be generated using heat stored in heated/molten sand. Ultimately its about energy transfer, efficiency, and storage.
  • tuatoru 4y ago
    It's an accumulator for a district heating system, which are apparently common in Nordic countries. Traditionally district heating systems use waste heat from thermal generation of electricity, which heat is free.