Storage and renewable energy

Sand batteries

Sir, – One of the problems with renewable energy is storage. The Finnish company Polar Night Energy has come up with a cheap solution, that of a “sand battery”.

Sand is stored in a well-insulated container then heated using either renewable energy or excess energy from the like of data centres.

The sand can be heated up to 600 Celsius for a few months then used when needed.

Ireland has many data centres and can generate heat via solar panels or wind turbines. In the Finnish case, the stored heat is to be used in a district heating scheme.


With the dwindling and insecure supply of traditional energy sources, we must make use of what we have and be inventive in their utilisation.

The sand battery could be one such innovation.

Further, with the correct design, every new build could have its own sand battery beneath the building, acting as a large storage heater, with the sand being heated through the summer months then utilised through the winter. – Yours, etc,



Co Donegal.