# Sand battery A type of [[energy storage]]. Seems like a good one, if the primary constituent is sand. Better than [[lithium]]. > Using low-grade sand, the device is charged up with heat made from cheap electricity from solar or wind. > > The sand stores the heat at around 500C, which can then warm homes in winter when energy is more expensive. > > – [Climate change: 'Sand battery' could solve green energy's big problem](https://www.bbc.co.uk/news/science-environment-61996520) That said, its storing heat, not electricity? So not exactly a battery. > Low-cost electricity warms the sand up to 500C by resistive heating (the same process that makes electric fires work). > > This generates hot air which is circulated in the sand by means of a [[heat exchanger]]. > > – [Climate change: 'Sand battery' could solve green energy's big problem](https://www.bbc.co.uk/news/science-environment-61996520) > Sand is a very effective medium for storing heat and loses little over time. The developers say that their device could keep sand at 500C for several months. > > So when energy prices are higher, the battery discharges the hot air which warms water for the [[district heating]] system which is then pumped around homes, offices and even the local swimming pool. > > – [Climate change: 'Sand battery' could solve green energy's big problem](https://www.bbc.co.uk/news/science-environment-61996520)