PORNAINEN, Finland — Engineers will soon begin testing a new "sand battery" that will convert energy stored as heat back into power that can be fed into the electricity grid. However, they say challenges lie ahead, with investment cost potentially putting customers off.
Polar Night Energy's existing sand battery model stores renewable electricity by using power to heat up sand and sand-like materials to temperatures up to 752 degrees Fahrenheit (400 degrees Celsius). That heat is then extracted to deliver hot water, steam or hot air.
