Just like conventional energy storage systems, when excess power is generated through renewable sources than is required, it is directed towards the sand battery. Instead of trying to move electrons from one electrode to the other or power pumps to send water to a higher reservoir, a sand battery uses resistive heating to increase the temperature of the air, which is then transferred to sand through a heat exchanger.
With the melting temperature of the sand in hundreds of degrees Celsius, a tower of sand has a high potential to store energy. More importantly, sand store this energy for many months together, making it a viable long-term storage solution.
Naturally, the next question to be asked is if this technology is scalable, and through the establishment of their company, Polar Night Energy, the researchers have attempted to answer that as well.