Finnish researchers have installed the world's first ever fully functioning "sand battery," which is used to store green power for many months. This is a big win for Finland and its people considering that winter is on the horizon. Green power has also become a buzz word in recent discussions considering that Finland gets most of its gas from Russia and Russia has halted all gas exports to Finland after Finland’s decision to join the defense alliance NATO.

In today’s day and age, the ever-expanding question of concern is renewable energy. Because of climate change and now the increased prices for fossil fuels, there is more discussion around green power and renewable energy resources, such as solar and wind power. While renewable energy sources such as these are added to the power grid, there still needs to be power that is consistent. In order to resolve this concern of constantly having enough power, the simplest answer is large scale batteries, which is where the “sand battery” comes into play. In the present time, most batteries are made with lithium, which are both expensive and have a larger physical footprint, and the “sand battery” offers an alternative that is significantly more cost-effective.

This first ever “sand battery” is about 100 tonnes of builder's sand that is piled high inside a gray silo and was installed at the Vatajankoski power plant in Kankaanpää, Finland, which runs the heating system for the area. Sand is a very effective medium for storing heat and loses very little of this energy as time passes, and this “sand battery” may be the best way to store energy in a low-cost, low impact way. Markku Ylönen, one of the two founders of Polar Night Energy who developed this “sand battery” also explained that "whenever there's like this high surge of available green electricity, we want to be able to get it into the storage really quickly,” and the “sand battery” will do exactly that.

As for the process of how this “sand battery” works, essentially low-cost electricity from solar or wind power warms the sand up by resistive heating. This then generates hot air that is spread throughout the sand and the sand then stores this heat for many months. The stored heat is then used when energy prices become higher. The heat can then warm the water that is pumped to various locations, such as homes and offices, during the upcoming winter months when energy is more expensive. This “sand battery” in turn would solve the major issue of maintaining a year round supply of green power and bring some relief to the many of Finland’s concerned citizens as the long, cold winter will soon approach.