SAND BATTERIES NOVEL NEW WAY TO STORE ENERGY.

As a society, we have improved leaps and bounds in recent decades when it comes to renewable energy. Countries all over the world rely more and more on wind, solar, and wave energy to power their population’s lives. Nonetheless, a key problem still persists, and that’s how we can generate a steady supply of energy all year round. Enter the sand battery. Within the Vatajankoski power plant (about a three-hours’ drive northwest of Helsinki) stands a 23 ft (7 m) steel container. That container encloses 100 tons of sand, two heating pipes, and a fan. The sand becomes a battery when it is heated to 600°C, using electricity generated by wind turbines and solar panels in Finland. The battery stores around 8 MWh of thermal energy when it’s full, and it is surrounded by thick insulation, which keeps the sand hot even when it is freezing outside. When the demand for heat rises, the battery discharges around 200 kW of power through its heat exchange pipes. That is enough to heat and provide hot water for around 100 homes and a public swimming pool, supplementing power from the grid. The engineers of this renewable energy solution are very excited about it, and rightly so. The system is very low maintenance: it uses cheap, low quality sand that was rejected by builders.