Image: Polar Night Energy
Researchers throughout the world are working tirelessly to find new ways to store excessive heat or energy. It is due to the worldwide green initiative that urges everyone to switch to renewable energy. Now, the Finnish company Polar Night Energy has come up with the world’s first commercial sand battery for green power storage.
As the name indicates, this large-scale battery is based on regular sand. Plus, this thermal energy storage system consists of a large insulated sand-filled steel tank that’s around 4-meter-wide and 7-meter-high. When the added sand heats due to the presence of a heat exchanger in the middle, this unit can store an impressive 8 MWh of energy. The energy stored is at a rated output of around 100 kW with sand heated around to 500-600 degrees Celsius.
Since sand is a great energy storage medium that loses very less energy, researchers consider this large sand battery an effective medium for keeping green energy for several months. When needed, it is easy to extract the energy in form of heat in a similar way.
The company uses the stored heat (along with excessive heat from its data servers) for powering the local district heating system. This heating system further uses water pipes for transferring heat within the entire area. Furthermore, the generated energy is useful for heating buildings, industrial processes, swimming pools, and other places that need heat.
Image: Polar Night Energy
Hence, this new form of sand-generated energy becomes extremely efficient. According to the company, it is easier to convert electricity into heat but you require turbines and other complex equipment when turning heat into electricity. They also mention that this new energy storage unit has 99 percent of efficiency and can store with minimal loss for many months at a time. It can store green energy for decades, given further enhancement of the technology.
Polar Night Energy also mentions that the sand needs to be free of debris and completely dry to work for this battery. This also makes it an extremely cheap and zero-cost storage unit so far. The makers of this unit also believe that it’s easier to scale this project.
This large sand unit can store up to 20 GWh of energy by heating the sand to 1000 degrees Celsius. The same thermal accumulators are easy to create in abandoned mines, as well as other underground tanks in an accurate shape. It will further decrease the stored energy’s cost. For instance, it enables you to heat for $10.27 per kWh even for a small installation.
Via: Saur Energy