Sand Battery

Sand Battery
 

News: Finland has installed the world’s first sand battery that can store heat from renewable energy sources for months.
 

About:
 The battery, made of sand collected from construction sites, can solve the problem of round-the-year energy supply, a known limitation of renewable energy sources that can be harnessed intermittently.
 Sand can be heated up to 600 degrees Celsius (°C), whereas water starts to boil at 100°C. It also has low heat conductivity, which reduces energy loss.
 The storage system has three main components: the sand silo, an electrical air heater and an air-to-water heat exchanger. For charging the sand silo, the air is heated to 600°C in the electric air heater.
 The hot air is then circulated inside the silo using a heat-exchange pipe and blowers to raise the temperature of the sand at the silo’s core to 600°C.
 When the storage enters the discharging stage, the blowers are used to pump air into the pipe inside the sand silo.
 Once the air reaches 200°C, it is transferred to the air-to-water heat exchanger, where it is used to boil water. It is then sent to the heating network.
 The storage system requires electricity at all times.
 It is needed to charge the battery, monitor the temperature during standby and run the blowers when the battery is used.
 1,000 times more power is discharged as heat than is used as electricity.