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

What is a Sand Battery?

• A “sand battery” is a high temperature thermal energy storage that uses sand or sand-like materials as its storage medium. It stores energy in sand as heat.

• The battery uses sand as a medium to store thermal energy. It was invented by Polar Night Energy.

• The battery has four metres wide and seven metres high steel container with 100 tonnes of recycled sand.

• The latest battery model can store up to 8 megawatt-hours of energyas heat.

• The reservoir is so well-insulated from the outer environment thatit can retain temperatures up to 600 degrees Celsius and prevent heat losses over time.

• The sand at the core is very far from the boundary, so the heat stored in the core does not easily get lost, even if we wait for days or weeks.

• The battery receives electricity from the grid through excess solar and wind power, which is converted to heat and transferred to the sand.

Why sand?

• Sand is a very effective medium for retaining heat over a long period, storing power for months at a time.

• Its main purpose is to work as a high-power and high-capacity reservoir for excess wind and solar energy.The energy is stored as heat, which can be used to heat homes, or to provide hot steam and high temperature process heat to industries that are often fossil-fuel dependent.

• The sand battery helps to ambitiously upscale renewables production by ensuring there’s always a way to benefit from clean energy, even if the surplus is massive.

Significance

• Water-based storage systems are a renewable alternative to produce building heat.

• The sand battery can store heat up to 600 degrees Celsius, thus having a great significance.