The world’s largest sand battery just went live in Finland

This week, Finland has inaugurated a sandy battery on an industrial scale in the southern city of Pornenen, where the heating tasks take over from an old wood cart plant for the municipality. It is set to reduce the carbon emissions of the local heating network by no less than 70%and is the largest of its kind in the world.

Developed by the Finnish sturdy Polar Night Energy – which also built the world’s first commercial sand battery a few years ago – This battery is approximately 42 ft (13 m) long and 50 ft (15 m) wide. It serves as a storage medium for a maximum of 100 MWh, with a return efficiency of 90%. That makes it about 10 times larger than the very first sand battery and able to store enough heat for the entire city to use a week.

This reservoir for thermal energy storage (TES) is a critical tool for places such as Finland, which generates enormous amounts of wind and solar electricity at intervals, but also facial variations in demand and supply of energy. The sand battery charges when electricity is available cheaply and can be charged for months in a row, so that the energy letter can balance during periods of high demand. You can see that the battery is being put together in pornins, in the video below.

This is how it works: excess electricity from renewable sources is used to heat the sand in a large insulated silo through a closed loop-air pipe system, up to temperatures up to 1.112 ºF (600 ºC). The sand becomes hot and stays hot for a long time, acts as a battery.

Later, cool air is blown through the pipes of the battery, which absorbs heat from the sand while moving through the system. This heated air – which can reach temperatures of 752 ºF (400 ºC) – can then convert water into steam for industrial processes, or it can heat water for district heating using a device called a heat exchanger.

So if you wondered: no, this battery does not store and provides electricity directly. Polar Night says it is working on a system to convert the stored warmth of this tes into electricity; It will probably mean the use of steam turbines.

This battery has actually been in operation since June and the company says that it has already surpassed its efficiency goals in the early days of optimizing its functions. Many of the buildings of pornanans, including the town hall, are currently heated by the new TES.

Polar Night Energy

In the coming years it will play an important role in helping the city to reach carbon neutrality – and it can inspire more municipalities in regions with similar climate and energy sources to accept these gigantic batteries.

Source: Polar night