Swedish utility Vattenfall is about to start filling with water a 45-metre-high storage tower in Berlin that will act as a giant kettle that can store hot water for district heating as well as surplus energy from wind farms, reports the Energy-Storage.news website.
The tower can hold 56 million litres of water and filling it is expected to take two months.
It will be linked to the company’s Reuter West coal-fired combined-heat-and-power plant. In September 2019, this was connected to 60,000 households in northwest Berlin’s heating grid, forming northern Europe’s largest power-to-heat facility.
The system will now have another 200MW of energy provided by water raised to a temperature of 98°C.
Jornt Spijksma, project manager at Vattenfall, told the Energy-Storage.news website that the combination of Reuter West’s existing system and the storage tank would form an “optimal, fossil-free and future-proof component to supply our Berlin customers with heat”.
He added that the tower would be able to store surplus wind energy, reducing the need to take turbines offline during periods of low demand.
The storage tank can also integrate heat from other industrial processes, such as the city’s cleaning department or heat from waste water, and could potentially connect with other renewable heat sources, such as a large-scale heat pump.