A seasonal thermal energy storage will be built in Vantaa, which is Finland’s fourth largest city neighboring the capital of Helsinki.
The total thermal capacity of the fully charged seasonal thermal energy storage is 90 gigawatt-hours. This capacity could heat a medium-sized Finnish city for as long as a year. Broken down into smaller energy units, this amount of energy is equivalent to, for example, 1.3 million electric car batteries.
The project cost is estimated to be around 200 million euros, and it has already been awarded a 19-million-euro investment grant from Finland’s Ministry of Economic Affairs and Employment. Construction of the storage facility’s entrance is expected to start in summer 2024. The seasonal thermal energy storage facility could be operational in 2028.
Artificial lakes / Pumped-storage hydroelectricity sounds a lot more reasonable than heating water. And it already exists
The problem with pumping is low energy density, especiall when compared to deating water. Heating 1 kg of water by 1°C requires 4186 joules of energy. So to store the same energy by “lifting” water, it would require 4186 j / (1 kg * 9.81 m/s^2) = 426 m of height difference. This value seems unbelievable, but I have triple checked it. And that is only 1 degree of difference, 50 degrees difference would equal 27 km of height difference.
Yes. The problem is that the best locations for harvesting wind energy are flat and the best places to pump store energy ideally needs some terraine