The battery system will have a discharge capacity of 38 MW and a storage capacity of up to 70.8 MWh, designed to operate for around twenty years. An environmental assessment is required because the investor, the local company Funicula, plans to develop the site as a standalone solar power plant.
[pdf] Finland has unveiled the world’s largest sand battery, a groundbreaking energy storage system designed to capture surplus power from renewable sources such as wind and solar. Standing 13 metres tall in the southern municipality of Pornainen, the facility can hold up to 100 megawatt-hours of energy.
[pdf] Other well-known mechanical energy storage technologies include flywheels,compressed air energy storage (CAES), and liquid air energy storage (LAES). In PHS, potential energy is stored by pumping water to an up-hill reservoir.
[pdf] 
