The Finnish energy company Vantaa Energy is constructing the world’s largest cavern thermal energy storage in terms of size. Called Varanto, the project will be completed in 2028 with a capacity of 90 GWh and 1.1 million cubic meters. In equivalent terms, this amount of energy is equal to 1.3 million electric car batteries. With this project, a mid-sized Finnish city can have covered heating demand for up to a year. The construction is expected to start in the summer of 2024.
“The world is undergoing a huge energy transition. Wind and solar power have become vital technologies in the transition from fossil fuels to clean energy. The biggest challenge of the energy transition so far has been the inability to store these intermittent forms of energy for later use. Unfortunately, small-scale storage solutions, such as batteries or accumulators, are not sufficient; large, industrial-scale storage solutions are needed. Varanto is an excellent example of this, and we are happy to set an example for the rest of the world,” says Vantaa Energy CEO Jukka Toivonen.
The project will be located in the southern Finnish city of Vantaa, where thermal energy will be stored in underground caverns and used via the existing district heating network whenever needed. The project will be built around 100 meters (328 ft) underground, with a cavern length of 300 meters (984 ft), 40 meters height (131 ft), and 20 meters width (66 ft).
Furthermore, the facility will include a pair of 60 MW electric boilers that will power the hot water heating, which will be powered by cheap renewable energy. The pressure allows heating of the water to temperatures of up to 140 °C (284 °F) without water evaporation or boiling. An additional feature is the smart control system for balancing energy sources. Regarding costs, the project is estimated at 200 million euros, of which 19 million are granted by the Finnish Ministry of Economic Affairs and Employment.
Article & Image Source: Vantaan Energia
