Swiss authorities managed to build a unique underground hydroelectric power plant Nant de Drance, located at a depth of 600 meters. The plant is located between two reservoirs and operates only at a time when it is beneficial for consumers, local media reported.
The station is worth for $2.3 billion, and was in the works for 14 years. The facility has six turbines with a capacity of 900 MW, this is one of the most powerful hydroelectric power plants in Europe.
The facility, which was put into operation in July, functions as a giant accumulator in the canton of Valais. At peak demand, the plant generates electricity from hydropower.
When wind and solar power generation exceeds demand, the facility accumulates excess energy by pumping water into the Vieux Emosson reservoir.
The building efficiency is 80%. It can store a huge amount of energy – about 20 gigawatt-hours. That would be enough to charge 400,000 electric car batteries. The station will officially open in September.