Giant Water Batteries: The Logical Alternative to Gas and Oil

Switzerland has announced the opening of a pumped storage hydroelectricity facility at the Nant de Drance, the largest ever in the country and one of the biggest in Europe, connecting two pre-existing reservoirs in the Alps whose capacity has been increased.

The twin-lake facility is essentially a huge water battery: in times of surplus power, generation from renewable sources or from nuclear power plants whose supply is impractical to interrupt, it allows water to be pumped to the upper reservoir, Lac du Vieux Émosson, from the lower reservoir, Lac d’Émosson, so that it can be sent back down to generate power in the corresponding turbines when needed.

To build the plant, eighteen kilometers of tunnels had to be dug under the Alps to transport the building materials and prefabricated elements for the facility. The central chamber containing the turbines is 200-meters long and 32-meters wide. The project, including the expansion of the reservoirs to increase the total capacity of the facility, has taken 14 years to build, due to the complexity of the logistics and engineering involved.

The hydroelectric power plant is built inside a cave between the two reservoirs, and is expected to play a major role in stabilizing the energy needs of the country and central Europe. It is equipped with six turbines, capable of generating a total of 900 MW. The system as a whole can store a total of 20 million kWh, which makes it possible to take full advantage of all the energy produced by intermittently operating solar or wind power systems with very little loss, even if it is not needed at the times when it is produced. These types of systems are valid for all types of needs, from balancing the generation infrastructure of an entire country or territory to small-scale systems applied to domestic use or small communities (pico hydro).

Undoubtedly, the invasion of Ukraine will be a great incentive to rethink the way in which we generate and store energy, particularly in countries that are dependent on Russian oil and gas.

After China, Japan and the United States, Spain has the largest reversible hydroelectric power plant capacity in the world, with a total of 106.7 GW of total installed generation capacity, which is consistent with the government’s plan to oversize the construction of wind or solar power generation systems, which are characterized by their intermittency.

Using such systems instead of gas to balance energy needs would enable great savings, in addition to reducing the need to import dirty Russian oil and gas.

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This post was previously published on MEDIUM.COM.

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Photo credit: iStock.com