A pumped-hydro facility in Switzerland has an energy storage capacity of 1,450 MW, and is an interesting story of innovative energy storage.
To generate electricity, water is released from Lake Mutt at 8,100 feet above sea level. It flows to a deep valley below and turns the GE pump turbines and variable-speed generators as it does. Almost 23 billion gallons of water is used within the system.
When demand for electricity decreases, the released water in the valley can be pumped back up to Lake Mutt at elevation to be stored for the next release.
The Linthal plant is the first facility to have these GE variable-speed generators and it has been said that the technology has a cycle efficiency of 80%. The GE technology is also said to have the ability to stop and start almost immediately, which allows the system to be calibrated for efficiency.
A GE representative said the system is like a giant natural battery and, “Linthal is GE’s first variable-speed machine on the grid and brings positive momentum for the future of hydropower. With variable speed in the game, GE proves that hydro is definitely the most reliable source of renewable energy on the grid. Hydro will lead the way to more flexibility for other sources of renewable power like solar and wind,” he explained.
There are two things that energy storage–conscious people would most likely want to know about this project: the cost and how long the technology can generate electricity when there is water available. Axpo, the Swiss utility that operates the plant, wrote on its website that, “investment costs for this project amount to around 2.1 billion francs.” A prior CleanTechnica article put the figure at $1.5 billion. Unfortunately, the number of megawatt-hours does not appear to have been released.
The same GE technology will be used at another Swiss energy plant, named Nant de Drance, and one in India called Tehri.
The Linthal village has a population of about 1,000.
Top image by BraunW, Creative Commons SA 3.0; other images by GE Reports/Tomas Kellner
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