Science & Technology: Using Geothermal Power Plant Wells to Store Pressurized Water Energy

A Texas startup's big energy idea: storing electricity underground (The Guardian)

The concept behind CEO Aaron Mandell Mandell’s startup, Quidnet Energy, sounds simple: pumping water deep into the earth to fill up the cracks in-between rocks that previously held fossil fuels. When the pressurized water is released, it acts like a spring as it races through a turbine-generator above ground, powering it to produce electricity.

Quidnet plans to run another pilot project, this time at an old geothermal well in northern Nevada. The well is 14 inches in diameter, larger than a typical oil and gas well, making it possible to inject a higher volume of water – and generating more power faster – at any time. The reservoir can hold up to 85k barrels of water, and produce 10 hours of electricity following a 14-hour charge.

The new pilot project will store electricity from the Blue Mountain geothermal power plant in Nevada run by AltaRock Energy, where Mandell is also CEO. The power plant sells electricity to NV Energy, the largest utility in Nevada.

Ultimately, Quidnet hopes to build its own wells in locations with a high demand for energy storage. Each of its projects will operate up to 20 wells, with each well measuring between 1000-5000 feet deep and capable of storing 35 megawatt hours of energy. The company is also working on software for automating a storage project’s operation so that a project owner can run it remotely.

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