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Salting away renewable energy for future use

The Crescent Dunes Power Plant. A large group of mirror in a circle surrounding a tower. They are in an empty desert.

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Mirrors track the sun, directing its energy to the receiver atop the Crescent Dunes tower in Tonopah, Nevada.

One of the biggest challenges in the solar energy field is how to store electricity from the sun. One solution may be no farther than your saltshaker.

SolarReserve, a California company, is pioneering a technology that uses molten salt as a medium for long-term energy storage.

The company’s Crescent Dunes solar power plant in Tonopah, Nevada, completed in 2015, is the first commercial plant in the United States to use this sophisticated storage technology.

The plant’s 110-megawatt capacity can power 75,000 homes and run for 10 hours from storage. That means overnight.

“The climate deal unveiled in Paris has the potential to catalyze a global energy transformation. It will further accelerate the implementation of renewables around the world, including within emerging markets such as Africa, Latin America, and Asia,” said SolarReserve chief executive Kevin Smith.

“Our proven U.S.-developed energy-storage technology deployed at the Crescent Dunes facility is already being used as a blueprint for projects in these emerging markets,” he added.

How does it work?

Mirrors that track the sun — 10,000 of them — reflect sunlight onto a receiver set atop a 195-meter tower. Liquid salt is piped through the heated receiver. The molten salt flows into an insulated thermal storage tank. As electricity is needed, the molten salt moves through a steam-generation system where water is heated to produce high-pressure steam. The steam drives a turbine that generates electricity. It works whether the sun is shining or not.

solar reserve diagram 400.png

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The steam-generation process is identical to those used to produce electricity from gas, coal or nuclear power plants, but it is 100 percent renewable, without harmful greenhouse gas emissions.

“So far, in the industry, that’s the state of the art — molten salt storage,” University of South Florida solar power expert Yogi Goswami told the Los Angeles Times.

salt tank 400.png

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Salt Tanks provide efficient thermal energy storage. They allow energy to be provided after the sun goes down. Energy output can be scheduled to meet demand requirements.

The molten salt storage technology deployed by SolarReserve resulted from decades of design and testing by U.S. aerospace companies Rockwell International, Rocketdyne, Boeing, Pratt & Whitney and Aerojet.

SolarReserve has advanced projects that use molten salt storage underway in other countries, in partnership with governments and private energy providers. Its Redstone thermal power project in South Africa’s Northern Cape province is slated for completion in 2018. Another project is being built in Chile. And the company recently sealed a deal with Shenhua Group to build 1,000 megawatts of advanced solar energy installations in China.

Source:

© 2020 by FHI 360. "Advanced Reading Practice: Salting Away Energy for Future Use" for the Online Professional English Network (OPEN), sponsored by the U.S. Department of State with funding provided by the U.S. government and administered by FHI 360. This work is an adaptation of "Salting Away Renewable Energy for Future Use" by Lea Terhune / ShareAmerica used under Public Domain/ U.S. Government Works. To view a copy of the license, visit (link to license copy). Adapted content is licensed under the Creative Commons Attribution 4.0 License, except where noted. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

Image Credits:

Crescent Dunes Solar Energy Project: This work is a derivative of “Crescent Dunes Solar Energy Project” by “Amble” via Wikimedia Commons used under the Creative Commons Attribution-Share-Alike License. This derivative is licensed under CC BY SA 4.0 by FHI 360 for use in the OPEN program, sponsored by the U.S. government and administered by FHI 360.

SolarReserve Process Diagram: This work is a derivative of “fan” by ainul muttaqin,, “turbine” by Flatart, “and “electricity” by iconixar used under CC BY. This derivative is licensed under CC BY 4.0 by FHI 360 for use in the OPEN program, sponsored by the U.S. Department of State with funding provided by the U.S. government and administered by FHI 360.

Salt Tanks This work is a derivative of "Thermal Energy Storage" by Energy.gov via Wikimedia Commons used under Public Domain / U.S. Government Works. This derivative is licensed under CC BY 4.0 by FHI 360 for use in the OPEN program, sponsored by the U.S. government and administered by FHI 360.