Breakthrough in thermal storage technology

The plant will use a technology that will be able to produce electricity for about 20 hours in a day

By Aruna Kumarankandath
Published: Tuesday 10 February 2015

Representative picture (Photo: Jonas Hamberg)

Brenmiller Energy, an Israeli firm, announced on Monday that it will build a 10 mega-watt (MW) concentrated solar power plant in Israel. The plant that will be constructed in Negev desert near the town of Dimona would be spread across 45 hectares.
The plant will use an energy storage technology that will be able to produce electricity for about 20 hours in a day. Brenmiller energy chief executive Avi Brenmiller tells Reuters, “For renewable energy to move to the next phase, we need to make it available whenever we, human beings need it, and not when the sun is shining or the wind is blowing. So storage is the name of the game. We will have this technology at conventional fuel numbers [prices] with the same availability around the clock. I think that's the major breakthrough here."

The plant plans to use parabolic mirrors to concentrate the heat of the sunrays to generate steam, which drives a turbine to produce electricity. Some of the solar heat accumulated will be stored underground, using a system which can operate during night time. The company is reluctant in disclosing the technological secret; however, it does say a cement-like material is the key to storing the heat. The company surmises that their system is more efficient than other systems, such as molten salt, which is expensive and has operational downsides as well.

The salt stores the heat in liquid form, but if the temperature drops below about 220 degrees Celsius, the salt freezes, potentially damaging parts of the system. This is not a concern for Brenmiller, the CEO said, as their system uses a solid cement-like storage medium and is buried underground below the mirrors.

Brenmiller Energy will fund the 10 MW plant itself, partly to promote the system and have a successful demonstration project. The plant is estimated to cost 300 million shekel ($77.27 million) and is expected to be operational by 2017.

Technology roadmap: solar photovoltaic energy

Technology roadmap: solar thermal electricity

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