high temperature

Around-the-clock clean energy

June 14, 2024 By EarthWise Leave a Comment

Using solar and wind power can go a long way toward replacing fossil fuel-generated electricity, particularly with the addition of battery energy storage. But because of the intermittent nature of both sun and wind, other sources are still needed. There is also the need for ways to produce high temperature for industrial processes. Complete decarbonization will require a host of complementary technologies.

A spinout company from MIT called 247Solar is building high-temperature concentrated solar power systems that make use of overnight thermal energy storage to provide electric power around the clock as well as industrial-grade heat.

The system uses a field of sun-tracking mirrors to reflect sunlight to the top of a central tower. A proprietary solar receiver heats air to over 1,800 degrees Fahrenheit. The heated air drives turbines that generate 400 kilowatts of electricity and produces 600 kilowatts of heat. Some of the hot air is routed through a long-duration thermal energy storage system and the stored heat is then used to drive the turbines when the sun isn’t shining. The unique part of the technology is not the concentrated solar power; it is the solar receiver.

The modular systems can be used as standalone microgrids for communities, or to provide power in remote places. They can also be used in conjunction with conventional wind and solar farms to enable around-the-clock renewable power.

The first deployment will be with a large utility in India. If it is successful, 247Solar hopes to scale up rapidly with other utilities, companies, and communities around the globe.

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Offering clean energy around the clock

Photo credit: 247Solar.

Earth Wise is a production of WAMC Northeast Public Radio

SuperHot Rock Geothermal Energy | Earth Wise

December 3, 2021 By EarthWise Leave a Comment

The United States in a world leader in geothermal energy. There are geothermal power plants in 7 states which produce about half a percent of the country’s electricity. Conventional geothermal energy plants take advantage of natural underground sources of heat such as geysers, superheated underground reservoirs, and such. Steam from these sources activates generators that produce electricity. However, there are not many places where these systems can be built.

More recently, there has been growing interest in so-called enhanced geothermal systems (or EGS systems) which generate geothermal electricity without the need for natural convective hydrothermal sources. There are many places where underground heat is available but no existing water taps into it. The idea is to tap into the earth’s deep geothermal resources by fracturing rock and pumping water into it to be heated.

AltaRock Energy, a Seattle-based company that develops EGS technology, has recently announced the results of a comprehensive technical and economic feasibility study demonstrating the potential benefits of an EGS system that could use high-temperature impermeable rock deep below the Newberry Volcano near Bend, Oregon. The so-called SuperHot rock there is in excess of 750 degrees Fahrenheit.

Based on measurements at the site and modeling, the study determined that an EGS system at the site could cut the levelized cost of electricity in half when compared with a conventional EGS resources at 400-500 degrees.

The company expects that the study will pave the way for the development of the first SuperHot Rock geothermal resource in the United States.

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AltaRock clears hurdle in quest for ‘next generation’ geothermal resource

Photo, posted June 26, 2018, courtesy of David Fulmer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Extreme Heat From Solar Power | Earth Wise

January 23, 2020 By EarthWise Leave a Comment

Renewable sources are playing a growing role in meeting our energy needs, but one place where they have continued to fall short is in industrial processes that require extreme heat. These include the cement, steel, and glass industries, among others. These industries account for a significant amount of CO2 emissions because the most effective way to reach the necessary temperatures continues to be combustion of fossil fuels. The cement industry alone accounts for 7% of global emissions and the need for cement continues to grow.

A previously stealthy startup company backed by Bill Gates and fellow billionaire Soon-Shiong has made a breakthrough in the area of using solar energy to achieve high temperatures. The company, called Heliogen, has created a solar oven that is capable of generating heat above 1800 degrees Fahrenheit, which is enough for high-temperature industrial processes.

The Heliogen technology uses concentrated solar power to generate heat. Concentrated solar power uses arrays of mirrors to reflect sunlight and focus it to a single point. That technology is not new; there are systems that use it to produce electricity and, to some extent, heat for industry. But it could not achieve high enough temperatures for producing cement or steel.

The new system uses computer vision software, automatic edge detection and other sophisticated technologies to focus the sun’s rays far more finely than ever before and thereby generate far higher temperatures at the focal point.

Heliogen is now focused on demonstrating how the technology can be used in a large-scale application, such as cement-making. The selling points to industry are that not only will there be no emissions generated, but that the fuel needed to obtain their extreme heat will be free.

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Secretive energy startup backed by Bill Gates achieves solar breakthrough

Photo courtesy of Heliogen.

Earth Wise is a production of WAMC Northeast Public Radio.