Fans of concentrating solar power have weathered a storm of criticism over the years, but the dream just won’t die. They speak of a 100-megawatt facility that can deliver electricity 24/7, just like a nuclear power plant but without the risk factor and the fancy price tag, too. That’s asking a lot, but the US Department of Energy has latched on to a new ceramic-based technology that could deliver the goods.
New Mexico will host a new concentrating solar power plant aimed at killing coal, gas and nuclear energy all at once (photo courtesy of US Department of Energy)
The Ups & Downs Of Concentrating Solar Power
For those of you new to the topic, concentrating solar power plants don’t use conventional photovoltaic panels to collect solar energy. Instead, they deploy a field of specialized mirrors that bounce sunlight onto a central point. The solar energy heats up a store of specialized oil or molten salt, which is then piped to a generating station where it can run a turbine.
If that sounds expensive, inefficient, and complicated, it can be. Even so, concentrating solar power has been catching on elsewhere around the world. The advantage is that the energy-absorbing medium, whether oil or salt, also acts as a built in energy storage reservoir, enabling the turbines to keep spinning long after the sun goes down.
Getting a foothold here in the US is a different kettle of fish. The Obama administration showcased a group of five CSP plants in the Southwest, but the program didn’t stimulate much follow-on interest among private investors.
The Energy Department went back to the drawing board in 2015 and came up with a program called CSP: APOLLO. The program aims to identify new technologies and systems that can provide for high-temperature operation, defined as more than 720°C, the idea being that higher temperatures can result in efficiency improvements while cutting costs. The official goal is a minimum of 50% thermal-to-electric conversion efficiency, which the Energy Department describes as “dramatically more efficient than current technology.”
One Weird Trick Could Make Concentrating Solar Power Happen: Ceramics
Oddly enough, the Trump administration continued to support the Energy Department’s R&D work on high temperature concentrating solar power, despite the former President’s oft-repeated promise to save coal jobs and a stab at creating more nuclear energy jobs, too.
During Trump’s first year in office, CleanTechnica caught wind of an Energy Department article extolling the benefits of CSP facilities. The article mentioned something about $62 million in funding for a new program called Generation 3 CSP Systems, and that’s where things get interesting.
Gen 3 CSP focuses on identifying new high-temperature technologies that have passed muster at the laboratory scale, and assembling them into systems that can be field tested under various conditions.
“This includes the development of a test facility that allows diverse teams of researchers, laboratories, developers and manufacturers to remove key technological risks for the next generation CSP technology and enable the reduction of the levelized cost of energy (LCOE) for electricity generated by CSP to 6 ¢/kWh or less, without subsidies, by the end of the decade,” the Energy Department explains.
By 2018, some of the new Gen 3 CSP projects began crossing the CleanTechnica radar on a regular basis, including an innovative “falling particle” system based on gravity and ceramics, developed by Sandia National Laboratories. We also had a chance to speak with the experts about another project involving new alloys for high-temperature CSP facilities.
A New Dawn For CSP
Another Energy Department focus of attention is the Bill Gates CSP venture Heliogen, which burst out of stealth mode in 2019 with a goal of operating at 1,000 degrees centigrade.
The last time we checked into Heliogen, they were on track to install their CSP system to help cut emissions at a boron mine in California.
That was back in 2021. If you have any breaking news about the project, drop us a note in the comment thread. Meanwhile, it looks like Sandia National Laboratory is off to the races. Last week, the Energy Department announced that it selected Sandia for a $25 million award aimed at building, testing, and operating a new CSP system at the agency’s National Solar Thermal Test Facility in Albuquerque, New Mexico.
The new concentrating solar power system culminates a total of $100 million in funding for high temperature CSP. It will showcase Sandia’s falling particle technology, which can operate at temperatures above 800°C.
“These particles can be used to transfer and store heat or power a supercritical carbon dioxide (sCO2) turbine. If successful, this type of solar power plant could provide 100 megawatts of power continuously, around the clock, at low cost,” the Energy Department enthused, adding that their electricity-plus-storage goal is 5 cents per kilowatt hour.