New solar conversion efficiency records are a dime a dozen these days, and the cost of PV panels is continuing to sink like a stone. Apparently, though, we ain’t seen nothing yet. Researchers point out that PV cells only use part of the solar spectrum. The next big thing in solar power is the use of high heat in systems that put the entire spectrum to work from one end to the other.
The Concentrating Solar Power Workhorse
If you’re thinking concentrating solar power is the key, that’s right. For those of you new to the topic, concentrating solar power refers to systems that gather energy from the sun, by collecting it in a field of specialized mirrors or reflective troughs, and focusing it on a smaller point or pipe.
Concentrating solar power systems don’t generate electricity directly, but they do generate a lot of heat, which can be used to boil water for steam to run a turbine, which does generate electricity.
If that sounds like a lot of work for a few clean kilowatts, it is. Back during the Obama administration, skeptics pointed out that CSP systems were overly complex and costly. However, CSPs rely on a heat-storing medium such as molten salt or oil, which means they can potentially generate electricity 24/7 without the expense of an additional battery system.
In addition, CSPs don’t need to generate electricity to be useful. Many industrial processes rely on heat, and that’s where the new hydrogen-perovskite angle comes in.
Concentrating Solar Power Beats Fossil Energy For High-Temperature Work
CleanTechnica first caught wind that something new was afoot back in 2018, when the US Department of Energy and its research partners began talking about the potential use of concentrating solar power in high-heat applications
In particular, a high-heat CSP system could generate temperatures far beyond the capabilities of typical fossil power plants. John Shingledecker of the Electric Power Research Institute explained the allure to CleanTechnica in a phone interview:
“A lot of the developments are being taken from fossil power plant steam cycles or coal boilers, but they only go up to 620 degrees C,” he said. “Seven hundred degrees and beyond has been the subject of much study — for example advanced supercritical technology, involving supercritical CO2 power cycles based on CO2 as a working fluid.”
Supercritical CO2 (sCO2) is the fluid form of carbon dioxide. Once the kinks are worked out, sCO2 could provide the concentrating solar power field with a nonflammable, nontoxic substitute for molten salt or oil.
When used to run a turbine, sCO2 could also be the basis for a new compact, high-efficiency power cycle. Researchers note that the typical steam-powered Rankine power cycle is 33% efficient, while sCO2 would allow the deployment of a Brayton cycle surpassing 40%. The impact on the size of turbines would be significant, shrinking a typical 20-meter …….