Posted on 02/09/2025 4:28:03 AM PST by Libloather
On a large scale we now know it's a bad idea.
On a medium scale CSP makes sense if you have a use for the 65% waste heat any thermal energy process yields due to the laws of physics. It doesn’t matter if those thermal turbines are gas heated, solar heated, nuclear heated, geothermal or biomass heated. If you’re heating a fluid or gas to drive a turbine you are limited by Carnot thems the laws. T1/T2 the Delta T set a fundamental limit on how much of your heat energy gets turned into shaft torque which then has to be turned into electrons this applies to every turbine equally based on peak turbine inlet temp vs ultimate heat sink temp.
Solar thermal would make sense if you had a use for its waste heat such as rapid spray desalination of brine ground water. Nearly every desert has huge saline aquifers under it full of huge amounts of brine and brackish water. While solar thermal electrons are expensive,solar thermal BTU of high grade heat is not expensive and with molten salt tanks you can store that heat in bulk for days or weeks at a time. You can also use masses of sand, gravel, or clay bricks to store huge quantities of high grade heat very cheaply. You could also drill down into the earth and pump hot supercritical CO2 or water into a square kilometer sized block and heat the whole thing up and store hundreds of gigawatts worth of heat for years at a time not just months.
Remember heat is heat it’s just molecular motion the fluid or gas doesn’t know or care if it was gas heated, nuclear, or solar the process is the same once you have hot fluids. CSP has advantages over geothermal,nuclear and gas it can reach temps in the 1000C + range this is hot enough to use molten metals to store and move heat with in densities that are denser than even hydrocarbons on a cubic meter basis. Gas turbines have a limit to how hot the first turbine stage can get being metal they are limited to temps that metals stay solid at. Once you get to 2000+ suns of iintensity you are using refractory ceramics then you can use molten salt or metals with metals being pumpable by magnetic pumps and no mmoving parts. You can also use thermalphotovoltaic to turn white hot heat into electrons directly and not be limited by Carnot it is a fundamentally different process. MIT has TPV cells that are more efficient than turbines by as a least 10% gross in the 40% vs 30s
This is MIT and with CSP you can heat the liquid metal directly.
https://news.mit.edu/2018/liquid-silicon-store-renewable-energy-1206
https://newatlas.com/energy/antora-carbon-heat-battery/
https://newatlas.com/energy/firebricks-industrial-process-heat-clean-energy/
https://newatlas.com/energy/sand-battery-finland/
Heat is heat, anything you can do with CSP you can do with nukes just at lower temps due to having to use metals and pressurized water vs ceramics. The sun is just a giant thermonuclear reactor in the sky showering down radiation to every square meter of the surface. That’s exactly how it should be viewed. How do you use this already thermonuclear reactor in the sky.
I experimented with heliostats before those became two axis PV trackers. 1000F was easy to reach with two poles and 8 mirror panels it would heat the solar oven to screaming pizza temps in under 45 min as in 900F and white hot on the side wall.
Turns out thin film lead ,arsenic, cadmium free PV panels have gotten so cheap it makes zero sense to go the thermal to steam to turbine to electron route. When it’s fractions of a cent to go directly solar photons to electrons for a 25 year lifetime of the panels. I harvest rain from under my panels and off them too that water gets tested twice a year it’s cleaner than what comes out of the pipes the country put in on a ppm TDS level. There is no metals other than some iron from the steel roof, no aluminum ,no silicon ,no copper no metals down to ppb levels. Modern panels don’t leech anything off them that was 1980/90s tech,modern thin film use silver and aluminum junctions vs lead solder joints and they are sealed under gorilla borosilicate hardened hail rated glass either way. My panels have taken golf ball sized hail twice now the metal roof was in bad shape the panels are flexible the hail just bounced off. This is the reason CSP projects like this one are not viable modern panels are simply too cheap and efficient to go the heat to steam to electrons way. The only reason to go CSP is heat storage for 24/7 use that’s it only advantage and heat storage is universal it can be applied to any energy source as a load leveling,load following, or load shifting system. The higher the temp the better the density and more uses for said heat.
Literally this.
I hope DOGE is all over the DOE.
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