was curious about mirrors, which are used to boil water, "most concentrated solar power technologies will have an efficiency somewhere between 7 and 25 percent."
"Though most commercial panels have efficiencies from 15% to 20%, researchers have developed PV cells with efficiencies approaching 50%."
"Both nuclear and coal plants show a range of efficiencies. Nuclear plants currently being built have about 34-36% thermal efficiency, while one of the new reactor designs boasts 39%. In comparison, new coal-fired plants approach 40% and CCGT plants reach 60%."
Coal is "40%", less the energy used in mining and transporting the coal, less the energy used in coping disposing of the ash and coping with the environmental and health harms arising from burning coal.
For PV, a higher "efficiency" means less land is used for a given nameplate power output. Desert land is not in noticeably short supply, though.
Or it might mean that PV is economically feasible in high-latitude or chronically cloudy areas.
"Though most commercial panels have efficiencies from 15% to 20%, researchers have developed PV cells with efficiencies approaching 50%."
"Both nuclear and coal plants show a range of efficiencies. Nuclear plants currently being built have about 34-36% thermal efficiency, while one of the new reactor designs boasts 39%. In comparison, new coal-fired plants approach 40% and CCGT plants reach 60%."