I don’t think it makes sense to compare those efficiencies, as one is for converting heat to electricity, while the other is for converting sunlight. If you use sunlight to heat water and then use that for a steam turbine, the efficiency is similar to a photovoltaic panel.
The efficiency numbers are still useful, but only when they refer to the same starting point for the conversion (e.g. only comparing things that turn heat into electricity).
Yeah, it’s comparing apples to crabs. It’s only looking at the very final stage and ignoring the efficiencies of the fuel, etc.
If you wanted to make the comparison more fair (and also show how bad it is), a coal power plant maybe has an efficiency of 35%. You can calculate that by dividing the thermal energy in by the electric energy out. You feed in enough coal to generate 8MW of heat, which generates 2.8MW of electricity, so 2.8/8 = 0.35. By contrast, a photovoltaic power plant generates say 2kW of electricity with 0 fuel, so it has an efficiency of ∞%.
Agree, the quantum-chem of it is amazing… Then again, solar has an efficiency of ~30% compared to the 90% for spinning steam
I don’t think it makes sense to compare those efficiencies, as one is for converting heat to electricity, while the other is for converting sunlight. If you use sunlight to heat water and then use that for a steam turbine, the efficiency is similar to a photovoltaic panel. The efficiency numbers are still useful, but only when they refer to the same starting point for the conversion (e.g. only comparing things that turn heat into electricity).
Yeah, it’s comparing apples to crabs. It’s only looking at the very final stage and ignoring the efficiencies of the fuel, etc.
If you wanted to make the comparison more fair (and also show how bad it is), a coal power plant maybe has an efficiency of 35%. You can calculate that by dividing the thermal energy in by the electric energy out. You feed in enough coal to generate 8MW of heat, which generates 2.8MW of electricity, so 2.8/8 = 0.35. By contrast, a photovoltaic power plant generates say 2kW of electricity with 0 fuel, so it has an efficiency of ∞%.
but crucially no moving parts. very little maintenance, especially compared to anything steam driven.
I am a big solar fan, but the moving part inertia thing is actually great for stabilizing the grid.
But it’s all profit baby! Let something else figure out cousin, put 0% effort in and collect the rewards!