In places that are consistently experiencing extreme heat, is it possible to convert some of that heat energy into electricity?
In: Technology
It is definitely possible in the sense that we can use heat to generate electrical power, but it’s most likely not economical.
Where heat becomes a useful/economical source is when you have a high enough temperature to cause rapid evaporation of a fluid, usually water turning into steam, which can then be used to spin a turbine – still our best way to make the sparks.
Also worth considering is that where there’s heat, there’s normally bright direct sunlight – this is good for solar PV panels and water heating (for washing), which can directly offset other sources of electricity instead, meaning we need less in total.
That’s more or less the idea behind geothermal and solar-steam generators: bring water in contact with the hot part, converting it to steam, which kinetically moves a turbine, which produces power. However you generally need both this middle man and/or something that *isn’t* extremely hot to get any usable form of energy from it.
SDome older solar plants worked like that. Focus the suns energy usong mirrors onto a point that is used to boil water into steam to power a turbine.
I think PV solar is more efficient than that nowadays though.
To turn heat into something useful, you need a temperature difference. You need both hot and cold. The maximum efficiency with which you can use heat energy is 1 – Tc/Th, where the temperatures are in some scale (like Kelvin) where 0 degrees is absolute zero. If Tc (cold temp) = Th (hot temp), then the efficiency is 0%. If Tc is 0 (absolute zero), then the efficiency can be as high as 100%.
So yes, if the air temp is *hot* and there is a nice cold lake nearby, you can use that heat. At least until you’ve heated up the lake too much. But lacking a cold sink, there is no way.
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