btw geothermal does not come from the earth’s rotation. it mostly comes from nuclear decay of heavy isotopes in the earth’s interior and the enormous heat capacity of the earth’s interior, which means it’s still warm from the friction heat from when the planet first formed. in other words it’s there since the Earth formed, independent of the sun.
also there’s another (practically accessible) form of energy that comes neither from geothermal nor from the sun: you can pull energy out of the tidal movement that comes from the moon’s changing gravity field as it orbits around our planet. i think that one’s not really being used though because the only way to really utilize it is to build dams across havens and important shipping routes and that interferes with trade, which is considered the more economically valuable activity from the two.
btw geothermal does not come from the earth’s rotation. it mostly comes from nuclear decay of heavy isotopes in the earth’s interior and the enormous heat capacity of the earth’s interior, which means it’s still warm from the friction heat from when the planet first formed. in other words it’s there since the Earth formed, independent of the sun.
also there’s another (practically accessible) form of energy that comes neither from geothermal nor from the sun: you can pull energy out of the tidal movement that comes from the moon’s changing gravity field as it orbits around our planet. i think that one’s not really being used though because the only way to really utilize it is to build dams across havens and important shipping routes and that interferes with trade, which is considered the more economically valuable activity from the two.