It is so obvious! If we have a kinetic interaction with exposed hydrogen is bound up in molecules, above the strong atomic force for hydrogen you will get nuclear fusion; forming helium and you have loads of heat!
Electrons are also incident on the exposed protons, to form neutrons! These wander off, bonds with other nuclei, and cause them to fission! And any atom gives off heat as it fissions! Converting the surface neutron into loads of light and heat.
We see this at waterfalls, green crops in light, animal blood systems-the usual suspects! It contributes 1050 Watts of heat to nature every year. This is a damn load of heat! With no carbon dioxide or toxic plutonium! For free.
Molecular nuclear fusion goes on as your heart beats! Which is why you breathe out helium-though you don’t breathe any in!