Actually, you could say 'solar', since everything derives from the sun, or the radioactive decay of heavy elements produced in other suns. But then fusion of hydrogen atoms, which were produced when the expanding universe cooled to the point where ... and the expansion was caused by the Big Bang, which was caused by ...

Ugh, I need a drink. I'll assume that everything will be powered by pints of Harp. I know I'm wrong, but at least I'll get to perform some happy experiments.