You could argue that the sun was pretty useful, quite the “essential companion” in the Stone Age as well. In fact, it is hard to imagine there would have been

You could argue that the sun was pretty useful, quite the “essential companion” in the Stone Age as well. In fact, it is hard to imagine there would have been enough dead trees to make oil if it were not for the sun. You could argue (pretty soundly) that oil is just a way of consuming the energy in trees which got that energy from the sun. So oil is just a way of extracting ancient solar energy.