If you think about it, the energy we use to power our cars, homes, cities eventually comes from the sun, with the exception of fission nuclear power plants.
Oil is essentially made out of frozen light. The sun provided the power to create the bonds out of which the plants which eventually turned into oil, are made out of. Same deal with coal and natual gas.
The sun provides the heat to lift water molecules into the air, increasing their PE. Then we convert their PE into KE into electricity with hydroelectric dams.
The sun heats the air, which creates convection currents, or wind, which we use to create electricity with our wind mills.. That's one thing I noticed. All our means of creating power comes either directly (solar arrays), or indirectly (with the exception of nuclear power).
A trend I noticed is that the more directly we get our power from the sun, the less undesired the effects on the environment are. Going by this obvservation, and the fact that breakthoughs in nanoscience are allowing photovoltaics to be made cheaper and more customizable, I'd say solar arrays are going to play a big role in the future of energy.