Power

The vast majority of our energy, coal, wood, fossil fuel, gas, solar, wind and hydro comes originally from the sun and we believe the sun is our solar systemic generator. Wind and hydro might not immediately strike us as being due to the sun, but the sun creates weather and the rain that lands on high ground that can be harnessed.

However, there are some energy sources that are not sun dependent. Tidal, for example, is derived from the movement on the moon around our planet and something important drives that, which I'll come to later. 

You may think nuclear energy doesn't come from the sun, but the heavy elements used in nuclear power were formed in stars. Without stars baking the heavy elements and distributing throughout the cosmos through supernovae, there would be no nuclear energy.

But where does the sun's energy come from? Stars, such as our sun, only burn because of the mutual attraction of matter, which we call gravity. Massive clumps of gas came together and were compressed to a state where the temperature produced by the compression initiated a fusion-based thermonuclear reaction.

Gravity is therefore the basis of all our energy. If only we could harness it for power generation, but then we'd need to be able to control it somehow. Currently there is no known science that says control of gravity is impossible, which is quite good news.