As Einstein’s famous equation E=mc2Â tells us, the only true source of energy is the conversion of matter. The two natural processes that create energy are nuclear fission and nuclear fusion. Nature has provided us with one primary source for each: in the Earth’s core for nuclear fission and in the Sun’s core for nuclear fusion. The energy from these primary natural energy sources is captured in a number of secondary ways to provide humans with energy.
Currently the only way we have to use the Earth’s energy is by drilling deep holes to heat water into steam. In volcanically active areas these do not need to be so deep.
- Solar Thermal
When we need heat, the most efficient natural source is to capture the sun’s energy directly. This only works in the daylight, of course, but heat can be stored more efficiently than electricity. Higher temperatures can be achieved by concentrating the sunlight using lenses or mirrors.
- Solar Electric
Energy from the sun can be converted into electricity by photovoltaic (PV) cells. Efficiency depends very much on the materials used.
- Wind and Waves
As the sun heats the atmosphere at different rates, winds are created. In areas where these are strong and regular, their energy can be transformed into electricity or mechanical power by windmills. Wind energy also gets transferred to ocean waves, so on the coastlines these waves can be a natural energy source.
Plants naturally capture the sun’s energy. Photosynthesis is much less efficient at capturing the sun’s energy than mechanical methods, but plants are easier to produce. Three types of biomass are popular: wood, ethanol, and biodiesel. Wood can produce heat directly or be transformed into charcoal; it can even be used to produce a gas that can run cars.
As you can see, nature provides us with many sources of energy.