Solar Powered Systems

Suffice to say, our modern standard of living is already, at its core, solar powered. We just don't appreciate where the energy we consume comes from and how it was created in the first place. In fact, with the exception of nuclear-power, that uses fissile elements (Uranium or Plutonium), and geothermal energy which captures heat stored in the Earth's core, humanities primary sources of energy are really just direct or stored forms of solar energy.

• Hydrocarbons, also known as fossil fuels (coal, oil, gas etc) are compressed and morphed forms of plants and tiny animals that used solar energy to affix carbon and grow millions of years ago. Today, by combusting the fossil fuels to run our transportation systems and generate electricity, we are just releasing the energy those ancient plants and animals stored when they absorbed sunlight. Without the Sun, these sources of energy would not have been formed and we could not use them today.


• Wind power that turns a wind turbine comes from the atmospheric heating and cooling caused by the Sun. Without the Sun there would be no wind to turn the wind turbines to generate electricity.


• Hydro power, which is energy extracted by water flowing down hill through a turbine either in a river or released through a dam, only exists because the Sun evaporated the water in the first place. Once evaporated into the atmosphere the water eventually falls as precipitation in mountains to once again flow downhill where it can run a hydro turbine. Without the Sun the water would not have been evaporated and the turbines would not turn to make electricity.


• Wave and Current power, like hydro power, relies on the movement of water to turn a turbine to generate electricity. Waves are caused by the wind, and oceanic currents are caused by differential heating and cooling of the seas, both of which rely on the Sun. Tidal power, though principally caused by the gravitational pull of the moon, is only possible because the moon is in a stable orbit around the Earth, which is itself in a stable orbit around the Sun. Without that stable orbit there would be no moon as we know it and thus very different tides.


• Biomass is the oldest form of energy that humans have used. Biomass can be in the form of plants, wood or animal waste and, similar to fossil fuels, it is combusted to release its energy.

• Solar Energy: The above sources of energy are all indirect forms of solar energy. We can of course also capture the Sun's energy directly either in the form of heat-energy (solar thermal) or through a process called the Photoelectric effect (solar electric). Both these forms of energy capture energy directly from the Sun and turn it into useful power. In Solar Thermal systems, the Sun's heat is used to raise the temperature of a working-fluid (such as water) so that the stored energy can be used later either in either low temperature applications providing domestic hot water or space-heating, or higher temperature applications such as turning a steam turbine to generate electricity. Solar Electric applications capture photons directly from the Sun's rays and convert the photons into electrons to generate a direct current. Another form of solar energy is "passive solar" where, for example, a building is designed to maximize day light and heat-gain during the day to reduce the use of artificial lighting or supplemental heat.