Solar Power

Solar energy is the capture and use of the radiant energy from the Sun. Solar power is the conversion of sunlight into electricity, either by photovoltaics and concentrating solar thermal devices, or by one of several experimental technologies such as thermoelectric converters, solar chimneys or solar ponds.

The Earth receives 175 petawatts of incoming solar radiation in the upper regions of the atmosphere. Approximately 30% is reflected back to space while the rest is absorbed by clouds, oceans, and land. The spectrum of solar light at the Earth's surface is mostly spread across the visible ranges with a small part in ultraviolet.

The absorbed solar light heats the land surface, oceans and atmosphere. The warm air containing evaporated water from the oceans rises, driving atmospheric circulation or convection. When this air reaches a high altitude, where the temperature is low, water vapor condenses into clouds, which rain onto the earth's surface, completing the water cycle. The latent heat of water condensation amplifies convection, producing atmospheric phenomena such as cyclones and anti-cyclones. Wind is a by product of the atmospheric circulation driven by solar energy. Sunlight absorbed by the oceans and land masses keeps the surface at an average temperature of nearly sixty degrees fahrenheit. The conversion of solar energy into chemical energy by photosynthesis produces food, plants, and the biomass from which fossil fuels are derived.

Solar radiation along with secondary solar resources such as wind and wave power, hydroelectricity and biomass account for nearly all of the available flow of renewable energy on Earth.  This is more energy in one hour than the world uses in one year.  The amount of solar energy reaching the surface of the planet is so vast that in one year it is about twice as much as will ever be obtained from the all of earth's non-renewable resources of coal, oil, natural gas, and mined uranium combined.