Solar Power

Solar power is by far the Earth's most available energy source, easily capable of providing many times the total current energy demand. The largest solar power plants, like the 354 MW SEGS, are concentrating solar thermal plants, but recently multi-megawatt photovoltaic plants have been built. Completed in 2008, the 46 MW Moura photovoltaic power station in Portugal and the 40 MW Waldpolenz Solar Park in Germany are characteristic of the trend toward larger photovoltaic power stations. Much larger ones are proposed, such as the 550 MW Topaz Solar Farm, and the 600 MW Rancho Cielo Solar Farm. Covering 4% of the world's desert area with photovoltaics could supply all of the world's electricity. The Gobi Desert alone could supply almost all of the world's total energy demand.




Solar power is an intermittent energy source, meaning that solar power is not available at all times, and is normally supplemented by storage or another energy source, for example with wind power and hydropower.

Solar power is the conversion of sunlight into electricity. Sunlight can be converted directly into electricity using photovoltaics (PV), or indirectly with concentrating solar power (CSP), which normally focuses the sun's energy to boil water which is then used to provide power, and other technologies, such as the sterling engine dishes which use a sterling cycle engine to power a generator. Photovoltaics were initially used to power small and medium-sized applications, from the calculator powered by a single solar cell to off-grid homes powered by a photovoltaic array.



The only significant problem with solar power is installation cost, although cost has been decreasing due to the learning curve. Developing countries in particular may not have the funds to build solar power plants, although small solar applications are now replacing other sources in the developing world.



One fundamental difference between renewable energy and non-renewable energy is that non-renewable resources can be purchased as they are consumed, whereas with renewable resources, you pay up front for the next twenty years or so of energy.[