Solar power is the capture and harnessing of the sun's energy, which can then be used to heat or power our homes.
How It works.
Photovoltaic (solar cell) systems convert sunlight directly into electricity. A solar or PV cell consists of semiconducting material that absorbs the sunlight. The solar energy knocks electrons loose from their atoms, allowing the electrons to flow through the material to produce electricity. PV cells are typically combined into modules that hold about 40 cells. About 10 of these modules are mounted in PV arrays. PV arrays can be used to generate electricity for a single building or, in large numbers, for a power plant. A power plant can also use a concentrating solar power system, which uses the sun's heat to generate electricity. The sunlight is collected and focused with mirrors to create a high-intensity heat source. This heat source produces steam or mechanical power to run a generator that creates electricity.
Solar water heating systems for buildings have two main parts: a solar collector and a storage tank. Typically, a flat-plate collector-a thin, flat, rectangular box with a transparent cover-is mounted on the roof, facing the sun. The sun heats an absorber plate in the collector, which, in turn, heats the fluid running through tubes within the collector. To move the heated fluid between the collector and the storage tank, a system either uses a pump or gravity, as water has a tendency to naturally circulate as it is heated. Systems that use fluids other than water in the collector's tubes usually heat the water by passing it through a coil of tubing in the tank.
Impact on the environmental.
There are three main ways of capturing the sun's energy: While the technology itself is usually visible (i.e. solar panels), the use of solar power has positive implications for the environment as the technologies used produce no air pollution and emit little or no noise during operation.
Benefits of using solar power.
As the electricity is generated at the same point at which it is used, transmission and distribution costs and any environmental impacts are avoided.
With no moving parts, the operation of solar technology is virtually silent and also means that maintenance and life-spans of the systems are high, at around 15-20 years. Panels placed on roofs mean that there is minimal visual intrusion.
Cost of the technology.
For most buildings, heating bills can be reduced by 20 per cent at negligible capital cost by applying passive solar design.
The cost of a professionally installed active solar heating domestic system can vary from £2,000 to £4,000 depending on the size and type of system. There are some indications that costs and prices of active solar systems are falling, which will increase the economic attractiveness of systems
PV technology has a long way to go before establishing itself competitively with conventional electricity and other renewables. Costs typically range from 60-70p/kWh.
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