Due to the increased consumption of solar energy, the manufacture of photovoltaics arrays has increased hugely in recent years. Photovoltaics (PV), covers the technology and research around converting sunlight directly into electricity using solar cells. The call for solar power has increased so much that photovoltaic production has doubled every two years, increasing by 48% since 2002, it is in fact the world’s fastest-growing energy technology! Financial incentives are offered to promote the use of solar-generated electricity and PV instillations in many countries, including Germany, Japan and the US and although the selling price of modules is too high to compete with grid electricity this has triggered a huge growth in demand.

The basic process photovoltaics uses to generate solar power is by packaging solar cells in photovoltaic modules, when more power is needed than a single cell can produce the cells are connected in multiples as solar photovoltaic arrays to convert energy from the sun into electric current – solar panels. The cells are protected from the environment with a glass sheet. A single module is enough to power an emergency telephone, for something like a house or a power plant the modules must be arranged in arrays. Basically, photons from the sun knock electrons into a higher state of energy, creating electricity.

Solar cells can produce a direct current from absorbing light, which can then be used to power equipment or recharge a battery, originally photovoltaics were used to power orbiting satellites but more recently photovoltaics are mostly used for grid connected power generation, using an inverter to convert DC to AC. Approximately 90% of photovoltaic generating capacity comes from grid-tied electrical systems which can be ground mounted or built into buildings and at the end of 2007 cumulative global production amounted to 12,400 megawatts. A small amount of off grid power is used for things such as roadside emergency telephones and remote dwellings.

The biggest issues with photovoltaic solar panels is the cost of insulation and materials. New alternatives have been developed to the standard crystalline silicon modules, i.e. casting wafers instead of sawing, thin film and continuous printing processes. The price of solar panels decreases as they become more popular and demand and manufacture goes up, the cost is expected to drop considerably over the next few years.

Photovoltaics are essentially so positive because they do not produce any harmful emissions as they generate power and do not eat away at the earths resources like fossil fuel based technology. The production of the panels does produce some pollution so a type of equation is made – an input to output ration, as long as the energy input for production is lower than the output it produces then the product is environmentally beneficial. The placement of photovoltaics can also affect the environment. If they are located where photosynthesizing plants would normally grow, they simply substitute one potentially renewable resource (biomass) for another, however the biomass cycle converts solar energy to electricity with significantly less efficiency than photovoltaic cells alone. If these cells are placed on the sides of buildings, fences, rooftops or in the desert they can only be a positive renewable power base.

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