Photovoltaics is the method of direct conversion of light to electricity. Some substances manifest a property called the photoelectric effect which causes them to absorb photons and release electrons which can be captured to produce an electric current. This is the principal behind solar energy where a surface with this property is exposed to the sun to absorb photons from natural light available to generate electricity. This need not be confined to laboratories and may even be used to generate electricity for your own home.
Working of photovoltaic (PV) cells:
A PV cell contains a series of semiconductors which are used for generation and storage of electricity which can then be used to power your home. The light absorption leads to the creation of an electric field due to freed electrons which can be used to generate the flow of electricity by placing metal conductors. These conductors act as negative (low potential) and positive terminals (relatively higher potential) which causes a current to be induced.
Solar-power your home:
There are a few things to remember while fixing up a system to harness solar energy for your home. The angle of inclination of your roof may not be ideal to capture a maximum amount of the sun's rays. A general rule of the thumb is to incline the panels at an angle equal to the latitude of the area. Care should be taken to ensure that the panels are not in the shade of nearby trees at any point during the day. The production of electricity depends on weather conditions and is never predictable and even if one of the panels is shaded, production can be significantly impacted. Always try to aim for the worst case scenarios and plan based on the worst possible month as predicted by your local meteorological department.
Costs and savings:
Costs of PV cells may vary a lot depending on the materials and equipment used. An average system that produces 2.2 kW costs around £12,000 including VAT. Costs per kW should reduce with an increase in capacity in general, thus leading to greater savings. A 2.2 kW system can power 40% of a households annual electricity need and if the system is eligible for a Feed in Tariff, it could generate significant savings which can be estimated at £900 per year. Maintenance costs are minor. Also, you may sell any excess electricity to the grid.
The most efficient panels are the one that give the most power with the least area possible. One should take into consideration technical factors like energy density while choosing the right panel based on energy consumption needs. The cost of solar power has been falling in the past decade. It is an incredibly clean source of energy with household savings of up to 1 tonne of CO2 or even more possible by using your own solar panels to power your home.