Have you ever noticed solar panels on top of a house and wondered how they work? In 1839 French physicist Alexandre Becquerel discovered the photovoltaic effect which explains how electricity can be generated from sunlight, claiming “shining light on an electrode submerged in a conductive solution would create an electric current.” Solar energy was mostly used in calculators in the 1970s, since then with research increasing into the use of photovoltaic cells, solar energy has become a cost effective use of power production. Mr Obama in the White House certainly agrees, in 2010 he ordered the installment of solar panels and solar water heater, three years later they were installed.
Photovoltaic cells are made from layers of semi-conducting material, usually silicon. An electric field is created when light is shined across the layers in the cell, the stronger the light, the more electricity produced. To create the large panels that sit on top of a roof or on the ground in solar farms, the panels are mounted together for maximum efficiency. Power generated from a called is measure in kilowatts peak (kWp) which is the rate energy is generated at peak performance in full direct sunlight during the summer. Cells are now available in a variety of shapes and sizes with tiles becoming more popular instead of the larger panels as they have a more aesthetic appeal.
Not only can you cut your electricity bills but you can be paid for the electricity you generate and sell electricity back to the national grid. The government operates a Feed in Tariff scheme where your energy provider pays you for the electricity you generate, even if you use it. Looking at British Gas they estimate the following for the scheme:
|The Feed-In tariff – illustrative table|
|The size of the solar panels||4 kWp|
|The cost of getting solar panels||£6,599|
|What you’ll save with FIT, at 14.38p x 3,572 kWh||£513.65|
|The extra you get paid for, that goes back to the grid: 50% @ 4.77p x 3,572 kWh||£85.19|
|How much you’ll save on your electricity bill: 50% @ 16.2p x 3,572 kWh||£289.33|
|Your total saving each year (FIT + NAtional Grid + savings on your bill)||£888.17|
|How long you’ll be paying for the panels||7 years 4 months|
|Tax free return on investment over 25 years||12.8%|
Alongside saving money and seeing a return on your investment, you can feel great about reducing your carbon footprint. Solar power is a green renewable energy source and doesn’t release any harmful carbon dioxide or other pollutants. A typical home solar power system could save over a tonne of carbon dioxide a year – that’s more than 30 tonnes over its lifetime.
With demand growing for renewable energy sources, smaller more aesthetic tiles are being brought to market. Although these tiles are more expensive that the larger panels more commonly used, new builds are seeing the integration of these tiles in slate roofing. Period buildings are also using them in refurbishment and energy upgrade so as not to disturb the exterior features of the building.