Solar Photovoltaic
Solar electricity systems capture the suns energy using photovoltaic (PV) cells. The cells convert the sunlight into electricity, which can be used to run household appliances & lighting. PV cells don't need direct sunlight to work- you can still generate some electricity on a cloudy day.
How it works
PV cells convert solar radiation into electricity, and consist of one or two layers of semi conducting material, usually silicone. When light shines on the cell it creates an electric field across the layers, causing electricity to flow. The greater the intensity of the light, the greater the flow of electricity.
The benefits
Photovoltaic Systems generate no greenhouse gases. A typical domestic system can save approximately 1.2 tonnes of carbon dioxide emissions per year- adding up to almost 30 tonnes over a system's lifetime!
Solar PV can be an expensive technology, costing between £8,000 and £14,000 depending on the type & size of the system that you are installing, yet the savings can be greater.
The Energy Saving Trust estimate that a 2.5kWp sized system can save you up to £250 a year on your electricity bill and meet 40% of your electricity needs
Domestic solar PV systems qualify for a government scheme called Feed In Tariffs (FIT) which provides guaranteed payments for all the electricity that is generated by the system, meaning that Solar PV can become a money-making technology.
The Types of PV Panels
Monocrystalline cells tend to be more efficient than polycrystalline cells (13-17% efficiency compared with 11-15% efficiency), yet polycrystalline cells can be cheaper.
Therefore it is important when comparing quotes to make sure you know what type of solar PV cells you are being quoted for.
PV Systems can be used for a building with a roof or wall that faces within 90 degrees of south, as long as no other buildings or large trees overshadow it. Less energy will be generated if the surface is in shadow for parts of the day, yet it will generate some electricity.
Only daylight is needed to create energy. Solar panels work from the sun’s irradiance, not just sunshine. This means you can enjoy free renewable energy in your home, even on a winter’s day.
Efficiency depends on the number of solar light hours and climate.
Depending on the manufacturer, each solar PV Panel typically has an area of 1.2 to 1.8 square meters and will produce about 180-250 watts. So to produce 1kw of power, you would need 4-5 solar panels.
In addition to all these benefits, you are also playing your part in helping the environment, as solar power is an entirely clean and renewable energy source.
