Solar Electricity – Photovoltaic (PV)...

Solar power is energy that is harnessed from the sun’s rays.  Solar energy is free; the only thing we have to pay for is the technology to harness and transform the power. Solar panels have been used for many years in calculators that have an LCD screen. Technology has now evolved and larger solar panels are now available.

In the home environment, large solar panels can be placed on the roof, in a South facing position. The energy these panels create can be used all around the home. Lighting for example can be run from solar energy.  Heating, either for your home or for your water can be obtained from solar power.

Gardens are the ideal place to use solar energy. Pond pumps, patio and deck lighting can all be ran by solar power. Solar powered shed lights are now available.

Photovoltaic or PV panels use the energy from the sun to create electricity. They work with daylight, and do not necessarily need the suns rays to operate. 

How Does It Work?
A solar electricity system comprises of individual Photovoltaic cells that are connected to form a module. These modules are linked together to form an array.  Each cell is made from one or two layers of silicon.  When the light shines on the cells, it causes an electric field across the layers. The greater the intensity of the light, the greater the electricity flows.
The amount of electricity generated depends on how many cells are installed. A PV on a south-facing roof could generate 100kw of electricity per square metre per year.

How Is Electric Generated?

• Daylight is converted to electric when it hits the PV panel.
• An Inverter converts the electricity generated from DC (Direct Current) to AC (Alternating Current). AC currents are suitable for use in the home.
• The system is then connected to the mains
• A meter registers just how much electricity is generated.  Electricity is generated all day, not just when the sun shines.
• Any unused electricity that is generated flows back out to the grid. This excess electricity can be sold back to your electricity supplier.

What Do PV Panels Look Like?
The PV panels come in all shapes and sizes. You can get grey solar tiles that look like roof tiles, or transparent cells that can be used on conservatories.

Is My House Suitable For PV Solar Panels?
PV panels can be used on buildings that have a roof or wall that faces south. Make sure that chimneys, trees or other buildings do not cause a shadow over the panel, as this could impair the amount of electricity generated. A typical installation would require an area of at least 7-15 square metres. Your roof must be strong enough to hold the weight of the panels, if they are to be fitted on top of your existing tiles. You can have integral PV tiles fitted, but it is best to do this if you plan to have major roof repairs.

How Much Does It Cost?
It all depends on the size and the system you require. A 1kw peak system could cost you approximately £5,500. This size would produce around 25% of an average household’s annual consumption. This size of panel would require a 7.5 square meter area.

What About Planning Permission?
Depending on where you live, you may have to apply for planning permission.  Contact your local council for details.

What Are The Benefits Of Having Solar Electricity?

• A 1kw peak system could generate 800kw hours of electricity per year. This could mean an annual saving of 25% on your existing electric.
• They reduce your carbon footprint. A typical PV system could prevent over 16 tonnes of carbon dioxide emissions in its lifetime.
• Little maintenance is required.
• They are silent to run, as they have no moving parts.
• The system could add value to your property. A recent survey showed that people are willing to pay up to £10,000 more for an environmentally friendly property.

What About Ongoing Maintenance?
Very little maintenance is required once the system has been fitted. A visual check from ground level is all that is required. See if any panels are showing signs of accidental damage  and if damage has occurred, the panels should be replaced as soon as possible.

Are There Any Grants Available?
Grants may be available for this project. Visit www.est.org.uk for details.