Solar Photovoltaics (PV) Installation

Unlike Solar Thermal which describes the conversion of light into heat (specifically water or air), Solar Photovoltaics or Solar PV for short describes the conversion of light into electricity.

Solar PV consists of Monocrystalline or Polycrystalline panels usually set in arrays of silicone cells which converts solar radiation into direct current electricity.

Although most of the electricity produced goes into the grid system, the technology has very practical uses particularly in rural or remote areas where mains electricity is not available as the energy produced can be stored in battery cells.

How does a Solar Photovoltaic Installation (PV) Work ?

The panels work best when mounted on a South facing roof elevation (pitched or flat) and fixed at a 45 degree angle of orientation. The semi-conductive cells (usually silicon) absorb light photons converting them into usable electricity. Negatively charged electrons become separated from their atoms allowing them to flow through the cell material which creates Direct Current Electricity (DC). The power generated is sent to an inverter which converts DC electricity from the solar cells into Alternating Current (AC) which powers the household appliances. The inverter sends electricity to the mains board of the property from where it is distributed to the household appliances. If there is a surfeit of electricity being produced, this can be exported to the grid for which a payment is received and this is known as a 'Feed In Tariff' (FIT).

Benefits of a Solar Photovoltaic Installation (PV)

Grid connected Solar PV systems actively reduce CO2 emissions and also significantly cut ongoing energy costs which are inflation proof at the point of demand.

Energy prices have risen exponentially at a rate of 7% per annum but the installation of a 1.8 kWp PV system will produce about 1650 kWp/year which equates to approximately 45% of annual electricity demand of a typical 3 bed property with appropriate roof orientation.

With the Renewable Heat Initiative (RHI) coming into force in April (April 2011 for other renewables), utility companies will continue to pay consumers that produce their own energy from renewable sources such as solar PV via the feed in tariff.

For more details on tariffs, please visit the link below:

Department of Energy & Climate Change Information        

Or

http://www.energysavingtrust.org.uk/Generate-your-own-energy/Sell-your-own-energy/Clean-Energy-Cashback-Feed-in-Tariffs

In remote properties, where there is no utility grid, appliances can be powered straight from the DC as can RV’s (vehicles) and boats etc.

One of our more unusual projects was to produce solar energy to power a clay pigeon shooting trap in the middle of a wood but more common uses are lighting (including security lighting) for outbuildings used by animals (eg, stables etc) in remote locations.

It should be noted that given the expanse of South facing roof required (about 20 sqm), for solar PV to be viable, it is not as well suited to retro fitting on existing buildings as say solar thermal or air source heat pumps.

It is however very suitable for new builds where the construction design can be sympathetic to the requirements of solar PV to be successful.

Another barrier particularly on retro fits is the cost which can be anywhere between £8,000 - £12,000 for an average size property even after the grant which is well over double the cost of a solar thermal system.  

If you are a commercial user, the system qualifies for Enhanced Capital Allowances (ECA) which means that 100% of the cost can be offset against that years business tax liability and there is also a very tax efficient lease scheme by which to fund the purchase of this technology subject to status

http://www.carbontrust.co.uk/cut-carbon-reduce-costs/products-services/pages/eca.aspx

Is a Photovoltac Solar Installation system suitable for my home?

As previously stated, about 20 Sqm of South facing roof (pitched or flat) is required to produce meaningful amounts of electricity.

It is not cost effective for the production of domestic hot water Evacuated tube solar is designed for this!

Savings

This is very much dictated by the area of panel coverage but typically you could expect to generate about 40% of your electricity requirements but feed in payments from the utility companies when you are either making too much or not using it need to be factored in.

Maintenance of A Photovoltaic Solar Installation

No maintenance is required but a yearly inspection is recommended which we are happy to undertake