Solar PV Frequently Asked Questions (FAQ)

How do photovoltaic panels work?

Put simply, solar photovoltaic panels convert light into electricity for use in your home. A photovoltaic panel or tile is made up of photovoltaic cells; these cells consist of a positive and negative layer of silicon, or a similar semi-conducting material, which is placed under glass. When light shines on the semi-conducting material, the electric field across the junction between these two layers causes electricity to flow.

The electricity generated by the panels is produced as direct current, which needs to be converted to alternating current in order for the electricity to be used in the home. To do this, the electricity is passed through an inverter which is installed in the home at the same time as the panels and commissioned with the rest of the system.

What is the difference between solar photovoltaic panels and solar thermal panels?

Photovoltaic panels generate electricity to be used anywhere in the home direct from sunlight. Solar thermal panels use the suns energy to heat water.

How much can I expect to save on my energy bills by installing a Solar Photovoltaic (PV) panels on my roof?

Using a solar PV system can reduce or even completely remove the need to purchase electricity from your energy provider. Not only does this help to reduce our reliance on pollutant fossil fuels, the Energy Saving Trust estimates that in the UK average savings stand at £230 per year from utilising the sun's energy through PV.

Do I need to apply for planning permission before I install a PV system?

If your property is in England or Scotland you don't need planning permission to install a solar PV system as long as the system does not protrude more than 200mm above your roof line when installed. However, if your home is a listed building, lies in a conservation area or World Heritage Site you must contact your local planning office to check what you are able to do under permitted development rights.

Legislation regarding permitted development rights for the installation of renewable technologies in Wales and Northern Ireland is still yet to be passed; therefore you still need to get planning permission before installing a solar PV system. This is currently up for review with the Welsh and Northern Irish governments. Until a decision is reached please contact your local planning office to discuss any installations you wish to proceed with.

Will the UK climate support the use of solar panels?

The solar panels we supply are not contingent on the UK climate; they will work in cold and cloudy weather. PV panels use light to generate electricity rather than heat so generation will always occur as long as there is light. Obviously, the brighter the light the more electricity will be generated.

Can I mount solar panels on a wall instead of a roof?

It is possible to put solar panels on a wall, but it is important to note that performance will be lower and you must endeavour to mount them on a wall that sees sunlight for the longest possible time during the day. You can not place solar tiles on a wall.

Do you give any advice on the export rates available from different utility companies?

Currently, we are not able to advise on this due to the constantly changing nature of the market. The export rates change regularly depending on the need of the energy generators to reach their carbon reduction targets. We would recommend you check one of the numerous price comparison websites on the internet to find the best supplier.

What's the difference between kilowatt peak (kWp) and kilowatt hours (kWh)?

Kilowatt peak (kWp) is a measure of power output which stands for peak power. This value specifies the output power achieved by a solar panel under full solar radiation (1,000 watts per square metre), and allows a comparison to be made between different systems. A kilowatt hour (kWh) is the output of that system depending on the orientation and system losses and is measured over a unit of time, typically a year.

Do you install the systems as well as supply them?

Predominantly we are a distribution business rather than an installer so we would use either your preferred installer or find an approved one local to you to subcontract out the installation. By subcontracting the install we can provide you with one invoice for the supply and fit of your system meaning you are only required to pay 5% VAT.

Of course if you would just like to buy the systems from us in a supply only arrangement, that is fine too.

What rate of VAT is currently charged on a PV system?

Currently (February 2010), if you purchase a system from us as a supply only proposition, you would be charged VAT at a rate of 17.5%. If you buy a system from us as a supply and fit proposition as outlined in the question above, then we would be in a position to offer the reduced rate of 5% VAT.

What does a home survey entail and how long would it take?

A full survey of your home should take no longer than 2 hours and involve a loft, roof and electrical inspection.

Will solar PV panels work in winter?

Yes, our range of solar PV panels will still function through the winter as the panels use light rather than heat to generate electricity.

Is a PV installation complicated?

No, PV installations are undertaken by trained and accredited installers who can typically fit a system on to your building in less than two days.
 
Are PV panels fragile?

PV panels are very robust as they need to last a long time mounted on the outside of buildings exposed to the elements. The panels are actually strong enough to be walked on during installation, although we would not recommend that.

Can PV panels significantly reduce my carbon emissions?

Yes, any electricity your PV system generates is ?clean energy?; i.e. it has not come from a coal fired power station or other source of energy generation which emits carbon. The more units of clean energy your building uses, the less it will rely on units from the grid, and this will reduce your personal or business carbon footprint.

Do PV panels make our roof more insecure in high winds?

No, there are three main types of PV system, none of which make your roof more susceptible to damage from high winds. On roof panels, in roof panels and PV roof tiles can all be installed and leave minimal space for wind to blow through; thus the pressure from the wind keeps the panels or tiles in place on your building.

Will I still receive an electricity bill?

Yes, you will still receive an electricity bill from your energy supplier (e.g. British Gas) because a typical PV installation on your home or building will not provide you with 100% of your electricity requirements. However, you should find that your bills will be much lower than they were before you had a PV system installed as you are generating your own free electricity during daylight hours.