Our quick and easy guide to Solar PV
How does Solar PV work?
Energy generated by the sun is absorbed by the photovoltaic cells on the panels. This energy is converted into DC electricity, in order for us to be able to use the electricity it must be converted to AC – this is done by an inverter. The AC electricity can then be used in your home.
What is an EPC survey and do I need one?
An EPC (Energy Performance Certificate) survey is required if your system is to be registered for the Feed in Tariff. This is a new requirement that the government has recently introduced. Your home must be a grade D or above to qualify. Gemini work in conjuction with independent EPC surveyors to ensure that your home will meet the EPC requirement: your new PV system can even be included in the calculation to be sure you make the grade.
What size system can I have?
Solar panels can be mounted on a standard roof, a flat roof or at ground level. Panel sizes vary from manufacturer to manufacturer depending on their rated output (kWp) and efficiency. The panels can be mounted in a combination of portrait and landscape orientation to best utilise the area available. A 4kW installation will normally require 16 or 17 panels, a 3kW installation 12 panels and a 2kW installation 8 panels. If you have a standard single phase electricity supply to your property in most cases you will be limited to a 4kW installation however our surveyor will be happy to explore all options with you.
Is my house suitable?
As most PV panels are fitted on the roof of your property, the roof needs to be structurally sound in order to take the weight of the panels. As part of Gemini’s survey your roof is checked for suitability. To get the best results, the modules need to be fitted on the south, south east, or south west facing roof and to be free of any shading from trees or other buildings for long periods of the day. If your roof is partially shaded we can discuss various options with you to maximise the yield from your system.
Does Solar PV generate electricity only when the sun is shining?
Solar PV systems will still generate electricity on cloudy and dull days, and even in the rain.
What if the system does not produce enough electricity for my needs?
Any extra requirement for electricity will automatically be drawn from the National Grid if your system is not generating a sufficient amount. This will be necessary on winter days and of course night time when your solar PV system will not be generating electricity.
What if the system is producing more electricity than my needs?
Any surplus electricity is exported to the National Grid; your electricity supplier for will pay you for this electricity under the FiT (Feed In Tariff) scheme.
How long will my solar PV system last for?
Do I need planning permission?
In most circumstances planning permission is not required, but there are exceptions such as listed buildings or buildings in conservation areas. We can offer general advice based on our extensive experience but we would always advise that you talk to your local planning department if you are in doubt.
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