Gemini Solar UK Ltd

 Solar PV, Solar Thermal

Microgeneration Certification Scheme

Tel: 01286 675718

FAQ about Solar Photovoltaics (PV)

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 used to provide information about a building's current energy efficiency and estimated energy use. It also provides recommendations on how to increase the energy efficiency of the building. Your home can be graded A (the most effient) to E (the least efficient). Gemini work in conjuction with independent EPC surveyors to advise on the system that will best suit your home and required energy use. An EPC is required by law if you're selling your house or renting it out.

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; Now that the FiT (Feed In Tariff) scheme has ended your electricity supplier will pay you for this electricity under the planned smart export guarantee (SEG). The SEG will be coming in to force from 1st January 2020.

How long will my solar PV system last for?

Most systems come with a 20 year warranty from the manufacturer, but because there are no moving parts in the system you can expect a lifetime of at least 25 years or even longer.

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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