Frequently Asked Questions
1. How does a solar PV electric system work?
Solar panels generate electricity using energy from the sun. The panels produce energy from daylight, not direct sunlight, so they still produce energy on cloudy or overcast days. An inverter converts the electricity from direct to alternating current, for use in the property. The electrical energy produced is either used directly in the property, or when the system is producing more power than is needed it is exported to the grid. At night, power is imported from the grid in the normal way.
2. How much will I save?
Savings depend on how much you pay for electricity at the moment and how much electricity prices increase in the future. We will estimate your savings when we prepare your quote.
3. Are there different types of solar panels?
There are two types of solar panels: Solar thermal for hot water and solar PV (also called solar electric) which produce electricity. Better Planet design, supply and install both types of systems. These FAQs are about solar electric panels.
4. What does PV stand for in "Solar PV"?
PV stands for photovoltaics, the term used in physics for electricity produced by light.
5. What is a kWp (kilowatt peak)?
This is the power generated under standardised test conditions with a light intensity that roughly corresponds to full sunshine in England.
6. What is the lifetime of the panels?
The panels have a warranted life of 25 years. The working lifetime is much longer.
7. What structural checks are undertaken prior to installation?
We will make an assessment during our site visit. If we have any doubts regarding the structural strength, we will recommend you to get a survey by a structural engineer.
8. Does the efficiency of the panels drop if the panels get dirty?
Usually any dirt is washed off when it rains if the roof-angle is at least 15 degrees.
9. What happens if there is a power cut?
The systems we install are grid connected. If there is a power cut, the system will automatically be switched off as a safety measure.
10. Will I need a new electricity meter?
All our installations come with a meter dedicated to measure the electricity produced by the solar panels. It is widely expected that so called "smart meters" will become compulsory. Those meters will be able to measure how much electricity is exported back to the grid.
11. What size system is suitable for my property?
The system can either be sized in relation to how much suitable roof space there is or in relation to the available budget. Our domestic installations typically range from 6 to 21 panels.
12. What is the best panel inclination?
It depends on where in the UK you are. It varies from 30 degrees for southern England to 40 degrees for Scotland.
13. Do the panels have to face exactly south?
No. While south facing is optimal, many panels are installed east facing or west facing or between south - and east/west facing. Compared to straight south facing panels, east/west facing panels generate 80% of the output.
14. What is the payback of an installation?
With conservative assumptions it takes between 8 and 12 years to pay back the initial investment.
15. Do I need planning permission?
Solar panels are a permitted development and you do not need planning permission unless your property is listed or if it is located in a conservation area or an "area of outstanding natural beauty". If you are uncertain, please check with your council.
16. Do the systems need batteries?
All the systems we install are connected to the grid and no batteries are needed.
17. What are the "Feed in Tariffs"?
Read more about Feed in Tariffs on Solar PV - Government Incentives.
18. Do the PV panels need direct sunlight to work?
No, solar PV panels works from any light. Obviously, they produce more power the stronger the light is.
19. What is the effect of shade?
PV systems are sensitive to shade and panels should not be located close to chimneys etc.
20. Can solar electric panels be installed vertically on south facing walls?
Yes, but they would typically produce around 30% less electricity compared to panels installed on a roof.