1. What is PV?

PV stands for Photo (light) Voltaic (Electric).  PV panels convert light in to electricity.  Note the word light, not sunlight.  They will continue to produce electric on cloudy days and their output will be higher the brighter the light is.  This is not new technology in fact the use of light to produce electric dates back to the 19th Century.

2. What does an inverter do?

Inverters change the DC current from the panels to AC current for the grid. For more information on inverters, view our inverters page.

3. How do I know I’m using the power from the PV panels?

Your inverter monitors grid voltage and ensures that it is putting the power from your inverter in to your system at a slightly higher voltage than the grid.  Voltage is best thought of as pressure, the force behind the electric.  If the inverter produces a higher voltage when you switch an electrical appliance on it will naturally use the power from the panels first.

4. How much electric will my PV panels generate?

A 4kWp system in Cornwall on an unshaded south facing roof can generate over 4000 units (kWh) per year.  If your roof is East or West facing you’re still likely to generate 3400 units (kWh) per year.  The average household in the UK uses around 3000 units per year.  Depending on when and how you use your electric depends on how much impact your PV system will have on your bills.

5. How much will I earn?

Cornwall Solar Panels use PV Sol software to accurately calculate your expected output.  PV Sol accurately takes in to account panel performance, inverter performance, shading, roof pitch, roof orientation and your local weather data to calculate how much electric you will generate.  We then include these figures and how much money you are likely to earn, based on your usual usage and the amount that will be returned to the grid.

6. What happens when there’s not enough light?

You will simply draw from the grid in the normal way.

7. What happens if my PV Solar Panels are producing more than I’m using?

The excess energy will be pushed back in to the grid.

8. Do I need planning permission for PV Solar panels?

Only if you’re in a conservation area or in a listed building.  More info is available on the Government Planning Portal.

9. What size system can I fit on my roof?

Cornwall Solar Panels use a Professional PV design software package called PV Sol.  We can build a 3D model of your property to see which panels will fit best on your roof.  There are over 400 panel manufacturers in the PV Sol database and every panel listed has details of the panels performance.

10. Do I need to inform Building Control?

No, Cornwall Solar Panels are accredited to notify all their work to Building Control.

11. How are PV solar panels attached to the roof?

The brackets used fix to the rafters of your roof which ensures the fabric is free from loadings.

12. What happens in a power cut?

For the safety of linesmen who may be repairing the fault your inverter will need to shut down.

13. Who will fit the system?

Cornwall Solar Panels have their own fully qualified trades men.  A domestic system team is made up of two qualified roofers and a qualified electrician.

14. How long does a PV Solar Panel installation take?

Domestic size installations take 1-2 days to install.

15. What is FITs?

FITs (Feed In Tariff) is the government backed scheme which means your electric supplier (eg EON, N-Power, EDF, Utility Warehouse etc) will pay you for every unit that your system generates, whether you use it or if it goes back in to the grid.  More info on FITs is available on the Energy Saving Trust website.

16. How long will it take before I see a return on my initial investment?

Payback depends on many variables including quality of panels and inverters, your local weather conditions, shading, pitch and orientation of your situation.  Typically in Cornwall you can expect to pay a system off in 8 -12 years.

17. Are there schemes to help me get me a solar panel installed on my property?

The FIT (Feed in Tariff) is there to encourage the installation of PV panels as it allows you to be paid for the electricity you generate. For more information, look at our FITs page.

18. I rent a property, would I be able to get PV solar panels installed?

You would have to check with your landlord.

19. I have a thatched cottage – could PV panels be installed on my roof?

There is currently no mounting system to put Solar PV panels on thatched roofs.  You may be able to have a ground mounted Solar PV system.

20. I have a loft conversion – could I still have PV panels installed?

Yes, PV solar panels can be fitted to a roof, even if there is no access to the loft.