Solar PV Frequently Asked Questions
Contents
How much does it cost?
The total installed cost of a PV system will depend upon the size of the system and how it is mounted. It is not therefore possible to give precise figure without a more detailed analysis of the property in question. As a general guideline however a solar PV system will typically cost £3,500 - £4,500 per kWp.
An average sized domestic system therefore of 16 panels totalling 2.8kWp would cost £9,800 - £12,600 fully installed.
How much energy will it generate?
There are five main factors that will impact how much energy a solar PV system will generate:
- The total size of the PV array.
- The latitude of the location.
- Which direction the PV panels face.
- What slope the panels are mounted on.
- Anything which shades the panels.
As an example south facing roof mounted 1.3kWp PV array in the Midlands should generate approximately 1,200 - 1,300 kWh per year, saving around £400 - £500 per year depending upon the price you pay for your electricity.
More detailed information may be found on our Solar PV Siting page
How do I get paid for my generated energy?
The Government announced in July 2009 the details of the feed-in tariff for small wind and solar photovoltaic systems which went into law from April 2010.
In summary the feed-in tariff (FIT) provides all generators of renewable energy with a higher rate of income from all their generated power than they previously received and significantly higher than the cost of purchasing electricity from the grid, making renewable energy systems very economic. The rate of income is determined by the size of the system and the current rates are as detailed below:
| Band (kW) | Current generation tariff (p/kWh) | Proposed generation tariff (p/kWh) |
|---|---|---|
| <=4kW (new build) | 37.8 | 21.0 |
| <=4kW (retrofit) | 43.3 | 21.0 |
| >4 - 10kW | 37.8 | 16.8 |
| >10 - 50kW | 32.9 | 15.2 |
| >50 - 100kW | 19 | 12.9 |
The feed-in tariff is paid for every unit of electricity generated by your solar photovoltaic system, irrespective of if you use that energy yourself or export it to the grid. In addition to the feed-in tariff for any energy you generate and use you save purchasing that from your electricity supplier and any surplus energy you don't use and export to the grid, you get paid an export tariff.
For more detailed information on the Feed-in Tariff see the Energy Saving Trust web site.
Do I need planning permission?
Most properties will not need planning permission, but you should contact you Local Authority at an early stage to establish the situation for your specific project.
More information may be found in the Government's guidance for planning for solar PV systems on the planning portal web site.
How does it connect to the grid?
Your solar PV panels are all linked together and connected into an inverter which converts the DC power from the solar PV panels into mains voltage compatible AC.
For Solar PV systems less than 4kWp you do not need permission from your electricity company to do this, but you must inform them afterwards.
Any power that you generate will first be used by your property thereby reducing your electricity bill. If you generate more power than you use then any surplus is exported to the grid and you will need to negotiate with your electricity supplier to get paid for any excess.
This will provide a budgetary price for the various systems we offer.