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Solar panels

Generate cheap, green electricity from sunlight

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What are solar panels?

Solar panel electricity systems, also known as photovoltaics (PV), capture the sun's energy using photovoltaic cells. These cells don't need direct sunlight to work – they can still generate some electricity on a cloudy day. The cells convert the sunlight into electricity, which can be used to run household appliances and lighting.

The benefits of solar electricity

  • Cut your electricity bills. Sunlight is free, so once you've paid for the initial installation, your electricity costs will be reduced.
  • Get paid for the electricity you generate. The UK government’s Feed-in Tariff scheme pays you for the electricity you generate, even if you use it.
  • Sell electricity back to the grid. If your system is producing more electricity than you need, you can sell the surplus back to the grid through the Feed-in Tariff scheme.
  • Cut your carbon footprint. Solar electricity is green renewable energy and doesn't release any harmful carbon dioxide or other pollutants. A typical home solar PV system could save nearly two tonnes of carbon per year.

How do solar panels (PV) cells work?

PV cells are made from layers of semi-conducting material, usually silicon. When light shines on the cell it creates an electric field across the layers. The stronger the sunshine, the more electricity is produced. Groups of cells are mounted together in panels or modules that can either be mounted on your roof or on the ground.

The power of a PV cell is measured in kilowatts peak (kWp). That's the rate at which it generates energy at peak performance in full direct sunlight during the summer. PV cells come in a variety of shapes and sizes. Most PV systems are made up of panels that fit on top of an existing roof, but you can also fit solar tiles.

Solar tiles and slates

Solar tiles are designed to be used in place of ordinary roof tiles. A system made up of solar tiles will typically cost about twice as much as an equivalent panel system. Solar tile systems are not normally as cost-effective as panel systems, and are usually only considered where panels are not considered appropriate for aesthetic or planning reasons.

Costs, savings and financial support for solar

England, Scotland and Wales

A 4kWp system can generate around 3,800 kilowatt hours of electricity a year in the south of England – that's the same amount of electricity as it takes to turn the London Eye 50 times. It will save nearly two tonnes of carbon dioxide every year. A 4kWp system in Scotland can generate about 3,200 kilowatt hours of electricity a year – that’s the same amount of electricity as it takes to turn the Falkirk Wheel 2,100 times. It will save more than a tonne and a half of carbon dioxide every year.

The average domestic solar PV system is 4kWp and costs £5,000 - 8,000 (including VAT at 5 per cent). 

Location Feed-in Tariff generation and export payments based on a 4kW PV system (£/year) Electricity bill savings (£/year) Carbon dioxide (kgCO2/year)
System eligible for the tariff between 1st January 2017 and 31st March 2017 (Q1) System eligible for the tariff between 1st April 2017 and 30th June 2017 (Q2)
Cap not reached in previous quarter Cap reached in previous quarter
London, South England £250 £250 £235 £70 1,900 kg
Aberystwyth, Wales £235 £235 £220 £70 1,770 kg
Manchester, North England £225 £220 £210 £70 1,670 kg
Stirling, Scotland £210 £210 £200 £70 1,580 kg

Tariffs will also be subject to an adjustment for RPI (Retail Prices Index) so may change from those stated in this table.

For more information about the FITs scheme and recent changes please visit Feed-In Tariffs.

Northern Ireland 

A 4kWp system can generate around 3,400 kilowatt hours of electricity a year – roughly equivalent to a typical household's electricity needs. It will save over a tonnes and a half of carbon dioxide every year.


System size NIROCs payment (£/year) Export tariff payment (£/year)

Electricity bill savings (£/year)

Carbon dioxide savings (kgCO2/year)

Belfast, Northern Ireland 4kWp £270 £70 £80 1,700 kg

If your system is eligible for the NIROC (Northern Ireland Renewable Obligations Certificates), you could generate savings and receive payments of around £340 a year (based on a 4kWp solar PV system eligible for a generation tariff of 7.94p/kWh, using a ROC rate of 3.97p/kWh). You will get paid for both the electricity you generate and use, and what you don't use and export to the grid if you register before September 2015.  When applying for NIROCs you will need to apply through Power NI if your system is below 50kW.

If you know your system size, you can get a tailored estimate of FIT payments for your system using the Solar Energy Calculator

Costs can vary between installers and products, so we recommend getting quotes from at least three installers. 

Other factors that affect PV installation costs are:

  • The more electricity the system can generate, the more it costs but the more it could save.
  • Larger systems are usually more cost-effective than smaller systems (up to 4kWp).
  • PV panels are all about the same price per kWp, but PV tiles cost much more than a typical system made up of panels.
  • Panels built into a roof are more expensive than those that sit on top.

Financial support for solar technology

​Solar PV is eligible for Feed-in Tariffs and you will earn a tariff for each kWh of electricity generated by your system. You will also receive another tariff for each kWh of electricity you export. 

Solar PV maintenance

Solar PV needs little maintenance – you'll just need to keep the panels relatively clean and make sure trees don't begin to overshadow them. In the UK panels that are tilted at 15° or more have the additional benefit of being cleaned by rainfall to ensure optimal performance. Debris is more likely to accumulate if you have ground mounted panels.

Once fitted, your installer should leave written details of any maintenance checks that you should carry out from time to time to ensure everything is working properly. This should include details of the main inverter fault signals and key trouble-shooting guidance. Ideally your installer should demonstrate this to you at the point of handover. Keeping a close eye on your system and the amount of electricity it’s generating (alongside the weather conditions) will familiarise you with what to expect and alert you to when something might be wrong.

The panels should last 25 years or more, but the inverter is likely to need replacing some time during this period, at a current cost of about £800. Consult with your installer for exact maintenance requirements before you commit to installing a solar PV system.

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