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Solar panels

Generate cheap, green electricity from sunlight

 

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. 

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.

Benefits of solar electricity

 

Getting the most out of your solar PV system

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.

Export payments

With any domestic PV system there will be times when the electricity you generate is more than you can use or store, so the surplus will be exported to the grid to be used by somebody else. If you want to be paid for this surplus you need to make sure you’re getting an export payment. If you were able to claim the Feed-in Tariff, then you will be getting export payments as part of that. If not, you need to find an energy company that will pay you for this surplus.

In Great Britain, the Government is introducing a Smart Export Guarantee which will require most suppliers to offer you at least something for your exported electricity, but this won’t start until January 2020. In the meantime, some companies are already offering export payments to their customers.

In Northern Ireland, you can get paid for any surplus you export – usually estimated on the basis of how much you generate. Contact Action Renewables for more information.
 

Costs and savings

 

Following the closure of the Feed-in Tariff scheme to new solar PV system applicants in March 2019, the Smart Export Guarantee (SEG) will be introduced to provide financial support to small-scale renewable energy generators for the electricity they export to the grid. As shown in the tables below, the savings from solar PV with the SEG are considerably higher than without it.

Visit our Smart Export Guarantee and Feed-In Tariffs page for more information about the SEG which applies to solar PV and other renewable energy generators.

London, South East England

Annual Savings

Simple Payback

Aberystwyth, Wales

Annual Savings

Simple Payback

Manchester, North England

Annual Savings

Simple Payback

Stirling, Scotland

Annual Savings

Simple Payback

Northern Ireland

Solar panels were eligible for Feed-In Tariff payments. The FITs scheme closed to new applications on 31 March 2019. If you have already installed solar PV with a MCS certificate dated on or before 31 March 2019 you may still be able to apply. For more information about the FITs scheme and recent changes please, visit our Feed-In Tariffs  page.

Please note: the Northern Ireland Renewables Obligation Certificates (NIROCs) scheme is now closed to all technologies since April 2017 and you can’t receive payments from generation tariffs any more. However, you can still cut your electricity bills by using the free electricity generated by solar PV and receive export payments from the electricity excess that you sell to the grid.

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

Annual savings when using the energy you generate

Annual income from export payments

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.
     

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 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 cost of about £800.

Consult with your installer for exact maintenance requirements before you commit to installing a solar PV system.

Helpful resources

More on this…

Solar Energy Calculator

Use the Solar Energy Calculator to gain an idea as to what financial benefits you may see from installing a solar PV system.

Try our tool

Financial support

Find out what support is available for renewable technology specifically in Scotland.

Discover more

Speak with an expert

For independent advice on solar technology, contact your local energy advice centre.

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