MCS-certified installers · Wales and surrounding areas

Solar Panels Wales – Compare Costs and Savings

Q: How much can I save with solar panels Wales?

A 4kWp system across Wales generates around 3,760 kWh a year . Using roughly 40% of that at home saves about GBP 393 off your electricity bill, and exporting the rest earns around GBP 338 through the Smart Export Guarantee - about GBP 731 a year in total. Being at home during the day, or adding a battery, pushes the bill saving higher.

Q: How much electricity will solar panels generate Wales?

Roofs across Wales produce about 940 kWh per kWp of panels each year , which is -1% vs the UK average. So a 4kWp array generates roughly 3,760 kWh and a 6kWp array around 5,640 kWh. Output is heavily seasonal: the months from April to September do most of the work, and a south-facing roof at around 30 degrees performs best.

Roofs across Wales produce around 940 kWh per kWp installed each year. That puts a typical 4kWp system at about 3,760 kWh a year – worth roughly £731 a year off your electricity bill and in export payments.

£731typical yearly benefit

3,760 kWhgenerated each year

£5,500 – £7,500installed, 4kWp

-1%sunlight vs UK average

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Solar panels across Wales at a glance

Every figure below is calculated for Wales specifically – the sunlight your roof gets here, the current July 2026 electricity price cap, and installed costs from our installer network. Nothing on this page is a national average dressed up as local.

940

kWh per kWp, per year

How much electricity one kilowatt-peak of panels produces annually across Wales.

3,760

kWh from a 4kWp system

Roughly 313 kWh a month on average, weighted heavily towards April to September.

£731

typical benefit each year

£393 off your bill plus £338 for the electricity you export.

£5,500 – £7,500

installed cost, 4kWp

10 panels, about 20m² of roof. VAT is zero-rated on domestic installs.

Work out your savings across Wales

Pick a system size and see what it produces on a Wales roof. Most national calculators use one UK-wide number; this one uses the sunlight figure for your part of the country, so the answer changes depending on where you live.

Solar savings calculator – Wales

Based on 940 kWh/kWp and the July 2026 price cap

What size system are you considering?

3kWp7 panels

4kWp10 panels

5kWp12 panels

6kWp14 panels

Adding a battery?

No batteryabout 40% used at home

With batteryabout 75% used at home

A battery stores what you generate during the day so you use more of it yourself instead of exporting it. It costs more up front, so it lifts the yearly benefit but usually lengthens payback.

Estimated benefit each year

£0

Electricity generated0 kWh
Used in your home0 kWh
Exported to the grid0 kWh
Saved on your bill£0
Export payments£0
Installed cost£0
Rough payback–

Get real quotes for this system →

Estimates are based on an average 4-5 bedroom household with annual electricity usage of 4,200 kWh, using the July 2026 price cap rates. Electricity export rate of £0.15 per kWh. Payback is shown as a range because installed cost varies with roof type, scaffolding and array layout. Your own usage pattern matters more than any single figure here – a quote is the only way to pin it down.

What solar panels cost across Wales

These are the ranges our installers actually quote, not list prices. The low end is a straightforward south-facing tiled roof; the high end covers split arrays, awkward access and in-roof mounting. The savings column is calculated using the 940 kWh/kWp figure for Wales.

System size	Installed cost	Generates across Wales	Yearly benefit	Payback	Battery (optional)
3kWp1-2 bedroom home / low usage7 panels · ~15m²	£4,500 – £6,000	2,820 kWh	£548	8.2–10.9 years	£2,500 – £4,000
4kWp2-3 bedroom home / average usage10 panels · ~20m²	£5,500 – £7,500	3,760 kWh	£731	7.5–10.3 years	£3,000 – £4,500
5kWp3-4 bedroom home / higher usage12 panels · ~25m²	£6,500 – £8,800	4,700 kWh	£914	7.1–9.6 years	£3,500 – £5,000
6kWp4+ bedroom home / EV or heat pump14 panels · ~30m²	£7,500 – £10,500	5,640 kWh	£1,097	6.8–9.6 years	£4,000 – £6,000

Domestic solar is zero-rated for VAT, so the figures above are what you pay. Prices reviewed against installer quotes; savings recalculated whenever the price cap changes.

See what installers quote for your roof →

How we work these numbers out

We would rather show the method than ask you to trust a headline. Here is exactly where each figure comes from.

Sunlight where you live

The amount of electricity a roof produces is set mostly by how much sunlight reaches it, and that varies considerably across the UK. Working from MCS irradiance datasets (MIS 3002 Issue 6.0), due south at 35 degree pitch, cross-checked against PVGIS 5.3, Wales comes out at 940 kWh per kWp installed, per year – -1% vs the UK average. The same panels on the same roof pitch generate meaningfully more in the far south than in the far north, which is why a single national estimate is not much use to you.

What that electricity is worth

Every unit you use yourself replaces one you would have bought at 26.11p per kWh under the July 2026 price cap. What you do not use is exported and paid for at around 15p per kWh through the Smart Export Guarantee. We assume 40% of what you generate is used at home without a battery, 75% with one.

What it costs to install

Cost ranges come from what installers on our network quote for real jobs, not from list prices. Payback is simply installed cost divided by yearly benefit, shown as a range so you can see both the good-roof and the difficult-roof case rather than only the flattering one.

Rates are held in one place and updated when Ofgem resets the cap in January, April, July and October – currently the July 2026 cap. Estimates are exactly that: your roof pitch, orientation, shading and usage pattern will move the answer, and only a survey settles it.

Getting solar installed across Wales

Solar panels on a house roof across Wales are normally permitted development, so most homeowners do not need planning permission. The usual exceptions are listed buildings, homes in a conservation area, and panels that would sit more than 200mm proud of the roof slope or above the highest part of the roof. If any of those apply to your property, a local installer will tell you at survey stage – it is a routine question, not a dead end.

Any installer worth quoting will be MCS certified. That certification is what makes your system eligible for Smart Export Guarantee payments from your electricity supplier, so it is not a nice-to-have. Every installer we pass your details to is MCS certified and covers Wales.

Your installer handles the grid connection paperwork with your local network operator. For a standard domestic system this is a notification after the work is done rather than an application you wait on, so it does not usually hold anything up.

What happens next. Tell us your postcode and a little about your roof, and we will match you with MCS-certified installers covering Wales. You compare their quotes side by side and decide whether to go ahead. There is no charge and no obligation at any point.

Compare installers across Wales →

Solar panels across Wales: common questions

How much do solar panels cost Wales?

A 4kWp system – the most common size for a three-bedroom home – typically costs £5,500 – £7,500 installed across Wales. Smaller 3kWp systems start lower and 6kWp systems for larger homes or households with an EV run higher. Domestic solar is zero-rated for VAT, so the quoted price is what you pay. The spread within each size band comes down to roof type, scaffolding and how the array has to be laid out.

How much can I save with solar panels Wales?

A 4kWp system across Wales generates around 3,760 kWh a year. Using roughly 40% of that at home saves about £393 off your electricity bill, and exporting the rest earns around £338 through the Smart Export Guarantee – about £731 a year in total. Being at home during the day, or adding a battery, pushes the bill saving higher.

How much electricity will solar panels generate Wales?

Roofs across Wales produce about 940 kWh per kWp of panels each year, which is -1% vs the UK average. So a 4kWp array generates roughly 3,760 kWh and a 6kWp array around 5,640 kWh. Output is heavily seasonal: the months from April to September do most of the work, and a south-facing roof at around 30 degrees performs best.

What is the payback period on solar panels Wales?

On these figures a 4kWp system across Wales pays for itself in roughly 7.5 to 10.3 years, depending on what you pay to have it installed. Panels are generally warranted for 25 years and keep producing after that, so most of the system's life sits beyond the payback point. Rising electricity prices shorten payback; falling prices lengthen it.

Do I need planning permission for solar panels Wales?

Usually not. Roof-mounted panels on a house are normally permitted development. You will need to check first if your home is listed or in a conservation area, or if the panels would project more than 200mm from the roof slope or sit above the highest part of the roof. An installer will flag any of this at survey stage.

Are the installers Wales MCS certified?

Yes. Every installer we match you with is MCS certified and covers Wales. MCS certification is what makes your system eligible for Smart Export Guarantee payments, so an uncertified install can quietly cost you the export income entirely.

Is it worth getting a battery Wales?

A battery stores daytime generation so you use more of it yourself rather than exporting it at a lower rate. That lifts the annual benefit, but it adds £3,000 – £4,500 to the install, so payback usually gets longer rather than shorter. It tends to make most sense if you are out during the day, have an EV, or are on a tariff with cheap overnight rates. Ask for quotes both with and without and compare.