The short answer
Welsh businesses are well placed for rooftop solar, with decent generation in the west and free advice available through Business Wales. Two network operators cover the country — NGED in the south and SP Energy Networks in the north. Run the free roof check for your numbers, and we'll tell you whether we can introduce you to an installer for a free site survey.
Picking a commercial solar installer is the step where businesses most often get a poor deal — the Wales market has plenty of firms, and quality varies. This page covers what is specific to going solar across Wales; our guide to choosing an installer sets out the full vetting criteria, and our quote-comparison checklist shows what a good quote must contain.
Who runs the grid across Wales?
Wales has two distribution network operators: National Grid Electricity Distribution (NGED) covers south, mid and west Wales, while SP Energy Networks (SP Manweb) covers the north. Your installer applies to the relevant one for the grid connection (a G99 application for exporting systems, typically 8–12 weeks).
| Local factor | Detail |
|---|---|
| Distribution network operator | National Grid Electricity Distribution and SP Energy Networks |
| Grid connection | G99 application for exporting systems — typically 8–12 weeks |
| Wider area | Wales |
How much will a roof generate in Wales?
Generation across Wales is broadly in line with or a little below the UK average of around 950 kWh per kWp per year, with the sunnier western and coastal areas at the higher end.
The number that matters most is how much you use during daylight: every unit you generate and use yourself displaces grid power at 25–30p. Our payback and ROI guide works through the returns, or get a figure for your own roof with the calculator below.
Are there solar grants for Wales businesses?
Business Wales, the Welsh Government's business support service, offers free advice on renewables. As of September 2026 there is no open Welsh Government grant for business rooftop solar: the Future Proofing Fund was a 2024 round for retail, hospitality and leisure businesses, and the Ynni Cymru capital grant is closed. The Development Bank of Wales offers green business loans. Since 1 April 2024 rooftop solar has been left out of business rates valuations in Wales, until 31 March 2035.
On top of any local scheme, every UK business can use the £1m Annual Investment Allowance to deduct the cost from profits — worth roughly 25% of the project back at the 25% corporation tax rate. Our grants and tax relief guide has the national picture.
The Wales installer market
The Welsh commercial solar market is led by regional installers, including specialists in west and south Wales. Independent vetting on certification, insurance and track record is the step that protects you, whichever firm you choose.
Planning permission in Wales
Planning is devolved in Wales, so it runs its own permitted development rules. Most commercial rooftop solar is still permitted, but confirm the current Welsh rules for your building with the local authority before assuming no permission is needed.
Full detail is on our commercial solar planning permission guide.
Get a free roof estimate in Wales
Frequently asked questions
Who runs the electricity grid in Wales?+
Two operators: National Grid Electricity Distribution (NGED) covers south, mid and west Wales, and SP Energy Networks (SP Manweb) covers north Wales. Your installer submits the grid connection (G99) application to the relevant one for any exporting system; approval usually takes 8–12 weeks.
Are there solar grants for Welsh businesses?+
Not as of September 2026. The Future Proofing Fund was a 2024 round for retail, hospitality and leisure businesses, and the Ynni Cymru capital grant is closed. The Development Bank of Wales offers green business loans, and the £1m Annual Investment Allowance returns roughly 25% of project cost in tax relief. Rooftop solar is also exempt from business rates in Wales until 31 March 2035.
Are the planning rules different in Wales?+
Yes. Planning is devolved, so Wales has its own permitted development rights that differ from England's. Many commercial rooftop systems remain permitted, but confirm the current Welsh rules for your specific building before assuming no permission is needed.
How would you choose an installer to introduce me to?+
Before we introduce any installer covering your part of Wales, we check MCS certification, adequate insurance, track record on systems of your size, and written maintenance terms. We are still signing up installers, so we can't promise a match yet, and we'll tell you honestly whether we can make one. You pay nothing and there is no obligation.
See what solar could save your Wales business
Enter your roof size, postcode and monthly bill — get your system size, savings and payback in 60 seconds. Free, no obligation.
Get my free estimateRelated guides
Updated June 2026 · By Taro Schenker, founder of Business Solar Check. We're independent — we don't install solar. Figures are indicative UK averages; your site survey confirms the numbers for your roof.