Key facts for commercial solar in Wales
| Network operators | National Grid Electricity Distribution (south and south west Wales); SP Energy Networks (north Wales and much of mid Wales) |
| Indicative yield | About 825 to 1,000 kWh per kWp per year for a typical rooftop array; higher on the south coast, lower in the north and uplands |
| Planning regime | Wales: Planning Policy Wales, Future Wales: the National Plan 2040, and the Welsh permitted development order |
| Vehicle charging zones | No charging clean air zones |
| Business rates | Welsh exemption for eligible onsite renewable plant and machinery, 1 April 2024 to 31 March 2035 |
| Nation support page | Wales (see below) |
| City pages | Cardiff |
Two network operators, north and south
National Grid Electricity Distribution (NGED, formerly Western Power Distribution) runs the network in south Wales, including Cardiff, Newport, Swansea, the valleys and south west Wales. SP Energy Networks runs north Wales and much of mid Wales through its Manweb licence area, which also covers Merseyside and Cheshire in England. The boundary through mid Wales does not follow county lines, so confirm your operator with the Energy Networks Association postcode tool.
G98 and G99 apply in Wales as they do in England: small systems notify after installation, larger ones need G99 approval before connection. Much of rural Wales is served by long overhead lines with limited spare capacity, and parts of the network already host significant wind and solar generation, so export can be restricted. Farm and rural business projects often rely on using generation on site, export limitation under G100, or a battery. See our G99 and DNO applications guide.
Yield across Wales
Wales has a wide spread of yields. In our PVGIS model (version 5.2, SARAH2 data, 14% system losses), a south-facing 1 kWp array at the optimum tilt gives about 1,030 kWh a year in Cardiff, about 930 kWh near Aberystwyth and about 810 kWh near Bangor. An east-west layout at 10 degrees in Cardiff gives about 850 kWh. The south coast compares well with southern England, while north west Wales and upland valleys are lower and more affected by cloud and terrain shading. Treat these as indicative; the survey models your site.
Planning in Wales
Planning is devolved. Planning Policy Wales sets national policy and Future Wales: the National Plan 2040 is the national development plan; both support renewable energy. Local development plans sit beneath them.
Non-domestic rooftop solar is covered by the Welsh permitted development order (Part 43), which was extended in 2019. Conditions apply, including restrictions for listed buildings, conservation areas and other protected land. England's December 2023 changes do not apply in Wales. See our planning permission guide for the general principles.
TODO for the site owner: Confirm the current Welsh permitted development conditions for non-domestic rooftop and ground-mounted solar (Part 43 of the Town and Country Planning (General Permitted Development) Order 1995 as amended in Wales), including any size or height limits.
Large ground-mounted schemes are handled differently. The Infrastructure (Wales) Act 2024 created a new infrastructure consent regime, which began in December 2025 and replaces the Developments of National Significance process for projects above set thresholds. This matters for solar farms, not for typical commercial rooftops.
Wales also has three national parks (Eryri, the Bannau Brycheiniog and the Pembrokeshire Coast) and several National Landscapes, where planning is more restrictive.
Business rates and support
Non-domestic rates are devolved in Wales. Under regulations made in 2023, eligible renewable plant and machinery used for on-site generation and storage, along with certain EV charging equipment, is excluded from rating assessments from 1 April 2024 to 31 March 2035. The Smart Export Guarantee applies in Wales as in the rest of Great Britain. For loans, advice and public sector support, see grants and support in Wales. Confirm tax and rates treatment with your accountant.
Wales's commercial buildings
- Farming. Livestock farming dominates, with sheep across the uplands and dairy in the south west and the borders. Dairy units with milking and cooling loads use generation every day. See our farms page.
- Manufacturing and steel. Deeside in Flintshire is a major industrial area, and Airbus builds aircraft wings at Broughton. In the south, Port Talbot's steelworks, the M4 corridor and the valleys host a wide range of manufacturing. See our factories page.
- Ports and energy. Milford Haven is one of the UK's main energy ports, and Holyhead, Swansea, Port Talbot and Newport handle freight. The Celtic Freeport and the Anglesey Freeport cover parts of these areas.
- Tourism and hospitality. Holiday parks, hotels and attractions along the coast and in the national parks have summer peaks that suit solar.
Cities with their own page
- Cardiff: the capital, its offices, public buildings and the M4 corridor.
How the free survey works in Wales
Complete the short form and we will call to understand the site and your use. If it looks suitable, we arrange a free survey with one MCS certified installer matched to the site, ideally one who works with the relevant operator and Welsh planning rules. For remote farms, a virtual first assessment from aerial imagery and meter data often comes before a site visit. Your details go to that installer only, with no obligation to proceed.
Cities in Wales
Frequently asked questions
Who is the network operator for my site in Wales?
South and south west Wales, including Cardiff and Swansea, is National Grid Electricity Distribution. North Wales and much of mid Wales is SP Energy Networks. The boundary through mid Wales does not follow county lines, so confirm with the Energy Networks Association postcode tool before the installer prepares a G99 application.
Do England's permitted development changes apply in Wales?
No. The December 2023 changes for non-domestic rooftop solar apply in England only. Wales has its own permitted development order, which covers non-domestic rooftop solar under separate conditions, including restrictions for listed buildings and conservation areas. Check the current Welsh rules, or ask your local planning authority, before assuming a project is permitted development.
Are solar panels exempt from business rates in Wales?
Eligible renewable plant and machinery used for on-site generation and storage is excluded from rating assessments in Wales from 1 April 2024 to 31 March 2035, under Welsh regulations made in 2023. This brought Wales broadly into line with England. Check with your accountant and the Valuation Office Agency how it applies to your property.
Our farm is in mid Wales and the grid is weak. Can we still install solar?
Usually, but export may be limited. Long rural lines often have little spare capacity, and a G99 application may come back with a low export limit or a reinforcement cost. Sizing the array to your own daytime use, applying G100 export limitation or adding a battery are common solutions. The survey should check the supply and likely export position early.
Related pages
- CardiffNGED South Wales grid approvals, Welsh permitted development for non-domestic solar, the proposed workplace parking levy, and roofs from Wentloog to Cardiff Bay.
- WalesCurrent solar support in Wales for businesses, farms, public bodies and community groups, with rates, planning and official contacts.
- G99 and DNO applicationsG98 versus G99, what goes into a DNO application, connection offers, export limitation under G100, reinforcement costs and how the survey checks your supply.
- FarmsDairy, poultry and grain enterprises can make good use of solar on sheds or land. A farm survey looks closely at seasonal demand, building condition and rural grid capacity.
Battery storageWhen a commercial battery pays: storing surplus solar, time of use tariffs, peak shaving, sizing from half-hourly data, illustrative costs, safety and siting.- Planning permissionPermitted development for commercial rooftop solar and car park canopies in England, prior approval, heritage limits, ground-mounted schemes and the other UK nations.