Solar in Merthyr Tydfil in figures
| Solar PV installations, end of 2025 | 1,542 |
| Installed capacity, end of 2025 | 6.9 MW |
| Capacity, end of 2024 | 5.7 MW |
| Capacity, end of 2020 | 2.7 MW |
| Generation in 2025 | 6.1 GWh |
| Installations per 1,000 households | 59.5 (UK median 67.0) |
| Average size per installation | 4.5 kW |
| Rank by capacity | 348th of 361 UK council areas; 22nd of 22 in Wales |
What the figures show
Capacity in Merthyr Tydfil has grown by 156% since the end of 2020, faster than the UK as a whole (69%). In 2025 alone it rose from 5.7 MW to 6.9 MW.
There are 59.5 installations for every 1,000 households, below the Wales median of 83.9 and below the UK median of 67.0. That is 218th of 361 council areas, and 21st of 22 in Wales.
At 4.5 kW on average, most installations here are home-sized, so business roofs make up a small share of what is installed so far.
What a business roof in Merthyr Tydfil could generate
Modelled with PVGIS for the centre of Merthyr Tydfil, a south-facing roof at 30 degrees produces about 938 kWh per kWp a year. That is 277th of 361 council areas; the UK median is 998 kWh.
| Item | Illustrative figure |
|---|---|
| System | 100 kWp, south facing at 30 degrees |
| Installed cost | £900 per kWp, so £90,000 excluding VAT |
| Generation | 938 kWh per kWp, about 93,800 kWh a year |
| Used on site | 70%, so 65,660 kWh at 24p = £15,758 saved |
| Exported | 30%, so 28,140 kWh at 5p = £1,407 earned |
| Total a year | About £17,165 |
| Simple payback | About 5.2 years before tax relief |
Same sums as our commercial solar calculator: illustrative, not a quote. East- or west-facing roofs, shading and how much power you use in daylight all move these figures, and a company paying corporation tax can usually shorten the payback with capital allowances. See the cost guide for price ranges by system size.
Planning and grid connection
Many non-domestic roofs are covered by the Welsh permitted development order (Part 43), with conditions for listed buildings, conservation areas and protected land. England's December 2023 changes do not apply in Wales. Ground-mounted arrays usually need an application to Merthyr Tydfil council, or to a national park authority inside a national park. Our planning permission guide sets out the conditions.
Most commercial systems need G99 approval from the local network operator before they are switched on. The operator follows the postcode rather than the council boundary: our Wales page covers the operators in the region, and the Energy Networks Association postcode tool confirms yours. See G99 and DNO applications.
For funding, see grants and reliefs in Wales.
Nearby council areas
- Blaenau Gwent, about 7 miles away
- Rhondda Cynon Taf, about 9 miles away
- Caerphilly, about 10 miles away
- Torfaen, about 14 miles away
- Bridgend, about 17 miles away
- Neath Port Talbot, about 18 miles away
Or see every council area and the Wales page.
Where these figures come from
Installations, capacity, generation and households: Department for Energy Security and Net Zero, Regional Renewable Statistics, renewable electricity by local authority 2014 to 2025 (workbook). They cover all solar PV, homes and businesses, including ground-mounted schemes. Yield: PVGIS 5.3 (European Commission Joint Research Centre), SARAH3 data and 14% system losses, for the council area's centre point (ONS boundaries, December 2024), modelled 4 November 2026. Distances are between centre points.
Frequently asked questions
How much solar is installed in Merthyr Tydfil?
At the end of 2025, Merthyr Tydfil had 1,542 solar PV installations with a combined capacity of 6.9 MW, which generated about 6.1 GWh in 2025, according to government figures. That covers homes, businesses and ground-mounted schemes.
How much would solar on a business roof in Merthyr Tydfil generate?
About 938 kWh per kWp a year for a south-facing roof at 30 degrees, modelled with PVGIS for the centre of Merthyr Tydfil. A 100 kWp system would make roughly 93,800 kWh a year. Orientation, pitch and shading change this, and a site survey models your own roof.
Can a business in Merthyr Tydfil get a free solar survey?
Yes. Answer six short questions and we match the site with one MCS certified installer, who surveys it on site or by video call. The survey is free and there is no obligation to go ahead. Get a free survey.
Related pages
- WalesNGED and SP Energy Networks connections, Planning Policy Wales and Welsh permitted development, the Welsh rates exemption to 2035, and farm, factory and port roofs.
- Council areasSolar installations, capacity, growth and modelled yield for all 361 UK council areas, with a page for each and a CSV download.
- Commercial solar calculatorEstimate commercial solar savings and payback, with the generation, price and cost assumptions shown and sourced, and the limits of a simple estimate explained.
- WalesCurrent solar support in Wales for businesses, farms, public bodies and community groups, with rates, planning and official contacts.
Commercial solar costIllustrative prices per kWp by system size, extra costs, running costs, VAT and tax.