Key facts
| Council area | Merthyr Tydfil |
| Population | 39,535 (Merthyr Tydfil built-up area, usual residents, Census 2021 (ONS)) |
| Network operator | National Grid Electricity Distribution (South Wales) |
| Main employment areas | Goat Mill Road employment site; Merthyr Tydfil Industrial Park, Pentrebach |
| Indicative yield | About 937 kWh per kWp a year (south facing, 30 degrees) |
| Nation support page | Grants and reliefs in Wales |
Where businesses are in Merthyr Tydfil
- Goat Mill Road employment site: A 19 acre site undeveloped since remediation in the 1990s, which a Welsh Government and Merthyr Tydfil Council joint venture announced in October 2025 is being serviced into investment ready plots, with about 228,000 sq ft of industrial space to follow.
- Merthyr Tydfil Industrial Park, Pentrebach: An industrial park in Pentrebach whose Pentrebach Enterprise Centre was listed on the Business Wales property database (in 2019) with office units of 90 to 650 sq ft and industrial units of 500 to 2,000 sq ft.
Large employers and sectors with sites here include:
- Healthcare (Prince Charles Hospital): Cwm Taf Morgannwg University Health Board said in March 2026 that it had secured £42 million from the Welsh Government for the third and final phase of the refurbishment of Prince Charles Hospital in Merthyr Tydfil.
- Meat processing (Kepak): Kepak's Merthyr Tydfil plant, described in June 2026 as Wales's largest meat processing plant, began a collective consultation that month over more than 80 possible job losses. In 2022 the site employed over 850 people.
Large, simple roofs on distribution sheds and modern industrial units are usually the quickest and cheapest to fit. Older mill, factory and workshop buildings can work well too, but often need a structural survey first, and roofs from before 2000 may contain asbestos cement: see asbestos roofs.
Grid connection
Merthyr Tydfil is served by National Grid Electricity Distribution (South Wales). Almost every commercial system needs G99 approval from the network operator before it is switched on, and the question is usually how much the local network can take back. Where export is limited, a G100 export limitation scheme can let a larger array connect. See G99 and DNO applications.
Planning in Merthyr Tydfil
Planning in Merthyr Tydfil is decided by Merthyr Tydfil council under the Welsh rules. Many non-domestic roofs are covered by Welsh permitted development, with conditions, but not within 3 km of an airport or aerodrome or on listed buildings.
Points that come up locally:
- Merthyr Tydfil has eight conservation areas, including the Town Centre Conservation Area along the High Street from St Tydfil's Church to Pontmorlais, Cyfarthfa Park and Dowlais, so check whether a building is inside one before planning roof panels.
- Article 4 Directions remove some permitted development rights in the Pontmorlais Quarter of the Town Centre Conservation Area and at named addresses in the Thomastown Conservation Area.
Our guides on listed buildings and conservation areas explain what these mean for a solar project.
What a business roof in Merthyr Tydfil could generate
Modelled with PVGIS for the town centre, a south-facing roof at 30 degrees produces about 937 kWh per kWp a year.
| Item | Illustrative figure |
|---|---|
| System | 100 kWp, south facing at 30 degrees |
| Installed cost | £900 per kWp, so £90,000 excluding VAT |
| Generation | About 93,700 kWh a year |
| Used on site | 70% at 24p = £15,742 saved |
| Exported | 30% at 5p = £1,406 earned |
| Total a year | About £17,147 |
| Simple payback | About 5.2 years before tax relief |
Illustrative, not a quote: the same sums as our commercial solar calculator. A company paying corporation tax can usually shorten the payback with capital allowances.
Funding and support
- Development Bank of Wales Green Business Loan Scheme: Discounted fixed interest rate loans for energy efficiency measures and low carbon projects, with renewables including solar PV listed as eligible projects. Limited companies, sole traders and partnerships must be based in Wales, have traded for at least two years and have at least one set of filed annual accounts. A grant of up to 50% of the cost of a detailed energy audit, to a maximum of £10,000 (£20,000 total costs), is also offered. Check the scheme's own page for eligibility and closing dates.
National reliefs apply too: see grants and reliefs in Wales.
Solar across Merthyr Tydfil
At the end of 2025, Merthyr Tydfil had 1,542 solar PV installations with 6.9 MW of capacity, up 156% since 2020, according to government figures. The Merthyr Tydfil page has the full local figures and how they compare.
Nearby towns
- Aberdare, about 4 miles away
- Bargoed, about 7 miles away
- Ebbw Vale, about 8 miles away
- Caerphilly, about 14 miles away
Sources
- ons.gov.uk: census2021
- ons.gov.uk: datadownload.xlsx
- media.service.gov.wales: joint venture to lay foundations for merthyr tydfil
- propertydatabase.business.gov.wales: Merthyr Tydfil Industrial Park Pentrebach Enterprise Centre Merthyr
- ctmuhb.nhs.wales: 42m funding secured for final phase of prince
- farmersguardian.com: fears 80 jobs lost welsh meat processing plant
- kepak.com
- gov.uk: growth and local jobs top of the agenda
- gov.uk: maps of celtic freeport tax sites
- businesswales.gov.wales: enterprise zones
- merthyr.gov.uk: conservation areas
- merthyr.gov.uk: article 4
- developmentbank.wales: green
- Yield: PVGIS 5.3 (European Commission Joint Research Centre), SARAH3 data, 14% system losses, for the town centre, modelled 4 November 2026.
- Council area figures: DESNZ, renewable electricity by local authority 2014 to 2025.
Frequently asked questions
Who is the electricity network operator in Merthyr Tydfil?
National Grid Electricity Distribution (South Wales). Most commercial solar systems need its G99 approval before they are switched on. The operator follows the postcode, so confirm yours with the Energy Networks Association postcode tool.
How much would a 100 kWp solar system generate in Merthyr Tydfil?
About 93,700 kWh a year for a south-facing roof at 30 degrees, modelled with PVGIS for the town centre. At 70% used on site at 24p and the rest exported at 5p, that is worth about £17,147 a year. Your own roof, orientation and use will change this.
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. It is free, with no obligation. Get a free survey.
Related pages
- Merthyr Tydfil1,542 installations, 6.9 MW of solar and about 938 kWh per kWp a year for a south-facing roof.
- 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.
- 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.
- 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.