Key facts
| Council area | Carmarthenshire |
| Population | 42,175 (Llanelli built-up area, Census 2021) |
| Network operator | National Grid Electricity Distribution (South Wales) |
| Main employment areas | Dafen Industrial Estate; Trostre Industrial Park; Bynea Business Park; Pentre Awel |
| Indicative yield | About 1,028 kWh per kWp a year (south facing, 30 degrees) |
| Nation support page | Grants and reliefs in Wales |
Where businesses are in Llanelli
- Dafen Industrial Estate: Established estate first built by the Welsh Development Agency, about a mile north-east of the town centre and four miles from M4 junction 48.
- Trostre Industrial Park: Industrial units on the east side of town near Trostre Retail Park and the Trostre tinplate works.
- Bynea Business Park: Off Heol Y Bwlch (B4297), about 2.5 miles east of Llanelli town centre.
- Pentre Awel: Carmarthenshire Council's health and wellbeing development at Delta Lakes. It includes business incubation space for healthcare technology, expected to be ready for occupation in 2026.
Large employers and sectors with sites here include:
- Steel packaging: Tata Steel Trostre: The UK's tinplate works, making tin, chrome and polymer-coated packaging steel. It kept its BRCGS AA+ food packaging safety grade in February 2026.
- Healthcare: Prince Philip Hospital (Hywel Dda University Health Board): General hospital in Llanelli run by Hywel Dda University Health Board.
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
Llanelli 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 Llanelli
Planning in Llanelli is decided by Carmarthenshire 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:
- The town centre has the Llanelli Conservation Area, designated in 1971. A council-commissioned appraisal and management plan covers it.
- The Burry Inlet (Loughor estuary) beside the town is a Special Protection Area, a Ramsar site and part of a Special Area of Conservation.
Our guides on listed buildings and conservation areas, bats, birds and ecology explain what these mean for a solar project.
What a business roof in Llanelli could generate
Modelled with PVGIS for the town centre, a south-facing roof at 30 degrees produces about 1,028 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 102,800 kWh a year |
| Used on site | 70% at 24p = £17,270 saved |
| Exported | 30% at 5p = £1,542 earned |
| Total a year | About £18,812 |
| Simple payback | About 4.8 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: Loans of £1,000 to £1.5m for energy efficiency and decarbonisation, including solar PV, funded by the Welsh Government and the Development Bank of Wales. The fund was extended to £20 million, with funding available until 2028. Business Wales energy audit grants cover up to 50% of costs. Check the scheme's own page for eligibility and closing dates.
National reliefs apply too: see grants and reliefs in Wales.
Solar across Carmarthenshire
At the end of 2025, Carmarthenshire had 10,214 solar PV installations with 210.0 MW of capacity, up 79% since 2020, according to government figures. The Carmarthenshire page has the full local figures and how they compare.
Nearby towns
- Port Talbot, about 17 miles away
- Barry, about 43 miles away
- Bridgwater, about 63 miles away
- Taunton, about 65 miles away
Sources
- citypopulation.de: W45000448 llanelli
- propertydatabase.business.gov.wales: Unit 5 Trostre Industrial Park Llanelli Carmarthenshire
- novaloca.com: Carmarthenshire Llanelli
- carmarthenshire.gov.wales: pentre awel updates and newsletters
- [npt.moderngov.co.uk: 6a Pentre Awel Progress Update Nov 25](https://npt.moderngov.co.uk/documents/s110238/6a - Pentre Awel Progress Update Nov 25.pdf)
- tatasteeluk.com: gold standard for tata steel’s trostre packaging site
- tatasteeluk.com: trostre
- hduhb.nhs.wales: living in the hywel dda area prince philip
- carmarthenshire.gov.wales: llanelli ca appraisal
- rsis.ramsar.org
- developmentbank.wales: green
- gov.wales: extra 10 million support welsh businesses their journey
- nation.cymru: swansea manufacturer invests 250000 in solar energy project
- gov.uk: maps of celtic freeport tax sites
- en.wikipedia.org: Llanelli
- 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 Llanelli?
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 Llanelli?
About 102,800 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 £18,812 a year. Your own roof, orientation and use will change this.
Can a business in Llanelli 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
- Carmarthenshire10,214 installations, 210.0 MW of solar and about 968 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.