Key facts
| Council area | Gwynedd |
| Population | 9,835 (Caernarfon built-up area, usual residents, Census 2021 (ONS)) |
| Network operator | SP Energy Networks (SP Manweb, Merseyside and North Wales licence area) |
| Main employment areas | Cibyn Industrial Estate; Cei Llechi (Slate Quay) |
| Indicative yield | About 874 kWh per kWp a year (south facing, 30 degrees) |
| Nation support page | Grants and reliefs in Wales |
Where businesses are in Caernarfon
- Cibyn Industrial Estate: Caernarfon's industrial estate, where a refurbished semi-detached unit of 10,866 sq ft in Zone 5 was listed on the Business Wales property database in July 2024.
- Cei Llechi (Slate Quay): A £5.9m regeneration by Caernarfon Harbour Trust with Galeri Caernarfon that turned the Harbour Office and derelict buildings behind it into 19 workspaces for local artisan and craft makers.
Large employers and sectors with sites here include:
- Heritage tourism (Caernarfon Castle): Caernarfon Castle, part of the Castles and Town Walls of Edward I World Heritage Site, recorded 155,109 visits in 2024 to 25, according to a Welsh Government freedom of information release in July 2025.
- Public administration (Cyngor Gwynedd): Gwynedd Council's headquarters is the Council Offices on Shirehall Street in Caernarfon, a Grade II listed building completed in 1869.
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
Caernarfon is served by SP Energy Networks (SP Manweb, Merseyside and North Wales licence area). 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 Caernarfon
Planning in Caernarfon is decided by Gwynedd 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:
- Caernarfon's castle and town walls are part of a World Heritage Site, and Gwynedd Council has refused roof solar panels on a town centre building (Llety Arall on Stryd y Plas) as clutter that would harm views from the castle, a decision the owners appealed, so expect close scrutiny of panels visible from the castle.
Our planning permission guide sets out the rules.
What a business roof in Caernarfon could generate
Modelled with PVGIS for the town centre, a south-facing roof at 30 degrees produces about 874 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 87,400 kWh a year |
| Used on site | 70% at 24p = £14,683 saved |
| Exported | 30% at 5p = £1,311 earned |
| Total a year | About £15,994 |
| Simple payback | About 5.6 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 Gwynedd
At the end of 2025, Gwynedd had 6,788 solar PV installations with 66.5 MW of capacity, up 72% since 2020, according to government figures. The Gwynedd page has the full local figures and how they compare.
Nearby towns
- Porthmadog, about 16 miles away
- Holyhead, about 19 miles away
- Llandudno, about 22 miles away
- Colwyn Bay, about 25 miles away
Sources
- ons.gov.uk: census2021
- ons.gov.uk: datadownload.xlsx
- propertydatabase.business.gov.wales: Cibyn Industrial Estate Unit 2b Zone 5 Caernarfon
- ceillechi.cymru: about us
- cadw.gov.wales: caernarfon castle
- gov.wales: atisn24872
- gov.wales: atisn24872
- en.wikipedia.org: Council Offices, Caernarfon
- gov.uk: maps of anglesey freeport tax sites
- businesswales.gov.wales: enterprise zones
- northwaleschronicle.co.uk: 18336853.appeal pointed gwynedd council solar panels headquarters just
- 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 Caernarfon?
SP Energy Networks (SP Manweb, Merseyside and North Wales licence area). 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 Caernarfon?
About 87,400 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 £15,994 a year. Your own roof, orientation and use will change this.
Can a business in Caernarfon 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
- Gwynedd6,788 installations, 66.5 MW of solar and about 841 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.