Solar Panels in Cardiff: Costs, Yields and Welsh Schemes

Does solar work in Cardiff?

Cardiff is one of Wales's sunnier cities, sitting on the south coast and benefiting from the Bristol Channel's moderating influence. Annual irradiance runs at roughly 950–1,050 kWh/m², translating to a typical panel yield of 850–950 kWh per kWp per year.

A 4 kWp system on a south-facing Cardiff roof can generate approximately 3,400–3,800 kWh per year — enough to cover a significant portion of a typical household's annual electricity consumption. That is broadly comparable to performance in the Midlands and noticeably better than northern England.

How much does solar cost in Cardiff?

Wales has some of the lowest average installation costs in the UK. Regional data for April 2026 puts the average at around £1,508 per kWp, compared with £1,591 per kWp for England as a whole. A typical 4 kWp system in Cardiff therefore comes in around £5,500–£7,000, depending on roof complexity and installer.

The combination of solid yield and below-average installation cost makes Cardiff a compelling location for solar investment.

Your electricity network: NGED

Cardiff is served by NGED — National Grid Electricity Distribution (nged.co.uk), formerly known as Western Power Distribution. If you previously heard WPD mentioned in the context of Welsh solar, NGED is the same network under its current name.

NGED handles your grid connection notification. For systems up to 3.68 kW per phase, your installer submits a straightforward G98 Fit and Inform notification. Larger systems require G99 pre-approval before installation. Your MCS-certified installer manages this process on your behalf.

Typical system for Cardiff homes

Cardiff's housing stock varies considerably by area. Inner suburbs such as Roath, Canton, and Pontcanna are dominated by Victorian and Edwardian terraced houses, where roof space is modest and a 3–4 kWp system (6–8 panels) is typical. Outer suburbs — Lisvane, Radyr, St Fagans — tend toward larger semis and detached houses that can accommodate 4–6 kWp or more.

Post-war social housing across areas like Llanrumney and Ely often features simple pitched roofs that are well-suited to solar. Rooftop area is rarely the constraint here; east-west orientation on some estates can reduce yield by 15–20% compared with a south-facing installation.

Local grants and schemes: Nest

Wales has its own energy support programme, separate from the GB schemes:

• Nest scheme — the Welsh Government's flagship home energy efficiency programme. Income-tested; eligible households can receive free solar panels alongside insulation and heating improvements, bundled as part of a whole-home upgrade. Visit nestwales.org.uk or call 0808 808 2244.
• Warm Homes Programme — a broader Welsh Government scheme that funds energy efficiency measures for low-income households; solar can be included.
• 0% VAT on solar — applies UK-wide including Wales, until March 2027.

The GB ECO4 scheme also covers Wales, offering a parallel route to free or subsidised solar for eligible households. Eligibility criteria can overlap with Nest — an energy adviser can assess which route is most suitable for your circumstances.

Planning and building regulations

Welsh planning rules for solar panels mirror England: permitted development rights allow roof-mounted solar without planning permission, subject to the 200 mm maximum projection above the roof plane and restrictions on street-facing elevations in conservation areas.

Cardiff has several designated conservation areas — including parts of Roath, Pontcanna, and the city centre. If your home is in a conservation area or is listed, contact Cardiff Council's planning department before proceeding.

Part P of the Building Regulations applies in Wales, as in England. Your installer must be registered with a government-approved competent persons scheme (such as NICEIC, NAPIT, or OZEV) and must self-certify the electrical work or notify your local building control authority.

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