Solar panels in Cardiff

Cardiff is the largest council area in Wales, with 362,308 residents at the 2021 census. Its dense terraces, suburbs and newer estates give installers plenty of roofs to work with. Solar Cymru is an independent guide, so we do not fit panels ourselves.

This page covers what a Cardiff roof can make, which planning rules to check and what the numbers look like. It also explains how to reach MCS-certified installers through our enquiry form.

What a Cardiff roof can generate

PVGIS models a south-facing roof at 35 degrees in Cardiff at about 1,040 kWh a year for each kWp. That sits near the top of the range for Wales. A typical 4.5 kWp home system would therefore make roughly 4,700 kWh in a year.

Roof direction matters more than most owners expect. East or west roofs make about 15 to 20 percent less than south, while north-facing roofs fall to around half. Our guide to solar yield in Wales explains how installers model shade and pitch.

Many Cardiff homes sit in tight terraces with chimneys and neighbouring gables close by. As a result, a shade assessment is worth more here than a headline yield figure. Ask your installer to show the shade factor in the written performance estimate.

Planning rules and conservation areas in Cardiff

Fixing panels to the roof of a single house often counts as permitted development in Wales. For example, the panels must stick out no more than 20 cm from the roof slope. They also stay below the highest part of the roof, and Cardiff Council is the planning authority.

Cadw’s boundary data records 27 conservation areas in the Cardiff planning area. In a conservation area, panels on a wall that faces a highway need planning permission. Councils can also remove permitted development rights through an Article 4 direction, so look at the planning register first.

Listed homes need planning permission, and listed building consent is likely. However, the steps differ from a standard house. Our post on solar rules for listed and conservation homes walks through the steps. For the wider rules, read the Wales planning permission guide.

Connecting to the National Grid Electricity Distribution network

National Grid Electricity Distribution runs the local network across South Wales, including Cardiff. Systems up to 16 A per phase, which is 3.68 kW on a single-phase supply, follow the G98 route. Your installer installs first and then notifies the operator within 28 days.

Larger systems follow G99, which needs agreement before commissioning. Since batteries count towards that rating, a solar and battery pair can tip into G99. Batteries count towards that rating. Our explainer on G98 and G99 network notification shows which route fits which system.

Exports earn money through a Smart Export Guarantee tariff. Ofgem found an average near 4.4p per kWh on untied tariffs in 2024-25, while the price cap electricity rate is about 26p. Using your own power is worth more than selling it.

Costs, funding and savings for Cardiff homes

Official cost data suggests roughly £6,500 to £8,800 for a typical 4.5 kWp home system. Households with solar typically save around £450 to £500 or more a year. The saving depends on how much power you use yourself.

VAT on home solar is 0% until 31 March 2027, while it rises to 5% after that. A home battery adds roughly £2,000 to £10,000, with £5,000 to £8,000 typical. Compare these figures against each quote.

Warm Homes Nest offers free advice and, for eligible households, improvements that can include solar. Green Homes Wales offers owner-occupiers interest-free loans of £1,000 to £25,000, but listed homes do not qualify. Our solar funding guide for Wales lists the current routes.

If you plan to sell, read what we know about selling a house with solar panels. Mortgage lenders can have views on leased roofs, so speak to your conveyancer early.

How to get Cardiff quotes through Solar Cymru

Fill in the short form and we pass your enquiry to MCS-certified installers who cover your postcode. They survey the roof, then send a written design and price. We do not install, lend or broker finance.

Because quotes vary, ask each installer for the MCS performance estimate, the equipment list and the warranty terms. MCS also requires installers to provide financial protection for customers. Our guide to choosing an installer lists the questions to ask.

Nearby roofs behave differently, so you can compare solar installers in Barry, solar quotes around Caerphilly and solar installers in Newport. For the full service overview, see solar panel installation across Wales.