Glamorgan
Solar panels in Cardiff, priced before anyone visits.
A 12-panel roof in Cardiff makes about 6,510 kWh a year and costs £6,360 installed; a free 30-minute video call sizes it to yours.
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Sunlight in Cardiff, in numbers
PVGIS puts Cardiff at 1,024 kWh per kWp a year, 9% above our Glamorgan county estimate. 69% of it arrives between April and September, peaking in May.
Generation per kWp, month by month
Show the monthly figures
| Month | kWh/kWp |
|---|---|
| January | 36.5 |
| February | 54.7 |
| March | 89.1 |
| April | 117 |
| May | 129 |
| June | 127 |
| July | 126 |
| August | 110 |
| September | 94.7 |
| October | 63.5 |
| November | 43.1 |
| December | 33.8 |
Source: PVGIS v5.2 (European Commission JRC), SARAH3 database, 1 kWp, 14% system loss, 35 degree pitch, due south, checked September 2026.
Our GB average is 925 kWh per kWp a year, the mean of the 85 county PVGIS estimates we publish; at 1,024, Cardiff is 11% above it.
How Cardiff compares
Cardiff is one of 32 Glamorgan towns we track, and it ranks 14th of 32 for solar yield. The House of Commons Library settlement classification puts it in the core city class, with a population of 367,426, which makes it one of the largest places we publish figures for. Scale changes nothing about the physics: PVGIS gives a roof here 1,024 kWh per kWp a year, 2.80 peak sun hours a day averaged across the seasons, and on the 12p scenario about £247 of the year one benefit comes from solar you use yourself, with export income adding £669.
Treat these as calibration rather than a quote. The calculator below runs the same model, opened on Cardiff's own yield, and prices a 12 panel system at £6,360 installed before any battery. Your free design call reworks every number for your actual roof, its shading and your usage.
Cardiff is its own local planning authority area, and its House of Commons Library settlement class is core city.
The charger is in the installed price but left out of payback: charging savings depend on your mileage and tariff, which the design call models properly.
Your real roof and usage, worked through on a free 30-minute video call. Use the full form or leave three details below.
Price this for your roof
Three details. We call or text within one working day to book your free 30-minute design call, on video or by phone if you prefer.
Modelled for Cardiff at 51.50191, -3.184 on PVGIS data, with imports valued at 26.32p/kWh and solar at £1,000 per kWp installed. Sources and assumptions: help page.
The network operator for Cardiff
On NESO's licence-area map, Cardiff is in South Wales, which National Grid Electricity Distribution (NGED) operates. That makes NGED the network operator for any system fitted here.
Most home systems stay within 3.68kW per phase of inverter output, which puts them on G98, a notification to NGED within 28 days of switch-on. Panel count does not decide it; the inverter and any battery do.
Larger systems go through G99 instead, applied for before installation. On timing: NGED's guaranteed standards give 45 working days for a low voltage generation quotation, with £80 paid for each working day late.
Sources: NESO DNO licence areas (3 May 2024); NGED, guaranteed standards of performance table, checked 25 September 2026. G98 vs G99, explained.
Heat pumps and EV charging in Cardiff
A heat pump in Cardiff
In December, the darkest month here, 12 panels in Cardiff make about 210 kWh. That is when a heat pump runs hardest, so its running cost in Cardiff comes down to the tariff and the flow temperature rather than the roof.
In Wales, the Boiler Upgrade Scheme pays £7,500 towards an air source or ground source heat pump and £2,500 towards an air-to-air one, with £1,500 more until March 2027 for homes heated by oil or LPG with no mains gas (gov.uk, checked 28 September 2026).
Charging an EV in Cardiff
Summer is where a car earns its place. In May, 12 panels in Cardiff make about 820 kWh, against roughly 70 kWh a typical home uses in daylight that month on our calculator's typical-use settings, so there is surplus a smart charger can put into the car instead of exporting it.
Renters and flat owners with private off-street parking can get 75% off a chargepoint and its installation, up to £500 per socket, until 31 March 2027 (gov.uk, checked 28 September 2026). The calculator above adds a 7.4kW smart charger from £1,100 installed.
What the named kit costs, installed
Every system is designed around your roof on the free call before anything is fitted.
What else is true of Cardiff
Census 2021 data published by the Welsh Government shows Cardiff has the lowest rate of home ownership of any Welsh local authority, at 58.3% against a 66.4% Welsh average, and the highest rate of private renting, at 24.3%, alongside a comparatively high share of one and two-room households. That tenure pattern matters for solar as much as roof shape does: in a city where nearly a quarter of homes are privately rented, the panel decision often sits with a landlord rather than the person paying the electricity bill.
Cardiff sits in National Grid Electricity Distribution territory, on its South Wales licence. National Grid Electricity Distribution's own published Guaranteed Standard is 45 working days for a low voltage generation quotation, with a complete application acknowledged within 10 working days; most single home systems use the quicker 28-day G98 route instead. Cardiff Council is the planning authority for household solar under the same Welsh Government permitted development rules that apply across Wales.
The council's One Planet Cardiff strategy targets carbon neutrality for the city, covering both its own operations and the wider city, by 2030. Cardiff Council has also unanimously approved a 1,000MW battery storage scheme on a former steelworks and sewage treatment site in Tremorfa, Splott, comprising 828 containerised units and reported as the largest battery storage scheme to secure planning permission in the UK so far.
Planning authority: Cardiff Council
Sources: oneplanetcardiff.co.uk · cardiffcapitalregion.wales
Solar panel servicing and repair in Cardiff
If a system in Cardiff is underperforming, start with the guides below: repair benchmarks, service scope, and the inverter question.
Solar in Cardiff: your questions answered
How much energy would 12 solar panels make in Cardiff?
Cardiff averages 2.80 peak sun hours a day, which PVGIS turns into 1,024 kWh per kWp a year. On a 12-panel, 6.36 kWp roof that is about 6,510 kWh, 69% of it between April and September.
What does a typical solar system cost in Cardiff?
Solar is priced at £1,000 per kWp installed wherever you live, so a 12-panel, 6.36 kWp system costs £6,360 in Cardiff, exactly as it would anywhere else, before any battery. Location changes what the system makes, not what it costs: here that is about 6,510 kWh a year. The final figure comes from your roof on the design call.
Who is the network operator in Cardiff, and do I need a G99 application?
The operator is National Grid Electricity Distribution (NGED). Most home systems use the G98 route, a notification within 28 days of switch-on for up to 3.68kW per phase, so nothing waits on the network. Above that, G99 applies and has to be granted first. NGED's guaranteed standards give 45 working days for a low voltage generation quotation, with £80 paid for each working day late. Your design call checks which route yours needs.
What happens to the solar I do not use in Cardiff?
Around £669 a year at 12p per kWh, for the roughly 5,576 kWh a 12-panel system in Cardiff exports with typical use. Rates vary by supplier and some need their own tariff; the export rates table is dated and sourced.
How does solar perform in Cardiff in the winter months?
December is the weakest month in Cardiff: about 210 kWh from 12 panels, against 820 kWh in May. The panels still generate on bright winter days; they just cover a smaller share of what the house uses.
How Cardiff compares with its neighbours
Same satellite dataset, same assumptions, so the differences are real geography rather than modelling noise.
| Town | kWh per kWp a year | vs Cardiff |
|---|---|---|
| Cardiff | 1,024 | this town |
| Penarth | 1,055 | +31 kWh |
| Dinas Powis | 1,058 | +34 kWh |
| Caerphilly | 1,018 | −6 kWh |
| Barry | 1,060 | +36 kWh |
| Church Village | 1,001 | −23 kWh |
| Rogerstone | 1,016 | −8 kWh |
Same PVGIS v5.2 query for every town. Small differences are within year-to-year weather; more than about 30 kWh per kWp apart is geography.
Also for Cardiff: Solar panels in Cardiff from OVO Solar & Battery
See a number before you speak to anyone
Answer a few questions about your roof and usage and see an instant solar and battery estimate. No email needed to see the result.
Further reading for Cardiff
Sourced, dated and written by us. The same ground we cover on your free call.
What solar actually costs in 2026, and where every pound goes
Around £8,677 average, £1,550 to £1,800 per kW. Where every pound actually goes.
Read the guide →What a battery gateway actually does
Without a gateway your system shuts down when the grid does. Here is what the box actually does.
Read the guide →Charging an EV from your own solar
Every surplus kWh is 3.6 to 5 miles. Whether that beats a 7p overnight rate is arithmetic.
Read the guide →What MCS certification actually buys you on a heat pump job
The gate on the £7,500 grant, the design standard behind your running costs, and the noise sign-off.
Read the guide →Why the best export rates always carry conditions
The top export rates are acquisition offers. Here is how to price the condition.
Read the guide →HIES explained: what the badge actually protects, and when
What HIES protects: deposits up to 25 percent capped at 5,000 pounds, and your workmanship guarantee.
Read the guide →Get my free quote
Takes about two minutes. We call or text within one working day to book your free 30-minute video design call at a time that suits you. We design it around your roof and your numbers, and our MCS-certified, fully insured installation teams install it.