Carmarthenshire
Solar panels in Llanelli, priced before anyone visits.
Twelve panels (6.36 kWp) here make about 6,770 kWh a year for £6,360 installed, designed around your roof on a free 30-minute video call.
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- Free 30-minute video design call
- Priced before anyone visits
- Installed by our MCS-certified, fully insured teams
Sunlight in Llanelli, in numbers
Llanelli's best month is May, at 134.2 kWh per kWp; December manages 32.8. Over the year that comes to 1,064 kWh per kWp, 14% above our Carmarthenshire county estimate.
Generation per kWp, month by month
Show the monthly figures
| Month | kWh/kWp |
|---|---|
| January | 37 |
| February | 58.2 |
| March | 93.5 |
| April | 125 |
| May | 134 |
| June | 132 |
| July | 130 |
| August | 115 |
| September | 97.6 |
| October | 64.7 |
| November | 43.5 |
| December | 32.8 |
Source: PVGIS v5.2 (European Commission JRC), SARAH3 database, 1 kWp, 14% system loss, 35 degree pitch, due south, checked September 2026.
Against Great Britain as a whole: Llanelli makes 1,064 kWh per kWp a year, and the mean of our 85 county PVGIS estimates (our GB average) is 925, so Llanelli is 15% above it.
How Llanelli compares
Among the places we publish figures for, Llanelli is one of 3 Carmarthenshire towns we track, and it ranks 1st of 3 for solar yield. It is a medium town in the House of Commons Library classification, with 42,685 residents, and its roofs see 2.91 peak sun hours a day across the year. That drives the standard 12 panel model to 6,767 kWh of generation, of which around 5,830 kWh is exported at 12p for £700 a year, with £247 saved on electricity you would otherwise buy at 26.32p.
Treat these as calibration rather than a quote. The calculator below runs the same model, opened on Llanelli'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.
Planning applications here go through Carmarthenshire; nationally, the House of Commons Library classes Llanelli as a medium town.
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.
Generation is modelled from PVGIS satellite data for Llanelli's own coordinates (51.68399, -4.14172), using the same 26.32p/kWh import value and £1,000 per kWp installed pricing as every Clearline estimate; the methodology is on our help page.
The network operator for Llanelli
National Grid Electricity Distribution (NGED) owns and runs the local electricity network in Llanelli, as part of its South Wales licence area.
For a typical home the paperwork is light: a system of up to 3.68kW per phase goes through G98, which means NGED is notified within 28 days of switch-on rather than asked beforehand.
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 Llanelli
A heat pump in Llanelli
Heating demand peaks when solar is weakest. In Llanelli, a 12-panel system makes about 210 kWh in December and 240 kWh in January, a fraction of its 850 kWh in May, which is why a heat pump here is costed on its tariff first.
The Boiler Upgrade Scheme, open in England and Wales, takes £7,500 off an air source or ground source heat pump, or £2,500 off an air-to-air unit. Homes on oil or LPG with no mains gas get £1,500 more until March 2027 (gov.uk, checked 28 September 2026).
Charging an EV in Llanelli
Summer is where a car earns its place. In May, 12 panels in Llanelli make about 850 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.
The calculator above includes a 7.4kW smart charger from £1,100 installed. Renters and flat owners with off-street parking can claim 75% of a chargepoint's cost, up to £500 per socket, until 31 March 2027 (gov.uk, checked 28 September 2026).
What the named kit costs, installed
Every system is designed around your roof on the free call before anything is fitted.
Solar panel servicing and repair in Llanelli
If a system in Llanelli is underperforming, start with the guides below: repair benchmarks, service scope, and the inverter question.
Solar in Llanelli: your questions answered
How much energy would 12 solar panels make in Llanelli?
Llanelli averages 2.91 peak sun hours a day, which PVGIS turns into 1,064 kWh per kWp a year. On a 12-panel, 6.36 kWp roof that is about 6,770 kWh, 69% of it between April and September.
What does a typical solar system cost in Llanelli?
Solar is priced at £1,000 per kWp installed wherever you live, so a 12-panel, 6.36 kWp system costs £6,360 in Llanelli, exactly as it would anywhere else, before any battery. Location changes what the system makes, not what it costs: here that is about 6,770 kWh a year. The final figure comes from your roof on the design call.
Who is the network operator in Llanelli, 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 Llanelli?
Around £700 a year at 12p per kWh, for the roughly 5,830 kWh a 12-panel system in Llanelli 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 Llanelli in the winter months?
December is the weakest month in Llanelli: about 210 kWh from 12 panels, against 850 kWh in May. The panels still generate on bright winter days; they just cover a smaller share of what the house uses.
How Llanelli 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 Llanelli |
|---|---|---|
| Llanelli | 1,064 | this town |
| Gorseinon | 1,040 | −24 kWh |
| Gowerton | 1,063 | −1 kWh |
| Swansea | 1,023 | −41 kWh |
| Ammanford | 969 | −95 kWh |
| Clydach | 981 | −83 kWh |
| Carmarthen | 980 | −84 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 Llanelli: Solar panels in Llanelli 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 Llanelli
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 →Three phase and EV charging: what actually changes
Three phase buys 22kW charging. Most cars cannot use it, and load balancing usually solves the real problem.
Read the guide →Are heat pumps worth it? The real 2026 numbers
Electricity costs 3.3x gas per kWh. A heat pump is about 3x as efficient. The numbers nearly cancel out.
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 →What MCS certification actually is, and why your export payments depend on it
The badge that decides whether your solar earns export payments. It cannot be added later.
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.