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Solar panel cost in Swansea (SA3)

See realistic solar installation costs, savings and payback for SA3 (Swansea) in under a minute using official UK data. Start with the calculator, then get a no-obligation quote from an MCS-certified installer. You can also ask the SolarByPostcode assistant to sanity-check your roof, bills and plans.

Solar Calculator

Change the settings below to see how costs and savings work for your situation.

System Size

Roof Direction

Battery Storage

Export Value

Your Numbers

Break-even
9.4 years
After this, it's pure profit
Upfront Cost
£9,767
What you pay to get started
Annual Benefit
£1,036
What you save every year
Profit Over 25 Years
£16,123
After paying itself off, you're this much ahead

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How we calculate this

Solar generation: Based on typical south-facing roof at 35° angle. We account for weather, dirt, and system losses (14%).

How much you'll use directly:

  • Without battery: You'll use about 40% of what you generate. The rest gets sold back to the grid.
  • With 5 kWh battery: You'll use about 70% (battery stores extra for evening use).
  • With 10 kWh battery: You'll use about 75% (more storage means less exported).
  • Panel-only payback: The official cost per kW is lower above 4 kW, so a 5–6 kW system can pay back a little faster than a 3–4 kW system on otherwise identical assumptions.
  • Battery & payback: Batteries raise self-use and cut bills, but added hardware cost often lengthens break-even at typical UK rates.
  • When a battery can still make sense:
    • Evening-heavy usage patterns
    • Time-of-use tariffs / cheap night rates
    • Low export rate vs. high unit rate
    • Heat pump or EV charging synergy
    • Optional backup/resilience (system-dependent)
    • Lower evening-hour CO₂ vs. grid

Panel costs: Uses March 2026 TIC mean installation costs: £1,827/kW up to 4 kW and £1,628/kW above 4 kW.

Other costs: Battery prices are modelled at £700 per kWh. Export tariffs vary by supplier (usually 5–15p per kWh).

Grid connection: Systems up to about 3.7 kW typically need just a notification (G98). Larger systems may need permission (G99).

These are typical values based on average usage patterns. Your actual results will vary based on your roof, shading, and how you use electricity.

Your area in context

In South Wales, the current unit rate is 26.33p/kWh with a 57.84p/day standing charge. Your postcode’s south-facing sunshine yield is 1044 kWh/kW — 76 above the regional median (968).

Read the full story

A typical roof here lands around 6.0 kW, with most eligible homes comfortably fitting within 3–6 kW. Each kilowatt of panels produces roughly 1044 kWh per year on a south-facing roof. We value self-used electricity at 26.3p and exported surplus at a baseline 10p via SEG. Use the calculator above for your exact tariff.

Unit rate
26.3p/kWh
Standing charge
57.8p/day
Sunshine yield (south)
1044 kWh/kW
Export price (baseline)
10p/kWh

Browse the scenarios below. Each battery size has its own expand — open the one that matches your plan (or just explore). For each system size (2–8 kW) we show annual output, how much you use directly, what gets exported, annual benefit, upfront cost, break-even, and a 20-year net. Negative numbers are possible — that’s the honest trade-off when adding more battery than your usage profile justifies.

No battery 5 kW example → Annual benefit: £863, Upfront: £8,139, Break-even: 9.4 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2088 kWh 835 kWh 1253 kWh £220 £125 £345 £3,256 9.4 yrs £3,648
3 kW 3132 kWh 1253 kWh 1879 kWh £330 £188 £518 £4,883 9.4 yrs £5,473
4 kW 4176 kWh 1670 kWh 2506 kWh £440 £251 £690 £6,511 9.4 yrs £7,297
5 kW 5220 kWh 2088 kWh 3132 kWh £550 £313 £863 £8,139 9.4 yrs £9,121
6 kW 6264 kWh 2506 kWh 3758 kWh £660 £376 £1,036 £9,767 9.4 yrs £10,945
7 kW 7308 kWh 2923 kWh 4385 kWh £770 £438 £1,208 £11,394 9.4 yrs £12,769
8 kW 8352 kWh 3341 kWh 5011 kWh £880 £501 £1,381 £13,022 9.4 yrs £14,594

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 1,628, battery £/kWh = 700.

3 kWh battery 5 kW example → Annual benefit: £1,033, Upfront: £10,239, Break-even: 9.9 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2088 kWh 1253 kWh 835 kWh £330 £84 £413 £5,356 13.0 yrs £2,912
3 kW 3132 kWh 1879 kWh 1253 kWh £495 £125 £620 £6,983 11.3 yrs £5,418
4 kW 4176 kWh 2506 kWh 1670 kWh £660 £167 £827 £8,611 10.4 yrs £7,925
5 kW 5220 kWh 3132 kWh 2088 kWh £825 £209 £1,033 £10,239 9.9 yrs £10,431
6 kW 6264 kWh 3758 kWh 2506 kWh £990 £251 £1,240 £11,867 9.6 yrs £12,937
7 kW 7308 kWh 4385 kWh 2923 kWh £1,155 £292 £1,447 £13,494 9.3 yrs £15,443
8 kW 8352 kWh 5011 kWh 3341 kWh £1,319 £334 £1,654 £15,122 9.1 yrs £17,949

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 1,628, battery £/kWh = 700.

5 kWh battery 5 kW example → Annual benefit: £1,119, Upfront: £11,639, Break-even: 10.4 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2088 kWh 1462 kWh 626 kWh £385 £63 £447 £6,756 15.1 yrs £2,194
3 kW 3132 kWh 2192 kWh 940 kWh £577 £94 £671 £8,383 12.5 yrs £5,041
4 kW 4176 kWh 2923 kWh 1253 kWh £770 £125 £895 £10,011 11.2 yrs £7,888
5 kW 5220 kWh 3654 kWh 1566 kWh £962 £157 £1,119 £11,639 10.4 yrs £10,736
6 kW 6264 kWh 4385 kWh 1879 kWh £1,155 £188 £1,342 £13,267 9.9 yrs £13,583
7 kW 7308 kWh 5116 kWh 2192 kWh £1,347 £219 £1,566 £14,894 9.5 yrs £16,430
8 kW 8352 kWh 5847 kWh 2506 kWh £1,539 £251 £1,790 £16,522 9.2 yrs £19,277

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 1,628, battery £/kWh = 700.

7.5 kWh battery 5 kW example → Annual benefit: £1,144, Upfront: £13,389, Break-even: 11.7 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2088 kWh 1524 kWh 564 kWh £401 £56 £458 £8,506 18.6 yrs £649
3 kW 3132 kWh 2286 kWh 846 kWh £602 £85 £687 £10,133 14.8 yrs £3,598
4 kW 4176 kWh 3049 kWh 1128 kWh £803 £113 £915 £11,761 12.8 yrs £6,548
5 kW 5220 kWh 3811 kWh 1409 kWh £1,003 £141 £1,144 £13,389 11.7 yrs £9,497
6 kW 6264 kWh 4573 kWh 1691 kWh £1,204 £169 £1,373 £15,017 10.9 yrs £12,446
7 kW 7308 kWh 5335 kWh 1973 kWh £1,405 £197 £1,602 £16,644 10.4 yrs £15,396
8 kW 8352 kWh 6097 kWh 2255 kWh £1,605 £226 £1,831 £18,272 10.0 yrs £18,345

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 1,628, battery £/kWh = 700.

10 kWh battery 5 kW example → Annual benefit: £1,161, Upfront: £15,139, Break-even: 13.0 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2088 kWh 1566 kWh 522 kWh £412 £52 £465 £10,256 22.1 yrs £-965
3 kW 3132 kWh 2349 kWh 783 kWh £619 £78 £697 £11,883 17.1 yrs £2,053
4 kW 4176 kWh 3132 kWh 1044 kWh £825 £104 £929 £13,511 14.5 yrs £5,070
5 kW 5220 kWh 3915 kWh 1305 kWh £1,031 £131 £1,161 £15,139 13.0 yrs £8,088
6 kW 6264 kWh 4698 kWh 1566 kWh £1,237 £157 £1,394 £16,767 12.0 yrs £11,106
7 kW 7308 kWh 5481 kWh 1827 kWh £1,443 £183 £1,626 £18,394 11.3 yrs £14,123
8 kW 8352 kWh 6264 kWh 2088 kWh £1,649 £209 £1,858 £20,022 10.8 yrs £17,141

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 1,628, battery £/kWh = 700.

13.5 kWh battery 5 kW example → Annual benefit: £1,178, Upfront: £17,589, Break-even: 14.9 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2088 kWh 1608 kWh 480 kWh £423 £48 £471 £12,706 27.0 yrs £-3,278
3 kW 3132 kWh 2412 kWh 720 kWh £635 £72 £707 £14,333 20.3 yrs £-193
4 kW 4176 kWh 3216 kWh 960 kWh £847 £96 £943 £15,961 16.9 yrs £2,893
5 kW 5220 kWh 4019 kWh 1201 kWh £1,058 £120 £1,178 £17,589 14.9 yrs £5,979
6 kW 6264 kWh 4823 kWh 1441 kWh £1,270 £144 £1,414 £19,217 13.6 yrs £9,065
7 kW 7308 kWh 5627 kWh 1681 kWh £1,482 £168 £1,650 £20,844 12.6 yrs £12,151
8 kW 8352 kWh 6431 kWh 1921 kWh £1,693 £192 £1,885 £22,472 11.9 yrs £15,236

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 1,628, battery £/kWh = 700.

Figures are illustrative and use the same method as the calculator above. For exact results, adjust your roof direction, tariff, and usage in the calculator.

Before you request quotes in Swansea

Use the numbers above to sanity-check installer quotes. The main things to compare are system size, battery assumptions, payback claims, MCS certification, DNO paperwork and export assumptions.

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Understand DNO, G98 and G99 export limits

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Insights for SA3

Figures below are tailored to SA3 — click through for full league tables.

Big-Roof Britain Rank #156 of 2182
6.3 kWp (UK avg 5.1 kWp)
~13 panels (≈430 W)
Solar Payback Index Rank #244 of 2996
9.4 years (UK avg 10.8 years)
~£1,036 /yr • £9,767 upfront
Standing-Charge Drag Rank #647 of 2996
20.4% (UK avg 26.6%) drag on savings
£211 fixed • ~£1,036 /yr value
Aspect Penalty View ranking →
East −19.8% West −22.5%
Typical output loss versus a south-facing roof (lower is better)

Seasonal solar output in SA3

Monthly generation per kilowatt of solar panels

kWh 36 Jan 55 Feb 90 Mar 123 Apr 133 May 131 Jun 128 Jul 115 Aug 95 Sep 64 Oct 41 Nov 32 Dec
Best month Worst month Winter (Dec–Feb) Other months

Winter output: 47.2% of an average month (Dec–Feb)

Best / worst month: May / Dec

These figures show output per kilowatt (kW) of panels installed. In winter, a 1 kW system here produces about 41 kWh per month; the average month produces around 87 kWh. So a typical 4 kW home system would generate roughly 164 kWh in winter, or 348 kWh in an average month.

Your Area at a Glance

Your Electricity Rate
26.33p/kWh
Daily Fixed Charge
57.84p/day
Local Sunshine
1044kWh/kW
A 1 kW system generates ~1044 kWh per year. A typical home uses ~2,700 kWh per year.
Typical System Size
6.0kW
For houses & bungalows in this area

Local Property Data

Property Types

Houses: 67% • Flats: 16% • Bungalows: 15% Based on 6,516 properties

Coverage

Swansea (100%)

Areas Covered

Mumbles, West Cross, Gower, Bishopston, Mayals, Pennard, Llansamlet, Uplands + 2 more

Data Sources & Assumptions

Solar yield: PVGIS (EU Joint Research Centre), January 2025 data

Electricity rates: Ofgem price cap, Q3 2026

Installation costs: DESNZ/MCS data, March 2026 (TIC)

Property data: EPC open data (Open Government Licence), aggregated

All estimates are typical values. Actual results vary based on your specific situation, roof characteristics, and usage patterns.

Compare nearby areas

Nearby in South Wales

SA2 (Swansea)
≈5.0 km away
Local sunshine: ~988 kWh/kWp · -5% vs SA3
SA1 (Swansea)
≈7.0 km away
Local sunshine: ~982 kWh/kWp · -6% vs SA3
SA5 (Swansea)
≈8.2 km away
Local sunshine: ~989 kWh/kWp · -5% vs SA3
SA80 (Swansea)
≈9.8 km away
Local sunshine: ~982 kWh/kWp · -6% vs SA3
SA4 (Swansea)
≈10.5 km away
Local sunshine: ~961 kWh/kWp · -8% vs SA3
SA99 (Swansea)
≈11.2 km away
Local sunshine: ~968 kWh/kWp · -7% vs SA3

Similar sunshine across the UK

ME13 (Swale)
~1,044 kWh/kWp · -0% vs SA3
ME15 (Maidstone)
~1,044 kWh/kWp · +0% vs SA3
TQ3 (Torbay)
~1,044 kWh/kWp · -0% vs SA3