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Solar panel cost in Wandsworth (SW15)

See realistic solar installation costs, savings and payback for SW15 (Wandsworth) 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
11.1 years
After this, it's pure profit
Upfront Cost
£5,481
What you pay to get started
Annual Benefit
£494
What you save every year
Profit Over 25 Years
£6,863
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 London, the current unit rate is 26.35p/kWh with a 44.78p/day standing charge. Your postcode’s south-facing sunshine yield is 995 kWh/kW — 4 above the regional median (991).

Read the full story

A typical roof here lands around 3.0 kW, with most eligible homes comfortably fitting within 3–6 kW. Each kilowatt of panels produces roughly 995 kWh per year on a south-facing roof. We value self-used electricity at 26.4p and exported surplus at a baseline 10p via SEG. Use the calculator above for your exact tariff.

Unit rate
26.4p/kWh
Standing charge
44.8p/day
Sunshine yield (south)
995 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: £823, Upfront: £9,134, Break-even: 11.1 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1990 kWh 796 kWh 1194 kWh £210 £119 £329 £3,654 11.1 yrs £2,930
3 kW 2985 kWh 1194 kWh 1791 kWh £315 £179 £494 £5,481 11.1 yrs £4,394
4 kW 3980 kWh 1592 kWh 2388 kWh £420 £239 £658 £7,307 11.1 yrs £5,859
5 kW 4975 kWh 1990 kWh 2985 kWh £524 £299 £823 £9,134 11.1 yrs £7,324
6 kW 5970 kWh 2388 kWh 3582 kWh £629 £358 £987 £10,961 11.1 yrs £8,789
7 kW 6965 kWh 2786 kWh 4179 kWh £734 £418 £1,152 £12,788 11.1 yrs £10,254
8 kW 7960 kWh 3184 kWh 4776 kWh £839 £478 £1,317 £14,615 11.1 yrs £11,719

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 1,827, battery £/kWh = 700.

3 kWh battery 5 kW example → Annual benefit: £986, Upfront: £11,234, Break-even: 11.4 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1990 kWh 1194 kWh 796 kWh £315 £80 £394 £5,754 14.6 yrs £2,131
3 kW 2985 kWh 1791 kWh 1194 kWh £472 £119 £591 £7,581 12.8 yrs £4,247
4 kW 3980 kWh 2388 kWh 1592 kWh £629 £159 £788 £9,407 11.9 yrs £6,362
5 kW 4975 kWh 2985 kWh 1990 kWh £787 £199 £986 £11,234 11.4 yrs £8,478
6 kW 5970 kWh 3582 kWh 2388 kWh £944 £239 £1,183 £13,061 11.0 yrs £10,594
7 kW 6965 kWh 4179 kWh 2786 kWh £1,101 £279 £1,380 £14,888 10.8 yrs £12,709
8 kW 7960 kWh 4776 kWh 3184 kWh £1,259 £318 £1,577 £16,715 10.6 yrs £14,825

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 1,827, battery £/kWh = 700.

5 kWh battery 5 kW example → Annual benefit: £1,067, Upfront: £12,634, Break-even: 11.8 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1990 kWh 1393 kWh 597 kWh £367 £60 £427 £7,154 16.8 yrs £1,382
3 kW 2985 kWh 2090 kWh 896 kWh £551 £90 £640 £8,981 14.0 yrs £3,823
4 kW 3980 kWh 2786 kWh 1194 kWh £734 £119 £854 £10,807 12.7 yrs £6,264
5 kW 4975 kWh 3483 kWh 1493 kWh £918 £149 £1,067 £12,634 11.8 yrs £8,705
6 kW 5970 kWh 4179 kWh 1791 kWh £1,101 £179 £1,280 £14,461 11.3 yrs £11,146
7 kW 6965 kWh 4876 kWh 2090 kWh £1,285 £209 £1,494 £16,288 10.9 yrs £13,587
8 kW 7960 kWh 5572 kWh 2388 kWh £1,468 £239 £1,707 £18,115 10.6 yrs £16,028

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 1,827, battery £/kWh = 700.

7.5 kWh battery 5 kW example → Annual benefit: £1,091, Upfront: £14,384, Break-even: 13.2 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1990 kWh 1453 kWh 537 kWh £383 £54 £437 £8,904 20.4 yrs £-173
3 kW 2985 kWh 2179 kWh 806 kWh £574 £81 £655 £10,731 16.4 yrs £2,366
4 kW 3980 kWh 2906 kWh 1075 kWh £766 £107 £873 £12,557 14.4 yrs £4,904
5 kW 4975 kWh 3632 kWh 1343 kWh £957 £134 £1,091 £14,384 13.2 yrs £7,443
6 kW 5970 kWh 4358 kWh 1612 kWh £1,148 £161 £1,310 £16,211 12.4 yrs £9,982
7 kW 6965 kWh 5085 kWh 1881 kWh £1,340 £188 £1,528 £18,038 11.8 yrs £12,520
8 kW 7960 kWh 5811 kWh 2149 kWh £1,531 £215 £1,746 £19,865 11.4 yrs £15,059

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 1,827, battery £/kWh = 700.

10 kWh battery 5 kW example → Annual benefit: £1,108, Upfront: £16,134, Break-even: 14.6 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1990 kWh 1493 kWh 498 kWh £393 £50 £443 £10,654 24.0 yrs £-1,793
3 kW 2985 kWh 2239 kWh 746 kWh £590 £75 £665 £12,481 18.8 yrs £811
4 kW 3980 kWh 2985 kWh 995 kWh £787 £100 £886 £14,307 16.1 yrs £3,415
5 kW 4975 kWh 3731 kWh 1244 kWh £983 £124 £1,108 £16,134 14.6 yrs £6,018
6 kW 5970 kWh 4478 kWh 1493 kWh £1,180 £149 £1,329 £17,961 13.5 yrs £8,622
7 kW 6965 kWh 5224 kWh 1741 kWh £1,377 £174 £1,551 £19,788 12.8 yrs £11,226
8 kW 7960 kWh 5970 kWh 1990 kWh £1,573 £199 £1,772 £21,615 12.2 yrs £13,829

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 1,827, battery £/kWh = 700.

13.5 kWh battery 5 kW example → Annual benefit: £1,124, Upfront: £18,584, Break-even: 16.5 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1990 kWh 1532 kWh 458 kWh £404 £46 £450 £13,104 29.1 yrs £-4,113
3 kW 2985 kWh 2299 kWh 687 kWh £606 £69 £674 £14,931 22.1 yrs £-1,444
4 kW 3980 kWh 3065 kWh 915 kWh £808 £92 £899 £16,757 18.6 yrs £1,225
5 kW 4975 kWh 3831 kWh 1144 kWh £1,009 £114 £1,124 £18,584 16.5 yrs £3,894
6 kW 5970 kWh 4597 kWh 1373 kWh £1,211 £137 £1,349 £20,411 15.1 yrs £6,562
7 kW 6965 kWh 5363 kWh 1602 kWh £1,413 £160 £1,573 £22,238 14.1 yrs £9,231
8 kW 7960 kWh 6130 kWh 1831 kWh £1,615 £183 £1,798 £24,065 13.4 yrs £11,900

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 1,827, 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 Wandsworth

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 SW15

Figures below are tailored to SW15 — click through for full league tables.

Big-Roof Britain Rank #1928 of 2182
4.2 kWp (UK avg 5.1 kWp)
~9 panels (≈430 W)
Solar Payback Index Rank #978 of 2996
9.9 years (UK avg 10.8 years)
~£987 /yr • £9,767 upfront
Standing-Charge Drag Rank #36 of 2996
16.5% (UK avg 26.6%) drag on savings
£163 fixed • ~£987 /yr value
Aspect Penalty View ranking →
East −22.1% West −19.5%
Typical output loss versus a south-facing roof (lower is better)

Seasonal solar output in SW15

Monthly generation per kilowatt of solar panels

kWh 40 Jan 52 Feb 85 Mar 111 Apr 117 May 119 Jun 121 Jul 107 Aug 93 Sep 68 Oct 47 Nov 36 Dec
Best month Worst month Winter (Dec–Feb) Other months

Winter output: 51.2% of an average month (Dec–Feb)

Best / worst month: Jul / Dec

These figures show output per kilowatt (kW) of panels installed. In winter, a 1 kW system here produces about 42 kWh per month; the average month produces around 83 kWh. So a typical 4 kW home system would generate roughly 170 kWh in winter, or 332 kWh in an average month.

Your Area at a Glance

Your Electricity Rate
26.35p/kWh
Daily Fixed Charge
44.78p/day
Local Sunshine
995kWh/kW
A 1 kW system generates ~995 kWh per year. A typical home uses ~2,700 kWh per year.
Typical System Size
3.0kW
For eligible homes in this area

⚠️ This area is predominantly flats. Many residents require freeholder approval for solar installations. System size shown reflects houses and bungalows only.

Local Property Data

Property Types

Houses: 24% • Flats: 67% • Bungalows: 1% Based on 18,400 properties

Coverage

Wandsworth (97%)|Kingston upon Thames (2%)|Richmond upon Thames (1%)

Areas Covered

West Putney, Roehampton, Thamesfield, East Putney, Coombe Hill, Mortlake & Barnes Common, West Hill, East Sheen

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 London

SW18 (Wandsworth)
≈2.3 km away
Local sunshine: ~992 kWh/kWp · -0% vs SW15
SW13 (Richmond upon Thames)
≈2.4 km away
Local sunshine: ~995 kWh/kWp · -0% vs SW15
SW6 (Hammersmith and Fulham)
≈2.5 km away
Local sunshine: ~992 kWh/kWp · -0% vs SW15
SW14 (Richmond upon Thames)
≈3.4 km away
Local sunshine: ~994 kWh/kWp · -0% vs SW15
SW10 (Kensington and Chelsea)
≈3.7 km away
Local sunshine: ~992 kWh/kWp · -0% vs SW15
W6 (Hammersmith and Fulham)
≈3.7 km away
Local sunshine: ~995 kWh/kWp · +0% vs SW15

Similar sunshine across the UK

MK16 (Milton Keynes)
~995 kWh/kWp · +0% vs SW15
NG31 (South Kesteven)
~995 kWh/kWp · +0% vs SW15
SM3 (Sutton)
~995 kWh/kWp · -0% vs SW15