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Solar panel cost in Greenwich (SE18)

See realistic solar installation costs, savings and payback for SE18 (Greenwich) 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
10.9 years
After this, it's pure profit
Upfront Cost
£5,481
What you pay to get started
Annual Benefit
£501
What you save every year
Profit Over 25 Years
£7,056
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 1011 kWh/kW — 20 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 1011 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)
1011 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: £836, Upfront: £9,134, Break-even: 10.9 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2021 kWh 809 kWh 1213 kWh £213 £121 £334 £3,654 10.9 yrs £3,033
3 kW 3032 kWh 1213 kWh 1819 kWh £320 £182 £501 £5,481 10.9 yrs £4,549
4 kW 4043 kWh 1617 kWh 2426 kWh £426 £243 £669 £7,307 10.9 yrs £6,065
5 kW 5053 kWh 2021 kWh 3032 kWh £533 £303 £836 £9,134 10.9 yrs £7,582
6 kW 6064 kWh 2426 kWh 3638 kWh £639 £364 £1,003 £10,961 10.9 yrs £9,098
7 kW 7074 kWh 2830 kWh 4245 kWh £746 £424 £1,170 £12,788 10.9 yrs £10,614
8 kW 8085 kWh 3234 kWh 4851 kWh £852 £485 £1,337 £14,615 10.9 yrs £12,131

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: £1,001, Upfront: £11,234, Break-even: 11.2 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2021 kWh 1213 kWh 809 kWh £320 £81 £400 £5,754 14.4 yrs £2,255
3 kW 3032 kWh 1819 kWh 1213 kWh £479 £121 £601 £7,581 12.6 yrs £4,432
4 kW 4043 kWh 2426 kWh 1617 kWh £639 £162 £801 £9,407 11.7 yrs £6,609
5 kW 5053 kWh 3032 kWh 2021 kWh £799 £202 £1,001 £11,234 11.2 yrs £8,787
6 kW 6064 kWh 3638 kWh 2426 kWh £959 £243 £1,201 £13,061 10.9 yrs £10,964
7 kW 7074 kWh 4245 kWh 2830 kWh £1,118 £283 £1,401 £14,888 10.6 yrs £13,141
8 kW 8085 kWh 4851 kWh 3234 kWh £1,278 £323 £1,602 £16,715 10.4 yrs £15,319

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: £1,084, Upfront: £12,634, 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 2021 kWh 1415 kWh 606 kWh £373 £61 £433 £7,154 16.5 yrs £1,516
3 kW 3032 kWh 2122 kWh 910 kWh £559 £91 £650 £8,981 13.8 yrs £4,023
4 kW 4043 kWh 2830 kWh 1213 kWh £746 £121 £867 £10,807 12.5 yrs £6,531
5 kW 5053 kWh 3537 kWh 1516 kWh £932 £152 £1,084 £12,634 11.7 yrs £9,039
6 kW 6064 kWh 4245 kWh 1819 kWh £1,118 £182 £1,300 £14,461 11.1 yrs £11,547
7 kW 7074 kWh 4952 kWh 2122 kWh £1,305 £212 £1,517 £16,288 10.7 yrs £14,055
8 kW 8085 kWh 5660 kWh 2426 kWh £1,491 £243 £1,734 £18,115 10.4 yrs £16,562

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: £1,108, Upfront: £14,384, 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 2021 kWh 1476 kWh 546 kWh £389 £55 £443 £8,904 20.1 yrs £-36
3 kW 3032 kWh 2213 kWh 819 kWh £583 £82 £665 £10,731 16.1 yrs £2,571
4 kW 4043 kWh 2951 kWh 1091 kWh £778 £109 £887 £12,557 14.2 yrs £5,178
5 kW 5053 kWh 3689 kWh 1364 kWh £972 £136 £1,108 £14,384 13.0 yrs £7,785
6 kW 6064 kWh 4427 kWh 1637 kWh £1,166 £164 £1,330 £16,211 12.2 yrs £10,392
7 kW 7074 kWh 5164 kWh 1910 kWh £1,361 £191 £1,552 £18,038 11.6 yrs £12,999
8 kW 8085 kWh 5902 kWh 2183 kWh £1,555 £218 £1,774 £19,865 11.2 yrs £15,606

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: £1,125, Upfront: £16,134, Break-even: 14.3 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2021 kWh 1516 kWh 505 kWh £399 £51 £450 £10,654 23.7 yrs £-1,654
3 kW 3032 kWh 2274 kWh 758 kWh £599 £76 £675 £12,481 18.5 yrs £1,019
4 kW 4043 kWh 3032 kWh 1011 kWh £799 £101 £900 £14,307 15.9 yrs £3,692
5 kW 5053 kWh 3790 kWh 1263 kWh £999 £126 £1,125 £16,134 14.3 yrs £6,365
6 kW 6064 kWh 4548 kWh 1516 kWh £1,198 £152 £1,350 £17,961 13.3 yrs £9,038
7 kW 7074 kWh 5306 kWh 1769 kWh £1,398 £177 £1,575 £19,788 12.6 yrs £11,711
8 kW 8085 kWh 6064 kWh 2021 kWh £1,598 £202 £1,800 £21,615 12.0 yrs £14,384

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: £1,141, Upfront: £18,584, Break-even: 16.3 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2021 kWh 1556 kWh 465 kWh £410 £46 £457 £13,104 28.7 yrs £-3,972
3 kW 3032 kWh 2335 kWh 697 kWh £615 £70 £685 £14,931 21.8 yrs £-1,233
4 kW 4043 kWh 3113 kWh 930 kWh £820 £93 £913 £16,757 18.4 yrs £1,507
5 kW 5053 kWh 3891 kWh 1162 kWh £1,025 £116 £1,141 £18,584 16.3 yrs £4,246
6 kW 6064 kWh 4669 kWh 1395 kWh £1,230 £139 £1,370 £20,411 14.9 yrs £6,985
7 kW 7074 kWh 5447 kWh 1627 kWh £1,435 £163 £1,598 £22,238 13.9 yrs £9,724
8 kW 8085 kWh 6226 kWh 1860 kWh £1,640 £186 £1,826 £24,065 13.2 yrs £12,463

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 Greenwich

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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Check what MCS certification means

Understand DNO, G98 and G99 export limits

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This is a practical sanity-check request, not an instant quote promise. The Blue Ape quote route above remains available if you already want installer introductions.

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Insights for SE18

Figures below are tailored to SE18 — click through for full league tables.

Big-Roof Britain Rank #2063 of 2182
4.0 kWp (UK avg 5.1 kWp)
~8 panels (≈430 W)
Solar Payback Index Rank #535 of 2996
9.7 years (UK avg 10.8 years)
~£836 /yr • £8,139 upfront
Standing-Charge Drag Rank #402 of 2996
19.5% (UK avg 26.6%) drag on savings
£163 fixed • ~£836 /yr value
Aspect Penalty View ranking →
East −21.7% West −20.1%
Typical output loss versus a south-facing roof (lower is better)

Seasonal solar output in SE18

Monthly generation per kilowatt of solar panels

kWh 40 Jan 52 Feb 85 Mar 112 Apr 119 May 121 Jun 124 Jul 111 Aug 95 Sep 68 Oct 47 Nov 36 Dec
Best month Worst month Winter (Dec–Feb) Other months

Winter output: 50.7% 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 43 kWh per month; the average month produces around 84 kWh. So a typical 4 kW home system would generate roughly 171 kWh in winter, or 337 kWh in an average month.

Your Area at a Glance

Your Electricity Rate
26.35p/kWh
Daily Fixed Charge
44.78p/day
Local Sunshine
1011kWh/kW
A 1 kW system generates ~1011 kWh per year. A typical home uses ~2,700 kWh per year.
Typical System Size
3.0kW
For houses & bungalows 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: 31% • Flats: 65% • Bungalows: 0% Based on 25,260 properties

Coverage

Greenwich (100%)

Areas Covered

Woolwich Arsenal, Plumstead & Glyndon, Shooters Hill, Woolwich Common, Plumstead Common, Woolwich Dockyard, West Thamesmead, Charlton Hornfair + 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 London

SE7 (Greenwich)
≈2.6 km away
Local sunshine: ~1,006 kWh/kWp · -0% vs SE18
SE28 (Greenwich)
≈2.8 km away
Local sunshine: ~1,010 kWh/kWp · -0% vs SE18
SE2 (Greenwich)
≈3.3 km away
Local sunshine: ~1,016 kWh/kWp · +1% vs SE18
DA16 (Bexley)
≈3.9 km away
Local sunshine: ~1,016 kWh/kWp · +1% vs SE18
E6 (Newham)
≈4.2 km away
Local sunshine: ~1,004 kWh/kWp · -1% vs SE18
E16 (Newham)
≈4.2 km away
Local sunshine: ~1,004 kWh/kWp · -1% vs SE18

Similar sunshine across the UK

BA12 (Wiltshire)
~1,011 kWh/kWp · -0% vs SE18
CF72 (Rhondda Cynon Taf)
~1,011 kWh/kWp · -0% vs SE18
BR5 (Bromley)
~1,011 kWh/kWp · -0% vs SE18