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Solar panel cost in Hounslow (TW8)

See realistic solar installation costs, savings and payback for TW8 (Hounslow) 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
£493
What you save every year
Profit Over 25 Years
£6,839
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 Southern, the current unit rate is 26.42p/kWh with a 49.70p/day standing charge. Your postcode’s south-facing sunshine yield is 991 kWh/kW — 10 below the regional median (1001).

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 991 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
49.7p/day
Sunshine yield (south)
991 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: £821, 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 1983 kWh 793 kWh 1190 kWh £210 £119 £329 £3,654 11.1 yrs £2,917
3 kW 2974 kWh 1190 kWh 1785 kWh £314 £178 £493 £5,481 11.1 yrs £4,375
4 kW 3966 kWh 1586 kWh 2380 kWh £419 £238 £657 £7,307 11.1 yrs £5,834
5 kW 4957 kWh 1983 kWh 2974 kWh £524 £297 £821 £9,134 11.1 yrs £7,292
6 kW 5949 kWh 2380 kWh 3569 kWh £629 £357 £986 £10,961 11.1 yrs £8,751
7 kW 6940 kWh 2776 kWh 4164 kWh £733 £416 £1,150 £12,788 11.1 yrs £10,209
8 kW 7932 kWh 3173 kWh 4759 kWh £838 £476 £1,314 £14,615 11.1 yrs £11,668

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: £984, 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 1983 kWh 1190 kWh 793 kWh £314 £79 £394 £5,754 14.6 yrs £2,119
3 kW 2974 kWh 1785 kWh 1190 kWh £472 £119 £590 £7,581 12.8 yrs £4,229
4 kW 3966 kWh 2380 kWh 1586 kWh £629 £159 £787 £9,407 11.9 yrs £6,339
5 kW 4957 kWh 2974 kWh 1983 kWh £786 £198 £984 £11,234 11.4 yrs £8,448
6 kW 5949 kWh 3569 kWh 2380 kWh £943 £238 £1,181 £13,061 11.1 yrs £10,558
7 kW 6940 kWh 4164 kWh 2776 kWh £1,100 £278 £1,378 £14,888 10.8 yrs £12,668
8 kW 7932 kWh 4759 kWh 3173 kWh £1,257 £317 £1,575 £16,715 10.6 yrs £14,778

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: £1,066, Upfront: £12,634, Break-even: 11.9 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1983 kWh 1388 kWh 595 kWh £367 £59 £426 £7,154 16.8 yrs £1,371
3 kW 2974 kWh 2082 kWh 892 kWh £550 £89 £639 £8,981 14.0 yrs £3,806
4 kW 3966 kWh 2776 kWh 1190 kWh £733 £119 £852 £10,807 12.7 yrs £6,241
5 kW 4957 kWh 3470 kWh 1487 kWh £917 £149 £1,066 £12,634 11.9 yrs £8,676
6 kW 5949 kWh 4164 kWh 1785 kWh £1,100 £178 £1,279 £14,461 11.3 yrs £11,112
7 kW 6940 kWh 4858 kWh 2082 kWh £1,284 £208 £1,492 £16,288 10.9 yrs £13,547
8 kW 7932 kWh 5552 kWh 2380 kWh £1,467 £238 £1,705 £18,115 10.6 yrs £15,982

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: £1,090, 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 1983 kWh 1448 kWh 535 kWh £382 £54 £436 £8,904 20.4 yrs £-184
3 kW 2974 kWh 2171 kWh 803 kWh £574 £80 £654 £10,731 16.4 yrs £2,349
4 kW 3966 kWh 2895 kWh 1071 kWh £765 £107 £872 £12,557 14.4 yrs £4,882
5 kW 4957 kWh 3619 kWh 1338 kWh £956 £134 £1,090 £14,384 13.2 yrs £7,415
6 kW 5949 kWh 4343 kWh 1606 kWh £1,147 £161 £1,308 £16,211 12.4 yrs £9,948
7 kW 6940 kWh 5066 kWh 1874 kWh £1,339 £187 £1,526 £18,038 11.8 yrs £12,481
8 kW 7932 kWh 5790 kWh 2142 kWh £1,530 £214 £1,744 £19,865 11.4 yrs £15,014

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: £1,106, 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 1983 kWh 1487 kWh 496 kWh £393 £50 £442 £10,654 24.1 yrs £-1,804
3 kW 2974 kWh 2231 kWh 744 kWh £589 £74 £664 £12,481 18.8 yrs £794
4 kW 3966 kWh 2974 kWh 991 kWh £786 £99 £885 £14,307 16.2 yrs £3,392
5 kW 4957 kWh 3718 kWh 1239 kWh £982 £124 £1,106 £16,134 14.6 yrs £5,990
6 kW 5949 kWh 4462 kWh 1487 kWh £1,179 £149 £1,327 £17,961 13.5 yrs £8,589
7 kW 6940 kWh 5205 kWh 1735 kWh £1,375 £174 £1,549 £19,788 12.8 yrs £11,187
8 kW 7932 kWh 5949 kWh 1983 kWh £1,572 £198 £1,770 £21,615 12.2 yrs £13,785

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: £1,123, Upfront: £18,584, Break-even: 16.6 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1983 kWh 1527 kWh 456 kWh £403 £46 £449 £13,104 29.2 yrs £-4,124
3 kW 2974 kWh 2290 kWh 684 kWh £605 £68 £674 £14,931 22.2 yrs £-1,460
4 kW 3966 kWh 3054 kWh 912 kWh £807 £91 £898 £16,757 18.7 yrs £1,203
5 kW 4957 kWh 3817 kWh 1140 kWh £1,008 £114 £1,123 £18,584 16.6 yrs £3,866
6 kW 5949 kWh 4581 kWh 1368 kWh £1,210 £137 £1,347 £20,411 15.2 yrs £6,529
7 kW 6940 kWh 5344 kWh 1596 kWh £1,412 £160 £1,572 £22,238 14.2 yrs £9,192
8 kW 7932 kWh 6107 kWh 1824 kWh £1,614 £182 £1,796 £24,065 13.4 yrs £11,856

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 Hounslow

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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Insights for TW8

Figures below are tailored to TW8 — click through for full league tables.

Solar Payback Index Rank #1008 of 2996
9.9 years (UK avg 10.8 years)
~£821 /yr • £8,139 upfront
Standing-Charge Drag Rank #907 of 2996
22.0% (UK avg 26.6%) drag on savings
£181 fixed • ~£821 /yr value
Aspect Penalty View ranking →
East −21.8% West −19.3%
Typical output loss versus a south-facing roof (lower is better)

Seasonal solar output in TW8

Monthly generation per kilowatt of solar panels

kWh 39 Jan 52 Feb 84 Mar 111 Apr 117 May 120 Jun 121 Jul 107 Aug 92 Sep 67 Oct 46 Nov 35 Dec
Best month Worst month Winter (Dec–Feb) Other months

Winter output: 50.6% 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 167 kWh in winter, or 330 kWh in an average month.

Your Area at a Glance

Your Electricity Rate
26.42p/kWh
Daily Fixed Charge
49.70p/day
Local Sunshine
991kWh/kW
A 1 kW system generates ~991 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: 14% • Flats: 82% • Bungalows: 0% Based on 10,351 properties

Coverage

Hounslow (100%)

Areas Covered

Syon & Brentford Lock, Brentford West, Brentford East, Osterley & Spring Grove, Chiswick Riverside, Chiswick Gunnersbury, Northfield

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 Southern

TW7 (Hounslow)
≈1.9 km away
Local sunshine: ~991 kWh/kWp · -0% vs TW8
W5 (Ealing)
≈2.7 km away
Local sunshine: ~990 kWh/kWp · -0% vs TW8
W7 (Ealing)
≈2.8 km away
Local sunshine: ~992 kWh/kWp · +0% vs TW8
W13 (Ealing)
≈3.3 km away
Local sunshine: ~991 kWh/kWp · -0% vs TW8
W4 (Hounslow)
≈3.3 km away
Local sunshine: ~991 kWh/kWp · -0% vs TW8
W3 (Ealing)
≈3.4 km away
Local sunshine: ~991 kWh/kWp · -0% vs TW8

Similar sunshine across the UK

HA3 (Harrow)
~992 kWh/kWp · +0% vs TW8
HA1 (Harrow)
~991 kWh/kWp · -0% vs TW8
E14 (Tower Hamlets)
~991 kWh/kWp · -0% vs TW8