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Solar Panels in TW8 (Hounslow)

See if solar pays off for you in Hounslow — price, savings and payback in under a minute (official UK data).

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
12.4 years
After this, it's pure profit
Upfront Cost
£6,104
What you pay to get started
Annual Benefit
£494
What you save every year
Profit Over 25 Years
£6,234
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: Bigger systems don’t shorten payback—cost and savings rise together per kW.
  • 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

Costs: Battery prices are typically £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 26.48p/kWh with a 44.62p/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 26.5p and exported surplus at a baseline 10p via SEG. Use the calculator above for your exact tariff.

Unit rate
26.5p/kWh
Standing charge
44.6p/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: £823, Upfront: £10,173, Break-even: 12.4 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1983 kWh 793 kWh 1190 kWh £210 £119 £329 £4,069 12.4 yrs £2,511
3 kW 2974 kWh 1190 kWh 1785 kWh £315 £178 £494 £6,104 12.4 yrs £3,767
4 kW 3966 kWh 1586 kWh 2380 kWh £420 £238 £658 £8,138 12.4 yrs £5,022
5 kW 4957 kWh 1983 kWh 2974 kWh £525 £297 £823 £10,173 12.4 yrs £6,278
6 kW 5949 kWh 2380 kWh 3569 kWh £630 £357 £987 £12,207 12.4 yrs £7,534
7 kW 6940 kWh 2776 kWh 4164 kWh £735 £416 £1,152 £14,242 12.4 yrs £8,789
8 kW 7932 kWh 3173 kWh 4759 kWh £840 £476 £1,316 £16,276 12.4 yrs £10,045

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 2,035, battery £/kWh = 700.

3 kWh battery 5 kW example → Annual benefit: £986, Upfront: £12,273, Break-even: 12.4 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 £315 £79 £394 £6,169 15.6 yrs £1,718
3 kW 2974 kWh 1785 kWh 1190 kWh £473 £119 £592 £8,204 13.9 yrs £3,627
4 kW 3966 kWh 2380 kWh 1586 kWh £630 £159 £789 £10,238 13.0 yrs £5,537
5 kW 4957 kWh 2974 kWh 1983 kWh £788 £198 £986 £12,273 12.4 yrs £7,446
6 kW 5949 kWh 3569 kWh 2380 kWh £945 £238 £1,183 £14,307 12.1 yrs £9,355
7 kW 6940 kWh 4164 kWh 2776 kWh £1,103 £278 £1,380 £16,342 11.8 yrs £11,264
8 kW 7932 kWh 4759 kWh 3173 kWh £1,260 £317 £1,577 £18,376 11.6 yrs £13,173

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 2,035, battery £/kWh = 700.

5 kWh battery 5 kW example → Annual benefit: £1,068, Upfront: £13,673, Break-even: 12.8 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 £368 £59 £427 £7,569 17.7 yrs £972
3 kW 2974 kWh 2082 kWh 892 kWh £551 £89 £641 £9,604 15.0 yrs £3,208
4 kW 3966 kWh 2776 kWh 1190 kWh £735 £119 £854 £11,638 13.6 yrs £5,444
5 kW 4957 kWh 3470 kWh 1487 kWh £919 £149 £1,068 £13,673 12.8 yrs £7,680
6 kW 5949 kWh 4164 kWh 1785 kWh £1,103 £178 £1,281 £15,707 12.3 yrs £9,916
7 kW 6940 kWh 4858 kWh 2082 kWh £1,286 £208 £1,495 £17,742 11.9 yrs £12,152
8 kW 7932 kWh 5552 kWh 2380 kWh £1,470 £238 £1,708 £19,776 11.6 yrs £14,388

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 2,035, battery £/kWh = 700.

7.5 kWh battery 5 kW example → Annual benefit: £1,092, Upfront: £15,423, Break-even: 14.1 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1983 kWh 1448 kWh 535 kWh £383 £54 £437 £9,319 21.3 yrs £-582
3 kW 2974 kWh 2171 kWh 803 kWh £575 £80 £655 £11,354 17.3 yrs £1,752
4 kW 3966 kWh 2895 kWh 1071 kWh £767 £107 £874 £13,388 15.3 yrs £4,086
5 kW 4957 kWh 3619 kWh 1338 kWh £958 £134 £1,092 £15,423 14.1 yrs £6,420
6 kW 5949 kWh 4343 kWh 1606 kWh £1,150 £161 £1,311 £17,457 13.3 yrs £8,754
7 kW 6940 kWh 5066 kWh 1874 kWh £1,342 £187 £1,529 £19,492 12.7 yrs £11,088
8 kW 7932 kWh 5790 kWh 2142 kWh £1,533 £214 £1,747 £21,526 12.3 yrs £13,422

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 2,035, battery £/kWh = 700.

10 kWh battery 5 kW example → Annual benefit: £1,108, Upfront: £17,173, Break-even: 15.5 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 £394 £50 £443 £11,069 25.0 yrs £-2,201
3 kW 2974 kWh 2231 kWh 744 kWh £591 £74 £665 £13,104 19.7 yrs £198
4 kW 3966 kWh 2974 kWh 991 kWh £788 £99 £887 £15,138 17.1 yrs £2,597
5 kW 4957 kWh 3718 kWh 1239 kWh £985 £124 £1,108 £17,173 15.5 yrs £4,997
6 kW 5949 kWh 4462 kWh 1487 kWh £1,181 £149 £1,330 £19,207 14.4 yrs £7,396
7 kW 6940 kWh 5205 kWh 1735 kWh £1,378 £174 £1,552 £21,242 13.7 yrs £9,795
8 kW 7932 kWh 5949 kWh 1983 kWh £1,575 £198 £1,774 £23,276 13.1 yrs £12,195

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 2,035, battery £/kWh = 700.

13.5 kWh battery 5 kW example → Annual benefit: £1,125, Upfront: £19,623, Break-even: 17.4 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1983 kWh 1527 kWh 456 kWh £404 £46 £450 £13,519 30.0 yrs £-4,521
3 kW 2974 kWh 2290 kWh 684 kWh £606 £68 £675 £15,554 23.0 yrs £-2,056
4 kW 3966 kWh 3054 kWh 912 kWh £809 £91 £900 £17,588 19.5 yrs £409
5 kW 4957 kWh 3817 kWh 1140 kWh £1,011 £114 £1,125 £19,623 17.4 yrs £2,874
6 kW 5949 kWh 4581 kWh 1368 kWh £1,213 £137 £1,350 £21,657 16.0 yrs £5,338
7 kW 6940 kWh 5344 kWh 1596 kWh £1,415 £160 £1,575 £23,692 15.0 yrs £7,803
8 kW 7932 kWh 6107 kWh 1824 kWh £1,617 £182 £1,800 £25,726 14.3 yrs £10,268

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 2,035, 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.

Insights for TW8

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

Solar Payback Index Rank #1082 of 2997
10.8 years (UK avg 11.3 years)
~£945 /yr • £10,173 upfront
Standing-Charge Drag Rank #777 of 2997
17.2% (UK avg 21.7%) drag on savings
£163 fixed • ~£945 /yr value

Your Area at a Glance

Your Electricity Rate
26.48p/kWh
Daily Fixed Charge
44.62p/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, Q4 2025

Installation costs: MCS certified installer data, March 2025

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