Solar explained to clever people by people who are not trying to be clever
Home Regions
Insights
Big Roof Britain Solar Payback Index Standing Charge Drag

Solar Panels in SO17 (Southampton)

See if solar pays off for you in Southampton — 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
11.9 years
After this, it's pure profit
Upfront Cost
£6,104
What you pay to get started
Annual Benefit
£513
What you save every year
Profit Over 25 Years
£6,725
After paying itself off, you're this much ahead

Ready to Get Started?

Get your free quote from Blue Ape Renewables. They'll connect you with MCS-certified installers in your area and handle all the paperwork.

Get Solar Quote →
4.8★ Trustpilot • Octopus Energy trusted partner • MCS certified • No obligation
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 1031 kWh/kW — 30 above 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 1031 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)
1031 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: £855, Upfront: £10,173, 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 2062 kWh 825 kWh 1237 kWh £218 £124 £342 £4,069 11.9 yrs £2,773
3 kW 3093 kWh 1237 kWh 1856 kWh £328 £186 £513 £6,104 11.9 yrs £4,159
4 kW 4124 kWh 1649 kWh 2474 kWh £437 £247 £684 £8,138 11.9 yrs £5,546
5 kW 5155 kWh 2062 kWh 3093 kWh £546 £309 £855 £10,173 11.9 yrs £6,932
6 kW 6185 kWh 2474 kWh 3711 kWh £655 £371 £1,026 £12,207 11.9 yrs £8,319
7 kW 7216 kWh 2887 kWh 4330 kWh £764 £433 £1,197 £14,242 11.9 yrs £9,705
8 kW 8247 kWh 3299 kWh 4948 kWh £874 £495 £1,368 £16,276 11.9 yrs £11,092

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: £1,025, Upfront: £12,273, Break-even: 12.0 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2062 kWh 1237 kWh 825 kWh £328 £82 £410 £6,169 15.0 yrs £2,032
3 kW 3093 kWh 1856 kWh 1237 kWh £491 £124 £615 £8,204 13.3 yrs £4,098
4 kW 4124 kWh 2474 kWh 1649 kWh £655 £165 £820 £10,238 12.5 yrs £6,164
5 kW 5155 kWh 3093 kWh 2062 kWh £819 £206 £1,025 £12,273 12.0 yrs £8,230
6 kW 6185 kWh 3711 kWh 2474 kWh £983 £247 £1,230 £14,307 11.6 yrs £10,296
7 kW 7216 kWh 4330 kWh 2887 kWh £1,147 £289 £1,435 £16,342 11.4 yrs £12,362
8 kW 8247 kWh 4948 kWh 3299 kWh £1,310 £330 £1,640 £18,376 11.2 yrs £14,428

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: £1,110, Upfront: £13,673, Break-even: 12.3 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2062 kWh 1443 kWh 619 kWh £382 £62 £444 £7,569 17.0 yrs £1,312
3 kW 3093 kWh 2165 kWh 928 kWh £573 £93 £666 £9,604 14.4 yrs £3,717
4 kW 4124 kWh 2887 kWh 1237 kWh £764 £124 £888 £11,638 13.1 yrs £6,123
5 kW 5155 kWh 3608 kWh 1546 kWh £955 £155 £1,110 £13,673 12.3 yrs £8,529
6 kW 6185 kWh 4330 kWh 1856 kWh £1,147 £186 £1,332 £15,707 11.8 yrs £10,935
7 kW 7216 kWh 5051 kWh 2165 kWh £1,338 £216 £1,554 £17,742 11.4 yrs £13,341
8 kW 8247 kWh 5773 kWh 2474 kWh £1,529 £247 £1,776 £19,776 11.1 yrs £15,747

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: £1,136, Upfront: £15,423, Break-even: 13.6 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2062 kWh 1505 kWh 557 kWh £399 £56 £454 £9,319 20.5 yrs £-234
3 kW 3093 kWh 2258 kWh 835 kWh £598 £84 £681 £11,354 16.7 yrs £2,273
4 kW 4124 kWh 3010 kWh 1113 kWh £797 £111 £908 £13,388 14.7 yrs £4,781
5 kW 5155 kWh 3763 kWh 1392 kWh £996 £139 £1,136 £15,423 13.6 yrs £7,289
6 kW 6185 kWh 4515 kWh 1670 kWh £1,196 £167 £1,363 £17,457 12.8 yrs £9,797
7 kW 7216 kWh 5268 kWh 1948 kWh £1,395 £195 £1,590 £19,492 12.3 yrs £12,304
8 kW 8247 kWh 6021 kWh 2227 kWh £1,594 £223 £1,817 £21,526 11.8 yrs £14,812

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: £1,153, Upfront: £17,173, 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 2062 kWh 1546 kWh 515 kWh £409 £52 £461 £11,069 24.0 yrs £-1,849
3 kW 3093 kWh 2320 kWh 773 kWh £614 £77 £692 £13,104 18.9 yrs £727
4 kW 4124 kWh 3093 kWh 1031 kWh £819 £103 £922 £15,138 16.4 yrs £3,303
5 kW 5155 kWh 3866 kWh 1289 kWh £1,024 £129 £1,153 £17,173 14.9 yrs £5,879
6 kW 6185 kWh 4639 kWh 1546 kWh £1,228 £155 £1,383 £19,207 13.9 yrs £8,454
7 kW 7216 kWh 5412 kWh 1804 kWh £1,433 £180 £1,614 £21,242 13.2 yrs £11,030
8 kW 8247 kWh 6185 kWh 2062 kWh £1,638 £206 £1,844 £23,276 12.6 yrs £13,606

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: £1,170, Upfront: £19,623, Break-even: 16.8 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2062 kWh 1588 kWh 474 kWh £420 £47 £468 £13,519 28.9 yrs £-4,163
3 kW 3093 kWh 2381 kWh 711 kWh £631 £71 £702 £15,554 22.2 yrs £-1,519
4 kW 4124 kWh 3175 kWh 948 kWh £841 £95 £936 £17,588 18.8 yrs £1,125
5 kW 5155 kWh 3969 kWh 1186 kWh £1,051 £119 £1,170 £19,623 16.8 yrs £3,768
6 kW 6185 kWh 4763 kWh 1423 kWh £1,261 £142 £1,403 £21,657 15.4 yrs £6,412
7 kW 7216 kWh 5557 kWh 1660 kWh £1,471 £166 £1,637 £23,692 14.5 yrs £9,056
8 kW 8247 kWh 6350 kWh 1897 kWh £1,682 £190 £1,871 £25,726 13.7 yrs £11,699

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 SO17

Figures below are tailored to SO17 — click through for full league tables.

Big-Roof Britain Rank #2090 of 2182
3.9 kWp (UK avg 5.1 kWp)
~8 panels (≈430 W)
Solar Payback Index Rank #438 of 2997
10.4 years (UK avg 11.3 years)
~£983 /yr • £10,173 upfront
Standing-Charge Drag Rank #649 of 2997
16.6% (UK avg 21.7%) drag on savings
£163 fixed • ~£983 /yr value

Your Area at a Glance

Your Electricity Rate
26.48p/kWh
Daily Fixed Charge
44.62p/day
Local Sunshine
1031kWh/kW
A 1 kW system generates ~1031 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: 43% • Flats: 55% • Bungalows: 1% Based on 6,517 properties

Coverage

Southampton (100%)

Areas Covered

Portswood, Swaythling, Freemantle, Bevois, Banister & Polygon, Bassett

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

SO9 (Southampton)
≈1.7 km away
Local sunshine: ~1,050 kWh/kWp · +2% vs SO17
SO18 (Southampton)
≈1.9 km away
Local sunshine: ~1,037 kWh/kWp · +1% vs SO17
SO2 (Southampton)
≈2.0 km away
Local sunshine: ~1,031 kWh/kWp · -0% vs SO17
SO14 (Southampton)
≈2.0 km away
Local sunshine: ~1,037 kWh/kWp · +1% vs SO17
SO1 (Southampton)
≈2.4 km away
Local sunshine: ~1,050 kWh/kWp · +2% vs SO17
SO15 (Southampton)
≈2.6 km away
Local sunshine: ~1,032 kWh/kWp · +0% vs SO17

Similar sunshine across the UK

CF32 (Bridgend)
~1,031 kWh/kWp · +0% vs SO17
TQ13 (Teignbridge)
~1,031 kWh/kWp · +0% vs SO17
EX3 (Exeter)
~1,031 kWh/kWp · +0% vs SO17