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Solar Panels in SO9 (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
11.7 years
After this, it's pure profit
Upfront Cost
£10,173
What you pay to get started
Annual Benefit
£871
What you save every year
Profit Over 25 Years
£11,606
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 1050 kWh/kW — 49 above the regional median (1001).

Read the full story

A typical roof here lands around 5.0 kW, with most eligible homes comfortably fitting within 3–6 kW. Each kilowatt of panels produces roughly 1050 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)
1050 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: £871, Upfront: £10,173, 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 2100 kWh 840 kWh 1260 kWh £222 £126 £348 £4,069 11.7 yrs £2,900
3 kW 3150 kWh 1260 kWh 1890 kWh £334 £189 £523 £6,104 11.7 yrs £4,350
4 kW 4200 kWh 1680 kWh 2520 kWh £445 £252 £697 £8,138 11.7 yrs £5,800
5 kW 5250 kWh 2100 kWh 3150 kWh £556 £315 £871 £10,173 11.7 yrs £7,250
6 kW 6300 kWh 2520 kWh 3780 kWh £667 £378 £1,045 £12,207 11.7 yrs £8,700
7 kW 7350 kWh 2940 kWh 4410 kWh £779 £441 £1,220 £14,242 11.7 yrs £10,150
8 kW 8400 kWh 3360 kWh 5040 kWh £890 £504 £1,394 £16,276 11.7 yrs £11,600

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: £1,044, Upfront: £12,273, 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 2100 kWh 1260 kWh 840 kWh £334 £84 £418 £6,169 14.8 yrs £2,184
3 kW 3150 kWh 1890 kWh 1260 kWh £501 £126 £627 £8,204 13.1 yrs £4,327
4 kW 4200 kWh 2520 kWh 1680 kWh £667 £168 £835 £10,238 12.3 yrs £6,469
5 kW 5250 kWh 3150 kWh 2100 kWh £834 £210 £1,044 £12,273 11.8 yrs £8,611
6 kW 6300 kWh 3780 kWh 2520 kWh £1,001 £252 £1,253 £14,307 11.4 yrs £10,753
7 kW 7350 kWh 4410 kWh 2940 kWh £1,168 £294 £1,462 £16,342 11.2 yrs £12,895
8 kW 8400 kWh 5040 kWh 3360 kWh £1,335 £336 £1,671 £18,376 11.0 yrs £15,038

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: £1,131, Upfront: £13,673, Break-even: 12.1 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2100 kWh 1470 kWh 630 kWh £389 £63 £452 £7,569 16.7 yrs £1,477
3 kW 3150 kWh 2205 kWh 945 kWh £584 £95 £678 £9,604 14.2 yrs £3,965
4 kW 4200 kWh 2940 kWh 1260 kWh £779 £126 £905 £11,638 12.9 yrs £6,453
5 kW 5250 kWh 3675 kWh 1575 kWh £973 £158 £1,131 £13,673 12.1 yrs £8,942
6 kW 6300 kWh 4410 kWh 1890 kWh £1,168 £189 £1,357 £15,707 11.6 yrs £11,430
7 kW 7350 kWh 5145 kWh 2205 kWh £1,362 £221 £1,583 £17,742 11.2 yrs £13,918
8 kW 8400 kWh 5880 kWh 2520 kWh £1,557 £252 £1,809 £19,776 10.9 yrs £16,406

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: £1,157, Upfront: £15,423, Break-even: 13.3 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2100 kWh 1533 kWh 567 kWh £406 £57 £463 £9,319 20.1 yrs £-66
3 kW 3150 kWh 2300 kWh 851 kWh £609 £85 £694 £11,354 16.4 yrs £2,526
4 kW 4200 kWh 3066 kWh 1134 kWh £812 £113 £925 £13,388 14.5 yrs £5,119
5 kW 5250 kWh 3833 kWh 1418 kWh £1,015 £142 £1,157 £15,423 13.3 yrs £7,711
6 kW 6300 kWh 4599 kWh 1701 kWh £1,218 £170 £1,388 £17,457 12.6 yrs £10,303
7 kW 7350 kWh 5366 kWh 1985 kWh £1,421 £198 £1,619 £19,492 12.0 yrs £12,895
8 kW 8400 kWh 6132 kWh 2268 kWh £1,624 £227 £1,851 £21,526 11.6 yrs £15,487

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: £1,174, Upfront: £17,173, 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 2100 kWh 1575 kWh 525 kWh £417 £53 £470 £11,069 23.6 yrs £-1,677
3 kW 3150 kWh 2363 kWh 788 kWh £626 £79 £704 £13,104 18.6 yrs £984
4 kW 4200 kWh 3150 kWh 1050 kWh £834 £105 £939 £15,138 16.1 yrs £3,645
5 kW 5250 kWh 3938 kWh 1313 kWh £1,043 £131 £1,174 £17,173 14.6 yrs £6,307
6 kW 6300 kWh 4725 kWh 1575 kWh £1,251 £158 £1,409 £19,207 13.6 yrs £8,968
7 kW 7350 kWh 5513 kWh 1838 kWh £1,460 £184 £1,644 £21,242 12.9 yrs £11,630
8 kW 8400 kWh 6300 kWh 2100 kWh £1,668 £210 £1,878 £23,276 12.4 yrs £14,291

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: £1,191, Upfront: £19,623, 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 2100 kWh 1617 kWh 483 kWh £428 £48 £477 £13,519 28.4 yrs £-3,989
3 kW 3150 kWh 2426 kWh 725 kWh £642 £72 £715 £15,554 21.8 yrs £-1,258
4 kW 4200 kWh 3234 kWh 966 kWh £856 £97 £953 £17,588 18.5 yrs £1,472
5 kW 5250 kWh 4043 kWh 1208 kWh £1,071 £121 £1,191 £19,623 16.5 yrs £4,203
6 kW 6300 kWh 4851 kWh 1449 kWh £1,285 £145 £1,430 £21,657 15.1 yrs £6,933
7 kW 7350 kWh 5660 kWh 1691 kWh £1,499 £169 £1,668 £23,692 14.2 yrs £9,664
8 kW 8400 kWh 6468 kWh 1932 kWh £1,713 £193 £1,906 £25,726 13.5 yrs £12,395

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 SO9

Figures below are tailored to SO9 — click through for full league tables.

Solar Payback Index Rank #289 of 2997
10.2 years (UK avg 11.3 years)
~£1,001 /yr • £10,173 upfront
Standing-Charge Drag Rank #595 of 2997
16.3% (UK avg 21.7%) drag on savings
£163 fixed • ~£1,001 /yr value

Your Area at a Glance

Your Electricity Rate
26.48p/kWh
Daily Fixed Charge
44.62p/day
Local Sunshine
1050kWh/kW
A 1 kW system generates ~1050 kWh per year. A typical home uses ~2,700 kWh per year.
Typical System Size
5.0kW
For houses & bungalows in this area

Local Property Data

Property Types

No EPC data available for this outcode

Coverage

Southampton (98%)|Test Valley (2%)

Areas Covered

Bargate, Banister & Polygon, Bevois, Freemantle, Shirley, Millbrook, Portswood, Redbridge + 5 more

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

SO14 (Southampton)
≈0.7 km away
Local sunshine: ~1,037 kWh/kWp · -1% vs SO9
SO17 (Southampton)
≈1.7 km away
Local sunshine: ~1,031 kWh/kWp · -2% vs SO9
SO15 (Southampton)
≈1.8 km away
Local sunshine: ~1,032 kWh/kWp · -2% vs SO9
SO1 (Southampton)
≈2.0 km away
Local sunshine: ~1,050 kWh/kWp · +0% vs SO9
SO2 (Southampton)
≈2.5 km away
Local sunshine: ~1,031 kWh/kWp · -2% vs SO9
SO18 (Southampton)
≈2.7 km away
Local sunshine: ~1,037 kWh/kWp · -1% vs SO9

Similar sunshine across the UK

CM8 (Braintree)
~1,050 kWh/kWp · +0% vs SO9
IP4 (Ipswich)
~1,050 kWh/kWp · -0% vs SO9
IP7 (Babergh)
~1,050 kWh/kWp · -0% vs SO9