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 SP9 (Wiltshire)

See if solar pays off for you in Wiltshire — 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
12.1 years
After this, it's pure profit
Upfront Cost
£10,173
What you pay to get started
Annual Benefit
£843
What you save every year
Profit Over 25 Years
£10,908
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 1016 kWh/kW — 15 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 1016 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)
1016 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: £843, Upfront: £10,173, 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 2033 kWh 813 kWh 1220 kWh £215 £122 £337 £4,069 12.1 yrs £2,677
3 kW 3049 kWh 1220 kWh 1830 kWh £323 £183 £506 £6,104 12.1 yrs £4,015
4 kW 4066 kWh 1626 kWh 2439 kWh £431 £244 £675 £8,138 12.1 yrs £5,353
5 kW 5082 kWh 2033 kWh 3049 kWh £538 £305 £843 £10,173 12.1 yrs £6,692
6 kW 6098 kWh 2439 kWh 3659 kWh £646 £366 £1,012 £12,207 12.1 yrs £8,030
7 kW 7115 kWh 2846 kWh 4269 kWh £754 £427 £1,180 £14,242 12.1 yrs £9,368
8 kW 8131 kWh 3253 kWh 4879 kWh £861 £488 £1,349 £16,276 12.1 yrs £10,707

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: £1,011, Upfront: £12,273, 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 2033 kWh 1220 kWh 813 kWh £323 £81 £404 £6,169 15.3 yrs £1,917
3 kW 3049 kWh 1830 kWh 1220 kWh £484 £122 £606 £8,204 13.5 yrs £3,925
4 kW 4066 kWh 2439 kWh 1626 kWh £646 £163 £809 £10,238 12.7 yrs £5,933
5 kW 5082 kWh 3049 kWh 2033 kWh £807 £203 £1,011 £12,273 12.1 yrs £7,942
6 kW 6098 kWh 3659 kWh 2439 kWh £969 £244 £1,213 £14,307 11.8 yrs £9,950
7 kW 7115 kWh 4269 kWh 2846 kWh £1,130 £285 £1,415 £16,342 11.5 yrs £11,959
8 kW 8131 kWh 4879 kWh 3253 kWh £1,292 £325 £1,617 £18,376 11.4 yrs £13,967

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: £1,094, Upfront: £13,673, Break-even: 12.5 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2033 kWh 1423 kWh 610 kWh £377 £61 £438 £7,569 17.3 yrs £1,187
3 kW 3049 kWh 2134 kWh 915 kWh £565 £91 £657 £9,604 14.6 yrs £3,530
4 kW 4066 kWh 2846 kWh 1220 kWh £754 £122 £876 £11,638 13.3 yrs £5,873
5 kW 5082 kWh 3557 kWh 1525 kWh £942 £152 £1,094 £13,673 12.5 yrs £8,217
6 kW 6098 kWh 4269 kWh 1830 kWh £1,130 £183 £1,313 £15,707 12.0 yrs £10,560
7 kW 7115 kWh 4980 kWh 2134 kWh £1,319 £213 £1,532 £17,742 11.6 yrs £12,904
8 kW 8131 kWh 5692 kWh 2439 kWh £1,507 £244 £1,751 £19,776 11.3 yrs £15,247

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: £1,120, Upfront: £15,423, Break-even: 13.8 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2033 kWh 1484 kWh 549 kWh £393 £55 £448 £9,319 20.8 yrs £-362
3 kW 3049 kWh 2226 kWh 823 kWh £589 £82 £672 £11,354 16.9 yrs £2,082
4 kW 4066 kWh 2968 kWh 1098 kWh £786 £110 £896 £13,388 14.9 yrs £4,525
5 kW 5082 kWh 3710 kWh 1372 kWh £982 £137 £1,120 £15,423 13.8 yrs £6,969
6 kW 6098 kWh 4452 kWh 1647 kWh £1,179 £165 £1,344 £17,457 13.0 yrs £9,413
7 kW 7115 kWh 5194 kWh 1921 kWh £1,375 £192 £1,567 £19,492 12.4 yrs £11,857
8 kW 8131 kWh 5936 kWh 2195 kWh £1,572 £220 £1,791 £21,526 12.0 yrs £14,301

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: £1,136, Upfront: £17,173, Break-even: 15.1 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2033 kWh 1525 kWh 508 kWh £404 £51 £455 £11,069 24.4 yrs £-1,978
3 kW 3049 kWh 2287 kWh 762 kWh £606 £76 £682 £13,104 19.2 yrs £533
4 kW 4066 kWh 3049 kWh 1016 kWh £807 £102 £909 £15,138 16.7 yrs £3,044
5 kW 5082 kWh 3812 kWh 1271 kWh £1,009 £127 £1,136 £17,173 15.1 yrs £5,554
6 kW 6098 kWh 4574 kWh 1525 kWh £1,211 £152 £1,364 £19,207 14.1 yrs £8,065
7 kW 7115 kWh 5336 kWh 1779 kWh £1,413 £178 £1,591 £21,242 13.4 yrs £10,576
8 kW 8131 kWh 6098 kWh 2033 kWh £1,615 £203 £1,818 £23,276 12.8 yrs £13,087

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: £1,153, Upfront: £19,623, Break-even: 17.0 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2033 kWh 1565 kWh 468 kWh £414 £47 £461 £13,519 29.3 yrs £-4,294
3 kW 3049 kWh 2348 kWh 701 kWh £622 £70 £692 £15,554 22.5 yrs £-1,716
4 kW 4066 kWh 3131 kWh 935 kWh £829 £94 £922 £17,588 19.1 yrs £862
5 kW 5082 kWh 3913 kWh 1169 kWh £1,036 £117 £1,153 £19,623 17.0 yrs £3,439
6 kW 6098 kWh 4696 kWh 1403 kWh £1,243 £140 £1,384 £21,657 15.7 yrs £6,017
7 kW 7115 kWh 5478 kWh 1636 kWh £1,451 £164 £1,614 £23,692 14.7 yrs £8,595
8 kW 8131 kWh 6261 kWh 1870 kWh £1,658 £187 £1,845 £25,726 13.9 yrs £11,173

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 SP9

Figures below are tailored to SP9 — click through for full league tables.

Big-Roof Britain Rank #938 of 2182
5.1 kWp (UK avg 5.1 kWp)
~11 panels (≈430 W)
Solar Payback Index Rank #585 of 2997
10.5 years (UK avg 11.3 years)
~£969 /yr • £10,173 upfront
Standing-Charge Drag Rank #687 of 2997
16.8% (UK avg 21.7%) drag on savings
£163 fixed • ~£969 /yr value

Your Area at a Glance

Your Electricity Rate
26.48p/kWh
Daily Fixed Charge
44.62p/day
Local Sunshine
1016kWh/kW
A 1 kW system generates ~1016 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

Houses: 78% • Flats: 17% • Bungalows: 5% Based on 3,910 properties

Coverage

Wiltshire (85%)|Test Valley (15%)

Areas Covered

Tidworth North & West, Tidworth East & Ludgershall South, Bellinger, Andover St Mary's, Ludgershall North & Rural

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

SP4 (Wiltshire)
≈10.3 km away
Local sunshine: ~1,018 kWh/kWp · +0% vs SP9
SP11 (Test Valley)
≈11.2 km away
Local sunshine: ~1,005 kWh/kWp · -1% vs SP9
SP10 (Test Valley)
≈13.2 km away
Local sunshine: ~1,011 kWh/kWp · -1% vs SP9
SN9 (Wiltshire)
≈13.6 km away
Local sunshine: ~989 kWh/kWp · -3% vs SP9
SO20 (Test Valley)
≈17.4 km away
Local sunshine: ~1,019 kWh/kWp · +0% vs SP9
SP1 (Wiltshire)
≈20.4 km away
Local sunshine: ~1,019 kWh/kWp · +0% vs SP9

Similar sunshine across the UK

SE2 (Greenwich)
~1,016 kWh/kWp · +0% vs SP9
CM24 (Uttlesford)
~1,017 kWh/kWp · +0% vs SP9
SG8 (North Hertfordshire)
~1,016 kWh/kWp · -0% vs SP9