Solar panel cost in Wiltshire (SP4)

See realistic solar installation costs, savings and payback for SP4 (Wiltshire) 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

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System Size

Roof Direction

Battery Storage

Export Value

Your Numbers

Break-even
9.6 years
After this, it's pure profit
Upfront Cost
£8,139
What you pay to get started
Annual Benefit
£844
What you save every year
Profit Over 25 Years
£12,952
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

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 1018 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)
1018 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: £844, Upfront: £8,139, Break-even: 9.6 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2037 kWh 815 kWh 1222 kWh £215 £122 £337 £3,256 9.6 yrs £3,494
3 kW 3055 kWh 1222 kWh 1833 kWh £323 £183 £506 £4,883 9.6 yrs £5,241
4 kW 4074 kWh 1629 kWh 2444 kWh £431 £244 £675 £6,511 9.6 yrs £6,987
5 kW 5092 kWh 2037 kWh 3055 kWh £538 £306 £844 £8,139 9.6 yrs £8,734
6 kW 6110 kWh 2444 kWh 3666 kWh £646 £367 £1,012 £9,767 9.6 yrs £10,481
7 kW 7129 kWh 2852 kWh 4277 kWh £753 £428 £1,181 £11,394 9.6 yrs £12,228
8 kW 8147 kWh 3259 kWh 4888 kWh £861 £489 £1,350 £13,022 9.6 yrs £13,975

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 1,628, battery £/kWh = 700.

3 kWh battery 5 kW example → Annual benefit: £1,011, Upfront: £10,239, Break-even: 10.1 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2037 kWh 1222 kWh 815 kWh £323 £81 £404 £5,356 13.2 yrs £2,731
3 kW 3055 kWh 1833 kWh 1222 kWh £484 £122 £607 £6,983 11.5 yrs £5,147
4 kW 4074 kWh 2444 kWh 1629 kWh £646 £163 £809 £8,611 10.6 yrs £7,563
5 kW 5092 kWh 3055 kWh 2037 kWh £807 £204 £1,011 £10,239 10.1 yrs £9,979
6 kW 6110 kWh 3666 kWh 2444 kWh £969 £244 £1,213 £11,867 9.8 yrs £12,394
7 kW 7129 kWh 4277 kWh 2852 kWh £1,130 £285 £1,415 £13,494 9.5 yrs £14,810
8 kW 8147 kWh 4888 kWh 3259 kWh £1,292 £326 £1,617 £15,122 9.3 yrs £17,226

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 1,628, battery £/kWh = 700.

5 kWh battery 5 kW example → Annual benefit: £1,094, Upfront: £11,639, Break-even: 10.6 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2037 kWh 1426 kWh 611 kWh £377 £61 £438 £6,756 15.4 yrs £2,000
3 kW 3055 kWh 2139 kWh 917 kWh £565 £92 £657 £8,383 12.8 yrs £4,751
4 kW 4074 kWh 2852 kWh 1222 kWh £753 £122 £876 £10,011 11.4 yrs £7,501
5 kW 5092 kWh 3564 kWh 1528 kWh £942 £153 £1,094 £11,639 10.6 yrs £10,251
6 kW 6110 kWh 4277 kWh 1833 kWh £1,130 £183 £1,313 £13,267 10.1 yrs £13,001
7 kW 7129 kWh 4990 kWh 2139 kWh £1,318 £214 £1,532 £14,894 9.7 yrs £15,751
8 kW 8147 kWh 5703 kWh 2444 kWh £1,507 £244 £1,751 £16,522 9.4 yrs £18,501

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 1,628, battery £/kWh = 700.

7.5 kWh battery 5 kW example → Annual benefit: £1,120, Upfront: £13,389, 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 2037 kWh 1487 kWh 550 kWh £393 £55 £448 £8,506 19.0 yrs £451
3 kW 3055 kWh 2230 kWh 825 kWh £589 £82 £672 £10,133 15.1 yrs £3,302
4 kW 4074 kWh 2974 kWh 1100 kWh £786 £110 £896 £11,761 13.1 yrs £6,152
5 kW 5092 kWh 3717 kWh 1375 kWh £982 £137 £1,120 £13,389 12.0 yrs £9,003
6 kW 6110 kWh 4461 kWh 1650 kWh £1,178 £165 £1,343 £15,017 11.2 yrs £11,853
7 kW 7129 kWh 5204 kWh 1925 kWh £1,375 £192 £1,567 £16,644 10.6 yrs £14,704
8 kW 8147 kWh 5948 kWh 2200 kWh £1,571 £220 £1,791 £18,272 10.2 yrs £17,554

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 1,628, battery £/kWh = 700.

10 kWh battery 5 kW example → Annual benefit: £1,136, Upfront: £15,139, 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 2037 kWh 1528 kWh 509 kWh £404 £51 £455 £10,256 22.6 yrs £-1,165
3 kW 3055 kWh 2291 kWh 764 kWh £605 £76 £682 £11,883 17.4 yrs £1,752
4 kW 4074 kWh 3055 kWh 1018 kWh £807 £102 £909 £13,511 14.9 yrs £4,670
5 kW 5092 kWh 3819 kWh 1273 kWh £1,009 £127 £1,136 £15,139 13.3 yrs £7,587
6 kW 6110 kWh 4583 kWh 1528 kWh £1,211 £153 £1,364 £16,767 12.3 yrs £10,504
7 kW 7129 kWh 5347 kWh 1782 kWh £1,413 £178 £1,591 £18,394 11.6 yrs £13,422
8 kW 8147 kWh 6110 kWh 2037 kWh £1,614 £204 £1,818 £20,022 11.0 yrs £16,339

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 1,628, battery £/kWh = 700.

13.5 kWh battery 5 kW example → Annual benefit: £1,153, Upfront: £17,589, Break-even: 15.3 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2037 kWh 1568 kWh 468 kWh £414 £47 £461 £12,706 27.5 yrs £-3,481
3 kW 3055 kWh 2353 kWh 703 kWh £622 £70 £692 £14,333 20.7 yrs £-497
4 kW 4074 kWh 3137 kWh 937 kWh £829 £94 £922 £15,961 17.3 yrs £2,487
5 kW 5092 kWh 3921 kWh 1171 kWh £1,036 £117 £1,153 £17,589 15.3 yrs £5,471
6 kW 6110 kWh 4705 kWh 1405 kWh £1,243 £141 £1,384 £19,217 13.9 yrs £8,456
7 kW 7129 kWh 5489 kWh 1640 kWh £1,450 £164 £1,614 £20,844 12.9 yrs £11,440
8 kW 8147 kWh 6273 kWh 1874 kWh £1,657 £187 £1,845 £22,472 12.2 yrs £14,424

Assumptions: south-facing, sensible tilt; self-use shares from site rules; export at 10p baseline. Costs: panels £/kW = 1,628, 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 Wiltshire

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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Seasonal solar output in SP4

Monthly generation per kilowatt of solar panels

kWh 40 Jan 53 Feb 88 Mar 115 Apr 124 May 122 Jun 122 Jul 110 Aug 95 Sep 67 Oct 47 Nov 35 Dec
Best month Worst month Winter (Dec–Feb) Other months

Winter output: 50.5% of an average month (Dec–Feb)

Best / worst month: May / Dec

These figures show output per kilowatt (kW) of panels installed. In winter, a 1 kW system here produces about 43 kWh per month; the average month produces around 85 kWh. So a typical 4 kW home system would generate roughly 171 kWh in winter, or 339 kWh in an average month.

Your Area at a Glance

Your Electricity Rate
26.42p/kWh
Daily Fixed Charge
49.70p/day
Local Sunshine
1018kWh/kW
A 1 kW system generates ~1018 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: 11% • Bungalows: 11% Based on 11,480 properties

Coverage

Wiltshire (99%)|Test Valley (1%)

Areas Covered

Amesbury East & Bulford, Old Sarum & Lower Bourne Valley, Amesbury West, Avon Valley, Winterslow & Upper Bourne Valley, Durrington, Amesbury South, Salisbury St Edmund's + 4 more

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.