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Solar panel cost in West Northamptonshire (NN3)

See realistic solar installation costs, savings and payback for NN3 (West Northamptonshire) 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

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
10.2 years
After this, it's pure profit
Upfront Cost
£8,139
What you pay to get started
Annual Benefit
£797
What you save every year
Profit Over 25 Years
£11,781
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

In East Midlands, the current unit rate is 25.10p/kWh with a 53.60p/day standing charge. Your postcode’s south-facing sunshine yield is 994 kWh/kW — 25 above the regional median (968).

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 994 kWh per year on a south-facing roof. We value self-used electricity at 25.1p and exported surplus at a baseline 10p via SEG. Use the calculator above for your exact tariff.

Unit rate
25.1p/kWh
Standing charge
53.6p/day
Sunshine yield (south)
994 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: £797, Upfront: £8,139, Break-even: 10.2 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1987 kWh 795 kWh 1192 kWh £199 £119 £319 £3,256 10.2 yrs £3,119
3 kW 2981 kWh 1192 kWh 1788 kWh £299 £179 £478 £4,883 10.2 yrs £4,678
4 kW 3974 kWh 1590 kWh 2384 kWh £399 £238 £637 £6,511 10.2 yrs £6,238
5 kW 4968 kWh 1987 kWh 2981 kWh £499 £298 £797 £8,139 10.2 yrs £7,797
6 kW 5961 kWh 2384 kWh 3577 kWh £598 £358 £956 £9,767 10.2 yrs £9,357
7 kW 6955 kWh 2782 kWh 4173 kWh £698 £417 £1,116 £11,394 10.2 yrs £10,916
8 kW 7948 kWh 3179 kWh 4769 kWh £798 £477 £1,275 £13,022 10.2 yrs £12,475

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: £947, Upfront: £10,239, Break-even: 10.8 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1987 kWh 1192 kWh 795 kWh £299 £79 £379 £5,356 14.1 yrs £2,219
3 kW 2981 kWh 1788 kWh 1192 kWh £449 £119 £568 £6,983 12.3 yrs £4,379
4 kW 3974 kWh 2384 kWh 1590 kWh £598 £159 £757 £8,611 11.4 yrs £6,538
5 kW 4968 kWh 2981 kWh 1987 kWh £748 £199 £947 £10,239 10.8 yrs £8,698
6 kW 5961 kWh 3577 kWh 2384 kWh £898 £238 £1,136 £11,867 10.4 yrs £10,857
7 kW 6955 kWh 4173 kWh 2782 kWh £1,047 £278 £1,326 £13,494 10.2 yrs £13,017
8 kW 7948 kWh 4769 kWh 3179 kWh £1,197 £318 £1,515 £15,122 10.0 yrs £15,176

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: £1,022, Upfront: £11,639, Break-even: 11.4 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1987 kWh 1391 kWh 596 kWh £349 £60 £409 £6,756 16.5 yrs £1,419
3 kW 2981 kWh 2086 kWh 894 kWh £524 £89 £613 £8,383 13.7 yrs £3,879
4 kW 3974 kWh 2782 kWh 1192 kWh £698 £119 £817 £10,011 12.2 yrs £6,338
5 kW 4968 kWh 3477 kWh 1490 kWh £873 £149 £1,022 £11,639 11.4 yrs £8,798
6 kW 5961 kWh 4173 kWh 1788 kWh £1,047 £179 £1,226 £13,267 10.8 yrs £11,257
7 kW 6955 kWh 4868 kWh 2086 kWh £1,222 £209 £1,431 £14,894 10.4 yrs £13,717
8 kW 7948 kWh 5564 kWh 2384 kWh £1,396 £238 £1,635 £16,522 10.1 yrs £16,176

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: £1,044, Upfront: £13,389, 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 1987 kWh 1451 kWh 536 kWh £364 £54 £418 £8,506 20.4 yrs £-151
3 kW 2981 kWh 2176 kWh 805 kWh £546 £80 £627 £10,133 16.2 yrs £2,399
4 kW 3974 kWh 2901 kWh 1073 kWh £728 £107 £835 £11,761 14.1 yrs £4,948
5 kW 4968 kWh 3626 kWh 1341 kWh £910 £134 £1,044 £13,389 12.8 yrs £7,498
6 kW 5961 kWh 4352 kWh 1609 kWh £1,092 £161 £1,253 £15,017 12.0 yrs £10,047
7 kW 6955 kWh 5077 kWh 1878 kWh £1,274 £188 £1,462 £16,644 11.4 yrs £12,597
8 kW 7948 kWh 5802 kWh 2146 kWh £1,456 £215 £1,671 £18,272 10.9 yrs £15,146

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: £1,059, Upfront: £15,139, Break-even: 14.3 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1987 kWh 1490 kWh 497 kWh £374 £50 £424 £10,256 24.2 yrs £-1,781
3 kW 2981 kWh 2235 kWh 745 kWh £561 £75 £636 £11,883 18.7 yrs £829
4 kW 3974 kWh 2981 kWh 994 kWh £748 £99 £847 £13,511 15.9 yrs £3,438
5 kW 4968 kWh 3726 kWh 1242 kWh £935 £124 £1,059 £15,139 14.3 yrs £6,048
6 kW 5961 kWh 4471 kWh 1490 kWh £1,122 £149 £1,271 £16,767 13.2 yrs £8,657
7 kW 6955 kWh 5216 kWh 1739 kWh £1,309 £174 £1,483 £18,394 12.4 yrs £11,267
8 kW 7948 kWh 5961 kWh 1987 kWh £1,496 £199 £1,695 £20,022 11.8 yrs £13,876

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: £1,074, Upfront: £17,589, Break-even: 16.4 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1987 kWh 1530 kWh 457 kWh £384 £46 £430 £12,706 29.6 yrs £-4,111
3 kW 2981 kWh 2295 kWh 686 kWh £576 £69 £645 £14,333 22.2 yrs £-1,441
4 kW 3974 kWh 3060 kWh 914 kWh £768 £91 £859 £15,961 18.6 yrs £1,228
5 kW 4968 kWh 3825 kWh 1143 kWh £960 £114 £1,074 £17,589 16.4 yrs £3,898
6 kW 5961 kWh 4590 kWh 1371 kWh £1,152 £137 £1,289 £19,217 14.9 yrs £6,567
7 kW 6955 kWh 5355 kWh 1600 kWh £1,344 £160 £1,504 £20,844 13.9 yrs £9,237
8 kW 7948 kWh 6120 kWh 1828 kWh £1,536 £183 £1,719 £22,472 13.1 yrs £11,907

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 West Northamptonshire

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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Understand DNO, G98 and G99 export limits

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This is a practical sanity-check request, not an instant quote promise. The Blue Ape quote route above remains available if you already want installer introductions.

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Insights for NN3

Figures below are tailored to NN3 — click through for full league tables.

Big-Roof Britain Rank #941 of 2182
5.1 kWp (UK avg 5.1 kWp)
~11 panels (≈430 W)
Solar Payback Index Rank #1309 of 2996
10.2 years (UK avg 10.8 years)
~£797 /yr • £8,139 upfront
Standing-Charge Drag Rank #1344 of 2996
24.6% (UK avg 26.6%) drag on savings
£196 fixed • ~£797 /yr value
Aspect Penalty View ranking →
East −21.8% West −20.0%
Typical output loss versus a south-facing roof (lower is better)

Seasonal solar output in NN3

Monthly generation per kilowatt of solar panels

kWh 39 Jan 53 Feb 85 Mar 111 Apr 119 May 118 Jun 121 Jul 109 Aug 93 Sep 66 Oct 46 Nov 34 Dec
Best month Worst month Winter (Dec–Feb) Other months

Winter output: 50.8% of an average month (Dec–Feb)

Best / worst month: Jul / Dec

These figures show output per kilowatt (kW) of panels installed. In winter, a 1 kW system here produces about 42 kWh per month; the average month produces around 83 kWh. So a typical 4 kW home system would generate roughly 168 kWh in winter, or 331 kWh in an average month.

Your Area at a Glance

Your Electricity Rate
25.10p/kWh
Daily Fixed Charge
53.60p/day
Local Sunshine
994kWh/kW
A 1 kW system generates ~994 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: 73% • Flats: 12% • Bungalows: 13% Based on 17,852 properties

Coverage

West Northamptonshire (100%)

Areas Covered

Billing, Headlands, Talavera, Moulton, Parklands, Blackthorn & Rectory Farm, Weston Favell & Abington Vale, Kingsley & Semilong + 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.

Compare nearby areas

Nearby in East Midlands

NN2 (West Northamptonshire)
≈3.8 km away
Local sunshine: ~994 kWh/kWp · +0% vs NN3
NN1 (West Northamptonshire)
≈4.2 km away
Local sunshine: ~990 kWh/kWp · -0% vs NN3
NN99 (West Northamptonshire)
≈5.0 km away
Local sunshine: ~987 kWh/kWp · -1% vs NN3
NN7 (West Northamptonshire)
≈5.7 km away
Local sunshine: ~993 kWh/kWp · -0% vs NN3
NN4 (West Northamptonshire)
≈5.9 km away
Local sunshine: ~993 kWh/kWp · -0% vs NN3
NN5 (West Northamptonshire)
≈6.5 km away
Local sunshine: ~990 kWh/kWp · -0% vs NN3

Similar sunshine across the UK

SE13 (Lewisham)
~993 kWh/kWp · -0% vs NN3
UB5 (Ealing)
~994 kWh/kWp · +0% vs NN3
SN12 (Wiltshire)
~994 kWh/kWp · +0% vs NN3