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Solar panel cost in Cornwall (TR12)

See realistic solar installation costs, savings and payback for TR12 (Cornwall) 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
9.0 years
After this, it's pure profit
Upfront Cost
£9,767
What you pay to get started
Annual Benefit
£1,090
What you save every year
Profit Over 25 Years
£17,480
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 Southern Western, the current unit rate is 26.39p/kWh with a 57.89p/day standing charge. Your postcode’s south-facing sunshine yield is 1097 kWh/kW — 84 above the regional median (1013).

Read the full story

A typical roof here lands around 6.0 kW, with most eligible homes comfortably fitting within 3–6 kW. Each kilowatt of panels produces roughly 1097 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
57.9p/day
Sunshine yield (south)
1097 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: £908, Upfront: £8,139, Break-even: 9.0 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2194 kWh 878 kWh 1317 kWh £232 £132 £363 £3,256 9.0 yrs £4,010
3 kW 3291 kWh 1317 kWh 1975 kWh £347 £197 £545 £4,883 9.0 yrs £6,015
4 kW 4389 kWh 1755 kWh 2633 kWh £463 £263 £727 £6,511 9.0 yrs £8,020
5 kW 5486 kWh 2194 kWh 3291 kWh £579 £329 £908 £8,139 9.0 yrs £10,026
6 kW 6583 kWh 2633 kWh 3950 kWh £695 £395 £1,090 £9,767 9.0 yrs £12,031
7 kW 7680 kWh 3072 kWh 4608 kWh £811 £461 £1,272 £11,394 9.0 yrs £14,036
8 kW 8777 kWh 3511 kWh 5266 kWh £927 £527 £1,453 £13,022 9.0 yrs £16,041

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: £1,088, Upfront: £10,239, Break-even: 9.4 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2194 kWh 1317 kWh 878 kWh £347 £88 £435 £5,356 12.3 yrs £3,349
3 kW 3291 kWh 1975 kWh 1317 kWh £521 £132 £653 £6,983 10.7 yrs £6,073
4 kW 4389 kWh 2633 kWh 1755 kWh £695 £176 £870 £8,611 9.9 yrs £8,798
5 kW 5486 kWh 3291 kWh 2194 kWh £869 £219 £1,088 £10,239 9.4 yrs £11,522
6 kW 6583 kWh 3950 kWh 2633 kWh £1,042 £263 £1,306 £11,867 9.1 yrs £14,246
7 kW 7680 kWh 4608 kWh 3072 kWh £1,216 £307 £1,523 £13,494 8.9 yrs £16,971
8 kW 8777 kWh 5266 kWh 3511 kWh £1,390 £351 £1,741 £15,122 8.7 yrs £19,695

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: £1,178, Upfront: £11,639, Break-even: 9.9 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2194 kWh 1536 kWh 658 kWh £405 £66 £471 £6,756 14.3 yrs £2,668
3 kW 3291 kWh 2304 kWh 987 kWh £608 £99 £707 £8,383 11.9 yrs £5,752
4 kW 4389 kWh 3072 kWh 1317 kWh £811 £132 £942 £10,011 10.6 yrs £8,836
5 kW 5486 kWh 3840 kWh 1646 kWh £1,013 £165 £1,178 £11,639 9.9 yrs £11,920
6 kW 6583 kWh 4608 kWh 1975 kWh £1,216 £197 £1,414 £13,267 9.4 yrs £15,004
7 kW 7680 kWh 5376 kWh 2304 kWh £1,419 £230 £1,649 £14,894 9.0 yrs £18,088
8 kW 8777 kWh 6144 kWh 2633 kWh £1,621 £263 £1,885 £16,522 8.8 yrs £21,172

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: £1,205, Upfront: £13,389, Break-even: 11.1 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2194 kWh 1602 kWh 592 kWh £423 £59 £482 £8,506 17.6 yrs £1,134
3 kW 3291 kWh 2403 kWh 889 kWh £634 £89 £723 £10,133 14.0 yrs £4,326
4 kW 4389 kWh 3204 kWh 1185 kWh £845 £118 £964 £11,761 12.2 yrs £7,518
5 kW 5486 kWh 4005 kWh 1481 kWh £1,057 £148 £1,205 £13,389 11.1 yrs £10,710
6 kW 6583 kWh 4806 kWh 1777 kWh £1,268 £178 £1,446 £15,017 10.4 yrs £13,902
7 kW 7680 kWh 5606 kWh 2074 kWh £1,480 £207 £1,687 £16,644 9.9 yrs £17,094
8 kW 8777 kWh 6407 kWh 2370 kWh £1,691 £237 £1,928 £18,272 9.5 yrs £20,286

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: £1,223, Upfront: £15,139, Break-even: 12.4 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2194 kWh 1646 kWh 549 kWh £434 £55 £489 £10,256 21.0 yrs £-472
3 kW 3291 kWh 2469 kWh 823 kWh £651 £82 £734 £11,883 16.2 yrs £2,792
4 kW 4389 kWh 3291 kWh 1097 kWh £869 £110 £978 £13,511 13.8 yrs £6,056
5 kW 5486 kWh 4114 kWh 1371 kWh £1,086 £137 £1,223 £15,139 12.4 yrs £9,319
6 kW 6583 kWh 4937 kWh 1646 kWh £1,303 £165 £1,467 £16,767 11.4 yrs £12,583
7 kW 7680 kWh 5760 kWh 1920 kWh £1,520 £192 £1,712 £18,394 10.7 yrs £15,847
8 kW 8777 kWh 6583 kWh 2194 kWh £1,737 £219 £1,957 £20,022 10.2 yrs £19,111

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: £1,241, Upfront: £17,589, Break-even: 14.2 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2194 kWh 1690 kWh 505 kWh £446 £50 £496 £12,706 25.6 yrs £-2,778
3 kW 3291 kWh 2534 kWh 757 kWh £669 £76 £745 £14,333 19.3 yrs £557
4 kW 4389 kWh 3379 kWh 1009 kWh £892 £101 £993 £15,961 16.1 yrs £3,893
5 kW 5486 kWh 4224 kWh 1262 kWh £1,115 £126 £1,241 £17,589 14.2 yrs £7,229
6 kW 6583 kWh 5069 kWh 1514 kWh £1,338 £151 £1,489 £19,217 12.9 yrs £10,565
7 kW 7680 kWh 5914 kWh 1766 kWh £1,561 £177 £1,737 £20,844 12.0 yrs £13,901
8 kW 8777 kWh 6758 kWh 2019 kWh £1,784 £202 £1,985 £22,472 11.3 yrs £17,236

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 Cornwall

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.

Compare solar quotes before you sign

Check what MCS certification means

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 TR12

Figures below are tailored to TR12 — click through for full league tables.

Big-Roof Britain Rank #103 of 2182
6.5 kWp (UK avg 5.1 kWp)
~14 panels (≈430 W)
Solar Payback Index Rank #118 of 2996
9.0 years (UK avg 10.8 years)
~£1,090 /yr • £9,767 upfront
Standing-Charge Drag Rank #384 of 2996
19.4% (UK avg 26.6%) drag on savings
£211 fixed • ~£1,090 /yr value
Aspect Penalty View ranking →
East −18.9% West −21.5%
Typical output loss versus a south-facing roof (lower is better)

Seasonal solar output in TR12

Monthly generation per kilowatt of solar panels

kWh 41 Jan 58 Feb 92 Mar 126 Apr 135 May 134 Jun 133 Jul 124 Aug 101 Sep 72 Oct 47 Nov 34 Dec
Best month Worst month Winter (Dec–Feb) Other months

Winter output: 48.5% 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 44 kWh per month; the average month produces around 91 kWh. So a typical 4 kW home system would generate roughly 177 kWh in winter, or 366 kWh in an average month.

Your Area at a Glance

Your Electricity Rate
26.39p/kWh
Daily Fixed Charge
57.89p/day
Local Sunshine
1097kWh/kW
A 1 kW system generates ~1097 kWh per year. A typical home uses ~2,700 kWh per year.
Typical System Size
6.0kW
For houses & bungalows in this area

Local Property Data

Property Types

Houses: 60% • Flats: 6% • Bungalows: 34% Based on 3,240 properties

Coverage

Cornwall (100%)

Areas Covered

Mullion & St Keverne, Helston South & Meneage, Constantine, Mabe & Mawnan

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 Southern Western

TR13 (Cornwall)
≈8.0 km away
Local sunshine: ~1,082 kWh/kWp · -1% vs TR12
TR11 (Cornwall)
≈14.3 km away
Local sunshine: ~1,021 kWh/kWp · -7% vs TR12
TR10 (Cornwall)
≈14.7 km away
Local sunshine: ~1,027 kWh/kWp · -6% vs TR12
TR14 (Cornwall)
≈19.5 km away
Local sunshine: ~1,008 kWh/kWp · -8% vs TR12
TR3 (Cornwall)
≈19.7 km away
Local sunshine: ~1,038 kWh/kWp · -5% vs TR12
TR15 (Cornwall)
≈20.6 km away
Local sunshine: ~1,012 kWh/kWp · -8% vs TR12

Similar sunshine across the UK

PO11 (Havant)
~1,096 kWh/kWp · -0% vs TR12
PO9 (Havant)
~1,096 kWh/kWp · -0% vs TR12
PO2 (Portsmouth)
~1,096 kWh/kWp · -0% vs TR12