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 TR22 (Isles of Scilly)

See if solar pays off for you in Isles of Scilly — 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
11.1 years
After this, it's pure profit
Upfront Cost
£10,173
What you pay to get started
Annual Benefit
£919
What you save every year
Profit Over 25 Years
£12,799
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 Western, the current unit rate is 26.82p/kWh with a 54.03p/day standing charge. Your postcode’s south-facing sunshine yield is 1099 kWh/kW — 85 above the regional median (1013).

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 1099 kWh per year on a south-facing roof. We value self-used electricity at 26.8p and exported surplus at a baseline 10p via SEG. Use the calculator above for your exact tariff.

Unit rate
26.8p/kWh
Standing charge
54.0p/day
Sunshine yield (south)
1099 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: £919, Upfront: £10,173, 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 2197 kWh 879 kWh 1318 kWh £236 £132 £368 £4,069 11.1 yrs £3,282
3 kW 3296 kWh 1318 kWh 1977 kWh £354 £198 £551 £6,104 11.1 yrs £4,923
4 kW 4394 kWh 1758 kWh 2637 kWh £471 £264 £735 £8,138 11.1 yrs £6,564
5 kW 5493 kWh 2197 kWh 3296 kWh £589 £330 £919 £10,173 11.1 yrs £8,205
6 kW 6592 kWh 2637 kWh 3955 kWh £707 £395 £1,103 £12,207 11.1 yrs £9,846
7 kW 7690 kWh 3076 kWh 4614 kWh £825 £461 £1,286 £14,242 11.1 yrs £11,487
8 kW 8789 kWh 3516 kWh 5273 kWh £943 £527 £1,470 £16,276 11.1 yrs £13,128

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: £1,104, Upfront: £12,273, 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 2197 kWh 1318 kWh 879 kWh £354 £88 £441 £6,169 14.0 yrs £2,660
3 kW 3296 kWh 1977 kWh 1318 kWh £530 £132 £662 £8,204 12.4 yrs £5,040
4 kW 4394 kWh 2637 kWh 1758 kWh £707 £176 £883 £10,238 11.6 yrs £7,420
5 kW 5493 kWh 3296 kWh 2197 kWh £884 £220 £1,104 £12,273 11.1 yrs £9,801
6 kW 6592 kWh 3955 kWh 2637 kWh £1,061 £264 £1,324 £14,307 10.8 yrs £12,181
7 kW 7690 kWh 4614 kWh 3076 kWh £1,238 £308 £1,545 £16,342 10.6 yrs £14,561
8 kW 8789 kWh 5273 kWh 3516 kWh £1,414 £352 £1,766 £18,376 10.4 yrs £16,941

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: £1,196, Upfront: £13,673, 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 2197 kWh 1538 kWh 659 kWh £413 £66 £478 £7,569 15.8 yrs £1,999
3 kW 3296 kWh 2307 kWh 989 kWh £619 £99 £718 £9,604 13.4 yrs £4,749
4 kW 4394 kWh 3076 kWh 1318 kWh £825 £132 £957 £11,638 12.2 yrs £7,499
5 kW 5493 kWh 3845 kWh 1648 kWh £1,031 £165 £1,196 £13,673 11.4 yrs £10,248
6 kW 6592 kWh 4614 kWh 1977 kWh £1,238 £198 £1,435 £15,707 10.9 yrs £12,998
7 kW 7690 kWh 5383 kWh 2307 kWh £1,444 £231 £1,674 £17,742 10.6 yrs £15,748
8 kW 8789 kWh 6152 kWh 2637 kWh £1,650 £264 £1,914 £19,776 10.3 yrs £18,497

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: £1,224, Upfront: £15,423, Break-even: 12.6 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2197 kWh 1604 kWh 593 kWh £430 £59 £490 £9,319 19.0 yrs £471
3 kW 3296 kWh 2406 kWh 890 kWh £645 £89 £734 £11,354 15.5 yrs £3,332
4 kW 4394 kWh 3208 kWh 1186 kWh £860 £119 £979 £13,388 13.7 yrs £6,192
5 kW 5493 kWh 4010 kWh 1483 kWh £1,075 £148 £1,224 £15,423 12.6 yrs £9,053
6 kW 6592 kWh 4812 kWh 1780 kWh £1,291 £178 £1,469 £17,457 11.9 yrs £11,913
7 kW 7690 kWh 5614 kWh 2076 kWh £1,506 £208 £1,713 £19,492 11.4 yrs £14,774
8 kW 8789 kWh 6416 kWh 2373 kWh £1,721 £237 £1,958 £21,526 11.0 yrs £17,634

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: £1,242, Upfront: £17,173, 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 2197 kWh 1648 kWh 549 kWh £442 £55 £497 £11,069 22.3 yrs £-1,131
3 kW 3296 kWh 2472 kWh 824 kWh £663 £82 £745 £13,104 17.6 yrs £1,803
4 kW 4394 kWh 3296 kWh 1099 kWh £884 £110 £994 £15,138 15.2 yrs £4,738
5 kW 5493 kWh 4120 kWh 1373 kWh £1,105 £137 £1,242 £17,173 13.8 yrs £7,672
6 kW 6592 kWh 4944 kWh 1648 kWh £1,326 £165 £1,491 £19,207 12.9 yrs £10,607
7 kW 7690 kWh 5768 kWh 1923 kWh £1,547 £192 £1,739 £21,242 12.2 yrs £13,541
8 kW 8789 kWh 6592 kWh 2197 kWh £1,768 £220 £1,988 £23,276 11.7 yrs £16,476

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: £1,261, Upfront: £19,623, Break-even: 15.6 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2197 kWh 1692 kWh 505 kWh £454 £51 £504 £13,519 26.8 yrs £-3,433
3 kW 3296 kWh 2538 kWh 758 kWh £681 £76 £756 £15,554 20.6 yrs £-425
4 kW 4394 kWh 3384 kWh 1011 kWh £908 £101 £1,009 £17,588 17.4 yrs £2,583
5 kW 5493 kWh 4230 kWh 1263 kWh £1,134 £126 £1,261 £19,623 15.6 yrs £5,592
6 kW 6592 kWh 5076 kWh 1516 kWh £1,361 £152 £1,513 £21,657 14.3 yrs £8,600
7 kW 7690 kWh 5921 kWh 1769 kWh £1,588 £177 £1,765 £23,692 13.4 yrs £11,609
8 kW 8789 kWh 6767 kWh 2021 kWh £1,815 £202 £2,017 £25,726 12.8 yrs £14,617

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 TR22

Figures below are tailored to TR22 — click through for full league tables.

Big-Roof Britain Rank #337 of 2182
5.8 kWp (UK avg 5.1 kWp)
~12 panels (≈430 W)
Solar Payback Index Rank #75 of 2997
9.6 years (UK avg 11.3 years)
~£1,057 /yr • £10,173 upfront
Standing-Charge Drag Rank #1203 of 2997
18.7% (UK avg 21.7%) drag on savings
£197 fixed • ~£1,057 /yr value

Your Area at a Glance

Your Electricity Rate
26.82p/kWh
Daily Fixed Charge
54.03p/day
Local Sunshine
1099kWh/kW
A 1 kW system generates ~1099 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: 62% • Flats: 0% • Bungalows: 38% Based on 21 properties

Coverage

Isles of Scilly (100%)

Areas Covered

St Agnes

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 Western

TR21 (Isles of Scilly)
≈3.3 km away
Local sunshine: ~1,066 kWh/kWp · -3% vs TR22
TR23 (Isles of Scilly)
≈6.7 km away
Local sunshine: ~1,101 kWh/kWp · +0% vs TR22
TR24 (Isles of Scilly)
≈7.0 km away
Local sunshine: ~1,096 kWh/kWp · -0% vs TR22
TR25 (Isles of Scilly)
≈8.6 km away
Local sunshine: ~1,092 kWh/kWp · -1% vs TR22
TR19 (Cornwall)
≈53.8 km away
Local sunshine: ~1,083 kWh/kWp · -1% vs TR22
TR18 (Cornwall)
≈62.6 km away
Local sunshine: ~1,066 kWh/kWp · -3% vs TR22

Similar sunshine across the UK

CM0 (Maldon)
~1,099 kWh/kWp · +0% vs TR22
CT13 (Dover)
~1,100 kWh/kWp · +0% vs TR22
PO11 (Havant)
~1,096 kWh/kWp · -0% vs TR22