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Solar panel cost in Gwynedd (LL39)

See realistic solar installation costs, savings and payback for LL39 (Gwynedd) 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
14.0 years
After this, it's pure profit
Upfront Cost
£12,207
What you pay to get started
Annual Benefit
£873
What you save every year
Profit Over 25 Years
£9,620
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: 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 North Wales and Mersey, the current unit rate is 29.09p/kWh with a 71.01p/day standing charge. Your postcode’s south-facing sunshine yield is 825 kWh/kW — 105 below the regional median (930).

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 825 kWh per year on a south-facing roof. We value self-used electricity at 29.1p and exported surplus at a baseline 10p via SEG. Use the calculator above for your exact tariff.

Unit rate
29.1p/kWh
Standing charge
71.0p/day
Sunshine yield (south)
825 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: £728, Upfront: £10,173, Break-even: 14.0 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1650 kWh 660 kWh 990 kWh £192 £99 £291 £4,069 14.0 yrs £1,751
3 kW 2475 kWh 990 kWh 1485 kWh £288 £149 £437 £6,104 14.0 yrs £2,627
4 kW 3300 kWh 1320 kWh 1980 kWh £384 £198 £582 £8,138 14.0 yrs £3,503
5 kW 4125 kWh 1650 kWh 2475 kWh £480 £248 £728 £10,173 14.0 yrs £4,379
6 kW 4951 kWh 1980 kWh 2970 kWh £576 £297 £873 £12,207 14.0 yrs £5,254
7 kW 5776 kWh 2310 kWh 3465 kWh £672 £347 £1,019 £14,242 14.0 yrs £6,130
8 kW 6601 kWh 2640 kWh 3960 kWh £768 £396 £1,164 £16,276 14.0 yrs £7,006

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: £885, Upfront: £12,273, Break-even: 13.9 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1650 kWh 990 kWh 660 kWh £288 £66 £354 £6,169 17.4 yrs £912
3 kW 2475 kWh 1485 kWh 990 kWh £432 £99 £531 £8,204 15.4 yrs £2,417
4 kW 3300 kWh 1980 kWh 1320 kWh £576 £132 £708 £10,238 14.5 yrs £3,923
5 kW 4125 kWh 2475 kWh 1650 kWh £720 £165 £885 £12,273 13.9 yrs £5,429
6 kW 4951 kWh 2970 kWh 1980 kWh £864 £198 £1,062 £14,307 13.5 yrs £6,935
7 kW 5776 kWh 3465 kWh 2310 kWh £1,008 £231 £1,239 £16,342 13.2 yrs £8,441
8 kW 6601 kWh 3960 kWh 2640 kWh £1,152 £264 £1,416 £18,376 13.0 yrs £9,946

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: £964, Upfront: £13,673, 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 1650 kWh 1155 kWh 495 kWh £336 £50 £386 £7,569 19.6 yrs £142
3 kW 2475 kWh 1733 kWh 743 kWh £504 £74 £578 £9,604 16.6 yrs £1,962
4 kW 3300 kWh 2310 kWh 990 kWh £672 £99 £771 £11,638 15.1 yrs £3,783
5 kW 4125 kWh 2888 kWh 1238 kWh £840 £124 £964 £13,673 14.2 yrs £5,604
6 kW 4951 kWh 3465 kWh 1485 kWh £1,008 £149 £1,157 £15,707 13.6 yrs £7,425
7 kW 5776 kWh 4043 kWh 1733 kWh £1,176 £173 £1,349 £17,742 13.1 yrs £9,246
8 kW 6601 kWh 4621 kWh 1980 kWh £1,344 £198 £1,542 £19,776 12.8 yrs £11,066

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: £987, Upfront: £15,423, 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 1650 kWh 1205 kWh 446 kWh £350 £45 £395 £9,319 23.6 yrs £-1,419
3 kW 2475 kWh 1807 kWh 668 kWh £526 £67 £592 £11,354 19.2 yrs £496
4 kW 3300 kWh 2409 kWh 891 kWh £701 £89 £790 £13,388 16.9 yrs £2,411
5 kW 4125 kWh 3012 kWh 1114 kWh £876 £111 £987 £15,423 15.6 yrs £4,327
6 kW 4951 kWh 3614 kWh 1337 kWh £1,051 £134 £1,185 £17,457 14.7 yrs £6,242
7 kW 5776 kWh 4216 kWh 1559 kWh £1,226 £156 £1,382 £19,492 14.1 yrs £8,157
8 kW 6601 kWh 4819 kWh 1782 kWh £1,402 £178 £1,580 £21,526 13.6 yrs £10,072

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: £1,003, Upfront: £17,173, Break-even: 17.1 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1650 kWh 1238 kWh 413 kWh £360 £41 £401 £11,069 27.6 yrs £-3,043
3 kW 2475 kWh 1856 kWh 619 kWh £540 £62 £602 £13,104 21.8 yrs £-1,065
4 kW 3300 kWh 2475 kWh 825 kWh £720 £83 £803 £15,138 18.9 yrs £913
5 kW 4125 kWh 3094 kWh 1031 kWh £900 £103 £1,003 £17,173 17.1 yrs £2,892
6 kW 4951 kWh 3713 kWh 1238 kWh £1,080 £124 £1,204 £19,207 16.0 yrs £4,870
7 kW 5776 kWh 4332 kWh 1444 kWh £1,260 £144 £1,404 £21,242 15.1 yrs £6,848
8 kW 6601 kWh 4951 kWh 1650 kWh £1,440 £165 £1,605 £23,276 14.5 yrs £8,827

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: £1,019, Upfront: £19,623, Break-even: 19.3 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1650 kWh 1271 kWh 380 kWh £370 £38 £408 £13,519 33.2 yrs £-5,367
3 kW 2475 kWh 1906 kWh 569 kWh £554 £57 £611 £15,554 25.4 yrs £-3,326
4 kW 3300 kWh 2541 kWh 759 kWh £739 £76 £815 £17,588 21.6 yrs £-1,285
5 kW 4125 kWh 3177 kWh 949 kWh £924 £95 £1,019 £19,623 19.3 yrs £757
6 kW 4951 kWh 3812 kWh 1139 kWh £1,109 £114 £1,223 £21,657 17.7 yrs £2,798
7 kW 5776 kWh 4447 kWh 1328 kWh £1,294 £133 £1,427 £23,692 16.6 yrs £4,839
8 kW 6601 kWh 5083 kWh 1518 kWh £1,479 £152 £1,630 £25,726 15.8 yrs £6,881

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 LL39

Figures below are tailored to LL39 — click through for full league tables.

Big-Roof Britain Rank #97 of 2182
6.6 kWp (UK avg 5.1 kWp)
~14 panels (≈430 W)
Solar Payback Index Rank #2668 of 2997
14.0 years (UK avg 12.6 years)
~£873 /yr • £12,207 upfront
Standing-Charge Drag Rank #2390 of 2997
29.7% (UK avg 24.6%) drag on savings
£259 fixed • ~£873 /yr value
Aspect Penalty View ranking →
East −15.0% West −21.7%
Typical output loss versus a south-facing roof (lower is better)

Your Area at a Glance

Your Electricity Rate
29.09p/kWh
Daily Fixed Charge
71.01p/day
Local Sunshine
825kWh/kW
A 1 kW system generates ~825 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: 75% • Flats: 6% • Bungalows: 19% Based on 73 properties

Coverage

Gwynedd (100%)

Areas Covered

Arthog a Llangelynnin, De Dolgellau

Data Sources & Assumptions

Solar yield: PVGIS (EU Joint Research Centre), January 2025 data

Electricity rates: Ofgem price cap, Q1 2026

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 North Wales and Mersey

LL38 (Gwynedd)
≈3.1 km away
Local sunshine: ~846 kWh/kWp · +2% vs LL39
LL42 (Gwynedd)
≈3.4 km away
Local sunshine: ~864 kWh/kWp · +5% vs LL39
LL37 (Gwynedd)
≈6.9 km away
Local sunshine: ~878 kWh/kWp · +6% vs LL39
LL43 (Gwynedd)
≈9.0 km away
Local sunshine: ~875 kWh/kWp · +6% vs LL39
LL40 (Gwynedd)
≈9.3 km away
Local sunshine: ~805 kWh/kWp · -2% vs LL39
LL44 (Gwynedd)
≈10.5 km away
Local sunshine: ~875 kWh/kWp · +6% vs LL39

Similar sunshine across the UK

PA2 (Renfrewshire)
~825 kWh/kWp · +0% vs LL39
PA9 (Renfrewshire)
~825 kWh/kWp · +0% vs LL39
PH16 (Perth and Kinross)
~825 kWh/kWp · -0% vs LL39