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Solar panel cost in Gwynedd (LL35)

See realistic solar installation costs, savings and payback for LL35 (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
14.7 years
After this, it's pure profit
Upfront Cost
£12,207
What you pay to get started
Annual Benefit
£830
What you save every year
Profit Over 25 Years
£8,540
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 24.43p/kWh with a 69.98p/day standing charge. Your postcode’s south-facing sunshine yield is 877 kWh/kW — 53 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 877 kWh per year on a south-facing roof. We value self-used electricity at 24.4p and exported surplus at a baseline 10p via SEG. Use the calculator above for your exact tariff.

Unit rate
24.4p/kWh
Standing charge
70.0p/day
Sunshine yield (south)
877 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: £692, Upfront: £10,173, Break-even: 14.7 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1754 kWh 702 kWh 1052 kWh £171 £105 £277 £4,069 14.7 yrs £1,463
3 kW 2631 kWh 1052 kWh 1579 kWh £257 £158 £415 £6,104 14.7 yrs £2,195
4 kW 3508 kWh 1403 kWh 2105 kWh £343 £210 £553 £8,138 14.7 yrs £2,927
5 kW 4385 kWh 1754 kWh 2631 kWh £428 £263 £692 £10,173 14.7 yrs £3,659
6 kW 5262 kWh 2105 kWh 3157 kWh £514 £316 £830 £12,207 14.7 yrs £4,390
7 kW 6139 kWh 2455 kWh 3683 kWh £600 £368 £968 £14,242 14.7 yrs £5,122
8 kW 7016 kWh 2806 kWh 4209 kWh £686 £421 £1,107 £16,276 14.7 yrs £5,854

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: £818, Upfront: £12,273, Break-even: 15.0 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1754 kWh 1052 kWh 702 kWh £257 £70 £327 £6,169 18.9 yrs £376
3 kW 2631 kWh 1579 kWh 1052 kWh £386 £105 £491 £8,204 16.7 yrs £1,614
4 kW 3508 kWh 2105 kWh 1403 kWh £514 £140 £654 £10,238 15.6 yrs £2,852
5 kW 4385 kWh 2631 kWh 1754 kWh £643 £175 £818 £12,273 15.0 yrs £4,090
6 kW 5262 kWh 3157 kWh 2105 kWh £771 £210 £982 £14,307 14.6 yrs £5,327
7 kW 6139 kWh 3683 kWh 2455 kWh £900 £246 £1,145 £16,342 14.3 yrs £6,565
8 kW 7016 kWh 4209 kWh 2806 kWh £1,028 £281 £1,309 £18,376 14.0 yrs £7,803

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: £881, Upfront: £13,673, Break-even: 15.5 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1754 kWh 1228 kWh 526 kWh £300 £53 £353 £7,569 21.5 yrs £-518
3 kW 2631 kWh 1842 kWh 789 kWh £450 £79 £529 £9,604 18.2 yrs £973
4 kW 3508 kWh 2455 kWh 1052 kWh £600 £105 £705 £11,638 16.5 yrs £2,464
5 kW 4385 kWh 3069 kWh 1315 kWh £750 £132 £881 £13,673 15.5 yrs £3,955
6 kW 5262 kWh 3683 kWh 1579 kWh £900 £158 £1,058 £15,707 14.9 yrs £5,446
7 kW 6139 kWh 4297 kWh 1842 kWh £1,050 £184 £1,234 £17,742 14.4 yrs £6,937
8 kW 7016 kWh 4911 kWh 2105 kWh £1,200 £210 £1,410 £19,776 14.0 yrs £8,428

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: £900, Upfront: £15,423, 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 1754 kWh 1280 kWh 474 kWh £313 £47 £360 £9,319 25.9 yrs £-2,116
3 kW 2631 kWh 1921 kWh 710 kWh £469 £71 £540 £11,354 21.0 yrs £-549
4 kW 3508 kWh 2561 kWh 947 kWh £626 £95 £720 £13,388 18.6 yrs £1,018
5 kW 4385 kWh 3201 kWh 1184 kWh £782 £118 £900 £15,423 17.1 yrs £2,585
6 kW 5262 kWh 3841 kWh 1421 kWh £938 £142 £1,080 £17,457 16.2 yrs £4,152
7 kW 6139 kWh 4481 kWh 1657 kWh £1,095 £166 £1,261 £19,492 15.5 yrs £5,719
8 kW 7016 kWh 5121 kWh 1894 kWh £1,251 £189 £1,441 £21,526 14.9 yrs £7,285

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: £913, Upfront: £17,173, Break-even: 18.8 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1754 kWh 1315 kWh 438 kWh £321 £44 £365 £11,069 30.3 yrs £-3,765
3 kW 2631 kWh 1973 kWh 658 kWh £482 £66 £548 £13,104 23.9 yrs £-2,147
4 kW 3508 kWh 2631 kWh 877 kWh £643 £88 £730 £15,138 20.7 yrs £-530
5 kW 4385 kWh 3289 kWh 1096 kWh £803 £110 £913 £17,173 18.8 yrs £1,088
6 kW 5262 kWh 3946 kWh 1315 kWh £964 £132 £1,096 £19,207 17.5 yrs £2,705
7 kW 6139 kWh 4604 kWh 1535 kWh £1,125 £153 £1,278 £21,242 16.6 yrs £4,323
8 kW 7016 kWh 5262 kWh 1754 kWh £1,285 £175 £1,461 £23,276 15.9 yrs £5,940

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: £926, Upfront: £19,623, Break-even: 21.2 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1754 kWh 1351 kWh 403 kWh £330 £40 £370 £13,519 36.5 yrs £-6,114
3 kW 2631 kWh 2026 kWh 605 kWh £495 £61 £555 £15,554 28.0 yrs £-4,446
4 kW 3508 kWh 2701 kWh 807 kWh £660 £81 £741 £17,588 23.8 yrs £-2,777
5 kW 4385 kWh 3376 kWh 1008 kWh £825 £101 £926 £19,623 21.2 yrs £-1,109
6 kW 5262 kWh 4052 kWh 1210 kWh £990 £121 £1,111 £21,657 19.5 yrs £559
7 kW 6139 kWh 4727 kWh 1412 kWh £1,155 £141 £1,296 £23,692 18.3 yrs £2,227
8 kW 7016 kWh 5402 kWh 1614 kWh £1,320 £161 £1,481 £25,726 17.4 yrs £3,895

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 LL35

Figures below are tailored to LL35 — click through for full league tables.

Big-Roof Britain Rank #406 of 2182
5.7 kWp (UK avg 5.1 kWp)
~12 panels (≈430 W)
Solar Payback Index Rank #2209 of 2997
13.2 years (UK avg 12.6 years)
~£928 /yr • £12,207 upfront
Standing-Charge Drag Rank #2186 of 2997
27.9% (UK avg 24.6%) drag on savings
£259 fixed • ~£928 /yr value
Aspect Penalty View ranking →
East −19.5% West −20.2%
Typical output loss versus a south-facing roof (lower is better)

Seasonal solar output in LL35

Monthly generation per kilowatt of solar panels

kWh 29 Jan 46 Feb 78 Mar 107 Apr 116 May 111 Jun 107 Jul 95 Aug 78 Sep 53 Oct 34 Nov 23 Dec
Best month Worst month Winter (Dec–Feb) Other months

Winter output: 44.5% 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 33 kWh per month; the average month produces around 73 kWh. So a typical 4 kW home system would generate roughly 130 kWh in winter, or 292 kWh in an average month.

Your Area at a Glance

Your Electricity Rate
24.43p/kWh
Daily Fixed Charge
69.98p/day
Local Sunshine
877kWh/kW
A 1 kW system generates ~877 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: 57% • Flats: 17% • Bungalows: 25% Based on 516 properties

Coverage

Gwynedd (100%)

Areas Covered

Aberdyfi, Gorllewin Tywyn

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

LL36 (Gwynedd)
≈5.4 km away
Local sunshine: ~940 kWh/kWp · +7% vs LL35
SY24 (Ceredigion)
≈7.7 km away
Local sunshine: ~880 kWh/kWp · +0% vs LL35
LL37 (Gwynedd)
≈13.7 km away
Local sunshine: ~878 kWh/kWp · +0% vs LL35
SY20 (Powys)
≈14.6 km away
Local sunshine: ~817 kWh/kWp · -7% vs LL35
SY23 (Ceredigion)
≈15.5 km away
Local sunshine: ~924 kWh/kWp · +5% vs LL35
LL38 (Gwynedd)
≈16.8 km away
Local sunshine: ~846 kWh/kWp · -4% vs LL35

Similar sunshine across the UK

M21 (Manchester)
~877 kWh/kWp · +0% vs LL35
KA19 (South Ayrshire)
~877 kWh/kWp · -0% vs LL35
PH1 (Perth and Kinross)
~877 kWh/kWp · -0% vs LL35