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Solar panel cost in Gwynedd (LL23)

See realistic solar installation costs, savings and payback for LL23 (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
13.4 years
After this, it's pure profit
Upfront Cost
£10,173
What you pay to get started
Annual Benefit
£758
What you save every year
Profit Over 25 Years
£8,777
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 860 kWh/kW — 70 below the regional median (930).

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 860 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)
860 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: £758, Upfront: £10,173, Break-even: 13.4 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1719 kWh 688 kWh 1031 kWh £200 £103 £303 £4,069 13.4 yrs £1,995
3 kW 2579 kWh 1031 kWh 1547 kWh £300 £155 £455 £6,104 13.4 yrs £2,992
4 kW 3438 kWh 1375 kWh 2063 kWh £400 £206 £606 £8,138 13.4 yrs £3,989
5 kW 4298 kWh 1719 kWh 2579 kWh £500 £258 £758 £10,173 13.4 yrs £4,987
6 kW 5157 kWh 2063 kWh 3094 kWh £600 £309 £910 £12,207 13.4 yrs £5,984
7 kW 6017 kWh 2407 kWh 3610 kWh £700 £361 £1,061 £14,242 13.4 yrs £6,982
8 kW 6877 kWh 2751 kWh 4126 kWh £800 £413 £1,213 £16,276 13.4 yrs £7,979

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: £922, Upfront: £12,273, Break-even: 13.3 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1719 kWh 1031 kWh 688 kWh £300 £69 £369 £6,169 16.7 yrs £1,207
3 kW 2579 kWh 1547 kWh 1031 kWh £450 £103 £553 £8,204 14.8 yrs £2,861
4 kW 3438 kWh 2063 kWh 1375 kWh £600 £138 £738 £10,238 13.9 yrs £4,515
5 kW 4298 kWh 2579 kWh 1719 kWh £750 £172 £922 £12,273 13.3 yrs £6,169
6 kW 5157 kWh 3094 kWh 2063 kWh £900 £206 £1,106 £14,307 12.9 yrs £7,822
7 kW 6017 kWh 3610 kWh 2407 kWh £1,050 £241 £1,291 £16,342 12.7 yrs £9,476
8 kW 6877 kWh 4126 kWh 2751 kWh £1,200 £275 £1,475 £18,376 12.5 yrs £11,130

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: £1,004, Upfront: £13,673, Break-even: 13.6 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1719 kWh 1203 kWh 516 kWh £350 £52 £402 £7,569 18.8 yrs £464
3 kW 2579 kWh 1805 kWh 774 kWh £525 £77 £602 £9,604 15.9 yrs £2,446
4 kW 3438 kWh 2407 kWh 1031 kWh £700 £103 £803 £11,638 14.5 yrs £4,428
5 kW 4298 kWh 3008 kWh 1289 kWh £875 £129 £1,004 £13,673 13.6 yrs £6,410
6 kW 5157 kWh 3610 kWh 1547 kWh £1,050 £155 £1,205 £15,707 13.0 yrs £8,392
7 kW 6017 kWh 4212 kWh 1805 kWh £1,225 £181 £1,406 £17,742 12.6 yrs £10,373
8 kW 6877 kWh 4814 kWh 2063 kWh £1,400 £206 £1,607 £19,776 12.3 yrs £12,355

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: £1,029, Upfront: £15,423, 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 1719 kWh 1255 kWh 464 kWh £365 £46 £411 £9,319 22.6 yrs £-1,089
3 kW 2579 kWh 1882 kWh 696 kWh £548 £70 £617 £11,354 18.4 yrs £991
4 kW 3438 kWh 2510 kWh 928 kWh £730 £93 £823 £13,388 16.3 yrs £3,071
5 kW 4298 kWh 3137 kWh 1160 kWh £913 £116 £1,029 £15,423 15.0 yrs £5,152
6 kW 5157 kWh 3765 kWh 1393 kWh £1,095 £139 £1,234 £17,457 14.1 yrs £7,232
7 kW 6017 kWh 4392 kWh 1625 kWh £1,278 £162 £1,440 £19,492 13.5 yrs £9,313
8 kW 6877 kWh 5020 kWh 1857 kWh £1,460 £186 £1,646 £21,526 13.1 yrs £11,393

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: £1,045, Upfront: £17,173, 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 1719 kWh 1289 kWh 430 kWh £375 £43 £418 £11,069 26.5 yrs £-2,708
3 kW 2579 kWh 1934 kWh 645 kWh £563 £64 £627 £13,104 20.9 yrs £-562
4 kW 3438 kWh 2579 kWh 860 kWh £750 £86 £836 £15,138 18.1 yrs £1,584
5 kW 4298 kWh 3223 kWh 1074 kWh £938 £107 £1,045 £17,173 16.4 yrs £3,730
6 kW 5157 kWh 3868 kWh 1289 kWh £1,125 £129 £1,254 £19,207 15.3 yrs £5,876
7 kW 6017 kWh 4513 kWh 1504 kWh £1,313 £150 £1,463 £21,242 14.5 yrs £8,022
8 kW 6877 kWh 5157 kWh 1719 kWh £1,500 £172 £1,672 £23,276 13.9 yrs £10,168

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: £1,062, Upfront: £19,623, Break-even: 18.5 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1719 kWh 1324 kWh 395 kWh £385 £40 £425 £13,519 31.8 yrs £-5,027
3 kW 2579 kWh 1986 kWh 593 kWh £578 £59 £637 £15,554 24.4 yrs £-2,815
4 kW 3438 kWh 2647 kWh 791 kWh £770 £79 £849 £17,588 20.7 yrs £-603
5 kW 4298 kWh 3309 kWh 989 kWh £963 £99 £1,062 £19,623 18.5 yrs £1,608
6 kW 5157 kWh 3971 kWh 1186 kWh £1,155 £119 £1,274 £21,657 17.0 yrs £3,820
7 kW 6017 kWh 4633 kWh 1384 kWh £1,348 £138 £1,486 £23,692 15.9 yrs £6,032
8 kW 6877 kWh 5295 kWh 1582 kWh £1,540 £158 £1,698 £25,726 15.1 yrs £8,243

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 LL23

Figures below are tailored to LL23 — click through for full league tables.

Big-Roof Britain Rank #639 of 2182
5.4 kWp (UK avg 5.1 kWp)
~11 panels (≈430 W)
Solar Payback Index Rank #2388 of 2997
13.4 years (UK avg 12.6 years)
~£758 /yr • £10,173 upfront
Standing-Charge Drag Rank #2641 of 2997
34.2% (UK avg 24.6%) drag on savings
£259 fixed • ~£758 /yr value
Aspect Penalty View ranking →
East −17.9% West −18.5%
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
860kWh/kW
A 1 kW system generates ~860 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: 72% • Flats: 12% • Bungalows: 14% Based on 991 properties

Coverage

Gwynedd (100%)

Areas Covered

Y Bala, Llandderfel, Llanuwchllyn

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

LL21 (Denbighshire)
≈16.4 km away
Local sunshine: ~785 kWh/kWp · -9% vs LL23
LL24 (Conwy)
≈20.7 km away
Local sunshine: ~811 kWh/kWp · -6% vs LL23
LL41 (Gwynedd)
≈24.2 km away
Local sunshine: ~808 kWh/kWp · -6% vs LL23
LL25 (Conwy)
≈25.1 km away
Local sunshine: ~823 kWh/kWp · -4% vs LL23
LL40 (Gwynedd)
≈26.7 km away
Local sunshine: ~805 kWh/kWp · -6% vs LL23
LL26 (Conwy)
≈28.6 km away
Local sunshine: ~870 kWh/kWp · +1% vs LL23

Similar sunshine across the UK

EH23 (Midlothian)
~860 kWh/kWp · +0% vs LL23
PR5 (South Ribble)
~860 kWh/kWp · +0% vs LL23
BT54 (Causeway Coast and Glens)
~860 kWh/kWp · +0% vs LL23