Independent solar numbers for your postcode using official UK data
Home Regions Guides Compare quotes Solar assistant
Insights
Big Roof Britain Solar Payback Index Standing Charge Drag Roof Direction Penalty Winter Solar Reality Seasonal Solar Output

Solar panel cost in Gwynedd (LL40)

See realistic solar installation costs, savings and payback for LL40 (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
11.8 years
After this, it's pure profit
Upfront Cost
£9,767
What you pay to get started
Annual Benefit
£824
What you save every year
Profit Over 25 Years
£10,846
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: 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 North Wales and Mersey, the current unit rate is 27.66p/kWh with a 70.76p/day standing charge. Your postcode’s south-facing sunshine yield is 805 kWh/kW — 125 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 805 kWh per year on a south-facing roof. We value self-used electricity at 27.7p and exported surplus at a baseline 10p via SEG. Use the calculator above for your exact tariff.

Unit rate
27.7p/kWh
Standing charge
70.8p/day
Sunshine yield (south)
805 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: £687, Upfront: £8,139, Break-even: 11.8 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1611 kWh 644 kWh 966 kWh £178 £97 £275 £3,256 11.8 yrs £2,241
3 kW 2416 kWh 966 kWh 1450 kWh £267 £145 £412 £4,883 11.8 yrs £3,362
4 kW 3221 kWh 1288 kWh 1933 kWh £356 £193 £550 £6,511 11.8 yrs £4,482
5 kW 4026 kWh 1611 kWh 2416 kWh £445 £242 £687 £8,139 11.8 yrs £5,603
6 kW 4832 kWh 1933 kWh 2899 kWh £535 £290 £824 £9,767 11.8 yrs £6,723
7 kW 5637 kWh 2255 kWh 3382 kWh £624 £338 £962 £11,394 11.8 yrs £7,844
8 kW 6442 kWh 2577 kWh 3865 kWh £713 £387 £1,099 £13,022 11.8 yrs £8,964

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: £829, Upfront: £10,239, Break-even: 12.3 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1611 kWh 966 kWh 644 kWh £267 £64 £332 £5,356 16.1 yrs £1,279
3 kW 2416 kWh 1450 kWh 966 kWh £401 £97 £498 £6,983 14.0 yrs £2,968
4 kW 3221 kWh 1933 kWh 1288 kWh £535 £129 £663 £8,611 13.0 yrs £4,658
5 kW 4026 kWh 2416 kWh 1611 kWh £668 £161 £829 £10,239 12.3 yrs £6,347
6 kW 4832 kWh 2899 kWh 1933 kWh £802 £193 £995 £11,867 11.9 yrs £8,036
7 kW 5637 kWh 3382 kWh 2255 kWh £936 £225 £1,161 £13,494 11.6 yrs £9,726
8 kW 6442 kWh 3865 kWh 2577 kWh £1,069 £258 £1,327 £15,122 11.4 yrs £11,415

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: £900, Upfront: £11,639, Break-even: 12.9 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1611 kWh 1127 kWh 483 kWh £312 £48 £360 £6,756 18.8 yrs £448
3 kW 2416 kWh 1691 kWh 725 kWh £468 £72 £540 £8,383 15.5 yrs £2,421
4 kW 3221 kWh 2255 kWh 966 kWh £624 £97 £720 £10,011 13.9 yrs £4,395
5 kW 4026 kWh 2819 kWh 1208 kWh £780 £121 £900 £11,639 12.9 yrs £6,369
6 kW 4832 kWh 3382 kWh 1450 kWh £936 £145 £1,080 £13,267 12.3 yrs £8,343
7 kW 5637 kWh 3946 kWh 1691 kWh £1,091 £169 £1,261 £14,894 11.8 yrs £10,317
8 kW 6442 kWh 4510 kWh 1933 kWh £1,247 £193 £1,441 £16,522 11.5 yrs £12,291

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: £922, Upfront: £13,389, Break-even: 14.5 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1611 kWh 1176 kWh 435 kWh £325 £43 £369 £8,506 23.1 yrs £-1,132
3 kW 2416 kWh 1764 kWh 652 kWh £488 £65 £553 £10,133 18.3 yrs £927
4 kW 3221 kWh 2351 kWh 870 kWh £650 £87 £737 £11,761 15.9 yrs £2,987
5 kW 4026 kWh 2939 kWh 1087 kWh £813 £109 £922 £13,389 14.5 yrs £5,046
6 kW 4832 kWh 3527 kWh 1305 kWh £976 £130 £1,106 £15,017 13.6 yrs £7,105
7 kW 5637 kWh 4115 kWh 1522 kWh £1,138 £152 £1,290 £16,644 12.9 yrs £9,164
8 kW 6442 kWh 4703 kWh 1739 kWh £1,301 £174 £1,475 £18,272 12.4 yrs £11,223

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: £936, Upfront: £15,139, Break-even: 16.2 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1611 kWh 1208 kWh 403 kWh £334 £40 £374 £10,256 27.4 yrs £-2,768
3 kW 2416 kWh 1812 kWh 604 kWh £501 £60 £562 £11,883 21.2 yrs £-652
4 kW 3221 kWh 2416 kWh 805 kWh £668 £81 £749 £13,511 18.0 yrs £1,464
5 kW 4026 kWh 3020 kWh 1007 kWh £835 £101 £936 £15,139 16.2 yrs £3,580
6 kW 4832 kWh 3624 kWh 1208 kWh £1,002 £121 £1,123 £16,767 14.9 yrs £5,696
7 kW 5637 kWh 4228 kWh 1409 kWh £1,169 £141 £1,310 £18,394 14.0 yrs £7,812
8 kW 6442 kWh 4832 kWh 1611 kWh £1,336 £161 £1,498 £20,022 13.4 yrs £9,928

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: £950, Upfront: £17,589, 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 1611 kWh 1240 kWh 370 kWh £343 £37 £380 £12,706 33.4 yrs £-5,104
3 kW 2416 kWh 1860 kWh 556 kWh £515 £56 £570 £14,333 25.1 yrs £-2,931
4 kW 3221 kWh 2480 kWh 741 kWh £686 £74 £760 £15,961 21.0 yrs £-758
5 kW 4026 kWh 3100 kWh 926 kWh £858 £93 £950 £17,589 18.5 yrs £1,415
6 kW 4832 kWh 3720 kWh 1111 kWh £1,029 £111 £1,140 £19,217 16.9 yrs £3,588
7 kW 5637 kWh 4341 kWh 1297 kWh £1,201 £130 £1,330 £20,844 15.7 yrs £5,760
8 kW 6442 kWh 4961 kWh 1482 kWh £1,372 £148 £1,520 £22,472 14.8 yrs £7,933

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 Gwynedd

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

New quote check

Want a quote sanity check for LL40?

Share the first part of your postcode and a few basics. We’ll help you check whether system size, battery, export and paperwork assumptions look sensible before you commit to installer conversations.

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.

Request a quote sanity check →

Insights for LL40

Figures below are tailored to LL40 — click through for full league tables.

Big-Roof Britain Rank #520 of 2182
5.6 kWp (UK avg 5.1 kWp)
~12 panels (≈430 W)
Solar Payback Index Rank #2472 of 2996
11.9 years (UK avg 10.8 years)
~£824 /yr • £9,767 upfront
Standing-Charge Drag Rank #2277 of 2996
31.3% (UK avg 26.6%) drag on savings
£258 fixed • ~£824 /yr value
Aspect Penalty View ranking →
East −16.1% West −18.5%
Typical output loss versus a south-facing roof (lower is better)

Seasonal solar output in LL40

Monthly generation per kilowatt of solar panels

kWh 22 Jan 37 Feb 71 Mar 99 Apr 109 May 106 Jun 103 Jul 90 Aug 74 Sep 47 Oct 29 Nov 18 Dec
Best month Worst month Winter (Dec–Feb) Other months

Winter output: 38.3% 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 26 kWh per month; the average month produces around 67 kWh. So a typical 4 kW home system would generate roughly 103 kWh in winter, or 268 kWh in an average month.

Your Area at a Glance

Your Electricity Rate
27.66p/kWh
Daily Fixed Charge
70.76p/day
Local Sunshine
805kWh/kW
A 1 kW system generates ~805 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: 68% • Flats: 14% • Bungalows: 16% Based on 1,190 properties

Coverage

Gwynedd (100%)

Areas Covered

Brithdir and Llanfachreth/Ganllwyd/Llanelltyd, Gogledd Dolgellau, De Dolgellau, Arthog a Llangelynnin, Abermaw, Llanuwchllyn, Trawsfynydd

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 North Wales and Mersey

LL39 (Gwynedd)
≈9.3 km away
Local sunshine: ~825 kWh/kWp · +2% vs LL40
LL42 (Gwynedd)
≈11.8 km away
Local sunshine: ~864 kWh/kWp · +7% vs LL40
LL38 (Gwynedd)
≈12.4 km away
Local sunshine: ~846 kWh/kWp · +5% vs LL40
LL43 (Gwynedd)
≈14.4 km away
Local sunshine: ~875 kWh/kWp · +9% vs LL40
LL44 (Gwynedd)
≈15.2 km away
Local sunshine: ~875 kWh/kWp · +9% vs LL40
LL37 (Gwynedd)
≈16.0 km away
Local sunshine: ~878 kWh/kWp · +9% vs LL40

Similar sunshine across the UK

IV13 (Highland)
~805 kWh/kWp · -0% vs LL40
KW16 (Orkney Islands)
~806 kWh/kWp · +0% vs LL40
BT47 (Derry City and Strabane)
~806 kWh/kWp · +0% vs LL40