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Solar panel cost in Cardiff (CF4)

See realistic solar installation costs, savings and payback for CF4 (Cardiff) 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
9.7 years
After this, it's pure profit
Upfront Cost
£8,139
What you pay to get started
Annual Benefit
£838
What you save every year
Profit Over 25 Years
£12,803
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: 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 South Wales, the current unit rate is 26.33p/kWh with a 57.84p/day standing charge. Your postcode’s south-facing sunshine yield is 1013 kWh/kW — 45 above the regional median (968).

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 1013 kWh per year on a south-facing roof. We value self-used electricity at 26.3p and exported surplus at a baseline 10p via SEG. Use the calculator above for your exact tariff.

Unit rate
26.3p/kWh
Standing charge
57.8p/day
Sunshine yield (south)
1013 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: £838, Upfront: £8,139, Break-even: 9.7 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2027 kWh 811 kWh 1216 kWh £213 £122 £335 £3,256 9.7 yrs £3,446
3 kW 3040 kWh 1216 kWh 1824 kWh £320 £182 £503 £4,883 9.7 yrs £5,169
4 kW 4054 kWh 1621 kWh 2432 kWh £427 £243 £670 £6,511 9.7 yrs £6,892
5 kW 5067 kWh 2027 kWh 3040 kWh £534 £304 £838 £8,139 9.7 yrs £8,615
6 kW 6080 kWh 2432 kWh 3648 kWh £640 £365 £1,005 £9,767 9.7 yrs £10,338
7 kW 7094 kWh 2838 kWh 4256 kWh £747 £426 £1,173 £11,394 9.7 yrs £12,061
8 kW 8107 kWh 3243 kWh 4864 kWh £854 £486 £1,340 £13,022 9.7 yrs £13,784

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: £1,003, Upfront: £10,239, Break-even: 10.2 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2027 kWh 1216 kWh 811 kWh £320 £81 £401 £5,356 13.3 yrs £2,670
3 kW 3040 kWh 1824 kWh 1216 kWh £480 £122 £602 £6,983 11.6 yrs £5,055
4 kW 4054 kWh 2432 kWh 1621 kWh £640 £162 £803 £8,611 10.7 yrs £7,440
5 kW 5067 kWh 3040 kWh 2027 kWh £800 £203 £1,003 £10,239 10.2 yrs £9,825
6 kW 6080 kWh 3648 kWh 2432 kWh £961 £243 £1,204 £11,867 9.9 yrs £12,210
7 kW 7094 kWh 4256 kWh 2838 kWh £1,121 £284 £1,404 £13,494 9.6 yrs £14,595
8 kW 8107 kWh 4864 kWh 3243 kWh £1,281 £324 £1,605 £15,122 9.4 yrs £16,980

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: £1,086, Upfront: £11,639, Break-even: 10.7 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2027 kWh 1419 kWh 608 kWh £374 £61 £434 £6,756 15.6 yrs £1,932
3 kW 3040 kWh 2128 kWh 912 kWh £560 £91 £652 £8,383 12.9 yrs £4,648
4 kW 4054 kWh 2838 kWh 1216 kWh £747 £122 £869 £10,011 11.5 yrs £7,364
5 kW 5067 kWh 3547 kWh 1520 kWh £934 £152 £1,086 £11,639 10.7 yrs £10,080
6 kW 6080 kWh 4256 kWh 1824 kWh £1,121 £182 £1,303 £13,267 10.2 yrs £12,796
7 kW 7094 kWh 4966 kWh 2128 kWh £1,307 £213 £1,520 £14,894 9.8 yrs £15,511
8 kW 8107 kWh 5675 kWh 2432 kWh £1,494 £243 £1,737 £16,522 9.5 yrs £18,227

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: £1,111, Upfront: £13,389, Break-even: 12.1 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2027 kWh 1480 kWh 547 kWh £390 £55 £444 £8,506 19.1 yrs £380
3 kW 3040 kWh 2219 kWh 821 kWh £584 £82 £666 £10,133 15.2 yrs £3,196
4 kW 4054 kWh 2959 kWh 1094 kWh £779 £109 £889 £11,761 13.2 yrs £6,011
5 kW 5067 kWh 3699 kWh 1368 kWh £974 £137 £1,111 £13,389 12.1 yrs £8,826
6 kW 6080 kWh 4439 kWh 1642 kWh £1,169 £164 £1,333 £15,017 11.3 yrs £11,641
7 kW 7094 kWh 5179 kWh 1915 kWh £1,364 £192 £1,555 £16,644 10.7 yrs £14,456
8 kW 8107 kWh 5918 kWh 2189 kWh £1,558 £219 £1,777 £18,272 10.3 yrs £17,272

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: £1,127, Upfront: £15,139, 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 2027 kWh 1520 kWh 507 kWh £400 £51 £451 £10,256 22.7 yrs £-1,237
3 kW 3040 kWh 2280 kWh 760 kWh £600 £76 £676 £11,883 17.6 yrs £1,644
4 kW 4054 kWh 3040 kWh 1013 kWh £800 £101 £902 £13,511 15.0 yrs £4,526
5 kW 5067 kWh 3800 kWh 1267 kWh £1,001 £127 £1,127 £15,139 13.4 yrs £7,407
6 kW 6080 kWh 4560 kWh 1520 kWh £1,201 £152 £1,353 £16,767 12.4 yrs £10,288
7 kW 7094 kWh 5320 kWh 1773 kWh £1,401 £177 £1,578 £18,394 11.7 yrs £13,170
8 kW 8107 kWh 6080 kWh 2027 kWh £1,601 £203 £1,804 £20,022 11.1 yrs £16,051

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: £1,144, Upfront: £17,589, Break-even: 15.4 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2027 kWh 1561 kWh 466 kWh £411 £47 £458 £12,706 27.8 yrs £-3,555
3 kW 3040 kWh 2341 kWh 699 kWh £616 £70 £686 £14,333 20.9 yrs £-607
4 kW 4054 kWh 3121 kWh 932 kWh £822 £93 £915 £15,961 17.4 yrs £2,340
5 kW 5067 kWh 3902 kWh 1165 kWh £1,027 £117 £1,144 £17,589 15.4 yrs £5,288
6 kW 6080 kWh 4682 kWh 1399 kWh £1,233 £140 £1,373 £19,217 14.0 yrs £8,236
7 kW 7094 kWh 5462 kWh 1632 kWh £1,438 £163 £1,601 £20,844 13.0 yrs £11,183
8 kW 8107 kWh 6243 kWh 1865 kWh £1,644 £186 £1,830 £22,472 12.3 yrs £14,131

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 Cardiff

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.

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Understand DNO, G98 and G99 export limits

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Insights for CF4

Figures below are tailored to CF4 — click through for full league tables.

Solar Payback Index Rank #438 of 2996
9.7 years (UK avg 10.8 years)
~£837 /yr • £8,139 upfront
Standing-Charge Drag Rank #1439 of 2996
25.2% (UK avg 26.6%) drag on savings
£211 fixed • ~£837 /yr value
Aspect Penalty View ranking →
East −19.8% West −21.6%
Typical output loss versus a south-facing roof (lower is better)

Seasonal solar output in CF4

Monthly generation per kilowatt of solar panels

kWh 37 Jan 54 Feb 88 Mar 115 Apr 126 May 125 Jun 124 Jul 109 Aug 93 Sep 65 Oct 44 Nov 33 Dec
Best month Worst month Winter (Dec–Feb) Other months

Winter output: 48.8% 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 41 kWh per month; the average month produces around 84 kWh. So a typical 4 kW home system would generate roughly 165 kWh in winter, or 338 kWh in an average month.

Your Area at a Glance

Your Electricity Rate
26.33p/kWh
Daily Fixed Charge
57.84p/day
Local Sunshine
1013kWh/kW
A 1 kW system generates ~1013 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

No EPC data available for this outcode

Coverage

Cardiff (95%)|Rhondda Cynon Taf (5%)

Areas Covered

Whitchurch and Tongwynlais, Rhiwbina, Llanishen, Heath, Lisvane and Thornhill, Pentyrch and St Fagans, Llandaff North, Gabalfa + 4 more

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 South Wales

CF14 (Cardiff)
≈1.0 km away
Local sunshine: ~1,008 kWh/kWp · -0% vs CF4
CF15 (Cardiff)
≈3.8 km away
Local sunshine: ~985 kWh/kWp · -3% vs CF4
CF23 (Cardiff)
≈4.3 km away
Local sunshine: ~1,004 kWh/kWp · -1% vs CF4
CF2 (Cardiff)
≈4.5 km away
Local sunshine: ~1,009 kWh/kWp · -0% vs CF4
CF5 (Cardiff)
≈4.6 km away
Local sunshine: ~1,024 kWh/kWp · +1% vs CF4
CF24 (Cardiff)
≈5.0 km away
Local sunshine: ~1,009 kWh/kWp · -0% vs CF4

Similar sunshine across the UK

GU31 (East Hampshire)
~1,013 kWh/kWp · -0% vs CF4
LN11 (East Lindsey)
~1,013 kWh/kWp · +0% vs CF4
RM6 (Barking and Dagenham)
~1,013 kWh/kWp · +0% vs CF4