Solar explained to clever people by people who are not trying to be clever
Home Regions
Insights
Big Roof Britain Solar Payback Index Standing Charge Drag

Solar Panels in NP2 (Caerphilly)

See if solar pays off for you in Caerphilly — price, savings and payback in under a minute (official UK data).

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
13.2 years
After this, it's pure profit
Upfront Cost
£10,173
What you pay to get started
Annual Benefit
£768
What you save every year
Profit Over 25 Years
£9,028
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: 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 South Wales, the current unit rate is 26.83p/kWh with a 51.69p/day standing charge. Your postcode’s south-facing sunshine yield is 918 kWh/kW — 50 below 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 918 kWh per year on a south-facing roof. We value self-used electricity at 26.8p and exported surplus at a baseline 10p via SEG. Use the calculator above for your exact tariff.

Unit rate
26.8p/kWh
Standing charge
51.7p/day
Sunshine yield (south)
918 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: £768, Upfront: £10,173, Break-even: 13.2 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1836 kWh 734 kWh 1102 kWh £197 £110 £307 £4,069 13.2 yrs £2,075
3 kW 2754 kWh 1102 kWh 1652 kWh £296 £165 £461 £6,104 13.2 yrs £3,113
4 kW 3672 kWh 1469 kWh 2203 kWh £394 £220 £614 £8,138 13.2 yrs £4,151
5 kW 4590 kWh 1836 kWh 2754 kWh £493 £275 £768 £10,173 13.2 yrs £5,188
6 kW 5508 kWh 2203 kWh 3305 kWh £591 £330 £922 £12,207 13.2 yrs £6,226
7 kW 6426 kWh 2571 kWh 3856 kWh £690 £386 £1,075 £14,242 13.2 yrs £7,264
8 kW 7344 kWh 2938 kWh 4407 kWh £788 £441 £1,229 £16,276 13.2 yrs £8,301

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: £923, 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 1836 kWh 1102 kWh 734 kWh £296 £73 £369 £6,169 16.7 yrs £1,211
3 kW 2754 kWh 1652 kWh 1102 kWh £443 £110 £554 £8,204 14.8 yrs £2,867
4 kW 3672 kWh 2203 kWh 1469 kWh £591 £147 £738 £10,238 13.9 yrs £4,523
5 kW 4590 kWh 2754 kWh 1836 kWh £739 £184 £923 £12,273 13.3 yrs £6,178
6 kW 5508 kWh 3305 kWh 2203 kWh £887 £220 £1,107 £14,307 12.9 yrs £7,834
7 kW 6426 kWh 3856 kWh 2571 kWh £1,035 £257 £1,292 £16,342 12.7 yrs £9,490
8 kW 7344 kWh 4407 kWh 2938 kWh £1,182 £294 £1,476 £18,376 12.4 yrs £11,145

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: £1,000, Upfront: £13,673, Break-even: 13.7 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1836 kWh 1285 kWh 551 kWh £345 £55 £400 £7,569 18.9 yrs £429
3 kW 2754 kWh 1928 kWh 826 kWh £517 £83 £600 £9,604 16.0 yrs £2,394
4 kW 3672 kWh 2571 kWh 1102 kWh £690 £110 £800 £11,638 14.6 yrs £4,359
5 kW 4590 kWh 3213 kWh 1377 kWh £862 £138 £1,000 £13,673 13.7 yrs £6,323
6 kW 5508 kWh 3856 kWh 1652 kWh £1,035 £165 £1,200 £15,707 13.1 yrs £8,288
7 kW 6426 kWh 4498 kWh 1928 kWh £1,207 £193 £1,400 £17,742 12.7 yrs £10,253
8 kW 7344 kWh 5141 kWh 2203 kWh £1,379 £220 £1,600 £19,776 12.4 yrs £12,218

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: £1,023, Upfront: £15,423, Break-even: 15.1 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1836 kWh 1340 kWh 496 kWh £360 £50 £409 £9,319 22.8 yrs £-1,135
3 kW 2754 kWh 2011 kWh 744 kWh £539 £74 £614 £11,354 18.5 yrs £922
4 kW 3672 kWh 2681 kWh 991 kWh £719 £99 £818 £13,388 16.4 yrs £2,980
5 kW 4590 kWh 3351 kWh 1239 kWh £899 £124 £1,023 £15,423 15.1 yrs £5,037
6 kW 5508 kWh 4021 kWh 1487 kWh £1,079 £149 £1,228 £17,457 14.2 yrs £7,094
7 kW 6426 kWh 4691 kWh 1735 kWh £1,259 £174 £1,432 £19,492 13.6 yrs £9,152
8 kW 7344 kWh 5361 kWh 1983 kWh £1,438 £198 £1,637 £21,526 13.2 yrs £11,209

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: £1,038, Upfront: £17,173, Break-even: 16.5 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1836 kWh 1377 kWh 459 kWh £369 £46 £415 £11,069 26.6 yrs £-2,762
3 kW 2754 kWh 2066 kWh 689 kWh £554 £69 £623 £13,104 21.0 yrs £-642
4 kW 3672 kWh 2754 kWh 918 kWh £739 £92 £831 £15,138 18.2 yrs £1,477
5 kW 4590 kWh 3443 kWh 1148 kWh £924 £115 £1,038 £17,173 16.5 yrs £3,596
6 kW 5508 kWh 4131 kWh 1377 kWh £1,108 £138 £1,246 £19,207 15.4 yrs £5,715
7 kW 6426 kWh 4820 kWh 1607 kWh £1,293 £161 £1,454 £21,242 14.6 yrs £7,834
8 kW 7344 kWh 5508 kWh 1836 kWh £1,478 £184 £1,661 £23,276 14.0 yrs £9,954

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: £1,054, Upfront: £19,623, Break-even: 18.6 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1836 kWh 1414 kWh 422 kWh £379 £42 £422 £13,519 32.1 yrs £-5,088
3 kW 2754 kWh 2121 kWh 633 kWh £569 £63 £632 £15,554 24.6 yrs £-2,907
4 kW 3672 kWh 2828 kWh 845 kWh £759 £84 £843 £17,588 20.9 yrs £-726
5 kW 4590 kWh 3534 kWh 1056 kWh £948 £106 £1,054 £19,623 18.6 yrs £1,455
6 kW 5508 kWh 4241 kWh 1267 kWh £1,138 £127 £1,265 £21,657 17.1 yrs £3,636
7 kW 6426 kWh 4948 kWh 1478 kWh £1,328 £148 £1,475 £23,692 16.1 yrs £5,817
8 kW 7344 kWh 5655 kWh 1689 kWh £1,517 £169 £1,686 £25,726 15.3 yrs £7,998

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 NP2

Figures below are tailored to NP2 — click through for full league tables.

Solar Payback Index Rank #1797 of 2997
11.5 years (UK avg 11.3 years)
~£884 /yr • £10,173 upfront
Standing-Charge Drag Rank #1679 of 2997
21.3% (UK avg 21.7%) drag on savings
£189 fixed • ~£884 /yr value

Your Area at a Glance

Your Electricity Rate
26.83p/kWh
Daily Fixed Charge
51.69p/day
Local Sunshine
918kWh/kW
A 1 kW system generates ~918 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

Caerphilly (74%)|Blaenau Gwent (26%)

Areas Covered

Pontllanfraith, Blackwood, Cefn Fforest and Pengam, Tredegar, New Tredegar, Sirhowy, Penmaen, Twyn Carno + 4 more

Data Sources & Assumptions

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

Electricity rates: Ofgem price cap, Q4 2025

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 South Wales

CF81 (Caerphilly)
≈1.5 km away
Local sunshine: ~935 kWh/kWp · +2% vs NP2
NP24 (Caerphilly)
≈2.1 km away
Local sunshine: ~881 kWh/kWp · -4% vs NP2
NP12 (Caerphilly)
≈4.6 km away
Local sunshine: ~926 kWh/kWp · +1% vs NP2
CF82 (Caerphilly)
≈6.3 km away
Local sunshine: ~934 kWh/kWp · +2% vs NP2
NP13 (Blaenau Gwent)
≈6.8 km away
Local sunshine: ~933 kWh/kWp · +2% vs NP2
CF46 (Merthyr Tydfil)
≈7.3 km away
Local sunshine: ~939 kWh/kWp · +2% vs NP2

Similar sunshine across the UK

DL15 (County Durham)
~918 kWh/kWp · +0% vs NP2
NE40 (Gateshead)
~918 kWh/kWp · +0% vs NP2
WA7 (Halton)
~918 kWh/kWp · +0% vs NP2