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Solar Panels in NP1 (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
12.1 years
After this, it's pure profit
Upfront Cost
£10,173
What you pay to get started
Annual Benefit
£838
What you save every year
Profit Over 25 Years
£10,773
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 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 1001 kWh/kW — 33 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 1001 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)
1001 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: £10,173, 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 2003 kWh 801 kWh 1202 kWh £215 £120 £335 £4,069 12.1 yrs £2,633
3 kW 3004 kWh 1202 kWh 1803 kWh £322 £180 £503 £6,104 12.1 yrs £3,950
4 kW 4006 kWh 1602 kWh 2403 kWh £430 £240 £670 £8,138 12.1 yrs £5,267
5 kW 5007 kWh 2003 kWh 3004 kWh £537 £300 £838 £10,173 12.1 yrs £6,584
6 kW 6009 kWh 2403 kWh 3605 kWh £645 £361 £1,005 £12,207 12.1 yrs £7,900
7 kW 7010 kWh 2804 kWh 4206 kWh £752 £421 £1,173 £14,242 12.1 yrs £9,217
8 kW 8012 kWh 3205 kWh 4807 kWh £860 £481 £1,341 £16,276 12.1 yrs £10,534

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: £1,006, Upfront: £12,273, Break-even: 12.2 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2003 kWh 1202 kWh 801 kWh £322 £80 £403 £6,169 15.3 yrs £1,882
3 kW 3004 kWh 1803 kWh 1202 kWh £484 £120 £604 £8,204 13.6 yrs £3,873
4 kW 4006 kWh 2403 kWh 1602 kWh £645 £160 £805 £10,238 12.7 yrs £5,864
5 kW 5007 kWh 3004 kWh 2003 kWh £806 £200 £1,006 £12,273 12.2 yrs £7,855
6 kW 6009 kWh 3605 kWh 2403 kWh £967 £240 £1,208 £14,307 11.8 yrs £9,846
7 kW 7010 kWh 4206 kWh 2804 kWh £1,128 £280 £1,409 £16,342 11.6 yrs £11,836
8 kW 8012 kWh 4807 kWh 3205 kWh £1,290 £320 £1,610 £18,376 11.4 yrs £13,827

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: £1,091, Upfront: £13,673, Break-even: 12.5 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2003 kWh 1402 kWh 601 kWh £376 £60 £436 £7,569 17.4 yrs £1,156
3 kW 3004 kWh 2103 kWh 901 kWh £564 £90 £654 £9,604 14.7 yrs £3,484
4 kW 4006 kWh 2804 kWh 1202 kWh £752 £120 £873 £11,638 13.3 yrs £5,812
5 kW 5007 kWh 3505 kWh 1502 kWh £940 £150 £1,091 £13,673 12.5 yrs £8,140
6 kW 6009 kWh 4206 kWh 1803 kWh £1,128 £180 £1,309 £15,707 12.0 yrs £10,468
7 kW 7010 kWh 4907 kWh 2103 kWh £1,317 £210 £1,527 £17,742 11.6 yrs £12,796
8 kW 8012 kWh 5608 kWh 2403 kWh £1,505 £240 £1,745 £19,776 11.3 yrs £15,124

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: £1,116, Upfront: £15,423, Break-even: 13.8 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2003 kWh 1462 kWh 541 kWh £392 £54 £446 £9,319 20.9 yrs £-392
3 kW 3004 kWh 2193 kWh 811 kWh £588 £81 £670 £11,354 17.0 yrs £2,037
4 kW 4006 kWh 2924 kWh 1082 kWh £785 £108 £893 £13,388 15.0 yrs £4,467
5 kW 5007 kWh 3655 kWh 1352 kWh £981 £135 £1,116 £15,423 13.8 yrs £6,896
6 kW 6009 kWh 4386 kWh 1622 kWh £1,177 £162 £1,339 £17,457 13.0 yrs £9,325
7 kW 7010 kWh 5117 kWh 1893 kWh £1,373 £189 £1,562 £19,492 12.5 yrs £11,754
8 kW 8012 kWh 5848 kWh 2163 kWh £1,569 £216 £1,785 £21,526 12.1 yrs £14,183

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: £1,133, Upfront: £17,173, Break-even: 15.2 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 2003 kWh 1502 kWh 501 kWh £403 £50 £453 £11,069 24.4 yrs £-2,007
3 kW 3004 kWh 2253 kWh 751 kWh £605 £75 £680 £13,104 19.3 yrs £490
4 kW 4006 kWh 3004 kWh 1001 kWh £806 £100 £906 £15,138 16.7 yrs £2,986
5 kW 5007 kWh 3755 kWh 1252 kWh £1,008 £125 £1,133 £17,173 15.2 yrs £5,483
6 kW 6009 kWh 4507 kWh 1502 kWh £1,209 £150 £1,359 £19,207 14.1 yrs £7,979
7 kW 7010 kWh 5258 kWh 1753 kWh £1,411 £175 £1,586 £21,242 13.4 yrs £10,476
8 kW 8012 kWh 6009 kWh 2003 kWh £1,612 £200 £1,812 £23,276 12.8 yrs £12,972

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: £1,150, Upfront: £19,623, 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 2003 kWh 1542 kWh 461 kWh £414 £46 £460 £13,519 29.4 yrs £-4,322
3 kW 3004 kWh 2313 kWh 691 kWh £621 £69 £690 £15,554 22.5 yrs £-1,758
4 kW 4006 kWh 3084 kWh 921 kWh £828 £92 £920 £17,588 19.1 yrs £806
5 kW 5007 kWh 3856 kWh 1152 kWh £1,034 £115 £1,150 £19,623 17.1 yrs £3,370
6 kW 6009 kWh 4627 kWh 1382 kWh £1,241 £138 £1,380 £21,657 15.7 yrs £5,934
7 kW 7010 kWh 5398 kWh 1612 kWh £1,448 £161 £1,609 £23,692 14.7 yrs £8,498
8 kW 8012 kWh 6169 kWh 1843 kWh £1,655 £184 £1,839 £25,726 14.0 yrs £11,062

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 NP1

Figures below are tailored to NP1 — click through for full league tables.

Solar Payback Index Rank #672 of 2997
10.6 years (UK avg 11.3 years)
~£964 /yr • £10,173 upfront
Standing-Charge Drag Rank #1330 of 2997
19.6% (UK avg 21.7%) drag on savings
£189 fixed • ~£964 /yr value

Your Area at a Glance

Your Electricity Rate
26.83p/kWh
Daily Fixed Charge
51.69p/day
Local Sunshine
1001kWh/kW
A 1 kW system generates ~1001 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 (71%)|Newport (27%)|Blaenau Gwent (2%)

Areas Covered

Newbridge, Crumlin, Bedwas and Trethomas, Graig, Risca West, Abercarn, Machen and Rudry, Risca East + 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

NP11 (Caerphilly)
≈4.6 km away
Local sunshine: ~930 kWh/kWp · -7% vs NP1
NP10 (Newport)
≈6.2 km away
Local sunshine: ~1,002 kWh/kWp · +0% vs NP1
CF8 (Caerphilly)
≈7.1 km away
Local sunshine: ~988 kWh/kWp · -1% vs NP1
CF83 (Caerphilly)
≈7.2 km away
Local sunshine: ~988 kWh/kWp · -1% vs NP1
NP12 (Caerphilly)
≈8.0 km away
Local sunshine: ~926 kWh/kWp · -8% vs NP1
CF82 (Caerphilly)
≈8.7 km away
Local sunshine: ~934 kWh/kWp · -7% vs NP1

Similar sunshine across the UK

NR9 (South Norfolk)
~1,001 kWh/kWp · -0% vs NP1
PE1 (Peterborough)
~1,001 kWh/kWp · -0% vs NP1
SG12 (East Hertfordshire)
~1,002 kWh/kWp · +0% vs NP1