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Solar panel cost in Lisburn and Castlereagh (BT27)

See realistic solar installation costs, savings and payback for BT27 (Lisburn and Castlereagh) 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
30.3 years
After this, it's pure profit
Upfront Cost
£9,767
What you pay to get started
Annual Benefit
£322
What you save every year
Profit Over 25 Years
£-1,717
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 Northern Ireland, the current unit rate is 0.00p/kWh with a 0.00p/day standing charge. Your postcode’s south-facing sunshine yield is 894 kWh/kW — 96 below the regional median (991).

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 894 kWh per year on a south-facing roof. We value self-used electricity at 0.0p and exported surplus at a baseline 10p via SEG. Use the calculator above for your exact tariff.

Unit rate
0.0p/kWh
Standing charge
0.0p/day
Sunshine yield (south)
894 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: £268, Upfront: £8,139, Break-even: 30.3 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1789 kWh 715 kWh 1073 kWh £0 £107 £107 £3,256 30.3 yrs £-1,109
3 kW 2683 kWh 1073 kWh 1610 kWh £0 £161 £161 £4,883 30.3 yrs £-1,664
4 kW 3577 kWh 1431 kWh 2146 kWh £0 £215 £215 £6,511 30.3 yrs £-2,218
5 kW 4472 kWh 1789 kWh 2683 kWh £0 £268 £268 £8,139 30.3 yrs £-2,773
6 kW 5366 kWh 2146 kWh 3220 kWh £0 £322 £322 £9,767 30.3 yrs £-3,327
7 kW 6261 kWh 2504 kWh 3756 kWh £0 £376 £376 £11,394 30.3 yrs £-3,882
8 kW 7155 kWh 2862 kWh 4293 kWh £0 £429 £429 £13,022 30.3 yrs £-4,436

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: £179, Upfront: £10,239, Break-even: 57.2 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1789 kWh 1073 kWh 715 kWh £0 £72 £72 £5,356 74.9 yrs £-3,925
3 kW 2683 kWh 1610 kWh 1073 kWh £0 £107 £107 £6,983 65.1 yrs £-4,837
4 kW 3577 kWh 2146 kWh 1431 kWh £0 £143 £143 £8,611 60.2 yrs £-5,749
5 kW 4472 kWh 2683 kWh 1789 kWh £0 £179 £179 £10,239 57.2 yrs £-6,661
6 kW 5366 kWh 3220 kWh 2146 kWh £0 £215 £215 £11,867 55.3 yrs £-7,574
7 kW 6261 kWh 3756 kWh 2504 kWh £0 £250 £250 £13,494 53.9 yrs £-8,486
8 kW 7155 kWh 4293 kWh 2862 kWh £0 £286 £286 £15,122 52.8 yrs £-9,398

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: £134, Upfront: £11,639, Break-even: 86.8 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1789 kWh 1252 kWh 537 kWh £0 £54 £54 £6,756 125.9 yrs £-5,682
3 kW 2683 kWh 1878 kWh 805 kWh £0 £80 £80 £8,383 104.1 yrs £-6,773
4 kW 3577 kWh 2504 kWh 1073 kWh £0 £107 £107 £10,011 93.3 yrs £-7,865
5 kW 4472 kWh 3130 kWh 1342 kWh £0 £134 £134 £11,639 86.8 yrs £-8,956
6 kW 5366 kWh 3756 kWh 1610 kWh £0 £161 £161 £13,267 82.4 yrs £-10,047
7 kW 6261 kWh 4382 kWh 1878 kWh £0 £188 £188 £14,894 79.3 yrs £-11,138
8 kW 7155 kWh 5008 kWh 2146 kWh £0 £215 £215 £16,522 77.0 yrs £-12,229

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: £121, Upfront: £13,389, Break-even: 110.9 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1789 kWh 1306 kWh 483 kWh £0 £48 £48 £8,506 176.1 yrs £-7,540
3 kW 2683 kWh 1959 kWh 724 kWh £0 £72 £72 £10,133 139.9 yrs £-8,684
4 kW 3577 kWh 2612 kWh 966 kWh £0 £97 £97 £11,761 121.8 yrs £-9,829
5 kW 4472 kWh 3264 kWh 1207 kWh £0 £121 £121 £13,389 110.9 yrs £-10,974
6 kW 5366 kWh 3917 kWh 1449 kWh £0 £145 £145 £15,017 103.6 yrs £-12,119
7 kW 6261 kWh 4570 kWh 1690 kWh £0 £169 £169 £16,644 98.5 yrs £-13,264
8 kW 7155 kWh 5223 kWh 1932 kWh £0 £193 £193 £18,272 94.6 yrs £-14,408

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: £112, Upfront: £15,139, Break-even: 135.4 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1789 kWh 1342 kWh 447 kWh £0 £45 £45 £10,256 229.3 yrs £-9,361
3 kW 2683 kWh 2012 kWh 671 kWh £0 £67 £67 £11,883 177.2 yrs £-10,542
4 kW 3577 kWh 2683 kWh 894 kWh £0 £89 £89 £13,511 151.1 yrs £-11,722
5 kW 4472 kWh 3354 kWh 1118 kWh £0 £112 £112 £15,139 135.4 yrs £-12,903
6 kW 5366 kWh 4025 kWh 1342 kWh £0 £134 £134 £16,767 125.0 yrs £-14,083
7 kW 6261 kWh 4695 kWh 1565 kWh £0 £157 £157 £18,394 117.5 yrs £-15,264
8 kW 7155 kWh 5366 kWh 1789 kWh £0 £179 £179 £20,022 111.9 yrs £-16,445

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: £103, Upfront: £17,589, Break-even: 171.0 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1789 kWh 1377 kWh 411 kWh £0 £41 £41 £12,706 308.8 yrs £-11,883
3 kW 2683 kWh 2066 kWh 617 kWh £0 £62 £62 £14,333 232.3 yrs £-13,099
4 kW 3577 kWh 2755 kWh 823 kWh £0 £82 £82 £15,961 194.0 yrs £-14,315
5 kW 4472 kWh 3443 kWh 1029 kWh £0 £103 £103 £17,589 171.0 yrs £-15,532
6 kW 5366 kWh 4132 kWh 1234 kWh £0 £123 £123 £19,217 155.7 yrs £-16,748
7 kW 6261 kWh 4821 kWh 1440 kWh £0 £144 £144 £20,844 144.8 yrs £-17,964
8 kW 7155 kWh 5509 kWh 1646 kWh £0 £165 £165 £22,472 136.6 yrs £-19,181

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 Lisburn and Castlereagh

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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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.

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Insights for BT27

Figures below are tailored to BT27 — click through for full league tables.

Aspect Penalty View ranking →
East −20.8% West −20.0%
Typical output loss versus a south-facing roof (lower is better)

Seasonal solar output in BT27

Monthly generation per kilowatt of solar panels

kWh 29 Jan 46 Feb 78 Mar 105 Apr 120 May 111 Jun 108 Jul 99 Aug 79 Sep 57 Oct 38 Nov 25 Dec
Best month Worst month Winter (Dec–Feb) Other months

Winter output: 44.6% 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 33 kWh per month; the average month produces around 75 kWh. So a typical 4 kW home system would generate roughly 133 kWh in winter, or 298 kWh in an average month.

Your Area at a Glance

Your Electricity Rate
0.00p/kWh
Daily Fixed Charge
0.00p/day
Local Sunshine
894kWh/kW
A 1 kW system generates ~894 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

No EPC data available for this outcode

Coverage

Lisburn and Castlereagh (100%)

Areas Covered

Blaris, Hilden, Hillhall, Harmony Hill, Magheralave, Ravernet, Lambeg, Drumbo + 4 more

Data Sources & Assumptions

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

Electricity rates: Ofgem price cap,

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 Northern Ireland

BT28 (Lisburn and Castlereagh)
≈2.3 km away
Local sunshine: ~895 kWh/kWp · +0% vs BT27
BT17 (Belfast)
≈4.7 km away
Local sunshine: ~886 kWh/kWp · -1% vs BT27
BT26 (Lisburn and Castlereagh)
≈6.2 km away
Local sunshine: ~889 kWh/kWp · -1% vs BT27
BT10 (Belfast)
≈6.2 km away
Local sunshine: ~884 kWh/kWp · -1% vs BT27
BT11 (Belfast)
≈7.5 km away
Local sunshine: ~884 kWh/kWp · -1% vs BT27
BT9 (Belfast)
≈8.7 km away
Local sunshine: ~893 kWh/kWp · -0% vs BT27

Similar sunshine across the UK

M44 (Salford)
~894 kWh/kWp · +0% vs BT27
PA66 (Argyll and Bute)
~894 kWh/kWp · -0% vs BT27
CA24 (Cumberland)
~894 kWh/kWp · -0% vs BT27