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Solar panel cost in Derry City and Strabane (BT81)

See realistic solar installation costs, savings and payback for BT81 (Derry City and Strabane) 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
32.4 years
After this, it's pure profit
Upfront Cost
£9,767
What you pay to get started
Annual Benefit
£301
What you save every year
Profit Over 25 Years
£-2,236
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 837 kWh/kW — 154 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 837 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)
837 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: £251, Upfront: £8,139, Break-even: 32.4 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1673 kWh 669 kWh 1004 kWh £0 £100 £100 £3,256 32.4 yrs £-1,247
3 kW 2510 kWh 1004 kWh 1506 kWh £0 £151 £151 £4,883 32.4 yrs £-1,871
4 kW 3347 kWh 1339 kWh 2008 kWh £0 £201 £201 £6,511 32.4 yrs £-2,495
5 kW 4184 kWh 1673 kWh 2510 kWh £0 £251 £251 £8,139 32.4 yrs £-3,118
6 kW 5020 kWh 2008 kWh 3012 kWh £0 £301 £301 £9,767 32.4 yrs £-3,742
7 kW 5857 kWh 2343 kWh 3514 kWh £0 £351 £351 £11,394 32.4 yrs £-4,366
8 kW 6694 kWh 2678 kWh 4016 kWh £0 £402 £402 £13,022 32.4 yrs £-4,989

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: £167, Upfront: £10,239, Break-even: 61.2 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1673 kWh 1004 kWh 669 kWh £0 £67 £67 £5,356 80.0 yrs £-4,017
3 kW 2510 kWh 1506 kWh 1004 kWh £0 £100 £100 £6,983 69.5 yrs £-4,975
4 kW 3347 kWh 2008 kWh 1339 kWh £0 £134 £134 £8,611 64.3 yrs £-5,934
5 kW 4184 kWh 2510 kWh 1673 kWh £0 £167 £167 £10,239 61.2 yrs £-6,892
6 kW 5020 kWh 3012 kWh 2008 kWh £0 £201 £201 £11,867 59.1 yrs £-7,850
7 kW 5857 kWh 3514 kWh 2343 kWh £0 £234 £234 £13,494 57.6 yrs £-8,809
8 kW 6694 kWh 4016 kWh 2678 kWh £0 £268 £268 £15,122 56.5 yrs £-9,767

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: £126, Upfront: £11,639, Break-even: 92.7 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1673 kWh 1171 kWh 502 kWh £0 £50 £50 £6,756 134.6 yrs £-5,751
3 kW 2510 kWh 1757 kWh 753 kWh £0 £75 £75 £8,383 111.3 yrs £-6,877
4 kW 3347 kWh 2343 kWh 1004 kWh £0 £100 £100 £10,011 99.7 yrs £-8,003
5 kW 4184 kWh 2929 kWh 1255 kWh £0 £126 £126 £11,639 92.7 yrs £-9,129
6 kW 5020 kWh 3514 kWh 1506 kWh £0 £151 £151 £13,267 88.1 yrs £-10,254
7 kW 5857 kWh 4100 kWh 1757 kWh £0 £176 £176 £14,894 84.8 yrs £-11,380
8 kW 6694 kWh 4686 kWh 2008 kWh £0 £201 £201 £16,522 82.3 yrs £-12,506

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: £113, Upfront: £13,389, Break-even: 118.5 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1673 kWh 1222 kWh 452 kWh £0 £45 £45 £8,506 188.2 yrs £-7,602
3 kW 2510 kWh 1832 kWh 678 kWh £0 £68 £68 £10,133 149.5 yrs £-8,778
4 kW 3347 kWh 2443 kWh 904 kWh £0 £90 £90 £11,761 130.1 yrs £-9,954
5 kW 4184 kWh 3054 kWh 1130 kWh £0 £113 £113 £13,389 118.5 yrs £-11,130
6 kW 5020 kWh 3665 kWh 1356 kWh £0 £136 £136 £15,017 110.8 yrs £-12,306
7 kW 5857 kWh 4276 kWh 1581 kWh £0 £158 £158 £16,644 105.2 yrs £-13,481
8 kW 6694 kWh 4887 kWh 1807 kWh £0 £181 £181 £18,272 101.1 yrs £-14,657

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: £105, Upfront: £15,139, Break-even: 144.7 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1673 kWh 1255 kWh 418 kWh £0 £42 £42 £10,256 245.1 yrs £-9,419
3 kW 2510 kWh 1883 kWh 628 kWh £0 £63 £63 £11,883 189.4 yrs £-10,628
4 kW 3347 kWh 2510 kWh 837 kWh £0 £84 £84 £13,511 161.5 yrs £-11,838
5 kW 4184 kWh 3138 kWh 1046 kWh £0 £105 £105 £15,139 144.7 yrs £-13,047
6 kW 5020 kWh 3765 kWh 1255 kWh £0 £126 £126 £16,767 133.6 yrs £-14,256
7 kW 5857 kWh 4393 kWh 1464 kWh £0 £146 £146 £18,394 125.6 yrs £-15,466
8 kW 6694 kWh 5020 kWh 1673 kWh £0 £167 £167 £20,022 119.6 yrs £-16,675

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: £96, Upfront: £17,589, Break-even: 182.8 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1673 kWh 1289 kWh 385 kWh £0 £38 £38 £12,706 330.1 yrs £-11,936
3 kW 2510 kWh 1933 kWh 577 kWh £0 £58 £58 £14,333 248.3 yrs £-13,179
4 kW 3347 kWh 2577 kWh 770 kWh £0 £77 £77 £15,961 207.3 yrs £-14,421
5 kW 4184 kWh 3221 kWh 962 kWh £0 £96 £96 £17,589 182.8 yrs £-15,664
6 kW 5020 kWh 3866 kWh 1155 kWh £0 £115 £115 £19,217 166.4 yrs £-16,907
7 kW 5857 kWh 4510 kWh 1347 kWh £0 £135 £135 £20,844 154.7 yrs £-18,150
8 kW 6694 kWh 5154 kWh 1540 kWh £0 £154 £154 £22,472 146.0 yrs £-19,393

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 Derry City and Strabane

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 BT81

Figures below are tailored to BT81 — click through for full league tables.

Aspect Penalty View ranking →
East −19.5% West −18.6%
Typical output loss versus a south-facing roof (lower is better)

Seasonal solar output in BT81

Monthly generation per kilowatt of solar panels

kWh 24 Jan 43 Feb 73 Mar 100 Apr 113 May 105 Jun 101 Jul 96 Aug 73 Sep 54 Oct 33 Nov 20 Dec
Best month Worst month Winter (Dec–Feb) Other months

Winter output: 41.9% 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 29 kWh per month; the average month produces around 70 kWh. So a typical 4 kW home system would generate roughly 117 kWh in winter, or 279 kWh in an average month.

Your Area at a Glance

Your Electricity Rate
0.00p/kWh
Daily Fixed Charge
0.00p/day
Local Sunshine
837kWh/kW
A 1 kW system generates ~837 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

Derry City and Strabane (99%)|Fermanagh and Omagh (1%)

Areas Covered

Glenderg, Castlederg, Newtownstewart, Finn, Drumquin

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

BT82 (Derry City and Strabane)
≈15.9 km away
Local sunshine: ~795 kWh/kWp · -5% vs BT81
BT78 (Fermanagh and Omagh)
≈20.6 km away
Local sunshine: ~832 kWh/kWp · -1% vs BT81
BT79 (Fermanagh and Omagh)
≈25.6 km away
Local sunshine: ~827 kWh/kWp · -1% vs BT81
BT93 (Fermanagh and Omagh)
≈28.3 km away
Local sunshine: ~829 kWh/kWp · -1% vs BT81
BT94 (Fermanagh and Omagh)
≈37.4 km away
Local sunshine: ~835 kWh/kWp · -0% vs BT81
BT48 (Derry City and Strabane)
≈37.6 km away
Local sunshine: ~827 kWh/kWp · -1% vs BT81

Similar sunshine across the UK

EH38 (Scottish Borders)
~837 kWh/kWp · -0% vs BT81
G53 (Glasgow City)
~837 kWh/kWp · +0% vs BT81
G73 (South Lanarkshire)
~837 kWh/kWp · +0% vs BT81