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Solar Panels in BT17 (Belfast)

See if solar pays off for you in Belfast — 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
38.3 years
After this, it's pure profit
Upfront Cost
£12,207
What you pay to get started
Annual Benefit
£319
What you save every year
Profit Over 25 Years
£-4,229
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 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 886 kWh/kW — 104 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 886 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)
886 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: £266, Upfront: £10,173, Break-even: 38.3 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1773 kWh 709 kWh 1064 kWh £0 £106 £106 £4,069 38.3 yrs £-1,942
3 kW 2659 kWh 1064 kWh 1596 kWh £0 £160 £160 £6,104 38.3 yrs £-2,912
4 kW 3546 kWh 1418 kWh 2127 kWh £0 £213 £213 £8,138 38.3 yrs £-3,883
5 kW 4432 kWh 1773 kWh 2659 kWh £0 £266 £266 £10,173 38.3 yrs £-4,854
6 kW 5319 kWh 2127 kWh 3191 kWh £0 £319 £319 £12,207 38.3 yrs £-5,825
7 kW 6205 kWh 2482 kWh 3723 kWh £0 £372 £372 £14,242 38.3 yrs £-6,795
8 kW 7092 kWh 2837 kWh 4255 kWh £0 £425 £425 £16,276 38.3 yrs £-7,766

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: £177, Upfront: £12,273, Break-even: 69.2 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1773 kWh 1064 kWh 709 kWh £0 £71 £71 £6,169 87.0 yrs £-4,751
3 kW 2659 kWh 1596 kWh 1064 kWh £0 £106 £106 £8,204 77.1 yrs £-6,076
4 kW 3546 kWh 2127 kWh 1418 kWh £0 £142 £142 £10,238 72.2 yrs £-7,401
5 kW 4432 kWh 2659 kWh 1773 kWh £0 £177 £177 £12,273 69.2 yrs £-8,727
6 kW 5319 kWh 3191 kWh 2127 kWh £0 £213 £213 £14,307 67.2 yrs £-10,052
7 kW 6205 kWh 3723 kWh 2482 kWh £0 £248 £248 £16,342 65.8 yrs £-11,377
8 kW 7092 kWh 4255 kWh 2837 kWh £0 £284 £284 £18,376 64.8 yrs £-12,703

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: £133, Upfront: £13,673, Break-even: 102.8 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1773 kWh 1241 kWh 532 kWh £0 £53 £53 £7,569 142.3 yrs £-6,505
3 kW 2659 kWh 1862 kWh 798 kWh £0 £80 £80 £9,604 120.4 yrs £-8,008
4 kW 3546 kWh 2482 kWh 1064 kWh £0 £106 £106 £11,638 109.4 yrs £-9,511
5 kW 4432 kWh 3103 kWh 1330 kWh £0 £133 £133 £13,673 102.8 yrs £-11,013
6 kW 5319 kWh 3723 kWh 1596 kWh £0 £160 £160 £15,707 98.4 yrs £-12,516
7 kW 6205 kWh 4344 kWh 1862 kWh £0 £186 £186 £17,742 95.3 yrs £-14,018
8 kW 7092 kWh 4964 kWh 2127 kWh £0 £213 £213 £19,776 93.0 yrs £-15,521

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: £120, Upfront: £15,423, Break-even: 128.9 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1773 kWh 1294 kWh 479 kWh £0 £48 £48 £9,319 194.7 yrs £-8,362
3 kW 2659 kWh 1941 kWh 718 kWh £0 £72 £72 £11,354 158.1 yrs £-9,917
4 kW 3546 kWh 2588 kWh 957 kWh £0 £96 £96 £13,388 139.8 yrs £-11,473
5 kW 4432 kWh 3236 kWh 1197 kWh £0 £120 £120 £15,423 128.9 yrs £-13,029
6 kW 5319 kWh 3883 kWh 1436 kWh £0 £144 £144 £17,457 121.6 yrs £-14,585
7 kW 6205 kWh 4530 kWh 1675 kWh £0 £168 £168 £19,492 116.3 yrs £-16,141
8 kW 7092 kWh 5177 kWh 1915 kWh £0 £191 £191 £21,526 112.4 yrs £-17,697

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: £111, Upfront: £17,173, Break-even: 155.0 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1773 kWh 1330 kWh 443 kWh £0 £44 £44 £11,069 249.7 yrs £-10,183
3 kW 2659 kWh 1995 kWh 665 kWh £0 £66 £66 £13,104 197.1 yrs £-11,774
4 kW 3546 kWh 2659 kWh 886 kWh £0 £89 £89 £15,138 170.8 yrs £-13,365
5 kW 4432 kWh 3324 kWh 1108 kWh £0 £111 £111 £17,173 155.0 yrs £-14,956
6 kW 5319 kWh 3989 kWh 1330 kWh £0 £133 £133 £19,207 144.4 yrs £-16,548
7 kW 6205 kWh 4654 kWh 1551 kWh £0 £155 £155 £21,242 136.9 yrs £-18,139
8 kW 7092 kWh 5319 kWh 1773 kWh £0 £177 £177 £23,276 131.3 yrs £-19,730

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: £102, Upfront: £19,623, Break-even: 192.5 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1773 kWh 1365 kWh 408 kWh £0 £41 £41 £13,519 331.5 yrs £-12,703
3 kW 2659 kWh 2048 kWh 612 kWh £0 £61 £61 £15,554 254.3 yrs £-14,330
4 kW 3546 kWh 2730 kWh 816 kWh £0 £82 £82 £17,588 215.7 yrs £-15,957
5 kW 4432 kWh 3413 kWh 1019 kWh £0 £102 £102 £19,623 192.5 yrs £-17,584
6 kW 5319 kWh 4095 kWh 1223 kWh £0 £122 £122 £21,657 177.0 yrs £-19,210
7 kW 6205 kWh 4778 kWh 1427 kWh £0 £143 £143 £23,692 166.0 yrs £-20,837
8 kW 7092 kWh 5461 kWh 1631 kWh £0 £163 £163 £25,726 157.7 yrs £-22,464

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.

Your Area at a Glance

Your Electricity Rate
0.00p/kWh
Daily Fixed Charge
0.00p/day
Local Sunshine
886kWh/kW
A 1 kW system generates ~886 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

Belfast (73%)|Lisburn and Castlereagh (27%)

Areas Covered

Dunmurry, Twinbrook, Lagmore, Poleglass, Derryaghy, Lambeg, Drumbo, Collin Glen + 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 Northern Ireland

BT10 (Belfast)
≈2.4 km away
Local sunshine: ~884 kWh/kWp · -0% vs BT17
BT11 (Belfast)
≈2.9 km away
Local sunshine: ~884 kWh/kWp · -0% vs BT17
BT27 (Lisburn and Castlereagh)
≈4.7 km away
Local sunshine: ~894 kWh/kWp · +1% vs BT17
BT28 (Lisburn and Castlereagh)
≈4.9 km away
Local sunshine: ~895 kWh/kWp · +1% vs BT17
BT9 (Belfast)
≈5.1 km away
Local sunshine: ~893 kWh/kWp · +1% vs BT17
BT12 (Belfast)
≈6.1 km away
Local sunshine: ~893 kWh/kWp · +1% vs BT17

Similar sunshine across the UK

EH25 (Midlothian)
~886 kWh/kWp · -0% vs BT17
CA19 (Cumberland)
~887 kWh/kWp · +0% vs BT17
LL33 (Conwy)
~886 kWh/kWp · -0% vs BT17