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Solar Panels in BT9 (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
38.0 years
After this, it's pure profit
Upfront Cost
£12,207
What you pay to get started
Annual Benefit
£321
What you save every year
Profit Over 25 Years
£-4,172
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 893 kWh/kW — 98 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 893 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)
893 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: £10,173, Break-even: 38.0 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1786 kWh 714 kWh 1071 kWh £0 £107 £107 £4,069 38.0 yrs £-1,926
3 kW 2678 kWh 1071 kWh 1607 kWh £0 £161 £161 £6,104 38.0 yrs £-2,889
4 kW 3571 kWh 1428 kWh 2143 kWh £0 £214 £214 £8,138 38.0 yrs £-3,853
5 kW 4464 kWh 1786 kWh 2678 kWh £0 £268 £268 £10,173 38.0 yrs £-4,816
6 kW 5357 kWh 2143 kWh 3214 kWh £0 £321 £321 £12,207 38.0 yrs £-5,779
7 kW 6250 kWh 2500 kWh 3750 kWh £0 £375 £375 £14,242 38.0 yrs £-6,742
8 kW 7142 kWh 2857 kWh 4285 kWh £0 £429 £429 £16,276 38.0 yrs £-7,705

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: £179, Upfront: £12,273, Break-even: 68.7 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1786 kWh 1071 kWh 714 kWh £0 £71 £71 £6,169 86.4 yrs £-4,741
3 kW 2678 kWh 1607 kWh 1071 kWh £0 £107 £107 £8,204 76.6 yrs £-6,061
4 kW 3571 kWh 2143 kWh 1428 kWh £0 £143 £143 £10,238 71.7 yrs £-7,381
5 kW 4464 kWh 2678 kWh 1786 kWh £0 £179 £179 £12,273 68.7 yrs £-8,701
6 kW 5357 kWh 3214 kWh 2143 kWh £0 £214 £214 £14,307 66.8 yrs £-10,022
7 kW 6250 kWh 3750 kWh 2500 kWh £0 £250 £250 £16,342 65.4 yrs £-11,342
8 kW 7142 kWh 4285 kWh 2857 kWh £0 £286 £286 £18,376 64.3 yrs £-12,662

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: £134, Upfront: £13,673, Break-even: 102.1 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1786 kWh 1250 kWh 536 kWh £0 £54 £54 £7,569 141.3 yrs £-6,498
3 kW 2678 kWh 1875 kWh 804 kWh £0 £80 £80 £9,604 119.5 yrs £-7,996
4 kW 3571 kWh 2500 kWh 1071 kWh £0 £107 £107 £11,638 108.6 yrs £-9,495
5 kW 4464 kWh 3125 kWh 1339 kWh £0 £134 £134 £13,673 102.1 yrs £-10,994
6 kW 5357 kWh 3750 kWh 1607 kWh £0 £161 £161 £15,707 97.7 yrs £-12,493
7 kW 6250 kWh 4375 kWh 1875 kWh £0 £187 £187 £17,742 94.6 yrs £-13,992
8 kW 7142 kWh 5000 kWh 2143 kWh £0 £214 £214 £19,776 92.3 yrs £-15,491

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: £121, Upfront: £15,423, Break-even: 128.0 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1786 kWh 1304 kWh 482 kWh £0 £48 £48 £9,319 193.3 yrs £-8,355
3 kW 2678 kWh 1955 kWh 723 kWh £0 £72 £72 £11,354 157.0 yrs £-9,907
4 kW 3571 kWh 2607 kWh 964 kWh £0 £96 £96 £13,388 138.8 yrs £-11,460
5 kW 4464 kWh 3259 kWh 1205 kWh £0 £121 £121 £15,423 128.0 yrs £-13,012
6 kW 5357 kWh 3911 kWh 1446 kWh £0 £145 £145 £17,457 120.7 yrs £-14,564
7 kW 6250 kWh 4562 kWh 1687 kWh £0 £169 £169 £19,492 115.5 yrs £-16,117
8 kW 7142 kWh 5214 kWh 1928 kWh £0 £193 £193 £21,526 111.6 yrs £-17,669

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: £112, Upfront: £17,173, Break-even: 153.9 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1786 kWh 1339 kWh 446 kWh £0 £45 £45 £11,069 248.0 yrs £-10,176
3 kW 2678 kWh 2009 kWh 670 kWh £0 £67 £67 £13,104 195.7 yrs £-11,764
4 kW 3571 kWh 2678 kWh 893 kWh £0 £89 £89 £15,138 169.6 yrs £-13,352
5 kW 4464 kWh 3348 kWh 1116 kWh £0 £112 £112 £17,173 153.9 yrs £-14,941
6 kW 5357 kWh 4018 kWh 1339 kWh £0 £134 £134 £19,207 143.4 yrs £-16,529
7 kW 6250 kWh 4687 kWh 1562 kWh £0 £156 £156 £21,242 136.0 yrs £-18,117
8 kW 7142 kWh 5357 kWh 1786 kWh £0 £179 £179 £23,276 130.4 yrs £-19,705

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: £103, Upfront: £19,623, Break-even: 191.1 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1786 kWh 1375 kWh 411 kWh £0 £41 £41 £13,519 329.2 yrs £-12,698
3 kW 2678 kWh 2062 kWh 616 kWh £0 £62 £62 £15,554 252.5 yrs £-14,321
4 kW 3571 kWh 2750 kWh 821 kWh £0 £82 £82 £17,588 214.1 yrs £-15,945
5 kW 4464 kWh 3437 kWh 1027 kWh £0 £103 £103 £19,623 191.1 yrs £-17,569
6 kW 5357 kWh 4125 kWh 1232 kWh £0 £123 £123 £21,657 175.8 yrs £-19,193
7 kW 6250 kWh 4812 kWh 1437 kWh £0 £144 £144 £23,692 164.8 yrs £-20,817
8 kW 7142 kWh 5500 kWh 1643 kWh £0 £164 £164 £25,726 156.6 yrs £-22,441

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
893kWh/kW
A 1 kW system generates ~893 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 (100%)

Areas Covered

Windsor, Stranmillis, Malone, Upper Malone, Blackstaff, Central, Musgrave

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

BT7 (Belfast)
≈2.1 km away
Local sunshine: ~893 kWh/kWp · +0% vs BT9
BT12 (Belfast)
≈2.4 km away
Local sunshine: ~893 kWh/kWp · -0% vs BT9
BT2 (Belfast)
≈2.6 km away
Local sunshine: ~893 kWh/kWp · +0% vs BT9
BT10 (Belfast)
≈2.7 km away
Local sunshine: ~884 kWh/kWp · -1% vs BT9
BT11 (Belfast)
≈3.1 km away
Local sunshine: ~884 kWh/kWp · -1% vs BT9
BT1 (Belfast)
≈3.2 km away
Local sunshine: ~885 kWh/kWp · -1% vs BT9

Similar sunshine across the UK

S32 (Derbyshire Dales)
~893 kWh/kWp · -0% vs BT9
EH21 (East Lothian)
~893 kWh/kWp · -0% vs BT9
AB1 (Aberdeen City)
~893 kWh/kWp · -0% vs BT9