Solar explained to clever people by people who are not trying to be clever

Solar Panels in BT2 (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
£-4,170
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

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 1072 kWh £0 £107 £107 £4,069 38.0 yrs £-1,926
3 kW 2679 kWh 1072 kWh 1607 kWh £0 £161 £161 £6,104 38.0 yrs £-2,889
4 kW 3572 kWh 1429 kWh 2143 kWh £0 £214 £214 £8,138 38.0 yrs £-3,852
5 kW 4465 kWh 1786 kWh 2679 kWh £0 £268 £268 £10,173 38.0 yrs £-4,814
6 kW 5358 kWh 2143 kWh 3215 kWh £0 £321 £321 £12,207 38.0 yrs £-5,777
7 kW 6251 kWh 2500 kWh 3751 kWh £0 £375 £375 £14,242 38.0 yrs £-6,740
8 kW 7144 kWh 2858 kWh 4286 kWh £0 £429 £429 £16,276 38.0 yrs £-7,703

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 1072 kWh 714 kWh £0 £71 £71 £6,169 86.4 yrs £-4,740
3 kW 2679 kWh 1607 kWh 1072 kWh £0 £107 £107 £8,204 76.6 yrs £-6,060
4 kW 3572 kWh 2143 kWh 1429 kWh £0 £143 £143 £10,238 71.7 yrs £-7,380
5 kW 4465 kWh 2679 kWh 1786 kWh £0 £179 £179 £12,273 68.7 yrs £-8,701
6 kW 5358 kWh 3215 kWh 2143 kWh £0 £214 £214 £14,307 66.8 yrs £-10,021
7 kW 6251 kWh 3751 kWh 2500 kWh £0 £250 £250 £16,342 65.4 yrs £-11,341
8 kW 7144 kWh 4286 kWh 2858 kWh £0 £286 £286 £18,376 64.3 yrs £-12,661

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 £-6,497
3 kW 2679 kWh 1875 kWh 804 kWh £0 £80 £80 £9,604 119.5 yrs £-7,996
4 kW 3572 kWh 2500 kWh 1072 kWh £0 £107 £107 £11,638 108.6 yrs £-9,495
5 kW 4465 kWh 3126 kWh 1340 kWh £0 £134 £134 £13,673 102.1 yrs £-10,994
6 kW 5358 kWh 3751 kWh 1607 kWh £0 £161 £161 £15,707 97.7 yrs £-12,492
7 kW 6251 kWh 4376 kWh 1875 kWh £0 £188 £188 £17,742 94.6 yrs £-13,991
8 kW 7144 kWh 5001 kWh 2143 kWh £0 £214 £214 £19,776 92.3 yrs £-15,490

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: 127.9 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1786 kWh 1304 kWh 482 kWh £0 £48 £48 £9,319 193.3 yrs £-8,355
3 kW 2679 kWh 1956 kWh 723 kWh £0 £72 £72 £11,354 157.0 yrs £-9,907
4 kW 3572 kWh 2608 kWh 964 kWh £0 £96 £96 £13,388 138.8 yrs £-11,459
5 kW 4465 kWh 3259 kWh 1206 kWh £0 £121 £121 £15,423 127.9 yrs £-13,011
6 kW 5358 kWh 3911 kWh 1447 kWh £0 £145 £145 £17,457 120.7 yrs £-14,564
7 kW 6251 kWh 4563 kWh 1688 kWh £0 £169 £169 £19,492 115.5 yrs £-16,116
8 kW 7144 kWh 5215 kWh 1929 kWh £0 £193 £193 £21,526 111.6 yrs £-17,668

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: 153.8 yrs
System Annual output Self-use Exported Bill saving Export income Annual benefit Upfront cost Break-even 20-year net
2 kW 1786 kWh 1340 kWh 447 kWh £0 £45 £45 £11,069 247.9 yrs £-10,176
3 kW 2679 kWh 2009 kWh 670 kWh £0 £67 £67 £13,104 195.6 yrs £-11,764
4 kW 3572 kWh 2679 kWh 893 kWh £0 £89 £89 £15,138 169.5 yrs £-13,352
5 kW 4465 kWh 3349 kWh 1116 kWh £0 £112 £112 £17,173 153.8 yrs £-14,940
6 kW 5358 kWh 4019 kWh 1340 kWh £0 £134 £134 £19,207 143.4 yrs £-16,528
7 kW 6251 kWh 4688 kWh 1563 kWh £0 £156 £156 £21,242 135.9 yrs £-18,116
8 kW 7144 kWh 5358 kWh 1786 kWh £0 £179 £179 £23,276 130.3 yrs £-19,704

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 £13,519 329.1 yrs £-12,697
3 kW 2679 kWh 2063 kWh 616 kWh £0 £62 £62 £15,554 252.4 yrs £-14,321
4 kW 3572 kWh 2750 kWh 822 kWh £0 £82 £82 £17,588 214.1 yrs £-15,945
5 kW 4465 kWh 3438 kWh 1027 kWh £0 £103 £103 £19,623 191.1 yrs £-17,569
6 kW 5358 kWh 4126 kWh 1232 kWh £0 £123 £123 £21,657 175.7 yrs £-19,192
7 kW 6251 kWh 4813 kWh 1438 kWh £0 £144 £144 £23,692 164.8 yrs £-20,816
8 kW 7144 kWh 5501 kWh 1643 kWh £0 £164 £164 £25,726 156.6 yrs £-22,440

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

Central, Blackstaff, Stormont

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.