If you own a 3-bed semi-detached home in Belfast with a south-facing roof and pay a typical UK household bill of £1,200 a year, you're in a great position to save with solar panels. Our calculator uses real data to show you exactly what a system could generate, save, and earn for your home. No jargon, just clear numbers you can trust.
Your Solar Savings Snapshot
If you live in a 3-bed semi in Belfast with a south-facing roof, you’re looking at a prime spot for solar panels. Based on your 30m² roof and typical UK household bill of £1,200, here’s what a system could do for you.
| Measure | Your Result |
|---|---|
| System size | 5.4 kWp |
| Annual generation | 4,644 kWh |
| Annual savings | £650 |
| Bill reduction | 38% |
| Install cost | £5,940 |
| Payback period | 9.1 years |
| CO₂ saved | 1.1 tonnes/yr |
| Export income | £195/yr |
A 5.4 kWp system on your 30m² roof could generate 4,644 kWh per year, saving you approximately £650 annually. The system would pay for itself in around 9.1 years.
How Solar Panels Work for Your Home
Solar panels turn sunlight into electricity. Even in Belfast, the UK’s south-facing roofs get enough light to make a big difference. Your 5.4 kWp system uses about 12-14 panels, fitting neatly on your 30m² roof. The electricity you generate powers your home first, and any surplus is exported to the grid for extra income.
What Affects Your Savings?
Your savings depend on three things: how much sun your roof gets, how much electricity you use, and the price you pay. In Belfast, the south-facing orientation is ideal. Your £1,200 annual bill means you use a typical amount of electricity for a 3-bed semi. The more you use during daylight, the more you save.
Export Income Explained
When your panels produce more than you need, the extra power goes to the grid. Under the Smart Export Guarantee (SEG), you get paid for every kWh exported. For your system, that means £195 a year on top of your £650 savings. That’s £845 total benefit annually.
Installation and Payback
The installation cost of £5,940 includes panels, inverter, and fitting by an MCS-certified installer. With annual savings and export income of £845, you’ll break even in 9.1 years. After that, your electricity is essentially free for the rest of the system’s 25+ year lifespan.
Finding a Trusted Installer
Always choose an MCS-certified installer. The MCS website lets you find accredited professionals in your area. They’ll ensure your system meets UK standards and qualifies for schemes like the Boiler Upgrade Scheme if you’re combining with a heat pump.
Environmental Impact
By going solar, you save 1.1 tonnes of CO₂ each year. That’s like planting 50 trees or driving 2,500 miles less. It’s a simple way to make your home greener and reduce your carbon footprint.
Next Steps
Check your Energy Performance Certificate (EPC) to see your home’s energy rating. Visit GOV.UK to find yours. Then get quotes from at least three MCS installers to compare prices and warranties. The Energy Saving Trust has more advice on solar panels for UK homes.
How these numbers were calculated
Our calculator uses standard UK solar generation data for Northern Ireland, adjusted for a south-facing 30m² roof. Annual generation is based on 5.4 kWp system output, using regional solar irradiation figures. Savings assume 50% self-consumption at current UK electricity rates. Export income is calculated at the typical SEG rate of 4.1p per kWh. Payback divides total install cost by annual benefit. All figures are estimates and may vary.
Sources
- Energy Saving Trust — Solar panels
- Ofgem — Smart Export Guarantee
- MCS Certified — Find an installer
