B9 group installation
How we work out solar savings
Every rate we use, its date and its source, then one worked example.
- Free survey
- Fixed written quote
- NIE paperwork handled
- Part of the B9 Energy group, in renewables since 1992
The rates we use
| Assumption | Value | Date | Source |
|---|---|---|---|
| Import price | 34p per kWh | From 1 July 2026 | Power NI unit rates. The standard rate is 34.15p including VAT; sums use 34p. |
| Export payment | 11.88p per kWh | 1 October 2026 to 30 September 2027 | Power NI microgeneration tariff rates |
| Yearly generation | 850–950 kWh per kWp (we use 900) | Our assumption | Typical for Northern Ireland, see the cost guide |
| Share of solar used at home | 35% with no battery, 50% typical, 70% with a battery | Our assumption | Our modelling assumption. Your own use will differ. |
| VAT on installs | 0%, then 5% | 0% until 31 March 2027 | See the grants and VAT guide |
| Battery spread | 22.12p per kWh | Import price minus export payment | Worked out from the two rates above. |
Last checked 7 October 2026.
Worked example: 4 kWp system
4 kWp × 900 kWh = 3,600 kWh a year, costing £5,800.
| Case | Used at home | Saving a year | Payback |
|---|---|---|---|
| Without a battery | 35% | £706 | 8.2 years |
| Typical home | 50% | £826 | 7.0 years |
| With a battery | 70% | £985 | 5.9 years |
Saving = units used at home × 34p + units exported × 11.88p. Our headline payback is 6–9 years because real roofs and homes vary.
Battery example
- a year, 5 kWh battery shifting 1,500 kWh
- £332
- a year, 10 kWh battery shifting 2,400 kWh
- £531
Each unit stored instead of exported is worth the 22.12p spread.
Export payments and MCS
Power NI requires MCS accreditation for export payments on solar PV. Check its current terms before you order. Our export payments guide has the detail.
Get a quote for your home
Send us your postcode and a recent bill. We'll model your roof and tell you whether solar is worth it there. If it is, we survey and give you a fixed written price.
- Free survey
- Fixed written quote
- NIE paperwork handled
- Part of the B9 Energy group, in renewables since 1992