I
Ian-LS
Ok its the weekend and I have time to provide some more realistic calculations......
Ok lets say the roof is 15 degrees, south facing and the location is Blackpool. Installed cost is £5,000
Ive inputted inverter and cable losses of 10 % which is on the conservative side as most 3 kW inverters are at least 94% efficient. Using 3 kWp, south facing and 15 degrees with 10 % losses PV GIS Comes out with year one ouput of 2,760 kWh.
Year one annual income and savings;
Feed in Tariff = 15.44p x 2,760 kWh = £426
Export = 50% of 2,760 kWh @ 4.5p/kWh = £62
In house savings with 30% used on site = 0.3 x 2,760 kWh x 13.4p = £111
Total Year One income and savings = £599.
Basic ROI 11.98 % and payback time of 8 years.
20 year income and Savings
£14,905
20 Year Profit
£9,905
Internal Rate of Return (IRR) = 9.91%
* RPI assumed to be 2.5% for FIT and export payments
* Electricity prices rise by 8% for first 5 years and then 5% for remaining 15 years
* Inverter replacement costs of £400 included in year 15
Put the £5000 into an ISA for 20 years at 3% interest you'll end up with £9,030. You'll need an interest rate of 3.5% to match the total profit from a PV system. I'm not saying my assumptions are right but a lot better than the energy saving trusts. I always when doing quotes make sure the finances make sense and offer a good return and are as accurate as possible. As i've said the finances still stack up even for low energy users and are a no brainer for high energy users.
Ok lets say the roof is 15 degrees, south facing and the location is Blackpool. Installed cost is £5,000
Ive inputted inverter and cable losses of 10 % which is on the conservative side as most 3 kW inverters are at least 94% efficient. Using 3 kWp, south facing and 15 degrees with 10 % losses PV GIS Comes out with year one ouput of 2,760 kWh.
Year one annual income and savings;
Feed in Tariff = 15.44p x 2,760 kWh = £426
Export = 50% of 2,760 kWh @ 4.5p/kWh = £62
In house savings with 30% used on site = 0.3 x 2,760 kWh x 13.4p = £111
Total Year One income and savings = £599.
Basic ROI 11.98 % and payback time of 8 years.
20 year income and Savings
£14,905
20 Year Profit
£9,905
Internal Rate of Return (IRR) = 9.91%
* RPI assumed to be 2.5% for FIT and export payments
* Electricity prices rise by 8% for first 5 years and then 5% for remaining 15 years
* Inverter replacement costs of £400 included in year 15
Put the £5000 into an ISA for 20 years at 3% interest you'll end up with £9,030. You'll need an interest rate of 3.5% to match the total profit from a PV system. I'm not saying my assumptions are right but a lot better than the energy saving trusts. I always when doing quotes make sure the finances make sense and offer a good return and are as accurate as possible. As i've said the finances still stack up even for low energy users and are a no brainer for high energy users.