Roof  faces South

roof pitch angle of 40 degrees

no overshading

Postcode 7E

 

250W x 16 x 866 x 1 =  3464kWh/year

 

Therefore the estimated PV array annual output is          3464kWh

 

 

This would attract an annual Feed In Tariff of 12.42p x 3454 = £428.98

 

Assuming that you use 50% (1648 units) of what your installation generates this is 1648 units you do not have to buy from United Utilities at 14p per unit.  This would save you £230.72   (1648 x 14p)  and feed back 50%  (1648  units) to United Utilities at 4.85p/unit  £79.92

The energy providers have decided to simply pay 50% of whatever you generate annually at 4.85p per unit.

This saves them having to keep a check on how much you feed back into the grid.

 

 

This makes a total income in year one of £739.62

 

Assuming installation cost of £5,000 this would make the payback period  6.5 years

Assuming installation cost of £6,500 this would make the payback period  8.4 years

 

The Performance of solar PV systems is impossible to predict with certainty due to the variability in the amount of solar radiation (sunlight) from location to location and from year to year.  This estimate is based upon the government’s standard assessment procedure for energy rating of buildings (SAP) and is given as guidance only.  It should not be considered as a guarantee of performance.

 

 

Example  16 panel south Facing Roof with no shading

Oct 2015 onwards