School Sports Hall Case Study (2)

Integrated Solar PV Roof

An integrated solar roof is a good way to repair or replace an existing roof that is damaged or leaking. It can be used to replace a flat roof or, as in this case, to replace the south facing side of a pitched roof with the north facing side repaired using traditional roofing methods (since the north side will not receive any sunlight).

Installation cost:

£77,000

Size of system:

51 kWp

Number of panels:

201

Estimated annual system generation:

41,910 kWh

Annual savings on energy costs:

£2,000

Annual income from feed-in tariff:

£5,400

Annual income from export tariff:

£1,700

Total annual income:

£9,100

Total income after 20 years:

£182,000

Total profit generated after 20 years:

£105,000

Payback period:

8.9 years

Return on investment:

11.9%

 

Polysolar glass roof installed by Barclay Electrical

Another roof replacement technique is to use solar glass. This can be used as a full replacement for both flat and pitched roofs as it absorbs light coming in from all directions. The glass can have an opaque coating on the back, or it can be left transparent to allow electricity to be generated by light coming through both sides of the glass and allow light to come down into room below. For example, in a sports hall, the hall would be predominantly lit by light from the sun through the solar glass roof, however LED lights in the hall would have photocells fitted allowing the lights to automatically come on when natural light levels are low.