There are a growing number of systems available to install full-sized solar panels within the roof, replacing slates or tiles rather than being fitted over the top of them. The result is a sleeker looking roof with the solar panels forming part of the roof's waterproofing.
Key issues to consider
MCS Accreditation
Your roof is a critical part of your home and it is essential that any roof integrated solar products are MCS Certified. The means that they have passed all of the tests set out in MCS012, which requires products to have extensive wind, rain and electrical tests, so that you do not end up with issues such as rain being driven up the roof and into the house by strong winds.
Track record
Traditional roofing products are expected to last decades on a roof without significant issues occurring. How long has the system you are considering been in service and can your installer show you systems that have been in service for a significant period of time?
Warranty
Most solar panels carry performance warranties of 25 years, but these panels are also going to be the waterproofing of your building. What is the weatherproofing warranty being offered?
Future maintenance
Is the system well sealed and yet still accessible and serviceable? Some systems leave gaps between the panels where debris and infestation can occur. Tiled or shingled panels are overlapped by the row of panels above them, so to replace or service a panel the rows above it need to be removed first. This can mean stripping most of the roof.
MCS Certified products for roof integrated solar
GB-Sol Integrated solar roof system
Any size of panel can be secured into an aluminium frame by riveted, colour matched aluminium bars and sealed by rubber gaskets, so the system is completely watertight and yet panels can be individually serviced. Sleek looking, with no gaps between panels. Minimum roof pitch 15 degrees. Panels can be fitted in portrait or landscape orientation, and triangular panels can also be made to make the most of more complex roof shapes. Generous clearances for ventilation underneath the whole system. Double or triple glazed units can replace individual panels and roof windows can also be incorporated. 25 year weatherproofing warranty. Made in Britain. Installed cost from around £1,850 per kWp. Smaller or more complex systems will be more expensive per kWp.
GSE In-Roof System
A low cost system of plastic trays which manage waterproofing and can accommodate most sizes and makes of standard framed solar panels, held in place by frame clamps. 15-20mm gaps between the panels. Panels can be fitted in portrait or landscape orientation. Ventilation path under each panel. Roof windows can be incorporated. 15 year weatherproofing warranty. Made in France. Installed cost from around £1,400 per kWp.
IRFTS Easy Roof System
A low cost system of plastic trays which manage waterproofing and can accommodate most sizes and makes of standard framed solar panels, held in place by frame clamps. 15-20mm gaps between the panels. Panels can be fitted in portrait or landscape orientation. Ventilation path under each panel. Roof windows can be incorporated. 10 year weatherproofing warranty. Made in France. Installed cost from around £1,400 per kWp.
Marley Solartile
A collaboration between roofing products manufacturer Marley and Viridian, listed below. The Marley Solartile is the Viridian product but labelled under the Marley brand. The name comes from an older Marley product that was a solar roof tile, which was discontinued and is no longer MCS Certified. The new Marley Solartile does not look like a roof tile, but a full-sized solar panel.
Solfit Toploader
A tiled system where the Solfit in-house range of panels interlock with each other, with each row sitting on top of the row below as you go up the roof. Sleek looking, with small gaps between panels. Panels are fitted in landscape orientation. 20 year weatherproofing warranty. British designed and made in the Far East. Installed cost from around £1,600 per kWp.
Viridian Clearline
A tiled system where the Viridian in-house range of panels interlock with each other, with each row fitting over the row below as you go up the roof. Sleek looking, with 5mm gaps between panels. Minimum pitch 20 degree. Panels can be fitted in landscape or portrait. Weatherproofing warranty not given. British designed and made in the Far East. Pricing from around £1,600 per kWp.
