The word on the “roofing contractor street” is such that a large PVC roofing manufacturer has problems with their Roof-integrated Solar PV systems. Apparently, the way they designed and installed these solar roofs, the electrical wiring which connects Solar PV panels to the inverter and essentially to the Electric Grid, is overheating and poses serious risks of fire. Since this information is still in rumor stage, and I doubt there will be an official announcement or acknowledgment of this, I for many reasons cannot name the manufacturer, the specifics of the problems or the source. However, there is evidence that it is real. If you are a large roofing contractor in Boston, MA area or in the rest of New England, you are getting the roofing bid lists, such as the Blue Book. Large commercial and government roofing jobs are a little out of our league, and we get plenty of work without paying huge sums of money for these bid lists (it costs anywhere from $3000/year to get periodic updates). However, in the last 3 weeks I’ve been contacted twice by two different gentlemen from Suffolk Construction. Basically Suffolk is arguably the largest GC in Boston area with $1.57 Billion in sales in 2008, has over 800 employees and are rated #313 of America’s Largest Private Companies by Forbes.
The picture below, shows a Solar roof produced by IB roof systems. This roof does NOT have overheating problems, and is intended to demonstrate what Solar Roofing is.
In any case, the two gentlemen from Suffolk, asked me to bid a new job in the pipeline of roof bidding lists: A 4,000 squares (400,000 sq. ft.) on the IRS building in Andover, MA, and also they wanted 500 KW solar PV system that would be roof integrated – essentially they were interested in our IB Solar Wise PV system, which in some ways is similar to the one above, but without the wiring overheating of course 🙂 The similarity is in the usage of the UniSolar Thin-Film PV laminates. Other than that, all other components of these Solar Roof systems are proprietary and are very different. So how are the two events connected? It is my understanding that the Solar roof described above was originally specified for this IRS roof, but because of the problems, they started looking for the one that works. Because IB SolarWise is about the only Solar Roof system out there that does not have any problems with it, Suffolk contacted us on two occasions. Aside from the cable overheating and fire hazards, most other flat roofing manufacturers that wanted to use their roofs with UniSolar PV laminates, ran into problems of solar panels delaminating from the roofing membrane. IB Roofs took their time designing the IB SolarWise PV system, and developed a special membrane called IB Solar Shield which is designed to provide excellent adhesion between the PVC material used in IB roofs and the Butyl adhesive on the UniSolar PV laminates. This eliminates the potential of delamination that most (if not all) other roofing manufacturers are facing. The earlier version of IB SolarWise used the solar panels made by Open Energy of California. Later UniSolar panels were chosen as a default integrated PV system, because it allows for greater flexibility for the contractor, system designers and the customer.
Today’s IB SolarWise PV systems are made in the following way: IB takes 6×19′ Solar Shield membrane and places 4 UniSolar 136 watt modules using a special process, which insures the proper bond between two products. Then, the whole IB Solar Wise module gets welded to the already installed IB Flat Roof. IB uses regular UniSolar modules with the connectors facing the outside of the module. Although this requires special housing to protect the connectors from UV rays, it eliminates the possibility of cable overheating, as all wires are exposed to the air and are ventilated. This makes IB Solar Wise the best solar-integrated roofing PV system. If you are looking for more information about solar roofing in general, or want to know if solar will work for you, we recommend that you read our Solar PV design & installation guide.