Solar shingles’ electricity is spurring considerable interest among renewable electricity champions. Following my last story about solar shingles, I had the pleasure of learning about another solar shingle company, Integrated Solar Technology (IST).
What follows is an interview I conducted with Oliver Koehler, the founder and CEO of IST.
Meyers: What is the life expectancy for your solar shingles and what kind of maintenance will be required?
Koehler: IST’s SunTegra Shingle solar roof system has a 30-year life expectancy. The solar component of the roof system uses the same materials and technology found in standard crystalline solar panels. The unique integrated mounting system is made with materials known for their ability to withstand long-term outdoor exposure, moisture and heat. The maintenance is limited and similar to what is expected for standard solar systems and roofs—periodic inspection of the system for any broken glass surfaces or loose flashings. One advantage versus a standard solar system is that all the cables are covered, so there is no chance of cables coming loose due to snow, leaves or hungry squirrels!
Meyers: Please elaborate on some of the partner programs you have developed.
Koehler: IST is currently developing partnerships with solar dealers and distributors to sell SunTegra Shingle and Tile products. Typically the solar dealers that IST targets are roofers with an existing solar division, established solar dealers and contractors. IST also encourages roofers and contractors to participate in its authorized installer program. In some cases a partner may sell the product, and also be interested in installing it for other customers. Clean Energy Distribution and August Roofing are examples of companies that are both selling and installing SunTegra products.
Meyers: Colorado, where I am located, is known for hail storms. How do your shingles hold up under these kinds of weather conditions? How about snow?
Koehler: IST’s SunTegra Shingle and Tile systems hold up just as well as standard solar panels and better than many roofing materials. They are designed with 3.2mm tempered glass and their smaller size and overlapping and interlocking method of attaching to the roof make them very durable against hail, wind and snow. Specific ratings are available on our data sheets, which you can find at www.ist-solar.com/products.
Concerning snow, SunTegra products include a snow rake built directly into the product. This protects people and landscaping below by slowing the fast-slide-off of snow from the solar system.
Meyers: Can you provide us with any case studies of roof repairs that have been made?
Koehler: We currently have not had any roof repair needs or issues. We do have installation case studies we can share. The case studies are currently being finalized, and I will be happy to share them once we have all the materials compiled.
Meyers: Converting a roof to provide solar electricity is an expensive proposition, regardless of scale. In general, how should a homeowner look at a return on investment?
Koehler: This is a great question as the return on investment has many aspects for a homeowner. First there are the energy savings and incentives which should be calculated against the upfront system costs. Then there are other potential roofing costs—either upfront or if the customer has an asphalt shingle roof, later when the solar system has to be removed and replaced in order to reroof the house. Finally, there is the question of curb appeal. Is the solar system something pleasant to look at which adds to the attractiveness of the house or something that neighbors and homeowners “live with” but don’t love? In the event of a home sale, a poor-looking system can reduce a home’s potential selling price.
The advantages of a SunTegra roof-integrated system is that you never have to remove the system to reroof the house—it is the roof and you reroof around it. This saves on the cost of removing and replacing a conventional rack-mounted system and saves on the roofing materials that would otherwise have to go under the system. Concerning curb appeal, IST has done a survey of prospective solar homeowners and 75% said they prefer they look of an integrated solar system compared to a rack-mounted solar system. An integrated system provides the homeowner the best prospect for maximizing the home’s selling price.
Meyers: If an owner converts to a partial or complete solar electric system, what issues might occur in working with the local utility?
Koehler: Interconnection of a SunTegra roof-integrated system is no different from that of a standard PV solar system. The electrical circuit ( number of cells per string or optimizer) is the same.
Permitting of a roof-integrated system also has an advantage as the systems are no heavier than the standard roofing materials and therefore often eliminates the requirement for structural review from a building department.
Meyers: Solar roof functionality is reduced on cloudy days by how much?
Koehler: SunTegra solar roof systems will generally function the same as standard solar panels. On cloudy days their performance is calibrated proportional to the amount of light coming into the solar panel through the clouds. Diffuse cloudy days would preserve some performance—typically 40-60%—whereas very cloudy days or harder shadows, could reduce performance completely.
Meyers: On sunny days, how can excess electricity be cost-effectively stored?
Koehler: Good question. While IST is not currently focused on developing storage technologies, we would look at incorporating such technologies into the systems when they become more cost-effective and proven.
Images provided via Integrated Solar Technology