Solar Shingles’ Electricity: Interview With Integrated Solar Technology
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
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So what’s the average cost per peak Watt of installing the system on a house being constructed. What is the average cost on a house with existing compatible roof tiles? Last time I checked it was north of $8/Watt before tax credits, a true financial black hole that you will never recover from.
If these really replace the roof shingles, then it is only for new construction or when replacing your existing shingles. So to get the WATT cost you should take Total cost – normal 30 shingle cost = extra for panels; then divide that by the number watts that area generates. But yes when they first came out they were very pricey.
A typical installation whether in new construction or retrofit is within 10% of the price of a traditional rack mounted solar electric system. When combined with the potential benefit of never having to remove the system when reroofing, and the replacement of roofing materials, the cost is typically within 5% of a traditional system. IST Business Development Manager
Do you have a reference to where we can get a quote now so that I can compare it with others?
+1 – for pricing reference
You can contact me at deborah.lewis@ist-solar.com for assistance in locating a installer and quotation.
A permanent solar shade will greatly increase the lifespan of an asphalt shingle. These solar shingles were designed to be installed precisely over individual asphalt shingle sections thereby extending the longevity of the inaccessible asphalt shingles.
The first question an installer will ask on a site visit is, “How old are your asphalt shingles?” The reason being, in 20 years there will be a crumbling ring of asphalt around the solar array, with near pristine asphalt shingles under the array. They suggest updating the asphalt shingles to push the labor costs of removing the solar panels and required racking further into the future (preferably to coincide with your selling your worn-down solar panels, and upgrading to the latest and greatest while the “sweet-spot” on your roof is accessible).
But with “mini” solar panels (i.e. solar shingles) that precisely line up with the individual asphalt shingles, the crumbling 20 year-old asphalt shingles will not be locked in place by the solar array. And the 20 year-old asphalt shingles that are locked in place will have many more years of moisture mitigating effectiveness, thanks to the solar shingle sitting exactly above.
Absolutely correct. Solar shade not only increases the lifespan of shingles, but also by blocking the sunlight from hitting the shingles, it will reduce the amount of heat that comes inside the home thereby cutting down the electricity consumption.
My next door neighbor is replacing a roof soon on their detached garage. South facing, 6/12 pitch, mostly sun 70% of the time due to some pines… morning shade. If, (big if), they were to go with solar shingles could or should they consider 100% coverage on their nearly true south facing (within 3 to 5 degrees) side with nothing on the north? Also, instead of putting asphalt shingles under the solar shingles, how about 100% coverage with a membrane like Grace Ice and Water shield? They make a high temperature membrane now, to go under metal roofs. Almost all of our local roofers use membranes on rakes, eaves, bulkheads, parapets, valleys, etc. Coastal southern part of Virginia…. hurricanes, nor’easters, some snow, occasional tornados, the usual hellacious summer T-storms that can bring some good sized hail occasionally. Remember, the membranes are considered to be self-sealing, too, for fastener penetration.