What are solar shingles?

By Christopher Fisher, product development leader of photovoltaics, CertainTeed Corp.

Solar shingles technically fall under the umbrella term “building-integrated photovoltaics (BIPV)” since they are integrated into the building envelope. Other examples of BIPV include photovoltaic modules integrated into skylights, ceilings, facades, awnings or canopies. BIPV products primarily attempt to do two things: 1) Integrate into the building structure to provide a more aesthetic solar installation, and 2) Replace traditional building materials, thereby saving material cost and labor to install those materials separately from the PV system (without compromising functionality with respect to the building structure).

What sets solar shingles and solar tiles apart from most other BIPV products is that they are designed for the residential market and can be integrated into over 85% of residential roofs.

Easy installation

Solar installers who have never worked on a BIPV project may be surprised at its installation simplicity. CertainTeed’s Apollo II systems, on the market since 2013, are carefully engineered to maximize efficiency in the installation process and provide long-term value to homeowners. No specialized training is necessary. If you can install a roof-mounted PV system, you can install solar shingles, like Apollo II.

Available for the most common U.S. roofing systems (including asphalt shingle, synthetic slate and flat concrete tile), the Apollo II and Apollo Tile II systems are tested to solar industry standards and roofing industry standards for fire, wind and rain protection. Apollo II must be installed on buildings with a roof slope of 4:12 or greater (3:12 for Apollo Tile II) and in an overlapping pattern to ensure water shed as a typical roofing system would. Flashing and underlayment are supplied with each system to minimize custom fitting and save installation time.

All Apollo II systems come with a starter strip that secures the first course of solar shingles or solar tiles to the roof, and wind clips to fasten one course to another. Integrated wire management with industry-standard connectors make it easy to connect solar shingles or solar tiles and prevent damage during installation. The result is a clean, tightly packed system.

Cost and time savings

One of the time-saving features of solar shingles is that you don’t have to spend time locating rafters as you would with a traditional rack-mounted PV system. Solar shingles and solar tiles attach directly to the roof deck using standard corrosion-resistant deck screws. Plus, due to the system’s low profile, wind does not get underneath the system and create significant uplift.

Due to the smaller form factor of each individual module (roughly 4 ft by 1 ft) and the ability to install those smaller modules in non-rectangular array shapes, Apollo II gives installers flexibility to use available roof space as effectively as possible. And because solar shingles and solar tiles weigh about the same or less than traditional roofing material, there’s typically no need to do a structural evaluation of the roof. However, when attaching directly to the deck, it is important to ensure that the roof deck is clean, flat and dry, and that the decking material is in good shape.

Solar shingles and solar tiles are designed to be independent of the surrounding roof. They can be added to an existing roof. They can also be left in place during the removal and replacement of traditional roofing material. This allows for a clean separation of solar and roofing trades and means the operating life of the solar shingles or solar tiles does not have to match the life of the traditional roof.

Simplicity and efficiency add up to substantial savings, which can be passed along to the homeowner. For a typical 6-kW Apollo II system, the average savings on roofing materials and labor alone when compared to separate roofing and roof-mounted PV installations is $770 to $1,210. For a typical 6-kW Apollo Tile II system, savings is usually between $1,260 and $2,520.

For many homeowners, solar shingles and solar tiles are more aesthetically attractive than traditional rack-mounted systems. This can add to the resale value of the home, and it becomes especially important where the roof is visible from the curb or the home is governed by a homeowners’ association. Installers who offer solar shingles and solar tiles can generate more leads and close more sales.