Dow Solar Shingles – Will they “energize” the market?
Dow’s announcement that their new line of Powerhouse solar shingles received Underwriters Laboratories (UL) certification last Tuesday. This is a major milestone for the company and earns them the distinction of being the first residential solar roofing shingle with an integrated connection system to receive UL safety certification.
According to Dow, the new solar shingles will reduce installation time and complexity using a design that eliminates on-roof wiring, minimizes through-roof penetrations, and allows the product to be installed in the same manner as a standard roofing shingle. The Dow Solar website says that the solar shingles can be installed by roofers using conventional tools and techniques. A nice prospect for many conventional roofing contractors, but don’t jump on board just yet.
Dow partnered with Global Solar Energy which produces thin-film, flexible CIGS solar panels for a variety of markets. Two other partnerships in the residential solar market were announced a couple of years ago with ASTI/Icopal and SRS/CertainTeed. Dupont, which currently manufactures secondary solar materials may be entering the market as well.
The new solar shingle uses thin-film CIGS (Copper Indium Gallium deSelenide) as the PV material. According to Dow, CIGS technology offers the best balance of low cost and highest sunlight conversion efficiency of the commercialized thin film technologies available today. But is it necessarily the most efficient material? Probably not.
The CIGS cells used by Dow were designed to meet a Solar America Initiative (SAI) 10% energy efficiency, below the efficiencies for the top polysilicon cells and conventional framed solar panels. The CIGS cells would cost 10 to 15 percent less on a per watt basis. While this is a less expensive option for the homeowner, it will also require massive amounts of roof space to generate large quantities of usable electricity. Small homes need not apply. Larger homes in the southern regions may even see some return on their investment in the long run, especially after government solar energy subsidies.
Given the current state of CIGS technology, residential solar shingle projects may only be a drop in the bucket compared to larger solar panel projects. Can Dow make a go of it? Time will tell, but it is an innovative start.