By Taylor Thompson, Analyst, MyDomino
PV Solar Report Contributor
Elon Musk is no stranger to creating buzz. That was true of the recent merger between Tesla and SolarCity, creating a company that’s trying to integrate clean energy into all facets of your lifestyle.
Shortly before this merger was the announcement of Tesla Solar Roof, which integrates solar cells into individual roof tiles. This announcement has created a lot of excitement and just as many questions. At MyDomino, we want to help answer some of the questions that you might have about integrated solar roofing.
What exactly are solar shingles?
Solar shingles are a great example of building-integrated photovoltaics (BIPV). That basically means solar panels that have been included into the original construction of a building, rather than added on after construction was completed.
The driving concept behind BIPV systems is that they’re more cost-efficient when compared to traditional systems — because you can build the roof and install panels at the same time. Plus, a lot of people find them more aesthetically pleasing.
Elon Musk echoed these sentiments during the unveiling of the Tesla Solar Roof: “The goal is to have solar roofs that look better than a normal roof, generate electricity, last longer, have better insulation, and actually have an installed cost that is less than a normal roof plus the cost of electricity.”
Tesla plans to offer four different styles: Tuscan tiles, slate, textured glass, and smooth glass. In typical Tesla fashion, the tiles of Solar Roof are engineered to survive in extreme conditions. Tesla brags that they can even survive hail in winds up to 200 miles per hour.
Is this a new technology?
Mr. Musk’s presentation was the first time that many people ever heard about the concept of integrating solar panels into regular rooftop construction. However, the technology has existed in a commercially available form since 2005.
Here’s how it works. When you get solar shingles installed, they don’t cover your whole roof. The shingles that actually produce energy are arrayed in an assembly of 24 individual cells. A typical home would have 45 of these arrays, with the rest of the roof being filled with “dummy tiles” — tiles that look the part, but don’t produce electricity.
Tesla is just the latest in a long line of solar shingle manufacturers, which has included Atlantis, AstroPower, UniSolar, BP Solar, PowerLight, Dow, Suntegra, and CertainTeed. Dow shuttered its solar shingle program last June. Of the other companies, only Suntegra and CertainTeed are still in business.
While going against the odds is certainly nothing new for Tesla, solar shingles have had a hard time catching on in the past. The reason for this is that solar shingles have had historically higher component and installation costs than traditional solar panels. Tesla/SolarCity has not yet released any pricing information on Solar Roof, but they will need to overcome the high costs associated solar shingles of the past in order to really make an impact.
As of right now, the company has not released updates on when it plans on making its Solar Roof available to consumers.
Will the Solar Roof be cheaper than a traditional solar panel system?
This article written by residential solar expert Barry Cinnamon outlines some of the prospective costs of the new Tesla solar shingles. Using historical data on solar shingles combined with the latest installation costs, he estimates a slower payback time on a solar shingle system compared to traditional rooftop solar installations. Barry estimates that with a solar shingle system, it would take you 2-4.5 more years to see returns on your investment than with a traditional solar installation.
We invited Barry to our office to have a conversation about solar shingle technology, why it has a longer payback time than traditional installations, and its role in the expansion of residential solar installations. He explained that the way solar shingles are produced and installed prevent them from taking advantage of the latest efficiency technologies.
When installing regular solar panels on a roof, installers attach devices like optimizers and microinverters to the panels. Solar shingles, sitting flush against the roof, don’t have space for these devices. That cuts into their overall efficiency. In addition, new regulations in the state of California will require safety electronics to be installed on each solar module, something that solar shingles are unable to accommodate.
Barry also told us about his experience in troubleshooting solar shingle systems. Oftentimes, he said, a single shingle will fail — triggering a shut-off protocol which then renders the whole solar array useless. Since there’s no room for air to flow under the solar shingles (like there is with solar panels), overheating risk can prevent the shingles from being as efficient as possible. And traditional solar panel installations are much easier to service and replace components for, allowing for cheaper repairs and longer-lasting systems.
Elon Musk proclaimed that Tesla Solar Roof will “cost less than a normal roof,” a tall order considering what most Americans consider a “normal roof” — asphalt shingling. While asphalt shingles are bad for the environment and may even be considered ugly, they’re cheap, at around $90 per 100 square feet. It’s hard to comprehend how a roof with sophisticated electronics could cost less than something so inexpensive.
Can Tesla change the solar conversation?
Despite the significant challenges that Solar Roof faces in its path to market, it has been a conversation starter. Perhaps the greatest outcome from the Solar Roof announcement will be that it brings solar into mainstream conversation, and catches the attention of people who might never have thought of putting solar on their home before.
Elon Musk has done wonders in making electric cars something of a status symbol. Could the spinmaster work his magic on residential solar? Only time will tell.