When Elon Musk unveiled the Tesla Solar Roof in 2016, it was the first that many people had heard of solar shingles. But the idea of a roofing product that can both generate energy and blend in with regular asphalt shingles has been around for decades.
Companies from Dow Chemical Company to the now defunct BP Solar have given the solar shingle a shot, but many of these products are no longer on the market. Solar shingles have been expensive to manufacture and install, and are not yet as efficient as regular solar panels. That's kept them from breaking into the mainstream.
Now GAF Energy, the sister company to one of the largest roofing companies in the world and a division of privately held Standard Industries, is launching a new solar shingle effort. It just released a product called Timberline Solar, which the company says will be cheaper and more reliable than Tesla's Solar Roof. It just won the Best of Innovation Award for Smart Cities at CES.
What sets GAF Energy apart
"We're part of the world's largest roofing manufacturer. We have access to materials that typical solar companies don't have access to," said Martin DeBono, President of GAF Energy. "No one has ever specifically tried to make a solar product that a roofer can install. And we've done it, and our product goes on with just a nail gun. It goes on twice as fast as typical solar."
Timberline Solar can be nailed to the roof just like a regular shingle, which GAF Energy says will reduce the complexity and cost of installation. At 17 inches tall and 64 inches long, the shingles are also larger than Tesla's, meaning there are fewer parts to manufacture and fewer individual wiring connections, which the company expects will also decrease costs while increasing reliability.
However the larger and bulkier design also means that GAF Energy's shingle doesn't blend in as well as Tesla's product, which is nearly indistinguishable from normal roofing material.
GAF Energy says its deep ties to the roofing sector will also help it save on sales and marketing expenses, since the company can attract solar customers from the large pool of people already coming to GAF for a new roof.
"The natural moment to actually put solar on a roof is that moment when you're already about to replace your roof. It makes literally no sense to put brand new PV on an old roof that's well into its warranty," said David Winter, Co-CEO of Standard Industries.
Winter says that one out of every three asphalt shingle roofs in the U.S. is a GAF roof. "So we're the people that are sitting at the proverbial kitchen table with the homeowner at that moment that they need to replace their roof, where we can introduce the idea of solar."
According to Wood Mackenzie, customer acquisition costs usually make up 23% of the total cost of a residential solar system, so saving here could be key.
GAF Energy also touts the fact that it assembles and partially manufactures its shingles at its facility in San Jose, California. While the company imports its PV cells from Thailand, it believes that having some domestic manufacturing is advantageous.
"What that allows us to do is take improvements in our product from the lab and get them to instantiate in the product very, very quickly," DeBono says. Alternately, teams would have to fly overseas to execute changes. "And what you see is changes to your product take quarters and years, literally, whereas here it takes hours and days."
Only real world performance over the product's 25-year warranty will show if GAF Energy has really cracked the code to an affordable and reliable solar shingle product.
GAF Energy did not provide CNBC with specific pricing information, though DeBono estimated that on average, Timberline Solar could cost about twice as much as replacing a roof with normal asphalt shingles.
"Let's say in many parts of the country, you have a fifteen thousand dollar cost for the roof. Getting a solar system, adding that would be another fifteen thousand," DeBono said.
Getting a $30,000 solar roof would be far cheaper than anything on the market today, and could cost less than getting a new roof plus regular solar panels.
For comparison, Tesla's projected cost for an average-sized 1,700 square foot Solar Roof in the Bay Area is about $40,700 before solar subsidies. But Tesla's product has been known to cost much more than initial estimates. The company was hit with a class-action lawsuit last year after it dramatically hiked Solar Roof prices for customers who had already signed contracts. (Tesla later told some customers it would reverse the price increases, according to legal filings.)
The efficiency of GAF's shingles in a real-world environment is also an open ended question, since previous solar shingle products haven't been comparable to regular panels.
"They fundamentally operate at a lower efficiency," said Barry Cinnamon, founder of Silicon Valley-based solar installer Cinnamon Energy Systems. "And the reason is that they're flush with the roof and the roof is hot. And so hot solar cells don't work as efficiently as cooler solar cells in conventional modules."
GAF Energy says that it's using high-efficiency mono-PERC cells, which perform better than traditional monocrystalline PV cells at high temperatures. Yet given the Timberline Solar shingle's dimensions and its stated 45 watt capacity, in ideal conditions it would still generate less energy per square foot than Tesla's latest 71.7 watt shingle or an average-sized 300 watt solar panel. Because GAF Energy's shingles overlap, each one has a lot of inactive material. The company claims that if you look only at the active solar cells, its shingle's efficiency is on par with Tesla's shingles, though still less efficient than a standard solar panel.
At the time of CNBC's interview with Cinnamon, GAF Energy's shingle had not been released. But speaking about solar shingles generally, he was doubtful that they would ever appeal to the masses.
"I really don't see anything that's going to change with any of these factors that are going to make it a widespread mainstream product. I think it's always going to be a niche product like a fancy sports car."
Yet Gabriela Bunea, Senior Vice President of Solar R&D at GAF Energy, maintains that Timberline Solar will be able to compete when it comes to cost, efficiency and reliability.
"It is my hope that maybe in five, ten years when you are thinking about changing your roof, you will pick the solar roof, because it makes economic sense, because it's attractive and because you will have the same warranty as the rest of the roof."
Watch the video to see CNBC's early look inside GAF Energy's R&D and manufacturing facility in San Jose, California, where it's assembling Timberline Solar shingles.
--Lora Kolodny contributed to this report.