Just before Halloween in 2016, Elon Musk stood on the "Desperate Housewives" set in Hollywood and unveiled the solar roof that he believed would revolutionize the solar industry.
Three years later, he predicted that 2019 would be the year of the solar roof – the central product Tesla planned to make at the South Buffalo factory that state taxpayers built for the company at a cost of nearly $1 billion.
Today, Tesla’s Solarglass roof still isn’t ready for the mass market, and this week Musk admitted that the company made “significant mistakes” that underestimated how difficult the new roofing product would be to install on some roofs.
The company earlier this year raised the price of the solar roof sharply to reflect those installation issues. It’s now requiring that homeowners installing a solar roof – or even conventional solar panels – to also put in a battery storage system using one of Tesla’s Powerwall batteries to make installations simpler and make the home much less dependent on utility-generated electricity.
The bottom line: While Musk said demand still is high for the solar roof and production at the Buffalo factory is going just fine, the rollout of the solar roof remains limited because it’s so complicated to install.
And low installations is bad news for the Buffalo factory, because it means it doesn’t have to make nearly as many solar roofing tiles as it could. Canary Media, a clean energy news website, estimates that Tesla has installed fewer than 1,000 solar roofs.
That’s a disturbingly low number, considering that Musk boasted that the Buffalo plant had briefly elevated its production before Covid hit to the point where it was producing enough solar tiles for 1,000 low-powered solar roof installations in a single week.
To fill out the Buffalo factory, Tesla has shifted electronics assembly work here and, earlier this year, asked local politicians to help promote job opportunities for high school-level data annotation specialist jobs tied to its self-driving vehicle initiatives.
“Production has gone fine, but we are choked at the installation point,” Musk said during a conference call to discuss Tesla’s first-quarter earnings on Monday evening.
Tesla has never disclosed any details about its solar roof installations, other than noting how rapidly they have increased on a percentage basis. In the first three months of this year, for instance, Tesla said solar roof installations were nine times greater than they were during the first quarter of last year.
While that sounds impressive, the percentage increase is meaningless without knowing how many roofs are involved. If Tesla installed, say, 10 solar roofs a year ago and it jumped to 90 this year, it’s a nine-fold increase, but production still is tiny. Going from 100 to 900, or from 1,000 to 9,000 would be much more impressive and still have the same growth rate.
We just don’t know for sure what the real number is. No one could be reached to comment at Tesla, which has disbanded its communications department. But Musk did answer an investor’s question about the solar roof during the earnings call.
“The demand for the solar roof remains strong,” Musk said. “Despite raising the price, the demand is still significantly in excess of our ability to meet the demand to install the solar roofs.”
The problem is not in the Buffalo factory. It’s in getting the solar tiles installed on the roof.
Installing the solar tiles is complicated enough on a regular, square roof, with the extra circuitry and engineering that the solar roof requires. One Tesla installer posted a time-lapse video of a solar roof installation that took four days, and that didn’t include the time to tear off the old roof. It’s even more difficult – and time-consuming – when a roof has nooks and crannies.
“We did find that we basically made some significant mistakes in assessment of difficulty of certain roofs, but the complexity of roofs varies dramatically. Some roofs are literally two times or three times easier than other roofs. So, you just can’t have a one size fits all situation,” Musk said.
“If a roof has a lot of protuberances or if the roof sort of the core structure of the roof is rotted out or is not strong enough to hold the solar roof, then the cost can be double, sometimes three times what our initial quotes were,” he said. In those cases, customers can get refunds on their deposits.
Musk said he thinks the shift to require battery storage on all Tesla solar systems – including the conventional rooftop systems that account for the vast majority of the 92-megawatts of solar capacity it installed during the first quarter – will make installations less complex.
“It will be much easier, because the power from the solar roof or the solar panels will only ever go directly into the Powerwall” battery, Musk said.
With the Powerwall in between the utility wires running to the house and the home’s electrical system, Musk said the installations with batteries won’t require Tesla installers to touch the house’s circuit breakers.
“Effectively almost every house, therefore, looks the same electrically instead of being a unique work of art and requiring exceptional ability to rewire the main panel,” he said. “This is extremely important for scalability. It’s the only way to do it, really.”
And for Buffalo – and the state taxpayers who paid for Tesla’s factory – scalability is what really matters.