Building and installing a residential roof with integrated solar is really difficult. Photovoltaic panels and roofing play very different roles, and combining the two typically compromises both — and at a premium cost. Tesla has demonstrated this in the false starts it has made with its still-in-development solar roof product, now on its fifth major design revision since its 2016 introduction.
The memo below went out late last month to contracted Tesla solar roof customers. It details a design change replacing the non-solar roof tiles (historically made of glass) with a steel roof tile “on an [expanded polystyrene] support,” according to a source familiar with the matter. The source suggests that this will make it difficult to create a “seamless aesthetic integration when new and under long-term weather exposure.” The source attests that other “serious design changes” have also been made.
Your humble narrator has seen enough Tesla solar roof tile installations on houses around Silicon Valley to make some observations:
- A standard shingle roof remove-and-install process typically takes eight hours over two days. The Tesla installs I’ve tracked were running ten days to two weeks and requiring a team of five to six people, with additional personnel brought in to install storage and electric. Perhaps the metal tiles will help improve installation time.
- The Tesla solar roofs are subjectively better-looking than the composite shingles they are replacing. In some cases, they are better-looking than the house they are installed on. Mismatched metal tiles might change that.
- Tesla has been targeting simple shed or gable roofs with minimal roof features or other protrusions. The metal tiles might expand the pool of eligible homes.
- No microinverters or optimizers are being used.
Tesla roof gallery
Weddle & Sons Roofing completed and filmed a 40-square (4,000-square-foot), 15-kilowatt Tesla solar roof installation near Topeka, Kansas last year. The time-lapse video covers four days of installing the PV tiles, glass tiles and flashings. The tear-off of the existing roof and dry-in with double-layer Firestone underlayment took one day and is not recorded.
The photo below shows a Version 3 install that was documented by the owner, along with real-time solar output and specs. This installation includes two Tesla battery units and three inverters, according to the homeowners. The garage is also equipped with tiles.
