3 ms·

I worked for a solar installer company for a while last year and we were doing a training in preparation for building out our first installation of a Tesla sola

I worked for a solar installer company for a while last year and we were doing a training in preparation for building out our first installation of a Tesla solar roof. I didn't participate in the build, but was helping the installers with the training. To your supposition about the construction and shading, the solar roof tiles are tempered glass plates with clips that mate with plastic standoff roof mounts, so there is a ~35mm air gap beneath the tiles and the roof membrane. This is the pathway that the electrical cables route to interconnect the tiles and other needed electrical appurtenances like electric feed-throughs, mppt devices and inline disconnects to satisfy newer NEC rules about the maximum string voltage in a system shutdown. The clip in design also allows for individual tiles to be removed and replaced without disturbing those around them, although scaling a glass roof sounds harrowing. I will say that the roof quality needed to execute the solar roofing system was intense. There was very little affordance for shimming the tiles into the plane, which seemed a oversight in design. The whole roof deck needed to be coplanar to (going from memory) ~1". In our area this would be rare to find houses with this quality of roof deck, requiring significant reworking to rip the decking and shim the supporting structure from below. Our housing stock is old. The estimated installation time was on the order of 10X of a traditional above-the-roof solar system at weeks vs ~2 days. The install really needed people with the skills of a roofer, which wasn't a significant overlap with the skills of a normal roof working solar installer.

01100011 6y ago
Interesting. I wonder if the seismic requirements change as well. I'd think with such tight tolerances you'd have problems with flexing from even a modest quake.
- rainbowzootsuit 6y ago
  I think that the reason for the coplanar requirements is that the tiles lap each other in the up-down slope direction, but only abut one another in the perpendicular. There's no interleaving or joining or flashing in that direction. Two abutting panels land into the same clip. Around penetrations and edges there are non-pv fractional tiles, and all of the ends edges and ridges etc are done with sheet metal. Leaving too much gap will get stuff underneath the tiles and also make them more susceptible to being removed by wind or exposure of the membrane to UV and other things it's not tolerant of. The real waterproofing layer is the membrane that's put down first. There are higher numbers of clips on the panels/tiles for high wind areas. If I was baller enough to afford this I would definitely invest in a continuous insulation roofing system to go on first.

01100011 6y ago

Interesting. I wonder if the seismic requirements change as well. I'd think with such tight tolerances you'd have problems with flexing from even a modest quake.

rainbowzootsuit 6y ago
I think that the reason for the coplanar requirements is that the tiles lap each other in the up-down slope direction, but only abut one another in the perpendicular. There's no interleaving or joining or flashing in that direction. Two abutting panels land into the same clip. Around penetrations and edges there are non-pv fractional tiles, and all of the ends edges and ridges etc are done with sheet metal. Leaving too much gap will get stuff underneath the tiles and also make them more susceptible to being removed by wind or exposure of the membrane to UV and other things it's not tolerant of. The real waterproofing layer is the membrane that's put down first. There are higher numbers of clips on the panels/tiles for high wind areas. If I was baller enough to afford this I would definitely invest in a continuous insulation roofing system to go on first.