The Tesla solar roof is made from tempered glass. Advertising mentions quartz glass which is a form of tempered glass, the other form is silica although the terms are used interchangeably. The product is called Solarglass and is textured. Last October in 2019, version 3 of the roof was released and the Tesla factory in Buffalo, NY had increased production to 1000 solar tiles per week. The plain glass tiles are apparently being sourced from China. The old tiles came in sets of three and each tile was about 14 x 8 inches.
The new tiles are much longer and wider at 15“ x 45″.
The larger tiles are more efficient to install and have fewer wiring connections. But the warranty has been reduced to 25 years for both the tile itself and power production. The former warranty was “infinity” on the roof tile and 30 years on solar production.
The tiles are hooked onto raised modules and overlap with metal flashing on the edges and rooftop
Each V3 solar tile outputs 58 watts of direct current. The connections are typical M4 solar wiring connections into a harness that runs under the tiles.
The harness provides shade control instead of micro-controllers so that power differences from shady areas do not detract from sunny areas.
Many of the roof tiles do not have photo electronics but are just plain tempered glass. The solar and the plain glass tiles are priced separately. Our house qualifies for 10.9 kw of solar power so I calculated that there are approximately 189 solar tiles and 490 plain tiles in our order.
The new version of the roof has a class 3 hail rating and I think the original roof was class 4. A Class 3 roof is earned if the sample does not crack when hit twice in the same spot by a 1.75 inch diameter steel ball. A Class 4 rating, the material should not get damaged when hit twice in the same spot by 2 inch diameter steel ball. It is interesting that the test is for the same spot hit twice since hail tends to distribute over a plane.
The Class F wind rating is the highest that is tested. Asphalt shingle test specimens passing the two-hour test duration at 60 mph are classified as Class A; those passing at 90 mph are classified as Class D; and those passing at 110 mph are classified as Class F.
The tiles are also very tough. Firefighters were given special instructions regarding breaking into the roof to fight a fire. Notice the ladder placed on the roof to steady the firefighter on the slippery glass roof and the use of a chainsaw to cut through the tile.
There are several opinions about the wisdom of an investment decision to purchase such a new roof product because of the long payback and lack of years of data. When we bought our first hybrid car there were similar arguments. Is it worth it? I believe that new and sleek technology is always expensive. People don’t question whether a fancy car is “worth it”. It is acceptable to buy a car that is very expensive and loses value over time for the technology and performance. Solar technology has the same attraction to us as homeowners and it costs less than a new Mercedes Benz or the new Tesla Model X.