This is caused by the squeegee being angled incorrectly forcing the water under the rubber blade out into the dry area of the glass or from solution being pushed up into the top edge of the window.
Although there is a slight difference between our original calculation and Teslaâs new oneâlast fall we built in a cost of $6,500, Teslaâs current cost for a Powerwall as part of a Solar Roof installation is $7,000.
So put all that together, and here's how Tesla would need to price its tiles to meet Musk's claims. Slate Tile would need to cost less than $98,500 (or about $3,300 per 100 square feet). Bottom line: For sure, $70,000 to $100,000 is a lot to spend on a roof.