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.
To get there, we pulled together ballpark pricing for the various roofing materials Teslaâs solar shingles mimic, from sources like the Slate Roofing Contractors Association, the Tile Roofing Institute, and the Remodeling 2016 Cost vs. Value Report.