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.
1 Solar roofing generally costs $25 to $35 per square foot installed, although keep in mind that you probably will only cover a portion of the roof, not the entire surface (covering 1/4 of the roof, or 375 square feet, would cost around $9,000 to $13,000). Wood shingles cost $6 to $9 per square foot installed ($9,000 to $13,500). 2  Galvanized steel is one of the most popular metal roof options and costs $9 to $13 per square foot installed ($13,500 to $19,500).