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.
Another way of estimating the cost of electricity would be the cost of an ordinary solar system, or $21,000 as shown in the example above. So the cost of a Tesla retrofit system would be in the range of $33,000 to $37,500.