Stephan:   The article in inhabit, a usually reliable site, about the Tesla solar roof is in error. The price quoted is $21.85 cents for square foot. When I read it again, I realized the author has confused an asphalt roofing "square"  a term that means 10' x 10' with a square foot. So I went to the Tesla site and confirmed that. This is what they say: "Solar Roof is more affordable than conventional roofs because in most cases, it ultimately pays for itself by reducing or eliminating a home’s electricity bill. Consumer Reports estimates that a Solar Roof for an average size U.S. home would need to cost less than $24.50 per square foot to be cost competitive with a regular roof. The cost of Solar Roof is less. The typical homeowner can expect to pay $21.85 per square foot for Solar Roof,¹ and benefit from a beautiful new roof that also increases the value of their home." My apologies for not catching this, and thanks for readers on both the site and the FB site for alerting me to this.