> Tesla does not suggest ordering an all-solar roof. Solar tiles cost $42 per square foot, while non-solar costs $11 per square foot. Tesla recommends $21.85 per square foot, based on 35 percent solar tiles. The design of the tiles, patented recently, mean the two appear the same to the untrained eye to create a single roof.

>Tobler bought a roof of around 2,000 square foot, with 40 percent of installed tiles solar. That costs around $50,000 once the federal solar Investment Tax Credit is factored in, and it produces around 9.85 kilowatts of power — which Tesla told Tobler was “the biggest system we have available.”