Elon Musk likes to think big. If he’s not trying to fly to Mars, he’s focused on making your next—electric—car the centerpiece of the power distribution to your home. From that approach, it makes sense that Musk—through the Tesla/Solar City combination—wants you to use your roof to generate solar energy. He showed off his new vision with prototypes of a new roof combining shingles and solar cells. Musk says it will cost homeowners less than a traditional roof plus typical electrical costs. Here comes the sun…