A study conducted by appraisers between 2010 and 2013 in six states (Arizona wasn’t one of them) found that solar homes with a typically-sized system sold, on average, for around $14,000 more. With our lower than average energy costs, metro Phoenix area solar owners may not realize an equivalent value boost. But as an informal rule of thumb, that amount can be used as a starting point when buyers, sellers and agents try to determine the value added to an owned solar home.