If you’ve been noticing more solar panels lately, you’re onto something. While only one in 100 houses has them, that’s 46 times as many as a decade ago. Some of that fast growth is due to a federal tax credit that is worth 30 percent of installation costs. According to the Solar Energy Industries Association (SEIA), there were more than 180,000 solar-related residential installations in 2014, and more than 50 percent growth over the year before. In addition, new financing options are making it easier for homeowners to also become solar panel owners.