The number of U.S. homeowners putting solar panels on their roofs declined last year after leading installers including Tesla Inc. abandoned aggressive sales practices that had helped drive breakneck growth. Residential solar had been on a tear, averaging 49% annual growth between 2010 and 2016, but the number of megawatts added last year dropped by 16% compared with the year before, according to new data from GTM Research, a firm that tracks renewable energy. It was the first annual decline since at least 2000, which is as far back as GTM tracks figures. Industry executives and energy experts said the slowdown was driven by a sharp retreat by national solar installers, including Tesla’s SolarCity and Vivint Solar Inc. VSLR 4.11% Those big outfits had deployed large sales forces to pitch homeowners on the benefits of rooftop solar, and heavily marketed deals to lease panels that required little to no […]