New data from the Solar Energy Industries Association (SEIA) show that the U.S. has exceeded five million solar installations, marking significant clean energy growth in states across the country. In 2016, by comparison, the U.S. reached its one million installation milestone, following the first grid-connected solar installation in 1973.

Data reflects solar installations on homes, businesses, and in large ground-mounted arrays across the country, according to the association, which forecasts that solar installations in the U.S. will double to 10 million by 2030 and triple to 15 million by 2034.

“Solar is scaling by the millions because it consistently delivers on its promise to lower electricity costs, boost community resilience, and create economic opportunities,” said SEIA president and CEO Abigail Ross Hopper. “Today 7% of homes in America have solar, and this number will grow to over 15% of U.S. homes by 2030. Solar is quickly becoming the dominant source of electricity on the grid, allowing communities to breathe cleaner air and lead healthier lives.”

Access more information on the data on SEIA’s website.