The number of solar installations in the United States has officially surpassed 2 million, according to the latest data from Wood Mackenzie Power & Renewables and the Solar Energy Industries Association (SEIA). The milestone comes just three years after the industry completed its 1 millionth installation, a feat that took 40 years to achieve. Wood Mackenzie analysts expect the U.S. to crack the 3 million mark in 2021 and 4 million in 2023. "The rapid growth in the solar industry has completely reshaped the energy conversation in this country," said Abigail Ross-Hopper, president and CEO of trade group SEIA.