There are now over 2 million solar photovoltaic (PV) installations in the U.S., according to new figures. The 2 million mark comes three years after installations hit 1 million, a figure it took the industry 40 years to reach.



The numbers, from Wood Mackenzie Power & Renewables and the Solar Energy Industries Association (SEIA), were released Thursday.

Solar power can be harnessed in several ways, including through photovoltaic and concentrated solar power systems. Photovoltaic refers to a way of directly converting light from the sun into electricity.



California was responsible for 51 percent of the first million installations and 43 percent of the second million, the SEIA said. It explained that this reduction was "in large part" down to a residential sector that was both growing and "rapidly diversifying across state markets."

Other states including Texas, Rhode Island, Florida, Utah and Maryland had helped to drive growth, the SEIA added.

Abigail Ross-Hopper, the CEO of the SEIA, said that the organization believed "that the 2020s will be the decade that solar becomes the dominant new form of energy generation."



For its part, Wood Mackenzie is forecasting that installations will reach 3 million in 2021 and 4 million in 2023.

"According to our latest forecasts, by 2024 there will be, on average, one solar installation per minute," Michelle Davis, senior solar analyst at Wood Mackenzie, said in a statement Thursday. "That's up from one installation every 10 minutes in 2010."



Looking at the bigger picture, the U.S. Energy Information Administration says it expects renewable sources, excluding hydropower, will provide around 11% of electricity generation this year, rising to 13% in 2020.