China will add 140 gigawatts of capacity from the clean energy sources, said Ms Tao Ye, a researcher with the National Development and Reform Commission, the country's top economic planning agency.
That is more than the rest of the world combined in 2020, according to BloombergNEF data.
The forecast is the latest sign that China is racing ahead of its official target for renewable adoption as local governments, wind and solar equipment producers and state-owned utility giants continue to push ambitious plans.
China is aiming for 1,200 gigawatts of wind and solar generation capacity by 2030, and had 678 gigawatts by the end of last year, according to BloombergNEF.
Solar power will contribute about 70 to 75 gigawatts this year before rising to 100 gigawatts a year starting in 2023, Ms Tao said at an online forum hosted by the China Photovoltaic Industry Association (CPIA).
Expanding the domestic solar market can help offset external pressure and risks for Chinese panel manufacturers, after the United States launched a trade probe on whether they're circumventing tariffs, chief secretary of CPIA Wang Shijiang said at the forum.
With a sizeable domestic industry building solar panels and wind turbines, aggressive renewable deployment also plays into the country's push for enhanced energy security amid global commodity market tumult.
For the same reason, Beijing is leaning on its coal industry to boost output and build and upgrade thermal power plants to help balance the variable wind and solar power generation.
"Our traditional energy, either coal or coal-fired power, will maintain certain growth, and the growth rate might be faster than the past one to two years," Ms Tao said.