Investment in the project is expected to total about 58.4 billion yuan ($8.45 billion), with construction anticipated to take 11 years to complete, excluding preparatory work.
The plan was approved by China's state planner, the National Development and Reform Commission, in April and is awaits approval via a general meeting of shareholders, the filing added.
Huaneng is one of China's five major state-owned power generators. The group's total installed capacity was around 127 GW at the end of 2022, with renewable power sources comprising an estimated 26%.
However, hydro power represented only 0.2% of the electricity sold by the group last year, with coal making up more than 85% of the total, Reuters calculations using data in the group's 2022 annual report found.
Beijing has led an ambitious drive to increase the share of renewables in the country's energy mix, and has said it aims for them to account for more than 50% of its electricity generation capacity by 2025.
($1 = 6.9121 Chinese yuan renminbi)
(Reporting by Andrew Hayley, Editing by Ed Osmond and Barbara Lewis)
By Andrew Hayley
