Chen Fei said the last two of the six power units are to come online then, Xinhua, the official government news agency, reported. Last year, the dam produced 78.29 billion kilowatt-hours of electrical power.
The dam, the largest hydropower operation in the world, was designed for both flood control and electrical power generation. Construction began in 1993.
Officials say the dam proved its worth last year with three major floods on the Yangtze River.