China Southern Power Grid, one of the country's two major power grids whose business covers Guangdong province, the Guangxi Zhuang autonomous region, Yunnan province, Guizhou province and Hainan province, said it will invest 200 billion yuan ($31.26 billion) in the next 10 years in constructing pumped storage projects, which could enable the consumption of 250 million kilowatts of clean energy in the five regions in the southern and southwestern parts of China.

The company is pushing forward construction of three pumped-storage hydropower stations in Guangdong and the Guangxi Zhuang autonomous region with a total investment of 24 billion yuan and a designed annual power generation capacity of 4.8 billion kilowatt-hours. The five regions will see a total pumped storage capacity of 14 million kilowatts by 2025, it said.

Pumped storage hydropower is the most common type of energy storage in use today. It saves excess power by using it to pump water from a lower reservoir to an upper one at night when electricity demand is low, and releasing it to generate power during the day when demand is high.

State Grid Corp of China, the largest power provider in the country, said earlier the company has constructed 21 pumped-storage hydropower stations during the 13th Five-Year-Plan period (2016-20) with a total installed capacity of 28.53 million kilowatts.

The company will continuously push forward the construction of pumped-storage hydropower stations during the 14th Five-Year-Plan period (2021-25) and will invest more than 100 billion yuan to build several pumped hydro storage plants across the country with a total installed capacity of 20 million kilowatts. The company will see its installed capacity for pumped storage reach 50 million kilowatts by 2025, it said.

The government said in an action plan for carbon dioxide peaking by 2030 that it will come up with favorable policies to spur development of this type of energy storage with a new round of medium- and long-term development plans for pumped-storage hydropower stations.

Other companies including China National Nuclear Corp and China Three Gorges Corp are also laying out medium- to long-term development plans for pumped-storage hydropower stations, and refining policies and mechanisms to spur development of this type of energy storage in response to the action plan.

The blueprint said that by 2025, installed capacity of new types of energy storage will reach 30 gigawatts or more. By 2030, installed pumped-storage hydropower capacity will hit approximately 120 gigawatts. Provincial-level electrical grids will be equipped with peak load response capacity of 5 percent or more, it said.

Peng Caide, chief engineer with the China Renewable Energy Engineering Institute, a think tank under China's National Energy Administration, said increasing pumped storage hydropower capacity is vital to promote green energy transition in China.

"As the use of wind and solar power increases, the market prospect of power storage is very promising," said Peng.

Lin Boqiang, head of the China Institute for Studies in Energy Policy at Xiamen University, echoed his view, adding that pumped hydro energy storage will see an increase in its market share as it is becoming cost competitive.

"Developing energy storage is vital in China's transition toward one that is dominated by renewable energy, while mitigating the impact of new energy's randomness, volatility, and intermittence on the grid," said Peng.

Peng suggests the country develop a batch of large-sized pumped storage hydropower in areas where nuclear and new energy were developed since this would lead to a win-win result.

A forecast released by CITIC Securities said development of new types of power storage and pumped-storage hydroelectricity is set for explosive growth during the 2021-25 period.