Pumped storage key to achieving green energy goals

Zhang Yiguo, deputy director of the China Institute of Renewable Energy Engineering, said that a significant number of pumped-storage projects are expected to be put into operation around 2028, effectively solving the mismatch between low renewable energy and high installed capacity, and further promoting renewable energy as a primary energy source.

CREEI’s latest report shows that last year, renewable energy accounted for 84.9% of newly added installed capacity but only 32% of electricity generation, while wind and solar combined accounted for just 15% of total generation.

Experts said the main reason for this is the low number of generation hours due to the intermittency and variability of renewable energy sources. The launch of numerous pumped-storage hydropower projects, coupled with the development of new energy storage technologies and grid advances, is expected to significantly improve the overall situation.

Energy storage systems, whether pumped-storage hydropower plants or large batteries, enable the integration of renewable energy sources – whose output can be unstable or variable depending on weather conditions – into the power grid while ensuring grid stability and reliability.

“The pumped-storage capacity currently being planned and constructed is significant. However, due to long project cycles, it is expected to start operating around 2028 or by the end of the 15th Five-Year Plan period (2026-2030). This will greatly help establish new energy as the backbone of the power generation system, which is part of China’s green commitment target,” Zhang said.

According to CREEI data, 49 new pumped-storage power plants were approved last year with a total capacity of 63.43 million kilowatts.

In 2023, 5.15 million kW of pumped-storage power plants were put into operation, increasing the total installed capacity to over 50 million kW. In the same year, new types of energy storage facilities reached 22.6 million kW, increasing the total installed capacity to 31.39 million kW by the end of the year.

It is expected that this year the new capacity of pumped-storage power plants will amount to about 6 million kW.

“In addition to traditional pumped-storage hydropower, innovation in new types of energy storage technologies is essential to improve the integration of new energy sources into the grid. This includes technologies such as flow batteries, compressed air energy storage and chemical energy storage. It is also essential to establish and improve large-scale power grids and distribution networks,” Zhang said.

Du Zhongming, head of the electricity bureau at the National Energy Administration, told a recent conference that further work is underway to accelerate the construction of power grids and improve power transmission mechanisms as China’s power grid faces increasing stability challenges from the growing share of electricity generated from variable new energy sources.

These actions include accelerating the implementation of 33 key projects, such as the Sichuan-Chongqing ultra-high-voltage AC power plant project, and accelerating the start of construction of 37 key projects.

“We will also strengthen the construction of a distribution network that connects the grid with users to meet the requirements of large-scale development of distributed new energy. By 2025, the distribution network will have the capacity to accommodate about 500 million kW of distributed new energy,” Du said.