Recently, Luotian Pingyuan Pumped Storage Power Station officially started construction, with a planned installed capacity of 1.4 million kilowatts. According to reports, it is not only the first approved pumped storage project in Hubei after many years, but also the preliminary work such as the feasibility study of the project took only one year, breaking the record for the shortest time spent in the feasibility study phase of similar projects. At present, in order to adapt to the new power system with new energy as the main body, the construction of energy storage facilities has ushered in a new trend. During the 14th Five-Year Plan period, domestic pumped storage investment will exceed one trillion yuan.

After the "dual carbon" goal is put forward, the new power system with new energy as the main body will add more clean energy such as wind power and photovoltaics. This power system puts forward higher requirements for the peak shaving capacity of the power grid, and needs to be equipped with corresponding storage able facilities. Pumped hydro storage is one of the most mature technologies at present. Pumped storage power station, like a super charging treasure, is a super charging treasure with functions of peak regulation, valley filling, energy storage emergency, etc. It is an important part of building a new power system.

The development of pumped storage in China began in the late 1960s with the Gangnan Power Station in Hebei. At present, the total scale of pumped storage power stations has been put into operation, with a total scale of 32.49 million kilowatts, mainly distributed in East China, North China, Central China and Guangdong; the total scale of pumped storage power stations under construction 55.13 million kilowatts, about 60% of which are distributed in East and North China. The scale of both built and under construction ranks first in the world. It is the largest in scale, and its technology is comparable to the international advanced. By the end of 2021, Hebei Fengning Pumped Storage Power Station with a total installed capacity of 3.6 million kilowatts will be put into operation, which can provide 7.2 million kilowatts of power regulation capacity, the highest in the world for pumped storage.

Only Bailianhe Pumped Storage Power Station and Tiantian Pumped Storage Power Station have been put into operation before, both in Luotian County, with a total installed capacity of 1.27 million kilowatts, and these two power stations were constructed earlier. The 1.2 million-kilowatt Bailianhe pumped-storage power station started construction in 2005, and all units were put into commercial operation in 2010. It has been the only one-million-kilowatt pumped-storage power station in Hubei Province for more than 10 years. According to the relevant person in charge of the New Energy Department of the Hubei Provincial Energy Bureau, in order to adapt to the development of the new power system, Hubei has begun to gather momentum.

In August 2021, the National Energy Administration issued the Medium and Long-Term Development Plan for Pumped Storage (2021-2035). 38 pumped-storage power station projects including Damu Mountain in Tongshan and Luotian Pingyuan in Hubei Province have been included in the national mid- and long-term development plan for pumped storage. These projects have a total installed capacity of 39.005 million kilowatts and a total investment of about 270 billion yuan. Accelerating the construction of Pingyuan, Damu Mountain in Xianning, Qingjiang in Yichang and other pumped storage projects has been included in the 2022 Hubei Provincial Government Work Report.

Pumped-storage power stations can bring many benefits to the local economy. For example, the Bailianhe pumped-storage power station in Luotian has paid more than 1 billion yuan since it was put into operation, and provided more than 400 local jobs. Does this mean that it can be dry and blooming everywhere? In fact, a major role of the pumped storage power station is to cooperate with the operation of new energy, to stabilize the volatility and randomness of the output of new energy, to reduce the adverse impact on the power grid, and to promote the large-scale development and consumption of new energy.

"In places with more electricity load centers or new energy projects, priority can be given to development, while in places with few new energy projects or low demand for electricity, there is no need to build large-scale pumped storage power stations." Provincial Energy Bureau New Energy Division The relevant person in charge said. To serve new energy projects and power load centers, such projects still have to be built on demand and developed scientifically.

"Pumped storage technology is relatively mature, but pumped storage requires terrain with a difference in height and depends on geographical conditions," said Ma Hongling, an associate researcher at the Wuhan Institute of Geomechanics, Chinese Academy of Sciences. In addition, the construction period of pumped storage power stations is relatively long, generally 5 years or even longer, and the investment is also relatively large.

Although there are many conditions, but under the premise of scientific planning, the pumped hydro storage industry still has good prospects. At present, China is further improving the pricing mechanism for pumped storage, and encourages social capital to invest in the construction of pumped storage. Accelerate the establishment of the independent market subject status of pumped storage power stations, and promote the equal participation of power stations in medium and long-term electricity transactions, spot market transactions, ancillary service markets or ancillary service compensation mechanisms. According to the planned target, by 2025, the total scale of China's pumped storage will be more than 62 million kilowatts; by 2030, the total scale of production will be about 120 million kilowatts.

Explore a variety of energy storage methods

Pumped hydro is not the only way to store energy. On February 11, State Grid Hubei Comprehensive Energy Service Co., Ltd. and China Energy Construction Digital Technology Co., Ltd. signed an investment cooperation agreement with the Yingcheng People's Government of Hubei Yingcheng 300,000-kilowatt compressed air energy storage power station demonstration project. This is also the first such project in Hubei Province.

"This project has unique advantages compared with pumped storage power stations," said Wang Jun, project leader of State Grid Hubei Comprehensive Energy Service Co., Ltd. The project selects the local salt cavern as the gas storage, uses the low valley electric energy to compress the air into the salt cavern, and releases the compressed air to generate electricity when the electricity consumption peaks. After the project is completed, the annual power generation capacity can reach 500 million kWh. While improving the power grid regulation ability and new energy consumption capacity, the investment and cycle of this energy storage facility is relatively short. "The first phase of the project, with an investment of 4 billion yuan, will start in May and be completed in 2023." Wang Jun said.

"The UGS is buried below 500 meters, the ground stress is enough to bear the pressure, and the sealing of the salt rock is very good, because the energy storage medium is air, even if there is a slight leakage, it will not affect the environment." Ma Hongling said. The State Grid "Power Grid New Technology Prospect Research" project advisory group believes that pumped storage, compressed gas storage and battery storage are the first choices for large-scale development of energy storage technologies. The Yingcheng project is conducive to the reuse of abandoned salt cavern resources, and its green energy economic benefits are more prominent.

In fact, in addition to pumped hydro energy storage and compressed air energy storage, there are various technical routes such as battery energy storage, flywheel energy storage, and molten salt energy storage. Wang Jun revealed that in the future, projects such as carbon dioxide energy storage and all-vanadium flow battery energy storage will be explored in Hubei. Editor/He Yuting