Episode 1：Huang Junling

China Three Gorges Corporation (CTG) is the China’s largest clean energy company and the world's biggest developer and operator of hydropower development. CTG also has a strong presence in other renewables, such as wind, solar, and other new energy sources. In light of your expertise, how important is energy storage for building renewable-rich energy systems in China and around the world?

CTG Corporation, operator of the Three Gorges Dam, is China’s largest clean energy corporation and the world largest hydro-power producer. In 2021, CTG produced the largest amount of clean electricity among all power companies in China, 340 TWh, a strong impetus to socio-economic development. CTG pays great attention to China’s power sector decarbonization.

China proposed that “China will strive to peak carbon dioxide emissions before 2030 and achieve carbon neutrality before 2060”. To achieve this goal, China announced that by 2030, the total installed capacity of wind and solar power in China will exceed 1200 GW. The intermittency of renewable energy resources, such as solar and wind energy, is a major concern when the generation systems are connected to the grid. With solar and wind power, together with other renewable energy modalities, to play the major role in China's energy mix, energy storage will play a key part in ensuring steady operation of the grid and its potential of flexible adjustment has not been played to its full extent.

Various technologies have been developed to store energy at different capacities and time scales, including commercially available solutions such as pumped storage hydropower, green hydrogen, and batteries. Which technologies is CTG most interested in to meet the storage needs of its huge renewable energy portfolio?

At present, the answer is pumped storage hydropower (PSH). PSH, as a mature and commercialized technology for longduration storage, acts similarly to a giant battery. It stores energy by pumping water from a lower reservoir to a higher elevation. Subsequently, it generates electricity by letting the water flow back down to the lower reservoir. PSH provides reliable energy storage that can mitigate the impact of renewable energy's intermittency on the grid.

China’s National Energy Administration (NEA) issued the “Pumped Storage Mid- and Long-term Development Plan (2021-2035)” on September 9, 2021. It announced that the total operational PSH capacity will exceed 62 GW by 2025 and 120 GW and 2030, respectively. With rich experience in large-scale engineering construction and management, CTG will take PSH as a new business opportunity. CTG has already incorporated PSH into its corporate strategy in the 14th Five-Year Plan.

By the end of 2021, CTG’s total installed capacity reached 140 GW in nearly 50 countries and regions across Asia, Europe, America, and Africa. Could you briefly share with us some successful projects developed by your company where energy storage technologies were adopted?

I would like to introduce the Changlongshan PSH plant, owned and operated by CTG. The  Changlongshan PSH plant is the largest PSH plant in East China in terms of installed capacity and named “the charger of East China's power grid”. With a total installed capacity of 2.1GW, the power station comprises a total of six pumped storage units and can generate nearly 2.5 billion kilowatt hours (kWh) of electricity each year. This PSH plant helps to improve the regulation capacity of east China's power grid, optimize the power supply structure and promote the development of clean energy.

In view of your experience as the Director of the International Clean Energy Research Office in CTG, what are some of the priorities that should be addressed by the international community in the field of energy storage research?

An understanding of how the energy innovation process works is necessary to answer your question. In simplified form, there are three stages to innovation: R&D → Demonstration → Deployment.

The innovation process begins with the scientific process of researching and developing new technologies. In the demonstration stage, new ideas and technologies are implemented in a prototype plant to evaluate performance and cost—information necessary to assess practical or commercial viability of a technology. “Deployment” refers to the commercialization of the new technology.

I think that the international community in the field of energy storage research should collaborate a lot at the early stage of R&D—basic and exploratory R&D. This early stage of R&D is far from the deployment stage where industry will be deeply engaged and can produce unexpected but extremely valuable results for a broad community.