Without long term energy storage to back up solar and wind when the sun doesn’t shine and the wind doesn’t blow, grids will face blackout and brownout, or a return to fossil fuels. We call this the ‘ignored crisis within the crisis’.  

As wind and solar energy production grows, increasing energy storage is imperative to keep the lights shining and almost 90% of installed global energy storage capacity in the form of pumped storage hydropower (PSH). That is well ahead of lithium-ion and other energy storage types.

PSH allows energy from sources such as solar and wind to be saved for periods of higher demand.

The International Hydropower Association (IHA) estimates that PSH projects worldwide store more than 9,000 GWh of electricity.

Studies show that there is significant potential for scaling up global PSH capacity. The Australia National University has identified more than 600,000 off-river sites outside protected or populated areas.

An example of PSH at scale is the State Grid Corporation of China’s 3.6 GW Fengning Pumped Storage Power Station, which began operation in 2022.  

It is the world’s largest project of its kind and one of the five pumped storage power stations that State Grid Corporation enacted in 2021.

Fengning was developed in two phases with a 1.8 GW capacity per phase, by the State Grid Xinyuan Company, a subsidiary of the state-owned State Grid Corporation of China, which manages and operates the facility.  

It is the first hydroelectric facility in China to integrate variable speed technology for efficient power generation.  

The key use of the plant was to ensure the 2022 Beijing Winter Olympics was green, according to the company's statement.  

In early 2022, it provided 600 MW of capacity to Beijing and Zhangjiakou, the host cities of the Winter Olympics, during the Games. This avoided the use of 480,000 tonnes of coal and cutting carbon emissions by 1.2 million tonnes annually.  

The project continues to boost reliability and increase the integration of solar and wind for resilience of the regional grid network.

Located in Fengning County, Chengde City, Hebei Province, the facility also boasts 190 caverns, and is one of the largest underground industrial facilities in the world. It is also one of the world’s first pumped storage power stations connected to the flexible DC grid, due to a connection made to the Zhangbeirou DC converter station.  

The project has 12 reversible pump-turbine generators, with each unit having a total generating capacity of 300 MW and pumped capacity for more than 10 hours.

PSH provides a critical platform in the renewable conversation to prevent energy wastage and keep a consistent source of power in times of need.  

International Hydropower Association President Designate, Malcolm Turnbull, said: “The cost of solar and wind energy is dropping all the time and it is getting faster to deploy. But there is a real risk that international storage capacity will not keep up with renewable generation.”

Find out more about PSH here.