In Rudong County of coastal Jiangsu Province, a team of Chinese engineers and their foreign counterparts are working on the country’s first commercial gravity-based energy storage project. The 100 megawatt-hour project is a joint undertaking of Swiss company Energy Vault, China Tianying, an international environmental management corporation, and Atlas Renewable, a company based in the U.S. city of Houston,Texas.
“There’s a tremendous acceleration in China in the conversion from fossil fuels to renewables, a process that we would very much like to be a part of,” CEO of Energy Vault Robert Piconi told Beijing Review.
In September 2020, China proposed its goals of peaking carbon emissions before 2030 and achieving carbon neutrality before 2060. Since then, the country has switched into full gear for the mass deployment of clean energy. And energy storage, or the capture of energy for later use, has provided a powerful solution to the intermittency and unreliability of wind and solar energy resources, thus allowing for a more efficient use of clean energy.
Shaped like a huge Jenga block, the facility will engage in the repeated lifting and lowering of 35-metric-ton composite bricks. As each block descends, the motors that lift the blocks start spinning in reverse, generating electricity that courses through the thick cables running down the side of the crane and onto the power grid. In the 30 seconds during which the blocks are descending, each one generates about 1 megawatt of electricity—enough to power roughly 1,000 homes.
Storing energy in this way could help solve the biggest problem facing the transition to renewable electricity: finding a zero-carbon way to keep the lights on when the wind doesn’t blow or the sun doesn’t shine.
As of now, the two major forms of energy storage in China are pumped hydropower and lithium ion batteries, both of which have serious shortcomings. With a market share of 90 percent, pumped hydropower may potentially alter the regular water flow, disrupt the existing pattern of sedimentation and displace aquatic life from their natural habitats. Lithium ion batteries, on the other hand, are extremely sensitive to heat and can constitute a fire hazard.
Compared with these and other energy storage solutions, gravity-based energy storage features multiple benefits.
According to Piconi, unlike lithium ion batteries, which normally have to be replaced every seven years, gravity does not degrade over time, therefore lending the facility a long lifespan. A second advantage is flexibility, as the technology can be deployed for use in cases that require up to 12 hours of storage capacity. Last but not least, facilities like the one in Rudong do not depend on any specific location or weather condition for operation.
“We took gravity, the foundation of all energy storage solutions, and designed a way to build a structure that you can build anywhere, build economically and build sustainably,” Piconi said.
For Piconi, the project is an example of how different countries unite in the common pursuit of sustainable goals and team up against the many geopolitical rifts currently tearing the world apart. “We have built a tremendous partnership with Tianying and Atlas Renewable, who are bringing their local expertise to minimize costs and increase system reliability,” he said, adding, “That’s a great compliment to what we bring.”
“Instead of criticizing China for being a major source of greenhouse gas emissions, I would like to see the rest of the world engage in supporting China’s dual carbon goal. Let us be part of the solution, not just throw stones at the problem,” he concluded.