Drives & Controls Magazine July/Aug 2024

42 n CLEAN ENERGY July/August 2024 www.drivesncontrols.com Energy storage pioneer joins up with architects to explore new ideas Energy Vault, the Swiss pioneer of gravity-based energy storage systems (GESSs), has formed a partnership with the architecture and engineering rm Skidmore, Owings & Merrill (SOM) – which has been responsible for some of the world’s tallest buildings, including Dubai’s Burj Khalifa and New York’s One World Trade Center – to work on GESSs. They will develop a new generation of xedframe and deployable GESS structures, including systems designed to be integrated into tall buildings, as well as into natural environments. These technologies will be designed to maximise sustainability, accelerate carbon payback, and cut the levelised cost of energy consumption. Energy Vault’s original GESS technology was based on heavy blocks designed to be lifted to substantial heights when energy costs are low, and then released to generate power when energy costs are high and/or there is a shortage of energy. The system relies heavily on technologies such as motor/generators, inverters/converters and motion controls. GESS decouples power and energy, allowing users to optimise storage while maintaining round-trip e‹ciencies that Energy Vault claims are higher than other mechanical or thermodynamic energy storage systems. The stores are also said to oŒer long operating lives – 35 years or more – without any degradation (unlike batteries). The modular architecture, which can be scaled to achieve multi-GWh storage capacities, was rst tested in Switzerland and has since been deployed in China (where projects totalling 3.7GWh have been announced), Egypt, Greece and the 16country South African Development Community. The 10-year SADC agreement is expected to result in multi-GWh of GESS deployments to help meet region’s energy storage demands – predicted to reach 25GW/125GWh by 2035. The GESS technology has attracted critics who have cast doubts on its economic and technical claims. Although Energy Vault is best-known for its gravity-based energy storage, it has also supplied battery-based installations, including a 275MWh system in California and a 440MWh system in Nevada. It is also combining hydrogen fuel cells with lithium-ion batteries for a 293MWh storage project, also in California. Together, Energy Vault and SOM are planning to optimise the structure, architecture and economics of GESS, as well as exploring new energy storage technologies including: n A tower design which integrates GESS into tall buildings (typically 300–1,000m high), improving the system’s economics. This technology, called EVu, will be able to achieve multi-GWh of gravity-based energy storage to power not only the building itself, but also nearby loads. Energy Vault predicts that such structures will result in carbon paybacks of 3-4 years. n Integrating large-scale pumped-hydro energy storage into tall buildings using a modular water-based system. This system, called EVc, will have a cylindrical shape designed to withstand wind and seismic events. n Applying gravity technology to existing slopes, such as hills, to store energy with A new partnership between a pioneer in gravity-based energy storage and one of the world’s leading architectural practices could lead to novel large-scale ways of storing energy. Motors and motion control technologies will be a key element of these technologies. Gravity-based energy storage built into tall buildings could achieve multi-GWh capacities to power the building itself and nearby structures, with rapid paybacks. Image: Business Wire

RkJQdWJsaXNoZXIy MjQ0NzM=