Maxwell Technologies is world leader in supercapacitors otherwise known as ultracapacitors. Michael Everett, Chief Technical Officer, tells us that they have just had their best quarter ever. They have now delivered over 600,000 Ultracapacitors for micro-hybrids - conventional vehicles that switch off the engine whenever they stop and start it again when the accelerator is depressed. Here the competition is in lithium-ion batteries, nickel metal hybrid batteries and advanced lead acid batteries.
A recent press release reveals that Shanghai ISSON Power Quality Company installed 126 of Maxwell's 125V Heavy Transportation Modules in a power system that operates 26 ship-to-shore cranes for loading and unloading container ships at the Yangshan Deep-Water Port, a national-grade super harbor connected to the mainland by a 20-mile long bridge. This installation, one of the largest ultracapacitor installations in the world and the biggest in Asia, stabilizes voltage and smoothes the fluctuation of the power output, for the electric cranes, allowing for uninterrupted operations.
Simultaneous operation of the many high-power, variable-voltage, variable-frequency (VVVF) cranes can create power demand peaks that overload the local electric grid. The ultracapacitor-based power system buffers those demand peaks to minimize their impact to the grid. Liaoning Baina, a Maxwell-certified integrator, installed the ultracapacitor bank into a control center where the system can communicate with the inverter while transferring data - such as system and module voltage, current and temperature - and send an alarm to back-end monitoring software. Equipment operation managers can monitor and operate the system via touch screens at each ultracapacitor bank that display the status of the bank.
"Using ultracapacitors for electrical grid network stabilization when the cranes are in operation eliminates voltage supply interruptions so the cranes can consistently lift loads and avoid the costs associated with port operation disruptions," said Jie Huang, a project manager and chief design engineer at ISSON. "The 10-year estimated lifespan of the ultracapacitor-based power system is double our initial expectation, reducing the maintenance cost worries we would have had with batteries."
Maxwell's Heavy Transportation Module provides the high power bursts that voltage sag applications require more efficiently than batteries, plus its long life means it can operate effectively for up to 10 years with little to no maintenance. The Heavy Transportation Module includes balancing, monitoring and thermal management capabilities, so the ultracapacitor module can be charged and discharged rapidly and repeatedly while maintaining its high reliability and long operational life.
"This large-scale electrical power storage installation demonstrates how ultracapacitor technology optimizes the power system's operation, and we expect this type of system to be duplicated at other harbors," said Brian Eichler, director of sales and marketing, Asia at Maxwell Technologies. ISSON's ultracapacitor-based power system smooths demand on the electrical grid and protects against voltage sags which can be detrimental to harbour crane operations.
Michael Everett tells us that "This size installation is reasonably large for ultracapacitors as energy storage only, and constitutes one of many opportunities in this application area. It is testimony to the efficiency and capability of the ultracapacitor to manage peak power demands. Using devices with a higher ESR and relatively lower power performance comparatively speaking, in such a heavy cycling application would certainly lead to shortened lifetime and oversizing of the systems to compensate for performance shortcomings. At this time there is still no hard evidence that the world is turning away from AN based ultracapacitors."
