Fuel Saving Flywheel Technology for Rubber Tired Gantry Cranes in World Ports

Terminal operators in ports around the world are seeing a sharp rise in their operating cost as a result of the amount of diesel fuel needed to operate cargo handling machinery. VYCON Energy®, a Southern California company, has developed a flywheel energy storage technology that can alleviate a significant amount of the cost while also reducing harmful emissions. A three phase test was conducted with the cooperation of Yantian International Container Terminal and Hutchison Port Holdings to determine the results obtained when using flywheel energy storage technology on Rubber Tired Gantry (RTG) cranes. The test measured the reduction in fuel consumption when regenerated energy produced by the crane is stored, then discharged when needed, in a real world environment.

RTG cranes are mobile cranes designed for the movement of shipping containers once they are placed into the distribution channels from the ship. The cranes are powered by a diesel generator set (genset), which consists of a diesel engine coupled with an alternator. An RTG crane is capable of moving containers weighing up to 50 metric tons at a rate of 20 moves per hour. Typically, the hoist motor dictates the diesel genset size. The hoist motor experiences the highest power demand because the lifting, or hoist, of a container requires both a large peak power and steady state power. During the lowering of a container, the hoist motor is used to control the decent and therefore acts as a generator by creating regenerative braking energy. This energy is routed to dissipating resistor banks and wasted as heat. This paper details the operation and fuel consumption test results of VYCON’s REGEN System, a flywheel energy storage technology, installed on a standard 1 over 5 ZPMC RTG crane at Hutchison’s Yantian International Container Terminal (YICT) during 2007.

The tests measured the following: 1) Average fuel consumption of an RTG crane in normal day to day operations. 2) Average fuel consumption of an RTGcrane when utilizing VYCON’s REGEN System. 3) Fuel consumption when replacing the existing diesel genset with a reduced power output diesel genset combined with the REGEN flywheel energy storage system. The final results indicate overall fuel savings up to 38% based on operational handling rates.