Greentech Media has an interesting article about Vycon Energy, which has cut diesel consumption at ports by 30% on average by installing power-capturing flywheels on the heavy cranes used to lift shipping containers.
It takes up to 300 kilowatts of electricity (about sixty times the demand of a typical household) to lift a container off a container ship. Due to their extreme power usage, ports typically have their own highly polluting diesel-powered generators. All that dirty electricity is expended to lift cargo, but when it is lowered, the motors simply run backwards, generating heat, but not much else – until Vycon’s systems came along.
The rotating mass of the flywheel captures the potential energy of the containers as they are lowered to the ground or onto a waiting truck (think of a yo-yo at the bottom of its trajectory, ready to fly back up). When the crane is ready to pick up another container, the flywheel feeds that energy back into the system – 200 kilowatts worth, according to the company. As a result, the technology will allow ports to install smaller generators.
Each system has a stand-alone cost of $120,000, and the company told Greentech Media they installed their 100th system in April.
Ports have come under renewed scrutiny, both as a source of pollution and as fertile ground for green efficiency improvements. The Ports of Los Angeles and Long Beach installed Vycon systems as part of an aggressive overhaul of their environmental policies, which also includes fleets of cleaner trucks and reducing emissions from ships at dock.