An innovative idea promises to make large cranes more energy efficient. The enormous cranes that are used to load and unload containers to and from cargo ships are usually powered by electricity from the power grid or have diesel generators animating them.
Inside a container yard, almost all of the energy is consumed by the action of lifting the container up. Bringing it down is aided by gravity and is only descent control is done by human hands. Unfortunately, much of the energy that was used to lift the container is consumed as heat on the brake pads – an action that occurs when the descent is being controlled.
The new idea that could massively bring down energy consumption is that gravity and the weight of the descending container could be used to generate energy that could be used to spin an electric generator or recharge batteries or even re-energize the grid.
What is being discussed is essentially a system of braking that regenerates energy. There would be large lithium-ion battery packs designed into the cranes, which would store the electricity that was generated by a container being lowered. This electricity could then be supplied to a motor which would in turn work to move the crane. This entire process would do away with the need to run an engine to power the crane. The gigantic cranes could be enormously energy efficient of this system is implemented – figures say that carbon emissions could be cut by 60%.
The only drawback is that initial costs may be high for many ports to bear, but considering that energy bills could be drastically reduced in a short time, there are likely to be takers.