How Can Ultracapacitor Energy Storage Boost Industrial Cranes?
February 12, 2018 | Jeff Brakley, Sr. Product Line Manager
Port cranes place high peak power demands on the grid.
Industrial cranes catch our eyes when driving down an interstate or past a port: they pierce the sky and impress us with the tonnage they handle. They are the mechanical strong arms of the industrial world.
These lifting giants require surges of power for their operation that can place a burden on the grid or their diesel power systems. As the grid becomes more loaded by energy demands, and as industry aims to achieve energy efficiency and reduced carbon emissions, it’s time to reevaluate how industrial cranes are powered.
Energy storage is a proven solution to energy efficiency challenges we face across industries today, and for heavy-duty equipment like cranes, energy storage can add excellent value
efficient and reliable operation.
Energy Storage for Port Cranes
At a port, the overhead cranes that lift and lower cargo
off the ships are typically electric and operate using power from the grid. The cranes are major energy guzzlers and often cause power imbalances that result in quality issues and grid instability.
These cranes can benefit from ultracapacitors for energy recuperation: Instead of having the cranes use power from the grid exclusively, ultracapacitors can be installed on the grid to recuperate the energy released from the crane when lowering the cargo containers (energy that would otherwise be lost as heat or electricity) and reuse that energy to lift the next load. Ultracapacitor energy storage reduces reliance on the grid and saves energy and operational costs.
Yangshan Deep Water Port
Operation of 23 quay cranes at an island port caused sags in the power lines and power losses on the island. The port, located 20 miles from shore where the power distribution center is located, faced having to install 20 miles of larger transmission lines to stabilize power.
In lieu of installing new transmission lines, the port chose Maxwell’s ultracapacitor energy storage system to balance fluctuations in power caused by crane operation. A
three megawatt ultracapacitor energy storage system provides 20 seconds of reserve power.
The port realized a 38% reduction in peak demand grid energy and an estimated 2.9 million savings over the system lifetime.
Flywheels are another energy storage option for supporting the high power demands of port cranes. Flywheels are a reliable technology but can be an expensive option for this application because of the complexity of the mechanics involved. Flywheels must be housed in hardened equipment in case they spin out of control and require higher maintenance than stationary ultracapacitor solutions.
Another type of port crane is the straddle carrier, which is usually diesel powered. These cranes pick up containers and move them to a storage location or load them on big rigs for delivery.
One problem that can occur with the straddle carriers is they fail to start and become stuck in the middle of a port and block traffic. These cranes benefit from ultracapacitor energy storage that is applied as a redundant system to start the diesel engines. Some of these carriers use ultracapacitors in addition to the standard batteries that come with the carrier. Ultracapacitors become the primary starting system with automated switching in the event the ultracapacitors fully discharge; in this case, the crane uses the batteries for additional starting power.
Localized Energy Storage for Mobile Cranes
Off-road cranes are the type of cranes you would see at a construction site. They may be on tracks or wheels depending on how much load they’re going to lift.
Off-road cranes often sit at construction sites for two or three weeks before they are needed for service, and when it comes time to start them, their lead-acid batteries are often dead. These cranes typically have a two-to-four battery system, and solving the problem is as straightforward as designating ultracapacitors for the starting function so that the cranes have reliable cranking power even after long periods of non-use. Ultracapacitors are also more resilient in cold weather conditions, another factor that often leads to equipment no-starts with lead-acid battery systems.
duty trucks that have cranes mounted on them; these have diesel engines that run hydraulics to operate the cranes. It’s possible to use ultracapacitors for energy recuperation in this instance as well to avoid reliance on diesel.
Awareness of ultracapacitor energy storage technology is growing in the industrial equipment industry as more businesses recognize the technology’s return on investment. Relying on grid power or traditional energy storage technologies is proving more difficult over time. Innovative energy storage solutions available on the market today are designed to overcome roadblocks to energy efficiency and optimal operation of industrial crane equipment.
Senior Product Line Manager
About this author
Brakley has contributed to the development of the Engine Start Module (ESM) from its inception. He is a member of SAE International and an Associate Corporate member of the American Trucking Associations (ATA) and the Technology & Maintenance Council (TMC). Jeff serves on the S.1 Electrical & Instruments Task Force, and recently contributed to the SAE J3053 Task Force to develop the Heavy Duty Truck Electrical Circuit Performance Requirement for 12/24 Volt Electric Start Motors Recommended Practice.
Throughout his 30-year career, Jeff has held both engineering management and program management positions for several leading national defense contractors and commercial companies, including General Dynamics, Martin Marietta, L3 Communications and Ametek Programmable Power. Jeff holds a Bachelor of Science in engineering from Purdue University and an MBA in technology management from the University of Phoenix.
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