The Washington, DC Network Distribution Center and Surface Transfer Center (NDC/STC) in Capitol Heights, MD, experienced significant lost productivity in its Powered Industrial Vehicle (PIV) operations due to charging and changing the lead acid batteries that powered their fleet of 92 vehicles. PIVs, such as forklifts, tow motors, and pallet jacks, are used to move mail within Postal Service™ plants.
On average, operators spent 20 minutes — and sometimes up to 35 minutes — to charge and change the lead acid batteries. Operators had to go to the battery room, wait in line, charge or change a battery, and return to their assignments.
On top of the long wait times, lead acid batteries had several other drawbacks. The recharging cycles were long and required each PIV to have three batteries — one for use while a second one charged and a third one cooled post-charge. The batteries posed environmental, health, and safety risks due to the sulfuric acid content. They also consumed large amounts of electricity, had a limited run-time, and ran a short lifespan of three years. Over time, the deteriorating charge further slowed the PIV. All these factors contributed to the high operation, maintenance, and compliance costs for using lead acid batteries.
To counter these drawbacks, the Washington, DC NDC/STC management team began a Lean Six Sigma project to research advanced battery technology options for this facility. They consulted with USPS® Headquarters Engineering and the U.S. Department of Energy (DOE) to identify alternatives. Hydrogen fuel cell (HFC) technology emerged as a potential solution.
On February 16, 2017, USPS commissioned the installation of an HFC generation system to replace the lead acid battery system at the Capitol Heights facility.
HFC technology has increased PIV operator productivity.
HFCs are considered by the industry as a best-in-class alternative to lead acid batteries as a power source for material handling equipment, particularly in high-throughput distribution centers. These electromechanical devices extract energy from a hydrogen-rich fuel, convert it into electrical energy, and release only two byproducts: heat and water.
Implementing the HFC system at the Capitol Heights facility shortened refueling times, increased maintenance intervals, and provided reliable voltages, which increased PIV operator productivity. HFC system operations are clean, consume significantly less electricity, and require less time and money to ensure compliance. HFCs are safer, more environmentally sound, and more efficient batteries than traditional lead acid batteries.
The first year of the Washington, DC NDC/STC pilot, led by Plant Manager Robert Borris, and In-Plant Support Manager Rusty Williamson, realized many successes:
n Equipment was made more readily available.
n The rate of containers moved per hour by PIV operators increased.
n In 2019, USPS continued to see a trend of decreasing labor hours despite an increasing workload.
n Electricity consumption decreased by 2.1 million kWh in the first year, which resulted in a $188,000 lower annual utility bill.
n USPS reached its Facility Energy Efficiency goal to reduce energy intensity (measured through data retrieved from utility bills, submetering systems, and other information systems).
In light of the successful pilot program, USPS has begun evaluating the scalability of HFC technology to other processing and distribution centers. Our goal is to drive operational efficiencies by replacing the lead-acid battery systems currently powering the PIVs with HFC systems at a minimum of two processing centers per year.
This strategy involves a review of our facilities’ existing PIV fleet, battery room, electrical capacity, and required space. When a good location for this change is identified, USPS will perform a pre-design hydrogen infrastructure assessment and battery room electricity consumption baseline to develop a site-specific business case. Last year, four facilities were reviewed for HFC technology expansion. Current target facilities are the New Jersey Network Distribution Center and the Brooklyn Processing and Distribution Center.
The DOE Hydrogen and Fuel Cell Technologies Office recognized our HFC project with its 2018 Power Award for setting the standard for other federal agencies and businesses to follow. Also, the project received the 2018 Federal Energy and Water Management Award for exceptional accomplishments in energy, water, and fleet management in the federal sector.
USPS plans to be a leader in environmental sustainability and continues to evolve with our changing future. For more information about current sustainability goals, visit usps.com/green.
— Energy Initiatives, Office of Environmental Affairs
and Corporate Sustainability, 9-23-21
