A day’s observation at an airfield inspired a food supply-chain expert to marshal engineering muscle behind fast-charge technology for lift trucks.

Glen A. Lewis, energy & supply chain management advisor, University of California-Davis and president, Glen Lewis Group, Elk Grove, CA

In the automotive industry, fast-charge battery systems are the new standard for powering material-handling equipment. The change had its genesis in the food industry, however, and the transition occurred in a remarkably short period of time. The technology was adapted from the aerospace arena, and collaborative engineering was necessary to create an integrated system. The transition was driven largely by one individual working outside the typical structures of an R&D project.

Glen A. Lewis, former director of energy and indirect procurement for Del Monte Foods, encountered fast-charge technology five years ago and saw it as a way to enhance the company’s competitive position while also improving enterprise energy management (EEM) and enterprise asset management (EAM). The effort became a springboard for a US Department of Energy Best Practices demonstration project that treats water, gas, electricity and other forms of energy as assets to be managed and optimized, just as equipment lifecycles and working capital are optimized. That project was recognized by the state of California with an energy education and leadership award.

Lewis did undergraduate work in aeronautical engineering and political science at UCLA and received an MBA from the College of William & Mary. He held management positions in operations, engineering and other areas over a quarter century in the paper-and-pulp industry and at Del Monte Corp. Lewis also leads an integrated enterprise energy/asset management effort for Gov. Arnold Schwarzenegger’s Green Action Team. He left Del Monte Foods in February and formed the Glen Lewis Group, an Elk Grove, CA-based consultancy.

Recharging stations resembling gas pumps quickly replenish AC batteries during scheduled downtime and eliminate the need for swapping DC batteries. Source: PosiCharge System Group, AeroVironment Inc.

FE: When did you first encounter fast-charge systems?

Lewis: To get ideas on how we could optimize asset utilization at Del Monte, I benchmarked American Airlines’ flight-line operations at Dallas-Fort Worth Airport in 2002. American can’t afford to have aircraft assets idle, and overall equipment effectiveness of ground support is critical.

One of the technologies I saw were fast-charge stations for ground-support equipment. The convention in food is to use DC batteries for forklifts in distribution centers and propane-powered internal-combustion forklifts in the plants. Fast charge had the potential to reduce operating and maintenance costs, increase asset utilization and extend operating life.

FE: What development work was necessary before bringing the technology to the commercial market?

Lewis: American Airlines’ charging stations were built by AeroVironment’s Posi-Charge division. The batteries were manufactured by EnerSys, a leader in material-handling battery applications. I worked with those firms and with Yale to develop new AC-powered forklift technologies. I also secured a grant from the Electric Power Research Institute to evaluate not only operating costs in a food processing facility but also the impact on power demand and the power grid if fast charging becomes widespread. Visibility, metrics and knowledge are needed to turn EEM and EAM from a black box to a glass box.

The charging technology actually had its genesis in the 1990s, when the California Air Resource Board was promoting electric cars. AeroVironment developed Posi-Charge to function as service stations for on-road vehicles. When the electric-car initiative collapsed in 1998, a new market had to be found.

FE: Was it simply a matter of bundling equipment already available from those firms?

Lewis: Rather than view this as various pieces of vendor equipment, we mapped out a strategy and took a team approach to develop an efficient system. The process of charging is the same, but the equipment is different, and the environment is more intensive than an airfield. The three key vendors collaborated to take material handling to the next level. You have to be sure that it works before you take it into a plant, where the rubber meets the road.

FE: What did you learn in the EPRI funded project?

Lewis: The EPRI grant helped quantify the economics and develop a roadmap for implementation. We also built what I called a lab-rat charger to demonstrate the technology. The subsequent report was published three years ago. Among the findings was that a fast charger can charge a battery three to six times faster than a conventional unit. In a three-shift operation, operational costs for the battery can be 20-25% less than for conventional batteries. We also recommended staggered recharging to lower electrical demand charges.

FE: How was the technology deployed at Del Monte?

Lewis: We initially set out to convert distribution centers, where electric forklifts already were used. As with any change-management endeavor, the people at some facilities are going to be more receptive to change than others, so you partner with them first.

Because the manufacturing sites used internal-combustion forklifts, expanding the technology to the plants was a bigger challenge. Noise equates with power, and there is the perception that electrically powered lifts have less power. The first step was to put the technologies head to head and dispel that myth.

I videotaped and interviewed the drivers in the early trials. One of the first things a driver of a propane forklift would say is, “I’m not breathing fumes when I’m driving backward now.” What are the work-loss days from pulmonary disease caused by breathing fumes? It’s a hazardous material, and you can’t store anything within 75 ft. of propane. By converting to electricity, insurance premiums are reduced, and non-value-added space is eliminated. Up to 22,000 sq. ft. were freed by taking out propane tanks at some facilities. Additionally, maintenance costs for AC forklifts are 60-80% lower than with propane.

From my days at UCLA, one John Wooden “Woodenism” that stuck with me is, “It’s what we learn after we know it all that counts.” You have to be open-minded when you approach a new way of doing things, and the safety and operation of AC forklifts is an example. Less noise is a good thing, but people are used to hearing forklifts and reacting to them. When you reduce decibel levels, drivers have to be retrained to use convex mirrors, honk their horns more often and use greater caution.

FE: How does fast-charge compare to DC-powered lift-trucks?

Lewis: A key savings is in eliminating battery changes. Our time studies indicated it takes 15-20 minutes to change a battery. Over three shifts, that’s almost an hour of lost productivity per day, per truck. There are several thousand forklifts at Del Monte. The potential to reduce the size of the fleet or realize incremental shipping advantages is significant. 

In a 24/7 scenario, a plant needs three 48-volt DC batteries. Batteries are changed at the end of each shift, which requires a hoist and adds the potential of personal injury. Batteries are recharging constantly, both at peak and off-peak hours, which increases energy costs and the facility’s carbon footprint and adds pressure on the electrical infrastructure in growing communities. DC batteries cost $5,000, so plants realize a $10,000 savings simply by buying two fewer batteries per truck.

With DC, batteries gradually lose power over a shift. Horizontal and vertical speeds decline, reducing productivity and increasing maintenance. With AC, voltage is constant until the supply is totally discharged. That means less mechanical stress on the equipment. Recharging can be shifted to nonpeak hours, with complete elimination between 11 a.m. and 6 p.m. during peak demand. Compared to AC, DC forklifts are analogous to a typewriter in a Pentium world.