Jul 1, 2008 12:00 PM

Pem Cells

There are several different types of fuel cells, each using a different chemistry.

One of the most promising for forklifts, especially in high-throughput warehousing and distribution applications, is the hydrogen-fueled proton exchange membrane (PEM) fuel cell, noted Gangi. In addition to having a high power density, this fuel cell has a relatively low operating temperature, meaning it doesn't take very long for the fuel cell to warm up and begin generating electricity.

In research for the US Department of Energy, Battelle Memorial Institute found that PEM fuel cell-powered forklifts on a lifecycle cost basis require approximately 48% to 50% less investment than battery-powered forklifts in applications where forklifts run continuously.

The study also showed that while PEM fuel cell-powered forklifts require more capital investment than present alternatives, they provide significant savings in operation and maintenance. For one thing, shifting from batteries to hydrogen fuel cells increases worker productivity as there is no need to stop and change batteries.

Efficiency Gains

Gangi said recent field tests indicated that hydrogen fuel cell forklifts ran three times as long between fueling, with much shorter refueling times - minutes compared to a half hour or longer to change out a battery. This resulted in “significant increases” in productivity and paybacks on investment of less than four years for many operations.

As for getting hydrogen, she said individual warehouses and distribution centers can install their own hydrogen fueling station inhouse, or use mobile fuel trucks.

“Another advantage of hydrogen fuel cells over conventional technology is weight and mass,” said Gangi. “Batteries are heavy and take up a lot of storage space while only providing up to six hours of run time.

“Fuel cells last more than twice as long - 12 to 14 hours, and there is no more need for battery storage and changing rooms, leaving more warehouse space for products.”

As fuel cell technology evolves and the costs come down, Gangi predicted more and more companies will incorporate fuel cell forklifts into their warehousing operations to reap the potential environmental and economic benefits.