Hybrid electric and natural gas engines are being developed to replace diesel engines in trucks.
We've been hearing for some time now about European shipping fleets, such as the German Postal fleet, that are converting delivery vehicles to hybrid electric fuel systems. But the need to move freight over great distances in the U.S. has largely prevented shipping companies here from trying the same.
What may happen first in the U.S., if Caterpillar Inc. has its way, is the conversion of diesel fuel systems to a cleaner burning natural gas engine. Caterpillar has begun manufacturing and supplying some trucking fleets with kits to convert Caterpillar C10 or C12 tractor trailer engines from diesel to liquefied natural gas engines. The clean-burning fuel is 90% natural gas and 10% diesel. Though national fleets might be reluctant to convert due to selective availability of the fuel, the move seems imminently practical for regional distributors such as San Antonio's HEB groceries, a company that distributes in south Texas, Mexico and Louisiana.
HEB currently has 18 tractor trailers converted and this year hopes to convert its complete Houston fleet of 61 vehicles.
Already, HEB's converted fleet prevents 74,000 pounds of particulate a year from going into the air. "We have to determine what's financially feasible in the market so we can maintain our edge and do something for the environment at the same time," says the company's fleet supervisor Mike Moynihan. "We feel it is the right thing to do as a good corporate citizen. We don't lose anything by it and in the long run it pays for itself," he adds, noting that the conversion means reduced fuel costs and a 25% longer engine life.
A few national fleets have also made the conversion to natural gas. United Parcel Service (UPS) has three liquefied, and 915 compressed, natural gas vehicles in operation in the U.S.
And-in a move that hints the company's favorite color truly has gone from brown to green-UPS also began testing its first hybrid electric vehicle (EV) late last summer. It'll continue it pilot study for two years, then determine if EVs will make their way permanently into the UPS fleet.