Jul 16 2008

DRIVING CLEAN FUEL TECHNOLOGY FORWARD

With medium- and heavy-duty cars representing the second-largest consumer of energy in the U.S. transportation sector (just behind light-duty vehicles but ahead of every other transportation mode), you can imagine NEXT100's delight in taking a tour of PG&E's clean fleet efforts in the East Bay. To our surprise, NEXT100 learned these medium-and heavy-duty alternative fuel vehicles do not just roll off the line; some assembly, which can take up to a year, is required.

First, a little background (and horn tootin')
PG&E has been exploring alternative fuel technologies for over 20 years for use in our 12,000 vehicle fleet. We own and operate the largest utility natural gas fleet in the country and have 39 natural gas stations throughout our service area, 27 of which are open to the public. In fact, we started our tour in Concord where we filled up our natural gas vehicle (NGV) at the first natural gas fueling station that opened west of the Mississippi in the early '90s.

While much of our day focused on our NGV efforts, PG&E's approach to alternative fuel is holistic and we look to explore a variety of clean transportation technologies, including hydrogen, hydrogen bridging technologies, PHEVs, natural gas and dedicated electric vehicles, among others. As we continue to green our fleet, we're looking at a blended technology portfolio where each application is matched with the appropriate technology.

Tracy, CA: Where PG&E CNG gas crew trucks are born.
It was hot and dusty out at the American Truck & Trailer Body Co. where they have been custom building PG&E's gas crew trucks for the past 35 years. We toured the production areas where the chassis, body, and NGV tanks that all arrive separately are integrated. Working with such companies provides us the control necessary to incorporate clean fuel technologies into vehicles that would be impossible to get otherwise.

Another highlight of this stop was seeing some of the innovative trucks in the works for other customers, including the incorporation of solar panels to power on-board tools.

Liquid Natural Gas Fueling 101
It may just be in another state, but fueling with liquid natural gas (LNG) is not the same as fueling with compressed natural gas (CNG). This NEXT100 blogger was quite impressed when we hit PG&E's LNG fueling station in Fremont. PG&E has five Class 8 heavy-duty LNG trucks in our fleet which fuel there. By using LNG, we're able to cut greenhouse gas emissions by 15-20% over equivalent diesel engines and reduce fuel costs by 50%.

To begin with, LNG is kept at a frosty -260ºF in a thermos-like container. This means it's necessary to be clad in safety gear and pre-cool the fueling hose before you connect it to the truck. Once this is done and you've grounded the vehicle, you can pump away at a speedy rate of 80 gallons a minute. If LNG vehicles aren't used as frequently and the fuel is sitting in the tank, it's necessary to release the tank's pressure prior to fueling as that could drive up the temperature of the fuel and change its state.

As my colleague Len Anderson noted, the focus on alternative fuel options for medium- and heavy- duty applications is gaining speed. In fact, Terex Utilities will show its new plug-in hybrid bucket truck at next week's Plug-in 2008 conference in San Jose.

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"PG&E" refers to Pacific Gas and Electric Company, a subsidiary of PG&E Corporation.