A lineman’s bucket truck can idle for up to seven hours a day on a job site. As crews raise and lower the boom on their trucks, the engines run continuously, burning through fuel, creating emissions and generating nonstop background noise.
To provide cleaner, greener power to its fleet, Commonwealth Edison (ComEd) turned to biodiesel fuel and hybrid technology. The utility now operates one of the largest private fleets of biodiesel vehicles in the U.S., consuming more than 1.7 million gal of biodiesel fuel annually. In fact, alternative fuel vehicles now represent 70% of ComEd’s total fleet of cars and trucks. Hybrid and plug-in hybrid electric vehicles (PHEVs) make up more than 8% of ComEd’s fleet, and they include vans, pickup trucks, bucket trucks, digger derricks and underground construction vehicles (known as splicer vans).
By investing in this technology for its fleet, ComEd has realized several key benefits. For example, rather than depending entirely on a fossil fuel, the utility can stretch its fuel dollars further by charging its vehicles during off-peak hours. In addition, the alternative fuel vehicles get more miles per gallon, have less idle time, have reduced emissions and require less maintenance in the long run.
Testing Hybrid Technology
ComEd first became involved with hybrid truck technology through the High-Efficiency Truck Users Forum (HTUF). Eight years ago, a dozen utilities partnered with Eaton, Navistar and Altec to build 24 prototype hybrid bucket trucks. As one of the utilities who participated in the HTUF, ComEd received its first hybrid bucket truck back in 2006.
Through collaboration with the manufacturers, ComEd was looking for an increase in miles per gallon and a more efficient duty cycle. In other words, the truck could run on either conventional fuel or electric, depending on the application.
When the manufacturers developed the first hybrid bucket trucks, they also looked to provide exportable power so linemen could supply electricity to a house in case of an outage. Up to this point, ComEd has not yet used this functionality of the new hybrids. Instead, linemen have used the electric power to recharge their battery-operated tools or run the lighting on their trucks.
Advancing the Technology
Because the first hybrid bucket trucks featured a smaller capacity, they often were used by first responders, who spent more time on the road than in their buckets. Over time, however, ComEd realized the hybrid trucks also could be used by construction and maintenance crews. Since the linemen on these crews often need to operate a bucket for six or seven hours at a time, the new trucks had to be equipped with a lower launch assist and a higher duty cycle applied to the power take-off than the original prototypes.
In other words, linemen needed a truck that could rely on a traditional engine on the road but then switch to the electric motor when the vehicle is stationary and performing aerial functions. Two years ago, ComEd introduced four small bucket trucks that use the Altec Job Energy Management System (JEMS). This system provides 100% battery use for the aerial device, tools, circuits, and heating, ventilation and air conditioning for the truck’s cab at the job site. The JEMS technology reduces fuel consumption, air emissions and noise pollution by allowing the truck to operate in electric mode.
Like the conventional Altec bucket trucks, the hybrid trucks also feature an internal combustion engine under the hood. The key difference is the hybrid trucks also feature an auxiliary electric motor, located under the mid-chassis section, connected to the hydraulic pump, and powered by a dozen high-capacity battery packs. These batteries can be charged in a single electric outlet overnight, and if the electric motor consumes all the power from the batteries, the hybrid vehicle will then switch over to conventional diesel power.
In addition to regular hybrid bucket trucks, ComEd also began testing out plug-in hybrid bucket trucks through a grant from the U.S. Department of Energy (DOE) and EPRI. The utility currently has eight plug-in hybrid bucket trucks as well as plug-in Toyota Priuses and Chevy Volts.
One of the key benefits of the plug-in hybrids is they have a larger battery and can run on the electric power for a longer period of time, which saves on fuel costs. In contrast, the regular hybrid vehicles must charge the battery more often.
Developing a Splicer Van
In addition to purchasing hybrid bucket trucks, ComEd also helped to develop the industry’s first plug-in hybrid electric underground splicer van. ComEd’s fleet department designed the PHEV splicer van from the ground up with the help of several vehicle technology partners including Odyne, Team Fenex and Freightliner. Also, through a DOE grant, ComEd was able to defray a portion of the cost for the van, which received the Green Award at the 2014 NTEA Work Truck Show.
This van provides quiet, emissions-free operation when ComEd’s linemen and splicers perform underground construction work in dense urban areas. The van can be parked over a manhole with the engine turned off and operate on electric power while the crew works in an underground vault. The vehicle’s large battery pack is capable of providing up to eight hours of power to lights, pumps and other electric tools needed for underground work, which eliminates the need for crews to carry noisy, problematic portable gasoline generators on the vehicle.
Also, the van provides environmental conditioning to the splicer such as ventilation to eliminate any harmful gases. In addition, the vehicle is equipped with manhole conditioning, which provides heated or cooled air directly into the manhole. The system can cool the inside of a manhole from 95°F to 75°F in as little as 20 minutes, which has improved the working conditions and safety of ComEd’s underground
personnel.
Vehicle Operation and Maintenance
While the alternative fuel fleet may cost more upfront, these vehicles often require less maintenance. For example, the hybrid vehicles use regenerative braking, which slows the vehicle down and generates electricity to charge the batteries. Instead of using electricity like in conventional hybrid mode, this system instead turns the motor into a generator, and the energy conversion places less stress on the brakes.
At the same time, however, the hybrid trucks can be more complex than traditional vehicles. The hybrid, chassis and hydraulic portions of the vehicle must all communicate with one another constantly. For example, the system needs to know how much power it needs and how it will be provided. As such, the hybrid vehicles are more technical, and the mechanics need more computer training to maintain them as they use laptops to diagnose problems and repair the vehicles.
ComEd stores the hybrid vehicles along with its other vehicles, and they are integrated with the utility’s regular fleet in various reporting centers throughout the utility’s 11,000-sq-mile service territory. To make it easy for field crews and managers to fuel their hybrid vehicles, ComEd has installed several charging stations in its operating centers through a grant from the DOE.
In 2012, through a rebate program offered by the Illinois Department of Commerce and Economic Opportunity, ComEd installed 15 electric-vehicle charging stations at several ComEd facilities including Chicago North, Chicago South, Lincoln Center, Tech Center, Commercial Center, Libertyville, Joliet, Glenbard and the new Rockford Training Center. The stations are connected to ChargePoint, a network of thousands of publicly accessible charging stations in the Chicago region and nationwide. Workplace charging is grid friendly and will help employees with electric vehicles to maximize their electric driving range and minimize vehicle emissions.
Deploying Vehicles
ComEd has deployed the hybrid vehicles across many different departments to get the field workforce used to the trucks and get feedback on how they perform. For example, meter readers are running the plug-in hybrid Toyota Priuses, and the line supervisors and employees are driving the hybrid Ford Escapes.
While some of ComEd’s employees are resistant to change, the technology will ultimately benefit them. However, one major drawback for the crews is reduced storage space because of the size of the batteries. On the flip side, the drivers do not need to fuel their vehicles as often, which saves time during the workday.
To ease the transition from conventional fuel vehicles to hybrid vehicles, ComEd invited vendors to provide training sessions to its line crews and technicians. These manufacturers explained that the vehicles had less idle time and their operation was seamless to the operator. Behind the scenes, however, when the driver turns the key, the system determines, based on the load or duty cycle, how much of the vehicle will run on electricity or petroleum and then allocates that to the powertrain.
While hybrid vehicles are more expensive than conventional fuel vehicles, through grants, ComEd has been able to get the majority of its units at the same cost as standard units. In the future, as the cost of hybrid vehicles comes down and is more in line with conventional vehicles, it will be a win-win for the utility, as its customers charge their vehicles at off-peak times.
Ronald Koskiewicz ([email protected]) is a fleet manager for Commonwealth Edison, responsible for managing the fleet. He has been with the utility for 30 years. He manages the procurement of new vehicles, the maintenance and repair of existing vehicles as well as the related infrastructure such as the garages.
Les Faul ([email protected]) is a manager in ComEd fleet operations with responsibility for planning, maintenance and repair activities of the ComEd fleet.
Bob Rogas ([email protected]) is a manager in ComEd fleet operations with responsibility for planning, maintenance and repair activities of the ComEd fleet.
Mentioned in this article:
Altec | www.altec.com
Commonwealth Edison | www.comed.com
Eaton Corp. | www.eaton.com
Freightliner Custom Chassis | www.freightlinerchassis.com
High-Efficiency Truck Users Forum | www.htuf2014.org
Odyne | www.odyne.com
Navistar | www.navistar.com
Team Fenex | www.teamfenex.com
A Snapshot of ComEd’s Green Fleet
ComEd has a diverse selection of vehicles within its fleet including digger derricks, material handlers, large bucket trucks, smaller bucket trucks used by first responders in a storm and dump trucks for hauling supplies. In addition, the utility also has trucks that can help pull underground cable in and out of conduit as well as backyard carts that fit through a gate. Here are some fast facts about the utility’s fleet:
• ComEd had 21 operation centers within its 11,000 sq-mile service territory. These centers often include a fleet maintenance and repair shop as well as a fuel island.
• To support its fleet, ComEd operates more than 76 electric vehicle-charging stations, including 35 stations available for use by employees.
• After piloting the use of B25 — biodiesel with 25% bio content — at one Chicago facility in 2012, ComEd has increased bio content at all on-site fueling locations from B20 to B25 during warmer months; in cooler months, a lower biodiesel percentage is used.
• There are close to 125 mechanics across the utility.
• The utility has approximately 3,174 drivable units, including 940 conventional fuel vehicles, 233 light-duty hybrids like Toyota Priuses and Ford Escapes, 35 plug-in hybrid electric vehicles (PHEVs), 27 electric power take-offs (PTOs) and 1939 vehicles that run on biodiesel.
•Through a partnership with EPRI, the utility is in the second year of a two-year pilot to test the Chevy Volt PHEV in fleet applications and display it at public forums.
•ComEd has acquired another six plug-in hybrid electric underground splicer vans in 2014 through a partnership with EPRI and the Department of Energy. Also, among the utility’s 2,100 green vehicles, 249 are hybrid or plug-in electric vehicles.
• PHEVs equipped with smart-charging technology help ComEd to learn how to manage the impacts of vehicle charging on the electrical grid.
