Fleets Must Evaluate EV Capabilities
This story appears in the May 15 print edition of Equipment & Maintenance Update, a supplement to Transport Topics.
Electrically propelled commercial vehicles are not new technology, but their practical application to trucking is evolving as battery technologies improve.
Richard WintersMany fleets are turning to electric or electric-hybrid solutions to reduce their corporate carbon footprint, but fleet managers must recognize they must evaluate their unique performance requirements and overall system of vehicle capability and charging infrastructure to determine the applicability of fully electric commercial motor vehicles, or CMVs, in a given operation.
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Global trucking manufacturers are accelerating their efforts to produce more vehicles utilizing electric drivetrains. Many factors are contributing to this trend, including newly enacted fuel economy standards, greater confidence in electric-powered vehicles and advances in battery technology. In the past 10 years, many OEMs have been taking up battery-electric vehicle, or BEV, development for many operations in fleet markets, municipalities, universities, and state and federal governments.
Battery Vehicle Basics
An estimated average CMV range and payload would dictate industry-segmented applications where a BEV would be acceptable. For deliveries that are limited to slower speeds, lighter loads and shorter trips, BEVs would have a more conducive capability. A delivery schedule that accommodates short operation time and significant recharging time would be preferred because, currently, the charging of such a large battery can range between five and eight hours of downtime.
Accordingly, faster and more convenient charging capabilities are under development. A wireless inductive charging standard, for example, has been in development by the Society of Automotive Engineers, or SAE, since 2010.
Battery
The shift from well-established nickel-metal hydride, or NiMH, batteries (mostly used in a hybrid electric vehicle or, HEV, applications) to lithium-ion represented a major endorsement of the ability of this chemistry to perform consistently in a trucking environment. This style of battery has the highest energy density, or Wh/kg., and life- span, lowest discharge rate and fastest recharge time commercially available.
The life and warranty of a battery pack is determined by the number of charge/discharge cycles. An electric vehicle that is used in normal daily operation would have a single charge cycle, which would equate to: 240 work days per year x 10 years = 2,400 charge cycles.
A battery that is projected to have a 2,400-charge cycle life should have an estimated service life of 10 years in this type of operation. A calculation such as this would be helpful when evaluating a battery warranty.
Factors in estimating the operating cost of a commercial BEV include:
• Useful life
• Percent of degradation over its projected lifespan
• Replacement cost
• Salvage value of the original battery
Charging
Level 1 charging is the technical term for plugging an electric car into an ordinary household outlet. At 120V (in the United States), charging a BEV may take the longest time in recharging a large battery for commercial applications. At the other end of the spectrum is DC Fast Charging, the fastest type of charging available. Between the relatively cheap Level 1 and expensive DC Fast Charging stations sits Level 2 charging.
Level 2 provides 240V, which supplies a household oven or shop welder. It goes through a box and a cord that improves safety by waiting to send power to the plug until it is plugged into the BEV. These charging stations are being developed nationwide depending on factors including state programs, government funding, fleet use and consumer locations.
Other than switching from a fuel nozzle to a plug, BEVs also are equipped with self-charging capabilities. Currently, regenerative braking, solar power and kinetic energies are most popular for BEVs. New charging methods have been influenced by wireless testing. Inductive charging allows a BEV to park over or be near a transmission unit that feeds power over the air by the magnetic field created from the unit and the BEV’s receiver unit.
Safety
The safety criteria for BEV batteries may be viewed from different perspectives, and each OEM will have a unique safety approach tailored for its vehicle platform. Fundamental to all efforts, though, is that the battery cell failure rate can never lead to thermal runaway, resulting in battery explosion. Other safety aspects for an industry approach include, but are not limited to, equipment sensibility to fire, emergency responder training, hazard representation and equipment alarms.
A fleet deciding on its equipment purchasing should rely on its existing safety plan first and alter if necessary for BEV consideration.
Fleet Considerations
TMC’s S.14 Light- & Medium-Duty and Specialty Study Group identified the following considerations for fleet managers planning to transition Internal Combustion Engine, or ICE, equipment assets to BEV assets:
A. Economics/Return on Investment — In many areas, there are substantial savings as a consequence of government incentives for reduced carbon emissions from CMVs comprising grants, reduced and, in some circumstances, zero taxation. This can include purchase and import taxes, capital concessions, and avoiding road and fuel taxes and concessions relating to parking, congestion, charging and other road use, especially in city centers.
B. Maintenance Reduction — Reduced energy consumption, lowered maintenance costs from fewer moving parts in electric drivetrains as compared with ICEs and more efficient operations are benefits. Avoiding fluctuating costs from the fossil fuel market also become associated disincentives to using ICEs.
C. Emissions — BEVs ensure compliance with increasing legal requirements for reduced exhaust emissions. More and more cities worldwide will continue to set up environmental zones requiring increasingly stringent reductions in exhaust emissions — leading eventually to zero emissions.
D. Public Image — BEVs are “clean.” They have a reduced carbon footprint as emissions are virtually nonexistent, making for cleaner air in the communities where the vehicles are driven. Many BEV charging station networks also can be associated with renewable energy generation sources. Early BEV adoption will be perceived as pioneering, progressive, and as caring for the environment and the well-being and quality of life for people in the community.
E. Operator and Customer Acceptance — Pride, commitment and job satisfaction are some intangible factors. BEVs encourage a shift in spending to local and domestic sources of energy and the use of company infrastructure to charge personal BEVs. They also are generally considered to be pleasant to drive.
F. Performance — If the performance expected from the CMV is light loading, short routes, low speeds and extended downtime for charging, then performance standards will be met. Also, they won’t violate quiet zones in and around hospitals, for example, and provide quiet deliveries during the night.
For more information, see TMC IR 2016-1, Battery Electric Vehicles in Light- & Medium-Duty and Specialty Truck Commercial Applications, available at: http://tmc.trucking.org.
Summary
Commercial BEVs have balanced design considerations that involve total vehicle cost, weight, energy storage capability and life cycle value. The primary consideration is the battery in which lithium-ion technology has grown to be most popular for its design. End users must understand their own applications before changing from ICE design or HEV fleet units to fully electric.
Richard Winters is manager, vehicle design and specification for Verizon Fleet Operations. He is the former chairman of the S.14 Light-& Medium-Duty and Specialty Trucks Study Group. Winters is a 2016 recipient of TMC’s highest honor — The Silver Spark Plug.
