ANN ARBOR, Michigan — Electric and fuel-cell vehicles provide a number of advantages over gasoline-powered models but still have significant challenges to overcome in order to become a practical alternative to gasoline-powered models, according to a new study from the University of Michigan Transportation Research Institute.
In their report, The Relative Merits of Battery-Electric Vehicles and Fuel-Cell Vehicles, UMTRI researchers Brandon Schoettle and Michael Sivak look at the plusses and minuses of the two primary alternative power sources currently available and compare them to gasoline vehicles in a number of areas.
The study provides valuable insight for car shoppers considering alt-fuel vehicles.
Although the study stops short of predicting which of the three current sources of propulsion will be dominant in the future, it's clear that if electric vehicles (EVs) and fuel-cell vehicles (FCVs) are to gain more widespread acceptance, improvements will need to be made, both in the vehicles themselves and in the infrastructure to support them.
EVs available for the 2016 model year include the Chevrolet Volt, Fiat 500e, Ford Focus Electric, Fusion Energi and C-Max Energi, Kia Soul EV, Mercedes-Benz B-Class Electric Drive, Mitsubishi i-MiEV, Nissan Leaf, Smart Fortwo Electric, Tesla Model X and Volkswagen e-Golf.
Meanwhile, only two models of FCV are currently available: the 2016 Hyundai Tucson Fuel Cell and 2016 Toyota Mirai, with the 2017 Honda Clarity scheduled to arrive at dealerships before the end of the year.
Both types of vehicles are driven by electric motors.
The difference is that in EVs, power for the batteries comes from the electrical grid, while in FCVs the batteries are charged via a chemical reaction that occurs when hydrogen stored in the vehicle's tank is mixed with oxygen from the air.
And that brings up one of the most significant challenges that FCVs need to meet: infrastructure.
The study points out that there are currently about 114,000 gasoline stations in the U.S., making that fuel readily accessible. And in the case of EVs, the electrical grid makes power available at houses and businesses, as well as from the 34,000 public charging outlets expected to be online by the end of the year.
But at the moment, infrastructure to support FCVs is still in its infancy.
Currently, there are just 14 public hydrogen fueling stations in only four states, 11 in California and one each in Connecticut, Massachusetts and South Carolina.
Even factoring in private hydrogen fueling stations (mostly used for fleet vehicles), the number rises to just 35 stations in 14 states.
Schoettle and Sivak also point out that differences in refueling times play a role in assessing the relative merits of the three types of power.
We are used to gassing up our cars in less than five minutes. And while the hydrogen tanks in FCVs can be topped up in as little as five minutes, the process may take as much as 30 minutes, depending on the pressure needed for the system in question.
But this is an area where, at the moment, EVs come up short.
Recharging times for the current models range from 3.5-12 hours using 240-volt AC Level-2 charging, although that can be reduced to 20-30 minutes for an 80 percent charge if a DC Level-2 fast charger is available.
Another challenge for EVs is range. The researchers note that the average gasoline-powered vehicle travels about 418 miles per tank. By comparison, FCVs average 289 miles per fill-up of hydrogen, while EVs average just 110 miles per charge.
But with such challenges to overcome, the question on the minds of shoppers considering an alternative-fuel vehicle is sure to be, what are the benefits?
The most obvious is cost savings. The current average fuel economy for gasoline-powered vehicles, according to UMTRI, is 23.3 mpg, although many especially fuel-efficient models can top 40 mpg.
The average rating for currently available FCVs is 58.5 MPGe, while the current lineup of EVs averages 105.2 MPGe. So, strictly from the standpoint of energy consumption, either alternative power source comes out ahead of gasoline, with EVs being a particular bargain.
Schoettle and Sivak note that comparing the actual expense of operating the three types of vehicles involves a complicated process, but there is a generally accepted method called gasoline gallon equivalent, or GGE.
Using this conversion factor and the national average cost of a gallon of gas and average MPGe of the currently available alternative-fuel models, they found that EVs cost $0.04 per mile to operate, and FCVs come in at $0.09 per mile. By comparison, the average gasoline-powered vehicle costs $0.10 per mile to operate.
And of course, for environmentally conscious shoppers, there are the emissions benefits of alternative-fuel vehicles to consider.
According to UMTRI, using the generally accepted GREET (Greenhouse gases, Regulated Emissions, and Energy use in Transportation) model for comparing emissions, EVs pollute the least, with a rating of 214 g/mi, while FCVs range from 260 to 364, depending on the type of hydrogen, and gasoline-powered vehicles come in last at 356 to 409, depending on model.
Edmunds says: Shoppers in the market for an alternative-fuel vehicle have a lot to think about, but this study may help clarify some of the complex issues.