If you’re reading Transport Evolved, the chances are you’re here because you’ve an interest in reading about cleaner, greener safer and smarter transportation. And if that’s the case, the chances are that you’re either interested in battery electric, plug-in hybrid, or hydrogen fuel cell cars.
Listen to advocates for each, and you’ll be given a wide range of benefits, ranging from the zero emission, cheap fuel and instant torque of an electric car through to the speedy refueling capabilities of a hydrogen fuel cell car and the ‘best of both worlds’ offered by a range-extended electric or plug-in hybrid car. In each case, owners will produly — and sometimes even ferociously — defend why their chosen propulsion method is more superior to any others. But which fuel source is the best choice for the vehicles of tomorrow — and why?
That’s a question researchers at the University of Michigan Transportation Research Institute (UMTRI) (via GreenCarCongress, Autobloggreen) have been trying to answer, reviewing technical literature covering the energy and carbon footprints associated with battery electric and hydrogen fuel cell cars, comparing them to gasoline vehicles and trying to arrive at a cogent overall picture of which fuel source is best.
Alongside existing scientific papers on the subject, Brandon Schoettle and Dr. Michael Sivak, the report’s authors, also interviewed experts in the automotive and energy sectors concerning their opinions on infrastructure and energy generation. Collating those responses alongside more formal academic studies, the duo came up with their final verdict as to which areas each vehicle excelled.
Their conclusion? While gasoline vehicles win when it comes to availability of mechanics, vehicle choice, refuelling time and overall range, electric cars had the edge when it comes to average fuel economy, effective cost per mile, and wheel-to-wheels greenhouse gas emissions. Hydrogen vehicles meanwhile, only came out on top when it came to wheel-to-wheels total petroleum usage.
Overall, the duo found battery electric vehicles to offer the most readily available alternative fuel source, thanks the way in which you can easily charge most electric cars from the grid. With high efficiency and easily-obtainable fuel, electric cars came out with the lowest effective running cost, averaging just 4 cents per mile. But with most electric cars having a range of around 100 miles per charge, they lost out to both hydrogen and gasoline cars on overall range.
Electric cars have the edge when it comes to greenhouse gas emissions too, even using the average U.S. mix of renewable and non-renewable sources of electricity. At 214 grams per mile, electric cars had the edge on gaseous hydrogen fuel cell cars, which managed an average of 260 grams per mile. Switch that hydrogen to liquid form however, and the extra energy required to compress it bumps up the effective emissions per mile to 364 grams of GCH per mile driven, placing liquid-fuelled hydrogen fuel cell cars at the bottom end of the most efficient direct-injection gasoline cars on the market today. As you might expect, gasoline cars came out with the worst GHG emission figures, ranging from 356 grams per mile to 406 grams per mile.
When it comes to maintenance however, gasoline vehicles come out top. That, says the report, is something that can be changed, with more training for service staff on both electric and hydrogen fuel cell vehicles likely as vehicles become more popular. It also noted that unlike battery electric vehicles, hydrogen fuel cell cars have very few qualified emergency responders who are trained to work on them in an emergency situation.
As for infrastructure? Based on the lower refueling times of hydrogen vehicles compared to battery electric cars, as well as the “significantly longer driving ranges” when compared with ‘similar’ electric vehicles, the report says there is a general consensus among experts that hydrogen fuel cell infrastructure investment is worthwhile for the future, but notes that when it comes to approximate costs for infrastructure, hydrogen is unbelievably expensive.
Citing an average cost of $3- to $5-million for a hydrogen filling station, and $1- to $2-million for a gasoline filling station, the study notes that electric cars win hands down on infrastructure costs, with the average cost of a home charging station now hovering around $1,000 and even the most expensive high-power public charging stations costing no more than $100,000 .
As with any study, there are some pretty large generalizations made by the report and some of the figures quoted are out of date in terms of range and energy costs. But from where we’re sitting, it paints electric vehicles as the next logical transportation choice.
Do you agree? Leave your thoughts in the Comments below.
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