Dedicated to the balanced discussion of global warming
AutoblogGreen – May 9, 2007
AutoblogGreen is a very well written blog and you should consider it in your regular reading. This particular article discusses a study by Univ. of New Hampshire that tried to determine the fuel footprint of a variety of vehicles that are generally considered to be fuel efficient.
The one thing that I think is missing in this analysis (and tends to be missing in many articles about hybrid vehicles) is the environmental cost of huge batteries. Many of these batteries contain metals that are not good for the environment and take energy and special care to build and to dispose of after their life is over.
automobiles, biofuel, diesel, footprint, fossil fuel, gasoline, Greenhouse gas, hybrid, hydrogen, prius, Toyota, water
The University of New Hampshire biodiesel group compared the energy use of six vehicles – a Jetta TDI using biodiesel, a Jetta TDI running on petroleum diesel, a Jetta 2.0L with a gasoline engine, a Toyota Prius burning gasoline, a Toyota Fuel Cell vehicle (hydrogen), and a Dodge ESX3 (diesel-hybrid) on biodiesel.
UNH found that the Prius costs less per mile to operate, but the biodiesel Jetta wins – by a lot – the fossil energy input/mile.
A footnote explains that energy input per mile was “calculated based on 50/50 average fuel mileage and energy balance of creating fuel, using 3.2:1 for biodiesel (when made from soy), 0.83:1 for petroleum diesel, 0.74:1 for gasoline, and 0.5:1 for hydrogen (based on electrolysis of water)” so that it “equals (energy density of fuel )/[(fuel efficiency (mpg))*Energy balance].”