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Environmental Research Web: Calculating the real carbon footprint of vehicles |
2 Comments |
| By Eric Spitzfaden in Conservation, Energy, Transportation | June 9, 2009 | ||
Environmental Research Web recently posted “Calculating the real carbon footprint of vehicles“, an article by Mikhail V Chester and Arpad Horvath of the Department of Civil and Environmental Engineering, University of California, which looks at the environmental impact of various forms of transportation (Planes, Trains, Buses and Automobiles) over their entire lifetime, to determine overall greenhouse gasses and energy used. The study includes vehicle manufacture, infrastructure, fuel, delivery of fuel and operation of the vehicle.
The energy usage numbers were simplified into MJ/PKT, mega-joules per passenger-kilometer-traveled. When looked at this way, many passengers riding a single vehicle, even if relatively inefficient, actually use less fuel each. 2 people riding an SUV (.9 MJ/PKT) can use less energy, per passenger, than 5 riders in a standard city bus (4 MJ/PKT); however, the numbers change once the bus is full (.5 MJ/PKT). Large Jet aircraft (1.4 MJ/PKT) compare quite favorably, simply because of how many passengers they can carry.
Energy consumption and GHG emissions per PKT (image from study)
My take-away from the article is that finding ways to share rides, rather than simply focusing on miles-per-gallon, can go along way toward conservation.
A PDF of the complete report can be downloaded from IOP Electronic Journals here. What’s your take?
Martin said,
In northern Africa, there is a transportation model called the louage. Passenger vans travel set routes and leave the station only when they are full. Fares are what the market will bear, which is often less than the equivalent of $5 USD to travel from one city to another.
Trevor Hunter said,
In our research we have found that every gallon of gasoline that is burnt, converts to 19.2 lbs of Co2 (carbon dioxide). We are working with 1 police dept right now that has 5400 police cruisers. They average 100,000 miles each, their Co2 output and fuel usage is substantial to say the very least. Once they have our system in use there numbers will reduce by approx. 11 million lbs per year. I created a calculator for fleets to be able to use to calculate their Co2 reduction and savings, you can find that calculator here http://hhotek.com/HHOTekcalculator.xlsx it is an excel file so you must have excel to open it, But it is very interesting play around with, if for nothing more than to calculate how much C02 your family or business contributes.