Environmental Engineering Reference
In-Depth Information
So even accounting for the fuel burned at a power plant to generate the
electricity for the battery (about half of the time it will be a coal-burning
plant), plug-in hybrids will signifi cantly reduce fuel use and carbon
dioxide pollution.
The 254 million privately owned vehicles in the United States have an
average life span of more than a dozen years, and the average age of
America's passenger cars was 9.2 years in 2007 (trucks 7.2 years). There-
fore, we will require conventional fuels for at least a decade, even if every
new vehicle produced from today onward runs on some alternative.
In mid-2009 Congress passed what became known as the cash-for-
clunkers bill, which lasted for 53 days. Its aim was to get highly polluting
cars off the road (and boost car sales in a down economy) more quickly
than would otherwise happen. Under the program, car buyers could
trade in their clunkers that were no older than 1994 models and receive
vouchers worth up to $4,500. To be eligible for the voucher, the clunker
had to have an average fuel economy of less than 19 miles per gallon,
about half of the cars on America's roads. The new car or truck then
had to get better gas mileage than the clunker that was being traded in.
The amount of the voucher depended on the difference in the fuel econo-
mies of the old and new cars. A new car getting at least 4 miles more
per gallon than the old car was eligible for a $3,500 voucher. A new car
getting at least 10 miles more per gallon could get a $4,500 voucher.
A similar plan in Germany boosted auto sales by 21 percent the fi rst
month of the program compared to the previous year. During the same
period, sales in the United States slumped 41 percent. But the German
plan had additional incentives not present in the American plan, so the
U.S. plan did not have the dramatic effect of the German one, which has
an additional tax of 50 cents per gallon on gasoline and a new tax based
on carbon dioxide emissions. In the United States, talk of a new tax,
even a small one, is anathema to most politicians. Taxes in the United
States are the lowest among Western countries, and most Americans
want to keep it that way.
Unconventional Oil
In 2008 the U.S. Geological Survey released a study of the Bakken For-
mation, a layer of oil-bearing rock located in North Dakota, Montana,
Wyoming, and two Canadian provinces.
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The oil is located in shale, a
rock with low porosity and very low permeability. The survey estimated
the amount of oil recoverable with today's technology at several billion
barrels, much more oil than occurs in Saudi Arabia. If even a small part
