EarthTalk: If you have an electric or plug-in
hybrid car, you’re paying for electricity rather than
gasoline all or most of the time. How does that cost compare
to a gas-powered car’s cost-per-mile? And since the
electricity may be generated from some other polluting source,
does it really work out to be better for the environment?
-- Kevin DeMarco, Milford, Connecticut
you compare battery to gasoline power, electricity
wins hands down. Pictured: The all-electric Tesla
Roadster sportscar from Tesla Motors.
© qviri," courtesy Flickr
you compare battery to gasoline power, electricity wins
hands down. A 2007 study by the non-profit Electric Power
Research Institute (EPRI) calculated that powering a plug-in
hybrid electric vehicle (PHEV) would cost the equivalent
of roughly 75 cents per gallon of gasoline—a price
not seen at the pump for 30 years.
calculation was made using an average cost of electricity
of 8.5 cents per kilowatt hour and the estimated distance
the car would travel on one charge, versus a car that gets
25 miles per gallon and is powered by $3 per gallon gasoline.
Change any of those variables and the relative costs change.
For example, substituting a car that gets 50 miles per gallon
doubles the comparative electrical cost (though it still
works out much cheaper than gasoline). On the other hand,
in some areas where wind or hydropower is wasted at night—just
when the PHEV would be charging—the utility might
drop the kilowatt hour cost to two to three cents, making
the charge much less costly.
don’t worry that we’ll run out of electrical
power: A 2005 study by the U.S. Department of Energy’s
Pacific Northwest National Laboratory estimated that three-quarters
of the country’s current small vehicle fleet could
be charged by our existing electrical grid without building
new power plants. (And if all those cars were replaced by
PHEVs, it would eliminate the need for 6.5 billion barrels
of oil per day, or 52 percent of current U.S. oil imports.)
environmental impact, charging up your car with electricity
from the grid also wins handily over filling up at the gas
station. In the most comprehensive PHEV study to date, released
in 2007 by EPRI and the non-profit Natural Resources Defense
Council (NRDC), results predict that all greenhouse gases
will be reduced as PHEVs begin to penetrate the car market.
Estimated cumulative greenhouse gas reductions from 2010
to 2050, depending upon how fast PHEVs take hold, range
from 3.4 to 10.3 billion tons.
than one half of our national energy grid is powered by
coal, and in areas where PHEVs are charged through coal-provided
electricity, says NRDC, there is the possibility of increased
levels of soot and mercury emissions. However, charging
up can be much less of a guilt-ridden affair where cleaner
electrical sources like wind and solar are available. The
website HybridCars.com points out that as more power plants
are required to develop green power and emit fewer greenhouse
gases, the environmental and health benefits will further
Power Research Institute; HybridCars.com;
EarthTalk: What is aerial wolf gunning and
why does Alaska governor Sarah Palin endorse the practice?
-- Vivian Anderson, Seattle, WA
Influential groups like the Alaska Outdoor
Council say that wolf populations need culling because
subsistence hunters rely on moose and caribou to feed
their families. Defenders of Wildlife disagrees, saying
that it is Alaska’s small but politically influential
commercial hunting interests -- not subsistence hunters
-- who want to keep aerial wolf-gunning alive.
© silverfang_10, courtesy flickr
Aerial wolf gunning
involves stalking and shooting wolves from low-flying planes
and helicopters. The practice yields better results than
traditional ground-based hunting since it allows hunters
to cover lots of ground quickly and track prey from an unobstructed
“bird’s eye” vantage point. For these
very reasons, some hunters—as well as many environmentalists
and animal rights advocates—consider aerial hunting
unsportsmanlike and even inhumane since it violates the
“fair chase” ethic.
is mostly forbidden on U.S. public lands per the Federal
Airborne Hunting Act, passed by Congress in 1972. But individual
states can allow it for the sake of protecting “land,
water, wildlife, livestock, domesticated animals, human
life or crops.” Alaska governor Frank Murkowski exploited
this language in 2003 and signed a state bill allowing Alaskans
to apply for permits to kill wolves—which some Alaskans’
fear take a large toll on the moose and caribou that hunters
like to shoot—from aircraft.
But when Sarah
Palin, herself an avid hunter, took over the governorship
in 2006, she instituted a $150 bounty for any hunter who
killed a wolf from an aircraft in select areas where moose
and caribou populations were not as large as hunters would
have liked. A state judge quickly put a halt on the bounty,
ruling that the Palin administration lacked the authority
to offer such payouts. But the judge was powerless to stop
aerial hunting itself as long as it was done in a permitted
fashion in the name of “predator control,” per
the loophole in the federal ban.
Palin also approved
a $400,000 state-funded campaign that helped undermine a
recent ballot initiative to ban aerial hunting, and also
introduced legislation to ease restrictions on the practice.
In the four years Palin has been governor, upwards of 800
wolves have been killed by aerial hunting in Alaska. Palin
has joined influential groups such as the Alaska Outdoor
Council in maintaining that wolf populations need culling,
as the great canines are literally stealing food from the
tables of Alaska’s many subsistence hunters who rely
on moose and caribou kills to feed their families through
the long cold winters.
But Rodger Schlickeisen
of the non-profit Defenders of Wildlife says that it is
Alaska’s small but politically influential commercial
hunting interests—not subsistence hunters—who
want to keep aerial wolf-gunning alive in the 49th state.
“Their clear intention is to eliminate as many of
nature’s major predators as possible to artificially
increase moose and caribou numbers where it’ll then
be easier for urban and wealthy out-of-state hunters to
shoot their trophy animals,” he says, adding that
scientific data do not show the need for stepping up predator
insists that most regular Alaskans are opposed to aerial
hunting, even for the purpose of predator control. “Twice
in the past 12 years, Alaska voters have approved state
ballot initiatives to limit the use of aircraft to kill
wildlife—and twice the state legislature, encouraged
and abetted by the [appointed] board of game, has overridden
the citizen-passed laws to restore use of aircraft,”
Outdoor Council; Defenders