EarthTalk: What would be the feasibility of
having hybrid cars run on E85 or biodiesel? Wouldn’t
this solve multiple problems?
--Bob Pendergrass, Broken Arrow, OK
advocates would love to see carmakers mass-produce a biofuel-electric
hybrid. From a technology standpoint, it’s a no-brainer:
Major automakers already turn out vehicles that can run
on E85, a blend of 85 percent ethanol, derived from corn
and other crops, and 15 percent standard gasoline. Ford’s
light duty F-series pickups are examples of such “flex
fuel” vehicles. And gasoline-electric hybrids, like
Toyota’s Prius, are all the rage and beginning to
be ubiquitous on the roads.
however, is an issue, says Jim Kliesch of the website greenercars.org.
Traditional cars and trucks powered by diesel, biodiesel
or ethanol cost more to manufacture than equivalent gasoline-power
vehicles. And gas-electric hybrids also cost more than conventional
cars, largely because their market share is still small
and economies of scale have not yet kicked in. Thus combining
two costly technologies in a biofuel-electric hybrid would
constitute “a double-whammy,” says Kliesch,
“limiting the vehicles to a very small slice of the
Ford last year unveiled a prototype of its popular Escape
Hybrid SUV that runs on E85. Like the gas-electric hybrids
now on the road, the E85-electric hybrid Escape maximizes
fuel economy by alternating between its internal combustion
and electric engines. And it never needs to be plugged in
because its high-capacity batteries store electricity generated
from braking and other processes in-car.
estimates that if only five percent of U.S. vehicles were
powered by ethanol-electric hybrids oil imports could be
reduced by 140 million barrels a year. Such vehicles would
also produce about 25 percent less carbon dioxide (CO2)—a
chief contributor to global warming—than traditional
cars and trucks. What’s holding up mass production,
says Ford, is a lack of E85 fueling outlets—only 1,200
exist across the U.S.
to be outdone, General Motors (GM) has its own ethanol-electric
hybrid in the works via its Sweden-based Saab subsidiary,
which unveiled a prototype in 2006. The company claims that,
whereas Toyota’s gas-electric Prius emits 104 grams
of CO2 per kilometer, their E85-based hybrid should emit
just 15-20 grams. Industry insiders don’t expect to
see such a vehicle available to the public until 2010 or
regard to diesel-electric hybrids, though diesel spews particulates
and other nasty ground level pollutants into the environment,
it contributes significantly less CO2 to the atmosphere
than gasoline. And biodiesel, a form of the fuel derived
from plants, is both carbon-neutral (burning it contributes
no additional carbon to the atmospheric balance of the pollutant)
and cleaner burning in regard to particulates. It can be
used interchangeably with regular diesel in most diesel
engines. Thus combining biodiesel with an electric motor
in a hybrid car or truck would yield one of the cleanest
burning engines on the road.
and Chrysler have already collaborated on developing a diesel-hybrid
platform that combines dual electric motors with a diesel
engine to offer unparalleled fuel efficiency. But whether
such vehicles ever see the showroom floor—and whether
consumers will be able to even afford them—is anybody’s
EarthTalk: OK, once and for all, which is more
environmentally friendly: paper or plastic at the grocery
checkout? And didn’t I just hear that San Francisco
has banned plastic bags?
-- Brian, Santa Clara, CA
Yes the city
of San Francisco did just recently ban plastic bags. Large
supermarkets and pharmacies there must eliminate plastic
shopping bags by early 2008 in favor of bags made from either
paper or compostable and biodegradable cornstarch. The city’s
Board of Supervisors cited the fact that plastic bags are
a challenge to recycle and as a result occupy much-needed
landfill space, while causing litter problems by easily
blowing into trees and waterways, where they can kill birds
and marine life.
But just because
San Francisco has outlawed plastic bags doesn’t mean
that all indications point to paper bags being more green-friendly
than plastic. A landmark 1990 study by the research firm
Franklin Associates—which factored in every step of
the manufacturing, distribution and disposal stages of a
grocery bag’s usable life—actually gave the
nod to plastic bags.
employed two critical measures in reaching their conclusion.
The first was the total energy consumed by a grocery bag.
This included both the energy needed to manufacture it,
called process energy, and the energy embodied within the
physical materials used, called feedstock energy. The second
measure used was the amount of pollutants and waste produced.
report concluded that two plastic bags consume 13 percent
less total energy than one paper bag. Additionally, the
report found that two plastic bags produce a quarter of
the solid waste, a fifteenth as much waterborne waste and
half the atmospheric waste as one paper bag.
Of course, many
environmentalists still side with paper as a better choice
than plastic at the checkout, mostly for the reasons cited
by San Francisco’s Board of Supervisors. Plastic is
not biodegradable, it litters our waterways and coastal
areas, and has been shown to choke the life out of unsuspecting
wildlife. A recent survey by the United Nations found that
plastic in the world’s oceans is killing more than
a million seabirds and 100,000 marine mammals and sea turtles
each and every year. According to the California Coastal
Commission, plastic bags are one of the 12 most commonly
found items in coastal cleanups. Paper bags do not cause
such after-the-fact problems, and are inherently easier
But to the non-profit
Institute for Lifecycle Environmental Assessment, “paper
versus plastic?” is not the question we should be
asking ourselves, since the answer is really “neither.”
After all, energy and waste issues aside, the manufacture
of paper bags brings down some 14 million trees yearly to
meet U.S. demand alone, while at the same time plastic bags
use up some 12 million barrels of oil each year.
The group urges
consumers to “just say no” to both options and
instead bring their own re-usable canvas bags, backpacks,
crates or boxes to haul away the groceries. Some supermarkets,
such as the Albertson’s and Wild Oats chains, even
offer a small discount (around five cents) to those who
do so. Another benefit of bringing your own, of course,
is setting a good example so that other shoppers might do
for Lifecycle Environmental Assessment.