Choo-Choo Trains on Energy Crunch
By Erik Baard
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2:00 a.m. July 3, 2002 PDT
Sierra Railroad thinks it can (It knows it can! It knows it can!) make
electricity to meet California's peak summer demands. The short-touring and
freight line, based in Oakdale, has 48 diesel locomotive engines in a rail
yard waiting to produce 100 megawatts of electricity for use on the power
Moreover, the company is going to fuel them with 100-percent biodiesel, a
cleaner-burning vegetable oil equivalent of the familiar petroleum product.
The California Consumer Power and Conservation Financing Authority has
signed on to buy the locomotive project's electrical output for five years
as part of the agency's plan to buy 250 megawatts of environmentally benign,
or "green," electricity per year.
"A typical modern locomotive is just a rolling generator," said Sierra
Railroad chief executive Mike Hart, whose company is the oldest independent
railroad in California, perhaps best known to steampunk aficionados for
providing the time traveling 19th century locomotive to the movie, Back to
the Future III.
In the 1982 GE diesel engines central to Sierra Railroad's PowerTrainUSA
project, electricity produced by the engine is normally sent to wheel motors
and converted into 3,000 horsepower of mechanical strength. But these
locomotives will run in place, instead pumping 2.1 megawatts each onto the
grid for 1,000 hours per year when electricity demand is exceptionally high.
The total output will be enough to supply 100,000 homes, though it will be
spread thinly among all users of the grid.
For the moment, however, PowerTrainUSA sits idle in all senses.
While regulators have approved most aspects of Hart's plan, California
currently has a short-term energy glut due to recent power plant building to
compensate for shortages and blackouts in summers past. "We've been standing
by since last August last year, month by month, ready to go. We're just
waiting for the governor's approval," Hart says.
PowerTrainUSA does have one key advantage: mobility. Being a cluster of
locomotives, after all, this power plant can chug over to where it's needed.
Often the biggest hurdle electrical system operators face isn't just making
enough electricity, but moving it from producers to users. Localized demand
spikes, power-plant failures and downed transmission lines can create
bottlenecks on the grid.
PowerTrainUSA has ABB solid-state inverters (to turn direct current into
marketable 60-Hz alternating current) loaded onto 12 former Long Island
Railroad commuter coaches. When PowerTrainUSA arrives at its destination,
all it needs is to hook up to a transformer to match the grid's voltage
specifications. In some ways, the concept isn't new -- as an island city,
New York does much the same with generator barges.
Another goal of PowerTrainUSA is to demonstrate that locomotive engines can
operate well using alternative fuels like biodiesel, which is derived mostly
from soy oil in the United States, but can also be made from other vegetable
oils, animal fat and discarded cooking grease.
PowerTrainUSA is buying its fuel from World Energy Alternatives, a
Massachusetts company that's the nation's largest biodiesel manufacturer.
Producing biodiesel is a relatively simple process. The triglyceride oil
molecule that is the basis of biodiesel is shaped like a trident. Its base
is glycerin and the three prongs are long chains of fatty acids, which can
be broken away by a chemical reaction with alcohols like methanol or
ethanol. Those fatty acids -- primarily 16 to 18 carbon atoms strung in a
line -- have a viscosity and power density similar to petrodiesel but with
Biodiesel burns cleaner because it contains oxygen (petroleum products must
be oxygenated artificially) and is also more biodegradable; and it is safer
to handle and transport because it is less likely to ignite than other
Biodiesel reduces particulate matter by 40 percent, and the remaining
particulate matter that shows up in emissions tests is primarily nontoxic
and biodegradable unburned fuel. Carbon monoxide is down 44 percent compared
with petroleum diesel and unburned hydrocarbons are cut 68 percent.
Most importantly for the PowerTrainUSA effort, as a no-sulfur fuel,
biodiesel meets the Environmental Protection Agency's 2006 fuel requirements
and won't clog up equipment to remove smog causing nitrogen oxide. Carbon
dioxide is also reduced 80 percent compared with conventional petroleum. It
also happens to smell like French fries when combusted.
"We've been very satisfied with biodiesel. There's been no negative side at
all," Hart says. But biodiesel is pricey, Hart says. "It can cost us $3 a
gallon. Then again, we were working for a number of years on a concept to
reduce pollution by using natural gas, but gas prices spiked and spooked us
off." Hart is also exploring buying biodiesel made from canola oil, which
might be a more suitable crop for California farmers.
Because the locomotives burning biodiesel will be operating in place but at
maximum capacity with output read by sensitive electrical meters, Sierra
Railroad says, engineers will have ideal conditions under which to study
emissions, power production, engine wear and other issues of concern with a