Safe Harbor: Protecting Ports with Shipboard Fuel Cells
Each year, the Port of Los Angeles--occupying 7,500
acres and 43 miles of waterfront--handles more than 162
million metric revenue tons of cargo (measured as 1,000
kilograms or 1 cubic meter, whichever is larger). With
the increase in Pacific commerce, port diesel emissions
have increased 60% since 2001, and the port complex has
in 10 years become the single largest air polluter in
the Los Angeles basin, according to the 25 September
2005 edition of the Los Angeles Times.
Nearby residents blame the port for illnesses ranging
from asthma to cancer, according to Diane Bailey, head
of the Health and Environment Program for the Natural
Resources Defense Council (NRDC) in San Francisco. Studies
have linked particulate matter from diesel fumes to respiratory
illness and cancer.
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Hot box. The 625 Molten
Carbonate Fuel Cell Reformer System (fuel
cell stack is out of view) produces methane
from high-sulfur logistics fuel to power
the fuel cell stack with an expected
efficiency of 47-50%. The system
is being land-tested by the Office of
Naval Research, and will be installed
at the Naval Sea System Command’s
engineering facilities in Philadelphia
in 2007 for extended testing.
image: Anthony Nickens/ONR |
In an August 2004 report titled Harboring Pollution:
Strategies to Clean Up U.S. Ports, the NRDC noted
that besides direct threats to human health,
growing harbor traffic could increase regional smog,
threaten
water quality and public lands, and increase
noise and light pollution. With three of the country’s
five largest harbors in California, Bailey says, cutting
port pollution and the health impacts on surrounding
communities is a “huge priority” for the
state.
The source of most ship-related emissions is Bunker
C fuel, a diesel that produces a thick, sticky residue.
(Bunker C gets its name from the era when steamships
were fired by coal stored in bunkers. When ships shifted
to diesel, crews still used the term “bunker” to
include liquid fuel tanks.) Ships in port can also use
a kind of extension cord plugged in to land power supplies,
but Scott Samuelsen, director of the National Fuel Cell
Research Center at the University of California, Irvine,
says these cords can be somewhat dangerous if they get
tangled during loading or unloading. Therefore, most
ships in port use diesel engines to provide “hoteling” power--basic
lighting, heating, ventilation, and light electricity.
The Beauty of Fuel Cells
Fuel cells are cleaner than diesel turbines and other
internal combustion engines. Samuelsen explains that
fuel cells convert energy from hydrogen directly to electricity
without combustion; the only residues are water and heat.
A fuel cell works using the same electrochemical reaction
as the battery under a car hood, Samuelsen explains.
But whereas the battery in your car primarily stores
energy while the engine is turned off, a fuel cell reaction
provides energy continuously as hydrogen fuel encounters
oxygen. Compared to internal combustion, says Samuelsen, “the
fuel cell is more of a one-stop shop, one reaction.” And
with fewer moving parts, there’s the prospect of
reduced maintenance.
The NRDC recommended fuel cells as a quieter, cleaner,
more efficient power source for ships in Harboring
Pollution. Since the report appeared, Bailey says
other technologies have gained momentum, at least in
the short run. Among them are diesel-electric hybrids,
more efficient versions of the locomotive engine, which
can cut emissions by 90% compared with the old diesel
engines used to assemble freights in port rail yards.
Another alternative is the gas turbine engine, which
has strong marketplace advocates.
In Los Angeles, though, says Samuelsen, “the
fuel cell will probably be the preferred choice.” He
adds that California’s regulatory action will likely
point the direction for maritime energy use elsewhere.
As in the drive toward greater fuel efficiency in automobiles,
Samuelsen suggests, the state’s regulatory process
will likely drive national technological advances.
Contemplating Naval Studies
The U.S. Navy has been exploring shipboard use of fuel
cells for some time, according to Anthony Nickens, a
program officer with the Office of Naval Research (ONR)
in Arlington, Virginia. Nickens says the Navy is very
interested in the technology for its efficiency and low
emissions. “There’s no [nitrogen oxide emissions]
coming out, there’s no flame,” he says. Fuel
cells also permit a “distributed” power system
design; they can be located at different points in the
ship, away from the ship’s principal exhaust stack
system, unlike conventional power-generation and propulsion
engines. This flexibility can improve ship survivability
in the event of an accident or enemy attack, according
to an ONR press release from February 2004.
So far, fuel cells are still in a demonstration phase
supervised by ONR’s science and technology staff. “I
think we can get there in five, seven years,” says
Nickens of the Navy’s plans for fuel cell-powered
vessels. One demonstration for the Navy by Sandia National
Laboratories and Plug Power, a company based in New York,
was completed in August 2005. The project tested 20 fuel
cells at naval support sites in California, New York,
and Hawaii, and proved their ability to provide heat
and power for land-based functions. Abbas Ali Akhil,
Sandia’s energy analyst on the project, says a
final report on that demonstration will be completed
later this spring. Meanwhile, test results from locations
in three states are available at the Sandia website [see
Suggested Reading below].
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Picturing
the future fleet. Artist’s concepts
of two potential ships that may use fuel
cells in the not-too-distant future:
(above) a design by a Northrop Grumman
Corporation-led team of the U.S.
Navy’s 21st century surface combatant,
and (right) Calá Corporation’s
fuel cell-powered luxury cruise
ship.
images: Top to bottom: U.S. Navy; Ray Francis/Calá Corporation Undersea
Resort Project |
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Steven Eschbach, director of investor relations and
communications for FuelCell Energy, based in Danbury,
Connecticut, says his company, too, has been working
for several years to provide the Navy with a land-based
demonstration of shipboard fuel cells for providing hoteling
power to stealth destroyers. Eschbach says the silence
of fuel cells is an important benefit for stealth destroyers,
but it also helps that these power sources are more efficient
(47% electrical efficiency--the portion of total energy
in the reaction that is translated into usable electrical
power--compared to 30-40% for diesel engines) and 99%
cleaner, especially in terms of nitrogen oxide, sulfur
oxide, and particulate emissions. The company is currently
testing peripheral components of the fuel cell power
plant and will soon integrate those with a fuel cell
stack for complete system verification.
Another key advantage to the fuel cell approach is
that the hydrogen needed for the electrochemical power
generation is internally purified in the fuel cell module. “We
don’t need a hydrogen infrastructure for our fuel
cells to operate,” Eschbach says. The company plans
to continue testing this spring, followed by delivery
of the fuel cell system later this year pending funding
from the Navy.
The German Navy also is exploring fuel cells and in
October 2005 commissioned two new fuel cell-powered submarines
from Siemens KWU, according to a 23 January 2006 report
by the online industry publication Fuel Cell Today.
The Siemens model uses a solid polymer electrolyte membrane
(PEM) fuel cell to direct hydrogen ions to a cathode
for reaction with oxygen inside a pressurized housing.
PEM cells, operating at temperatures less than 80ºC,
are reportedly 60% efficient, according to Fuel Cell
Today.
Commercial Applications
For commercial ships, Samuelsen expects to see design
prototypes in about five years, spearheaded by one or
two shipping companies that pave the way. He also expects
the shift to be gradual, with “a few decades before
the momentum grows,” he says. After all, the new
laws dictate reduced ship emissions, but they don’t
dictate fuel cells as the only way to get there.
For cruise operators wanting to spotlight an environment-friendly
fleet and give passengers a quieter cruise experience,
fuel cells may be especially appealing. Calá Corporation,
a cruise line operator based in Titusville, Florida,
has plans to build three cruise ships equipped with fuel
cells, says CEO Joseph Calá. The fuel cells will
provide hoteling power for electricity as well as power
at low speeds (under 8 knots). Calá expects the
first vessel to be ready by 2008. Each will be equipped
with about 20 cells providing 500 kilowatts apiece. Calá estimates
that the cells will save perhaps $1 million in fuel each
year. Cruising at 16 knots, he says a ship can burn up
to $35,000 in fuel a day.
Calá, who became interested in fuel cells’ promise
12 years ago, maintains that nautical engineers aren’t
moving fast enough in furthering the technology. “They
need to bring in people with vision,” he says. “They
need to expand their minds and imagination.”
Several technical challenges remain, notes John Weidner,
a chemical engineering professor at the University of
South Carolina. Unlike other forms of energy, fuel cells
don’t offer economies of scale for making the large
units needed for ships. This is due to the simplicity
of the fuel cell chemical reaction. There are no moving
parts you can accelerate for a bigger bang; the energy
output is strictly related to the size of the cell. “You
can make them big, but if you make it ten times bigger,
it costs ten times as much,” says Weidner. Furthermore,
in some applications, durability of the fuel cell’s
electrolyte is still an issue. For some types of fuel
cells, including molten carbonate cells, the high temperatures
involved decrease cell life.
Despite these challenges, the technology is promising
for maritime use. As more research comes online, we can
likely expect to see fuel cells surging full steam ahead.
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