Environmental Engineering Reference
vice territory. The GenSys5CS unit transforms natural gas to hydrogen.
LIPA will evaluate and measure the potential of fuel cells for heat
and power generation and backup supply, which will help achieve a goal
of 25 percent of New York's electricity needs supplied by alternative en-
ergy technologies within 10 years. LIPA has also been placing Plug Pow-
er fuel cells at various commercial locations around Long Island, includ-
ing Hofstra University, and the Babylon and East Hampton Town Halls.
Thousands of Long Island homes and businesses may eventually have
fuel cells to relieve LIPA of some of the resources needed to build addi-
tional on-island power plants.
Plug Power has delivered enough systems to generate over 1.6 mil-
lion kilowatt-hours of electricity, a large portion of it on Long Island. Plug
Power's fuel cell systems are to be sold globally through a joint venture
with General Electric.
NATURAL GAS FUEL CELLS
Fuel cells running on natural gas typically use about three of the four
hydrogen atoms in methane (CH 4 ) for power generation. The remaining
hydrogen goes into the flue gas or stack effluent with differing amounts of
CO 2 , CO, and water vapor, depending on the type of fuel cell. The flue gas
is sometimes vented to the atmosphere but it can be combusted for heat
and used for reforming.
Hydrogen can be separated from the flue gas at low cost in high-
temperature fuel cells. A SOFC system may be able to cogenerate hydro-
gen for about $3.00 per kg which can match gasoline. Since these fuel cells
could be part of the fueling station, there would be no need for a hydrogen
GRAVITY FUEL CELLS
A fuel cell with heat- and gravity-driven circulation of fuel and oxidiz-
ing gases would need no pumping equipment which consumes power and
requires servicing. Heat and gravity can take over the functions of a pump
or compressor for either a SOFC or PEMFC (Proton Exchange Membrane
Fuel Cell) system. With heated gaseous fuels and oxidizing agents, the gas
flow through the fuel cell is opposite to the gravity forces. In the lower part