Giner  Electrochemical  Systems, LLC  Delivers  A  Lightweight, 15-kilowatt Electrolyzer Stack For the Helios Prototype Flying Wing.

August 23, 2001 — Newton, MA — Giner Electrochemical Systems, LLC (GES), a specialized research and development firm that develops electrolyzers, fuel cells and related electrochemical systems, has delivered a 15 kW electrolyzer stack for the Helios flying wing, a high altitude lightweight plane developed by NASA and AeroVironment, Inc.

The electrolyzer stack is one half of the regenerative power system that will keep the plane aloft for extended flights, which will eventually last as long as six months.  The electrolyzer stack converts water, with the aid of electrical power provided by the solar panels installed on Helios, into gaseous hydrogen and oxygen. These reactants, when recombined into water in the power systems fuel cell stack, provide electrical power to keep the plane flying overnight, when solar power is unavailable.  A lightweight, high-pressure fuel cell stack is currently being tested by GES to complete the heart of the aircraft's power system.

The exciting and unique aspects of the electrolyzer stack are its lightweight design, weighing only 23 pounds (10.5 kg), combined with its high-pressure operation at 400 psig (2758 kPa).  The 15 kW stack consumes only 1450 watts of power per kilogram, a power-to-weight ratio that was thought to be unachievable only a few years ago.  The electrolyzer stack produces nearly 4000 l/hr of hydrogen and 2000 l/hr of oxygen for storage, and to power a fuel cell stack, completing the regenerative system.

The electrolyzer and fuel cell stacks are based on GES' proprietary molded graphite bipolar plate technology and use advanced membrane-electrode assemblies (MEA’s) developed by GES.  The electrolyzer stack contains 50 cells, each operating at 1.72 volts, with 174 Amperes (1076 mA/cm2) of applied current.  The electrolyzer stack has a total volume of less than 4 liters.  Operating conditions were chosen to optimize overall system and stack efficiency.

The Helios Prototype recently broke records by flying to an altitude of 96,863 ft (29,523 m), powered by the sun.  The plane's wingspan is longer than that of a Boeing 747, weighs less than one ton and utilizes solar power to run its 14 propellers. During the record-breaking flight, the aircraft flew at speeds ranging from 20 mph to 170 mph (32 kph to 273 kph).  Overnight test flights for the Helios are scheduled to begin in 2003, with an initial goal of a four-day continuous flight.

The electrolyzer stack was designed, built and tested with funding provided by NASA, Wright Patterson Air Force Base, and AeroVironment Inc., for NASA’s Environmental Research and Sensor Technology (ERAST) program. 

See the Related Story on the NASA website.

15 kW Electrolyzer Specifications

Operating Pressures:	400 psi water, 400 psi hydrogen, 400 psi oxygen
Operating Temperature:	100 - 180 degrees Fahrenheit
Gas Production:	1973 l/hr oxygen , 3946 l/hr hydrogen
Current Density:	1000 amps/square foot
Cell Voltage:	1.72 V/cell

 

Contact Information:

Richard J. Lawrance, Director ( ) Phone: (781) 529-0507

Matthew P. Steinbroner, Project Manager ( ) Phone: (781) 529-0536

Giner Electrochemical Systems, LLC

Phone: (781) 529-0500; Fax: (781) 893-6470