Page 278 - Alternative Energy Systems in Building Design

252 FUEL CELL TECHNOLOGY

in excess of 800°C. Heat captured by means of heat-exchange units is used to heat
water used for various applications, such as industrial and commercial processes.
When fuel cells are used as heat-energy cogenerators, total efficiency can reach
80–90 percent.
System applications, referred to as micro combined heat and power cogenerators,
are used extensively in residential buildings, office buildings, and commercial applica-
tions. These types of systems generate grid-connected electric power and produce hot
air and water for heating pools and buildings. Since there is a certain amount of heat
loss with the exhaust gas, the combined heat and power efficiency is typically around
80 percent.
Another fuel technology, which uses phosphoric acid fuel (PAFC), when used exten-
sively, can provide combined efficiencies close to 90 percent. Some fuel cell applications
include stationary base-load power plants, electric and hybrid vehicle auxiliary off-grid
power supplies, notebook computers, portable charging docks, and small electronic
appliances.

HISTORY
The principle of the fuel cell was discovered by German scientist Christian Friedrich
Schönbein in 1838. Within 5 years of Schönbein’s work, the first fuel cell was developed
by Welsh scientist Sir William Robert Grove in 1843. The first fuel cell used phosphoric
acid fuel. In 1955, W. Thomas Grubb, a chemist working for the General Electric
Company (GE), enhanced the original fuel cell design by using a sulfonated polystyrene
ion-exchange membrane as the electrolyte. Three years later, another GE chemist, Leonard
Niedrach, found a way to deposit platinum onto a membrane, which served as the catalyst
necessary for hydrogen-oxidation and oxygen-reduction reactions. This became known as
the Grubb-Niedrach fuel cell. In subsequent years, GE, in joint collaboration with NASA
and McDonnell Aircraft, produced a fuel cell that was used on the Project Gemini.
The commercialization of fuel cell technology came about when, in 1959, British engi-
neer Francis Thomas Bacon successfully developed a 5-kW stationary fuel cell. Also in
1959, a team led by Harry Ihrig designed and built a 15-kW fuel cell that was used in a
tractor manufactured by Allis-Chalmers. The fuel cell used potassium hydroxide as the
electrolyte and compressed hydrogen and oxygen as the reactants. In the 1960s, Pratt and
Whitney licensed Bacon’s U.S. patents for use in the U.S. space program to supply elec-
tricity and drinking water from hydrogen and oxygen recombination (which was stored
in the spacecraft’s tanks).
Today, fuel cells continue to power space vehicles and are being used by the Space
Shuttle program. They also have found extensive use in automobiles, buses, and cell
phone towers.

HYDROGEN AS AN ENERGY CARRIER

It should be noted that industrial hydrogen gas production generally involves the artifi-
cial extraction of hydrogen molecules from hydrocarbon fuels or water by an oxidation