Use
of Fuel Cells
The very
low emission and noise level make the fuel cell units
particularly appropriate for applications in the residential
and tertiary sector (houses, office buildings, hospitals,
hotels, etc.). Hand-held computing and communication devices
may be powered by miniature, circuit-like and easily „rechargeable“
fuel cells (using for instance a hydride cartridge). Ultra-light,
very efficient and low-polluting cars powered by intensive
low-temperature fuel cells may circulate in the streets
and also operate as small distributed electricity generators,
injecting electricity to the grid while parked.
Where convenient,
hydrogen micro-turbines and high-temperature fuel cells
are able to cover the heating and electricity needs of
larger commercial and industrial complexes, which are
allowed to trade their surpluses in the spot market.
Research
and development to solve certain technological problems
continues, while the use of less expensive material and
mass production is expected to reduce the capital cost.
|
Type
|
Development
status
|
Applications
|
|
Solid oxide fuel cells (SOFC) |
Tubular systems available for demonstration; planar
technology still under development |
Commercial and residential CHP, power generation,
ship propulsion, trains |
|
Intermediate temperature SOFC (IT-SOFC) |
Fundamental research still required |
Commercial and residential CHP, power generation,
ship propulsion, trains |
|
Molten carbonate fuel cell (MCFC) |
250kW systems being demonstrated, also previously
2MW, but further R&D needed |
CHP, power generation, ship propulsion, trains |
|
Phosphoric acid fuel cell (PAFC) |
200kW systems offered for sale, but not commercially
competitive |
CHP, power generation |
|
Alkaline fuel cell (AFC) |
Fully developed for space systems; Transport systems
available for initial demonstrations |
Space, transport |
|
Solid polymer fuel cell (SPFC), also known as proton
exchange membrane (PEM) fuel cell |
250kW CHP systems; Several cars and buses being
demonstrated, but not yet commercial |
Commercial and residential CHP, distributed power,
portable power, transport |
|
Direct methanol fuel cell (DMFC) |
Still at R&D stage with much fundamental research
still required |
Portable power, possibly transport |
Source:
U.K. Department of Trade and Industry- Energy Group
Solid oxide
fuel cells have good prospects for utility and industrial
applications of medium to large size (of the order of
MW) with efficiencies higher than 50%. The system provides
high quality waste heat, which is ideal for cogeneration
or for additional power production by a bottoming cycle.
It is envisaged that units of the order of tens of megawatts
can be combined with a gas turbine – steam turbine combined
cycle: hot gases leaving the cell stack will drive a gas
turbine. After their exit from the gas turbine they will
pass through an Heat Recovery Steam Generator – HRSG -
producing steam for thermal processes or for additional
power production by a steam turbine.
The fuel
cells that are being developed and are expected to be
used for power stations are phosphoric acid, molten carbonate
and solid oxide cells. These three types of fuel cell
are at different stages of development, and have different
characteristics.
Geothermal Energy and Other Distinctive Energy
Sources