A fuel cell is an electrochemical cell that converts a source of fuel into an electric current.
There are six basic types of fuels cell in production or development in the world today. They are classified by their operating temperature and the types of electrolyte they use, and like internal combustion engines, have different purposes that subsequently have determined their size and design.
The proton exchange membrane (PEM), which has the lowest operating temperature, is most often used in fuel cell vehicles, and has been the fuel cell that has received the most media attention. Buses and small vehicles are driving the roads today using this technology.
Next, the solid oxide fuel cell — it has the highest operating temperature, up to 1,000°C and is suited for large electrical generation facilities. The excess heat generated while it operates can be turned into steam and used for co-generation of power.
The solid oxide fuel cell is not well suited for cycling service, starting and shutting down reduce its service life, and yet it has the longest life of all fuel cells when operated continuously.
The alkaline fuel cell has been used by NASA since 1960 and helped to get man on the moon’s surface. It requires pure oxygen and hydrogen to function, making it very expensive to operate.
Molten carbonate fuel cells also operate at high temp and are suitable for stationary generation and, again, the heat can be used to generate steam for co-generation of power. Because it operates at a lower temperature, 600°C, it requires less expensive materials for construction.
Phosphoric acid fuel cells are designed for smaller stationary generation and are less expensive due to the cheaper materials required for construction. It operates at a higher temperature than a proton emitting membrane fuel cell, making it unsuitable for vehicle service.
Finally, the direct methanol fuel cell. This one is comparable in operating temperature to the PEM fuel cell, but needs larger quantities of platinum as a catalyst to operate. This requirement greatly adds to the cost of the fuel cell.
PEM fuel cells have two byproducts in the generation of electricity, heat and water.
Ballard Power, a Canadian fuel cell corporation, is working with companies in Japan and Germany in their development of residential co-generation units that will produce power and heat for utilization in the home.
Will fuel cell residential co-generation become a large player in home heating and power production in Alberta?
In the immediate future, not likely. Alberta is blessed in the energy resources department. We have enough coal and natural gas to last a number of lifetimes.
Countries with no hydrocarbon resources and large populations are working hard to develop this technology as rapidly as possible and some companies in Japan and Germany have units for sale now.
For those who are seriously interested in reducing their carbon footprint, or maybe because of their remote location, eventually this technology will be more easily available.
Lorne Oja is an energy consultant, power engineer and a partner in a company that installs solar panels, wind turbines and energy control products in Central Alberta. He built his first off-grid home in 2003 and is in the planning stage for his second. His column appears every second Friday in the Advocate. Contact him at: email@example.com