Ballard Power Systems Inc is engaged in design, development, manufacture, sale and service of proton exchange membrane ("PEM") fuel cell products for a variety of applications, focusing on power products for bus, truck, rail, marine, stationary and emerging market (material handling, off-road and other) applications, as well as the delivery of services, including technology solutions, after sales services and training. A fuel cell is an environmentally clean electrochemical device that combines hydrogen fuel with oxygen (from the air) to produce electricity. Key geographical revenue is derived from United States followed by Poland, Canada, and other countries.