Machine Design

Fuel Cells for Lawnmowers

Since the discovery of the fuel cell in 1838 by German Scientist Christian Friedrich Schönbein, the principle of it has come a long way.

Julie Kalista
Online Editor

How a fuel cell works.
Fuel cells produce electricity from external supplies of fuel and oxidant, reacting in the presence of electrolytes, and can operate virtually continuously when flows are maintained. Scientists from Princeton University have made a breakthrough that could make fuel cells practical for small machines like lawnmowers.

Standard fuel cells use electronics to control power, requiring complex systems to manage humidity, fuel recovery, and recycling in order to maintain acceptable efficiencies. Because fuel cells do not operate with a thermal cycle, they can have high efficiencies, especially when operated at low power densities. As a general rule, the more current drawn, the lower the efficiency. For example, a cell running at 0.6 V has an efficiency of about 50%, while the remaining 50% is converted into heat.

The new process feeds in hydrogen to match the required power output and functions as a closed system that uses waste water to regulate the size of the reaction chamber. The design uses 100% of the fuel and eliminates the need for a recycling system.

The next step is to connect several fuel cells together to increase power, and compete with internal-combustion engines in cars and trucks.

More Information:
Princeton University

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