About fuel cells
Fuel cells operate on the same principle as batteries. Whereas batteries consume their reactants and must be recharged, fuel cells operate so long as there is fuel. They use the hydrogen and oxygen to create electricity, heat, and water vapor. The trick to making them work is specialized materials called electrolytes in which ionized atoms are soluble, but electrons are not. Click here to see the Wikipedia discussion on fuel cells.
William Grove produced the first fuel cell in 1839. Fuel cells were used to power all onboard electronics in the US Apollo rocket program in the 1960’s. Those cells clocked over 10,000 hours without incident. In that program, they used molten potassium hydroxide (KOH). The table below lists various fuel cell approaches:
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Fuel cells are more efficient than traditional engines because there are no losses to mechanics. The chemical reaction converts directly to energy:
Traditional generator:
Reaction » mechanical motion » electricity
Fuel Cell:
Reaction » electricity
The typical fuel cell involves the flow of hydrogen and air on either side of the specialized material. With the help of a catalyst, the hydrogen is ionized and migrates through the material to combine with the oxygen. The electrons that the hydrogen gives up are collected in an external circuit --and electricity is made.
In a proton exchange membrane (PEM) fuel cell, hydrogen flows through layers separated by an electrolyte.
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In a tubular solid oxide fuel cell, the hydrogen flows through a tube that serves as the anode. In this case oxygen molecules from the air are ionized and carry electrons to generate electricity (picture: how-fuel-cell-works.jpg)
Not all fuel cells require hydrogen. Solid oxide fuel cells have very stable ceramics that operate at high temperature, and can often run directly from traditional hydrocarbons like natural gas, methane, or biofuels. While this still produces carbon dioxide (a greenhouse gas), it produces half the CO2 that a traditional small engine would. It is important to run of traditional fuels, because today hydrogen-fueled fuel cells can produce more CO2 than gasoline car, watt for watt.
Did You Know?
The “Volt” is named after the inventor of the first battery, or pile, Alessandro Volta. He stacked alternating discs of silver and zinc, and separated them by cardboard soaked in salt water. Volta did these first experiments in 1799!
We invite you to visit the rest of our knowledge center.
- Click here to link to some carbon calculators.
- Click here to review some white papers.
- Click here to view how governments are responding to climate change, and supporting fuel cells.