Fuel Cell FAQ

What is a Fuel Cell?

The fuel cell is an electrochemical device that converts energy into electricity and heat without combustion. Fuel cells can operate anything that a battery can, ranging from cell phones to automobiles to large power plants. Think of fuel cells as batteries that can be constantly recharged even while you are drawing power from them. Instead of recharging using electricity however, a fuel cell uses hydrogen and oxygen.

When was the Fuel Cell invented?

Sir William Grove first demonstrated the technology behind fuel cells in 1839. However, the first applicable fuel cells were built for the Apollo space program in the 1960s, and fuel cells are still used in space today. Original equipment manufacturers and systems integrators have recently begun selling commercial fuel cell systems for specialty applications such as premium back-up power.

How reliable is a Fuel Cell?

Fuel cells are very reliable because they operate with no moving parts that can wear out. The fuel cells used in the space program have been running for years without failure.

Are all Fuel Cells the same?

No. There are several different types of fuel cells. Fuel cell types include molten carbonate, solid oxide, phosphoric acid, alkaline and proton exchange membrane (PEM). The various types of fuel cells are differentiated by the manner in which they use hydrogen to produce electricity. PEM fuel cells include direct methanol fuel cells, which use unreformed methanol as the source of hydrogen.

The fundamental component of a PEM fuel cell is the membrane electrode assembly (MEA), which is principally comprised of a thin proton exchange membrane placed between two electrodes, the anode and the cathode. Between the membrane and each electrode is a platinum-based catalyst layer, which facilitates the chemical reaction that generates electricity. Layered on top of each electrode is a gas diffusion layer, or GDL, which distributes the hydrogen or oxygen across the electrode, catalyst and membrane area. As hydrogen fuel is fed into the fuel cell, the anode GDL distributes the gas across the anode, where it reacts with the catalyst and splits into free protons and electrons. The proton exchange membrane allows protons to pass through it, but restricts the flow of electrons. The electrons are conducted around the membrane through an external circuit, creating a usable electric current. Oxygen, typically drawn from the air, is simultaneously distributed across the cathode by the cathode GDL, where it combines with the protons and electrons and creates the by-products of water and heat.

Which fuels (gases) can be used for PEM Fuel Cells?

Hydrogen is the primary fuel source which can be used directly in a PEM fuel cell. Other fuels that can be used include methanol, ethanol, natural gas, coal gas, gasoline and other fuels containing hydrocarbons. PEM fuel cells today are running on many different fuels, even gas from landfills and wastewater treatment plants. Using a fuel other than pure hydrogen requires a reformer or fuel processor.

How big or small can a Fuel Cell be?

A fuel cell can be as small as a radio battery and as large as a power plant (consisting of several fuel cells). Some companies are developing micro-sized fuel cells for applications like cell phones and laptops.

Can PEM Fuel Cells be used in cars?

Yes. Many organizations are currently developing PEM fuel cells for use in automobiles. Global auto companies such as Nissan, General Motors, Honda and Toyota have made announcements regarding commercial sales of fuel cell cars in the next few years.

What are the advantages of PEM Fuel Cells?

Due to their performance characteristics, including relatively low operating temperatures, rapid start-up, high power output and energy efficiency, PEM fuel cells may be used in a wider range of applications than alternative fuel cell technologies, including the stationary power generation, automobiles and portable consumer electronics.