Fuel Cells

What are Fuel Cells?

Fuel cells are devices that are able to continuously convert chemical energy into electrical energy through an electrochemical reaction. The system inputs are a fuel, which is usually hydrogen, and an oxidant, typically oxygen (that is in the air). The outputs from the system are DC electricity, water vapour and heat. Fuel cells will generate electricity continuously provided there is sufficient fuel and available oxidant. Fuel cells are not limited by Carnot efficiency limits and thus are able to operate at much higher efficiencies than thermal heat engines, such as the internal combustion engine (see Figure 1). Combined with their ability to operate with reduced or even zero emissions, fuel cells are seen as an attractive sustainable power option.

Figure 1 (courtesy of the King County Department of Natural Resources and Parks, US).

Fuel cells are able to utilise a number of different fuels depending on the fuel cell technology used. Typical fuels are:

Hydrogen

Methanol

Natural gas

Diesel or petrol

The Need for Fuel Cells

Interest in fuel cells has been strengthened by the need for sustainable energy sources. Fuel cells are able to produce power without the high rates of emissions that are associated with traditional power sources. Some applications require an extremely reliable power supply and a fuel cell’s ability to produce continuous power is one reason that makes them ideal for these and many other situations. Modern fuel cells are able to produce sufficient electricity for remote areas where the normal electricity grid may not be available.
Transport is one of the most likely applications for fuel cell technology. Fuel cells are portable power sources and are able to produce energy at greater efficiencies than the internal combustion engine. However, it may be the decline in oil reserves that will drive the need for fuel cells. World energy consumption from transport will continue to rise (particularly in the Developing World) and it is expected that oil production will plateau and then decline in the decades to come. This will create a need for a new energy source for transport, with fuel cells being one attractive option.

History and Development

The principle of a fuel cell was discovered by Sir William Grove. In an experiment in 1839, he discovered that it was possible to produce electricity by reversing the electrolysis of water (see Figure 2). He then used the hydrogen to produce electricity to create water.

Figure 2 William Grove’s drawing of his “Gas Battery” Experiment (Source: Smithsonian Institute).

The term fuel cell was first used in 1889 by Charles Langer and Ludwig Mond who were developing a cell using coal gas and air. However, the discovery of the internal combustion engine halted the early progress of fuel cells. Interest was reignited during the mid-20th Century, with Francis Bacon developing the first successful fuel cell in 1932 and finally demonstrating a 5kW fuel cell system in 1959. In the same year, Harry Ihrig demonstrated a 20Hp Allis-Charmer tractor powered by a fuel cell. These successes led to greater research and development of fuel cells, particularly in military and space applications in the United States. Companies such as Union Carbide (who demonstrated a fuel cell powered mobile radar set) and Pratt & Whitney (who were contracted to produce power systems for NASA) set about showing the commercial benefits of fuel cells.

The Science of Fuel Cells

Generally, fuel cells are comprised of two electrodes (an anode and a cathode), and an electrolyte that separates the electrodes and an external circuit (PEC390). The electrochemical reaction that takes place in the cell is an oxidation-reduction reaction, involving an oxidation half-reaction and an oxidation half-reaction. The reaction takes place with the help of a catalyst, traditionally platinum (Pt).
Oxidation occurs at the Anode, with hydrogen molecules (H₂) oxidised (to “lose” electrons) to produce hydrogen ions (H⁺) and free electrons (e^-).

The general half-reaction at the Anode is:

2H₂ → 4H⁺ + 4e^-

The H+ ions are conducted through the electrolyte to the Cathode and the two electrodes are connected via an external circuit allowing the electrons to flow from the Anode to the Cathode.
Reduction occurs at the Cathode, with oxygen molecules (O₂) reduced by reacting with H⁺ ions and the free electrons to produce water (H₂O).

The typical half-reaction at the Cathode is:

O₂ + 4H⁺ + 4e^- → 2H₂0

The overall reaction of the fuel cell is:

2H₂ + O₂ → 2H₂O

So, in general, fuel cells use hydrogen and oxygen to produce electricity with water (and some heat) as the only emission. Because of this, fuel cells are seen as a sustainable source of power, bringing the benefits of reduced greenhouse gas (GHG) and other emissions.

Fuel Cell Types

There are many fuel cell types available and they are usually described by the electrolyte that is used. However the six most widely used at present are the:
·          Alkaline Fuel Cell (AFC)
·          Proton Exchange Membrane or (Polymer Electrolyte Membrane) Fuel Cell (PEMFC)
·          Direct Methanol Fuel Cell (DMFC)
·          Phosphoric Acid Fuel Cell (PAFC)
·          Molten Carbonate Fuel Cell (MCFC)
·          Solid Oxide Fuel Cell (SOFC)

The Alkaline Fuel Cell

These are one of the oldest fuel cells. They use compressed hydrogen and oxygen, with the electrolyte usually potassium hydroxide (KOH). Operating temperatures and pressures of AFC’s used to be traditionally hot and at high pressure, but now operate at low pressures and at temperatures more akin to 70ºC. At the anode, H₂ molecules are oxidized by the reaction with hydroxyl ions (OH^-), which flow through the electrolyte to produce water and free electrons. The half-reaction at the anode is:

4OH^- + 2H₂ → 4H₂O + 4e^-

The electrons flow to the cathode, where they are used in a reaction with oxygen and water to produce OH^- ions. The half-reaction at the cathode is:

O₂ + 2H₂O + 4e^- → 4OH^-

Therefore the overall reaction in an AFC is:

2H₂ +O₂ → 2H₂O

The main drawback of the AFC is that the fuel and oxidant need to be free of carbon dioxide and older AFC’s used expensive platinum catalysts, although newer AFC’s use a nickel-platinum alloy. Commercial applications may be limited whilst these costs remain. Alkaline fuel cells have been used by NASA in their Apollo program because of their high power generation efficiencies (up to 70% when used for cogeneration) and their ability to provide drinking water. The worlds leading AFC producer Astris, has developed its new Powerstack MC250 range of AFC’s eliminating the platinum catalyst and using cheaper materials to significantly reduce costs. These AFC’s can supply 300W to 10kW, which greatly extends the scope of AFC applications. Currently the majority of AFC’s use potassium hydroxide as an electrolyte.

The Proton Exchange Membrane Fuel Cell

Figure 3 An 80 kW PEM fuel cell (courtesy of the Bellona Foundation)

This fuel cell may also be called the Polymer Electrolyte Membrane Fuel Cell, but both names refer to this particular type of cell. The electrolyte is actually a thin solid organic polymer. This fuel cell operates at low temperatures (around 60 – 100ºC) (PEC390). Hydrogen fuel is oxidized at the anode to produce H⁺ ions and free electrons:

2H₂ → 4H⁺ + 4e^-

At the cathode, oxygen reacts with the H+ ions and the free electrons to produce water:

O₂ + 4H⁺ + 4e- → 2H₂0

The overall reaction for this fuel cell is the general fuel cell reaction:

2H₂ + O₂ → 2H₂O

Figure 4 A Proton Exchange Membrane Fuel Cell (Source: Ballard Power Systems).

PEMFC’s, like most fuel cells, have the disadvantage of using platinum as a catalyst, which drives up the production costs and which is subsequently being reduced in fuel cell developments. However, they have some distinct advantages including high power density and reduced volume and weight due to the Proton Exchange Membrane. In applications where the fuels are both pure hydrogen and pure oxygen, the overall reaction for the fuel cell is reversible. This is the principle behind the regenerative fuel cell. Electricity from an external source will be used to electrolyse water into hydrogen and oxygen. This hydrogen and oxygen can then later be used in the fuel cell to produce electricity as one form of energy storage.

This is an attractive option for systems that require continuous, 24 hour power. The external source operates during the day to provide sufficient power for the application as well as producing excess power, used to electrolyse the water. At night, the stored hydrogen and oxygen will be used to produce electricity. It is preferable that the external source is a renewable source (e.g. solar or wind) to ensure the emission reduction benefits of the fuel cell are not lost. A good example of this system is the AeroVironment Helios (an unmanned aircraft), which uses a solar powered regenerative fuel cell system, and the new Hornet (a micro air vehicle), which is fully powered by a small fuel cell see Figure 5).

Figure 5 The Hornet (left) and the Helios (right), (Courtesy of AeroVironment).

PEM fuel cells have been trialled in a number of transport applications. As discussed earlier, major car manufacturers have developed fuel cell vehicles. Ford and Volkswagen have been developing PEMFC vehicles, whilst there has been a large increase in government funded research in universities around the world. Some disadvantages of PEMFC’s are that they have a lower efficiency than AFC’s and that carbon monoxide can “poison” the catalyst. These cells require very pure hydrogen, which requires PEM systems to have very good reformers, if a reformer is required.

The Direct Methanol Fuel Cell

Direct methanol fuel cells are a unique type of PEMFC and are used almost exclusively for small, low current portable electronics. Methanol (CH₃OH) is used as the reducing agent, which removes the need for a fuel processor/reformer. The electrolyte used is a thin polymer. DMFC’s operate in a similar temperature range to other PEMFC’s (around 80 – 100ºC). Methanol is oxidized at the anode to produce CO₂ and H⁺ ions:

CH₃OH + H₂O → CO₂ + 6H⁺ + 6e^-

At the cathode, oxygen reacts with the H⁺ ions to create water:

3/2 O₂ + 6H⁺ + 6e^- → 3H₂O

Therefore, the overall cell reaction is:

CH₃OH + 3/2 O₂ → CO₂ + 2H₂O

The main advantage of the direct methanol system is that it does not require a fuel processor. Also this system is much simpler than systems that require fuel reforming. Another important feature is that methanol is already a common fuel, which makes the DMFC transition into commercialised systems somewhat easier. However methanol itself is known to be carcinogenic and toxic and many producers would rather avoid its use if possible. However the DMFC’s are amenable to miniaturisation and are being incorporated into portable devices requiring small amounts of power. The worlds smallest fuel cell (as of January 2006) is Toshiba’s direct methanol fuel cell (see Figure 6). Toshiba has incorporated this cell into two MP3 player prototypes.

Figure 6 The worlds smallest fuel cell produced by Toshiba
(courtesy of Engadget.com & Toshiba).

One of the players, measuring 1.4 x 4.3 x 0.8-inches is said to run for 35 hours on a single 3.5ml charge of highly concentrated methanol, while a hard drive based player swells to 2.6 x 4.9 x 1.1-inches and runs for about 60 hours on a single 10ml charge. These dimensions will become smaller when mass production commences (Engadget.com, 2005).

The Phosphoric Acid Fuel Cell

Figure 7 1MW (five 200kW fuel cells) UTC’s PAFC power plant in Alaska (courtesy of the Bellona Foundation).

As suggested by the name, this fuel cell uses phosphoric acid liquid (H₃PO₄) as it’s electrolyte. The PAFC operates at higher temperatures than the previous fuel cells, in the range of 175 – 200ºC. At the anode, hydrogen is oxidized to produce hydrogen ions and free electrons:

2H₂ → 4H⁺ + 4e^-

The cathode reaction is also the standard reaction at the cathode:

O₂ + 4H⁺ + 4e^- → 2H₂0

Making the overall reaction:

2H₂ + O₂ → 2H₂O

Phosphoric acid fuel cells have been traditionally developed as power plants and have been operational in this capacity for over 10 years. Systems of up to 200kW are in operation whilst systems of up to 11MW have been tested. There is also significant waste heat production in these systems, which make the use of heat recovery systems for cogeneration a viable option for industrial loads. In these systems, efficiencies of up to 80% are achievable.

One advantage of the PAFC system is that because it operates at higher temperatures than some other fuel cells, it is able to tolerate higher levels of carbon monoxide poisoning (formation) at the electrodes. One of the limitations of these fuel cells is the long start up time needed for the higher operating temperature, which limits the PAFC to stationary applications (HSW).
The UTC’s PAFC PC25 power plant (Figure 7) is an example of a phosphoric acid fuel cell power system.

Molten Carbonate Fuel Cell

Molten carbonate fuel cells use the carbonates of lithium, sodium or potassium as the electrolyte. Once the cell is heated to its operating temperature of more than 600ºC, the carbonate salts melt allowing charged particles to flow. At the anode, carbonate ions (CO₃^2-) react with hydrogen:

H₂ + CO₃^2- → H₂O + CO₂ + 2e^-

At the cathode, carbonate ions are formed by the reaction between oxygen and carbon dioxide:

½ O₂ + CO₂ +2e^- → CO₃^2-

The overall reaction is unique as carbon dioxide is both produced at the anode and consumed at the cathode:

H₂ + ½ O₂ + CO₂ → H₂O + CO₂

MCFC’s are used for largescale power generation and because of their high operating temperatures are also suitable for combined cycle electricity or combined heat and power (CHP) applications. They are capable of auto-reforming and operate at high efficiencies of around 60% and this can reach up to 80% if waste heat is utilized. Currently, 2MW units are in demonstration, with much larger units being designed, as this type of fuel cell is suitable for baseload power generation.

Solid Oxide Fuel Cells

Figure 8 The first hybrid fuel cell (SOFC) and turbine plant (220kW) (courtesy of the Bellona Foundation).

This is another type of fuel cell best suited to stationary applications. The electrolyte is a hard, non-porous ceramic and the operating temperature is between 600 and 1000ºC. At the anode, hydrogen is oxidized by oxygen ions (O₂^-) that are able to move across the electrolyte:

H₂ + O₂^- → H₂O +2e^-

Air is supplied at the cathode providing oxygen that is reduced to oxygen ions:

½ O₂ + 2e^- → O₂^-

The overall reaction for the SOFC is:

H₂ + ½ O₂ → H₂O

The high operating temperature has some distinct advantages. The operating efficiency is very high due to the availability of waste heat for cogeneration or electricity production. Also, conventional fuels may be used without reforming at such temperatures. Solid oxide fuel cells are a relatively immature technology and they are generally limited to stationary applications because of long startup times, large size and high heat output. Recent developments have decreased both the start-up times and the sizes of these systems, while the high heat output is a useful resource for combined heat and power loads. Newer systems are being designed for supplying domestic distributed power generation and heating loads around the lower kW range. This type of fuel cell is also auto-reforming and can use methane LNG, LPG etc for the input fuel.

The many different types of fuel cells allow the user to match their fuel cell’s characteristics to better suit the energy services required (see Table 1).

Table 1 A simplified reference for Fuel Cell comparisons (courtesy of the US Department of Energy).

Fuel Cell Applications

There are a variety of applications for fuel cells due to the wide range of system types and sizes (1W to over 1MW). Generally, fuel cells can be used for one of the following four applications:

Transportation
Portable power
Stationary power
Military and Space applications

Alternative Types of Fuel Cells

Microbial Fuel Cells

Microbial fuel cells produce current through the action of bacteria that can pass electrons to an anode, the negative electrode of a fuel cell. The electrons flow from the anode through a wire to a cathode, the positive electrode of a fuel cell, where they combine with hydrogen ions (protons) and oxygen to form water. Using a new electrically-assisted microbial fuel cell (MFC) that does not require oxygen, Penn State environmental engineers and a scientist at Ion Power Inc. have developed the first process that enables bacteria to coax four times as much hydrogen directly out of biomass than can be generated typically by fermentation alone (Science Daily, 2005). (See Figure 9).

Figure 9 Dr. Hong Liu , postdoctoral researcher in environmental engineering, and Dr. Bruce Logan, Kappe professor of environmental engineering, with the MFC (courtesy of Greg Grieco, Penn State).

Dr. Bruce Logan, the Kappe professor of environmental engineering and an inventor of the MFC, says, "This MFC process is not limited to using only carbohydrate based biomass for hydrogen production like conventional fermentation processes. We can theoretically use our MFC to obtain high yields of hydrogen from any biodegradable, dissolved, organic matter - human, agricultural or industrial wastewater and simultaneously clean the wastewater. While there is likely insufficient waste biomass to sustain a global hydrogen economy, this form of renewable energy production may help offset the substantial costs of wastewater treatment as well as provide a contribution to nations able to harness hydrogen as an energy source," Logan notes (Science Daily, 2005).

In the new MFC, when the bacteria eat biomass, they transfer electrons to an anode. The bacteria also release protons, hydrogen atoms stripped of their electrons, which go into solution. The electrons on the anode migrate via a wire to the cathode, the other electrode in the fuel cell, where they are electrochemically assisted to combine with the protons and produce hydrogen gas. A voltage in the range of 0.25 volts or more is applied to the circuit by connecting the positive pole of a programmable power supply to the anode and the negative pole to the cathode. It uses about one tenth of the voltage needed for electrolysis, the process that uses electricity to break water down into hydrogen and oxygen (Science Daily, 2005). Logan and Liu connected a MFC built on the Penn State design principles to run a three milliWatt fan and have shown that a wastewater plant with a Penn State MFC could power the little fan with a reactor smaller than a teacup. Also by modifying the original PEMFC to eliminate the expensive PEM components with inexpensive components, they have brought down the production costs markedly to assist the provision of cost effective wastewater treatment and additional small power generation capacity.

Some other less common fuel cells include other biological fuel cells (BFCs can use glucose in blood with bacteria on the anode for internal uses – such as pacemakers), direct borohydride fuel cells (DBFC’s), which use sodium tetrahydroborate) and formic acid fuel cells which use methanoic acid. However these fuel cells are not commonly used or are in early development stages.

Benefits of Fuel Cells

High efficiency
Fuel cells convert chemical energy directly into electrical energy and as a result will produce more power than combustion (as in traditional sources) given the same amount of fuel. Efficiencies can be as high as 90% if excess heat is utilised.

Cogeneration Possibilities
One of the by-products of a fuel cell is heat, particularly in PAFC, MCFC and SOFC. This excess heat can be recovered and used for space, process or water heating or possibly to create further electricity in a combined-cycle facility.

Low Emissions
When hydrogen is the fuel the by-products of a fuel cell are electricity, water and heat. Even when other fuels (methanol, coal, natural gas) are used, emissions are far lower than if the fuels were used in traditional combustion systems.

Reduced Environmental Impact
By producing hydrogen using renewable energy sources, the environmental impacts of oil and gas exploration and coal mining can be alleviated. Even if fossil fuels are used, the higher efficiencies of fuel cells mean fewer resources would need to be extracted. Also, hydrogen is lighter than air and will disperse quickly if a leak occurs unlike petrol or diesel.

Reduced Grid Dependence
One of the most promising aspects of fuel cells is their ability to supply distributed power. This is where power is generated closer to the end use, taking the pressure off the traditional electricity grid.

Simple and Flexible
There are no moving parts in fuel cells, which makes their operation much simpler than fossil fuel systems. This makes the system more reliable and reduces noise impact. Fuel cells are modular, meaning they can be stacked together to meet the load requirements. If the load changes, the system can be easily reconfigured to compensate for the change. Also, the siting of fuel cells is highly flexible and they can be appropriate for a wide range of applications from transport to residential or commercial/industrial uses. Ideally, pure hydrogen would be the fuel used but fuel cells are able to utilise a range of other fuels with or without reforming.

Energy Security
Energy security is one of the primary concerns of both the developed and developing nations. As the nature of the energy industry changes, countries will have to find new sources of energy that will be able to overcome the problems associated with traditional sources, such as environmental issues and resource depletion. The latter is particularly relevant to the transport industry as oil production is expected to go into decline. Fuel cells are able to power a new breed of passenger vehicles that will still provide the convenient transport options people (particularly those in the developed world) have become accustomed to.

Constraints to the Implementation of Fuel Cells

Cost
Fuel cells have high capital costs compared with traditional sources. As a developing technology, fuel cells do not have the mass production processes in place to make manufacturing commercially viable. Demand for fuel cells is not sufficient to drive down production costs. Also, most fuel cells use expensive materials, which help to keep production costs high.

Endurance and Reliability
Fuel cells have not demonstrated the ability to perform reliably over long periods of time. To compete with traditional sources, fuel cells must have demonstrated high use availability and durability over long periods.

Infrastructure
Development of new infrastructure will be required if fuel cells become more prominent. This will be particularly important in transport applications. Vehicle owners will demand convenient refueling of fuel cell vehicles, so new facilities (or redeveloping of old facilities) will be required. If fuel cells are developed in the utility scale, there will have to be careful integration of these facilities. Suitable sites will need to be chosen as well as appropriate decommissioning of existing plants. It is not economically efficient to prematurely de-commission large facilities, such as coal-fired power stations, despite the benefits that may be realized.

Non-Technical Barriers
Non-technical barriers are those related to legislation and economic barriers (other than production and infrastructure costs). For fuel cells to become a mainstream technology there needs to be appropriate regulation and standards put into place. The technology will have to be tested and developed further to allow legislators to become familiar with the technology and to establish the appropriate guidelines for their use.

On the economic side, barriers exist similar to those faced by renewable technologies. In particular, there is a risk associated with new technologies and gaining the financial backing required may be difficult or offered at higher than acceptable interest rates. Traditional economic analysis does not deal well with costs such as environmental degradation or pollution as they are difficult to quantify. Thus, the true cost of energy is not reflected by the price the consumer pays. Until the price of energy is inclusive of costs such as greenhouse gas emissions, technologies such as fuel cells will find it difficult to penetrate energy markets.

Fuel Cells in Australia

Australia's first operational fuel cell was installed at the Australian Technology Park, Sydney in 1998. A phosphoric acid fuel cell, it uses natural gas which is passed through a steam reformer to produce hydrogen produces up to 200kW of electricity and hot water (see Figure 10).

Figure 10 Australia’s first fuel cell (courtesy of Cheresources).

RISE
Western Australia's first fuel cell was installed at Research Institute for Sustainable Energy’s (RISE) Renewable Energy Systems Test Centre (ResLab) at Murdoch University in 2003. This small 5 kW alkaline system was designed to prove the concept in a RAPS test facility with a 30 kW wind turbine. The prototype alkaline fuel cell system was replaced with a commercial 5 kW PEM fuel cell in late 2004. The most recent fuel cell successfully tested at ResLab was a 1.2 kW alkaline fuel cell in January 2006.

The Fuel Cell Bus Trial
In August 2004 three fuel cell buses arrived in Western Australia as part of an international trial of 33 fuel cell buses. These buses operated on normal bus routes in Peth for three years and used 250 kW PEM fuel cells. The trial ended in September 2007 and various options are currently being considered to conduct trials for the next-generation of fuel cell vehicles.

CSIRO
The CSIRO is also active in solar-hydrogen production by water-splitting research. They aim to engineer materials with appropriate optical, electronic and chemical properties for use as photocatalysts in efficient and cost effective photoelectrochemical cells. Their current research encompasses the areas of materials science, plasma and thin film physics, electrochemistry and analytical chemistry. The main areas of research are:

Synthesis and modification of suitable semiconducting materials using a range of techniques (Flame Pyrolysis, Filtered-Arc Deposition, Oxidative Annealing, Sol-gel Preparations, Ball Milling, and Nanostructuring.
Materials characterisation of materials using different analytical techniques (X-ray Diffraction Spectroscopy (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), UV-Visible Spectroscopy, Electrical Measurements, Electrochemical Measurements, and Impedence spectroscopy).

Also CSIRO's, Dr Sukhvinder Badwal and his research team are developing a compact, lightweight PEM fuel cell that could power a laptop computer for up to 24 hours, or a mobile phone for up to a month, before requiring a recharge. One year into the project, Badwal’s team in Clayton, Victoria, has developed working prototypes of both hydrogen and methanol powered micro fuel cells, and aims to commercialise them in 2007.

Ceramic Fuel Cells Ltd
Australia is also home to Ceramic Fuel Cells Ltd, a world leader in the development of solid oxide fuel cells. Australia is competing with multinational companies in a fuel cell market predicted to be worth billions of dollars worldwide. Ceramic Fuel Cells Ltd has developed a solid oxide fuel cell stack the size of a 2 litre milk carton that produces 1.5 kilowatts, enough power to meet the needs of a typical household. The company has also demonstrated a larger, 5 kilowatt unit, operating it continuously for 200 hours. These solid oxide fuel cells promise to achieve a very efficient conversion of fossil fuels to electricity, while producing only very low levels of pollutants. Currently Ceramic Fuel Cells Ltd have a pre-commercial 1 kW SOFC microgenerator called NetGen that integrates a domestic hot water system to produce electricity and heat.

UNSW'S Solar Hydrogen Program
The UNSW team's particular expertise is in photosensitive oxide semiconductors. UNSW's research program aims for the development of a commercial (i.e., practical and inexpensive) device for the production of hydrogen from photolysis of water using solar energy. The UNSW hydrogen generating device can be marketed internationally and has no moving parts, so maintenance is minimal. Offers to be involved in UNSW's research are coming from the US, Europe and Asian countries (UNSW, 2004).

The Future for Fuel Cells

Whilst fuel cells provide an exciting prospect for future energy supplies there are still areas that need to be developed further in order for them to become a mainstream technology. In general, fuel cells require very clean fuels and do not deal well with contamination. By operating with less stringent fuel requirements, costs such as fuel processing and storage will be reduced. Similarly, fuel cell stack systems are often very expensive, particularly due to the lack of mass production of components. Developments in materials and research with current fuel cell installations are generating large amounts of information to continue the development of these technologies towards large-scale commercial production. For some of the most recent and innovative fuel cell developments see Engadget's fuel cell page.

Further Information

RISE Resources - Information regarding available renewable energy resources.

RISE Technologies - An extensive collection of information regarding renewable energy technologies.

RISE Applications & System Design - Renewable energy application information and system designs.

RISE System Displays - Case studies and information on installed renewable energy systems & performance data.

H2 Stations.org - Hydrogen Filling Stations Worldwide

Ballard Power Systems - For an excellent animation on the operation of fuel cell vehicles.

Ballard Power Systems - For an animated roadmap to further commercialisation of fuel cells and vehicles.

DPI – Western Australian Department of Planning and Infrastructure: Fuel Cells – Perth Fuel Cell Bus Trial

EERE – US Department of Energy: Energy Efficiency and Renewable Energy – Hydrogen, Fuel Cells and Infrastructure Technologies Program

FCS – Fuel Cell Store.com: Fuel Cell Benefits

FCW – Fuel Cell World

Ford Motor Company - For information on their Innovative Engines and Fuel Technology.

General Motors – How fuel cells work.

GME – General Motors Europe – Fuel Cell Marathon

HSW – How Stuff Works: How Fuel Cells Work

NASA1 – Putting Fuel Cells to the Test

NASA2 – What are Fuel Cells?

NFCRC – National Fuel Cell Research Center: Fuel Cells Explained

NHAA – The National Hydrogen Association of Australia

SAE – SAE International: Fuel Cell Initiative

SI – Smithsonian Institute: Collecting the History of Fuel Cells

US Department of Energy: Energy Efficiency and Renewable Energy – Hydrogen, Fuel Cells and Infrastructure Technologies Program

UTC – UTC Fuel Cells

Wikipedia – Fuel Cells

Zorbas, S. The Storage of Hydrogen. Australia: Fuel Cell Institute of Australia

References

Engadget, 2005. “Toshiba develops mp3 player with 60 hour fuel cell battery”. (Online) http://www.engadget.com/2005/09/16/toshiba-develops-mp3-player-with-60-hour-fuel-cell-battery/ (Accessed 23 February 2007).

Science Daily, 2005. “Microbial Fuel Cell: High Yield Hydrogen Source and Wastewater Cleaner”. (Online)
http://www.sciencedaily.com/releases/2005/04/050422165917.htm (Accessed 23 February 2007).

UNSW, 2004. “Solar hydrogen - energy of the future” (Online)
http://www.unsw.edu.au/news/pad/articles/2004/aug/Solar_hydrogenMNE.html (Accessed 23 February 2007).