World Library  
Flag as Inappropriate
Email this Article

Fuel cell

Demonstration model of a direct-methanol fuel cell. The actual fuel cell stack is the layered cube shape in the center of the image
Scheme of a proton-conducting fuel cell

A fuel cell is a device that converts the chemical energy from a fuel into electricity through a chemical reaction of positively charged hydrogen ions with oxygen or another oxidizing agent.[1] Fuel cells are different from batteries in that they require a continuous source of fuel and oxygen or air to sustain the chemical reaction, whereas in a battery the chemicals present in the battery react with each other to generate an electromotive force (emf). Fuel cells can produce electricity continuously for as long as these inputs are supplied.

The first fuel cells were invented in 1838. The first commercial use of fuel cells came more than a century later in NASA space programs to generate power for satellites and space capsules. Since then, fuel cells have been used in many other applications. Fuel cells are used for primary and backup power for commercial, industrial and residential buildings and in remote or inaccessible areas. They are also used to power fuel cell vehicles, including forklifts, automobiles, buses, boats, motorcycles and submarines.

There are many types of fuel cells, but they all consist of an anode, a cathode, and an electrolyte that allow positively charged hydrogen ions (or protons) to move between the two sides of the fuel cell. The anode and cathode contain catalysts that cause the fuel to undergo oxidation reactions that generate positive hydrogen ions and electrons. The hydrogen ions are drawn through the electrolyte after the reaction. At the same time, electrons are drawn from the anode to the cathode through an external circuit, producing direct current electricity. At the cathode, hydrogen ions, electrons, and oxygen react to form water. As the main difference among fuel cell types is the electrolyte, fuel cells are classified by the type of electrolyte they use and by the difference in startup time ranging from 1 second for proton exchange membrane fuel cells (PEM fuel cells, or PEMFC) to 10 minutes for solid oxide fuel cells (SOFC). Individual fuel cells produce relatively small electrical potentials, about 0.7 volts, so cells are "stacked", or placed in series, to create sufficient voltage to meet an application's requirements.[2] In addition to electricity, fuel cells produce water, heat and, depending on the fuel source, very small amounts of nitrogen dioxide and other emissions. The energy efficiency of a fuel cell is generally between 40–60%, or up to 85% efficient in cogeneration if waste heat is captured for use.

The fuel cell market is growing, and Pike Research has estimated that the stationary fuel cell market will reach 50 GW by 2020.[3]


  • History 1
  • Types of fuel cells; design 2
    • Proton exchange membrane fuel cells (PEMFCs) 2.1
      • Proton exchange membrane fuel cell design issues 2.1.1
    • Phosphoric acid fuel cell (PAFC) 2.2
    • High-temperature fuel cells 2.3
      • SOFC 2.3.1
      • Hydrogen-Oxygen Fuel Cell (Bacon Cell) 2.3.2
      • MCFC 2.3.3
    • Comparison of fuel cell types 2.4
    • Efficiency of leading fuel cell types 2.5
    • Theoretical maximum efficiency 2.6
    • In practice 2.7
  • Applications 3
    • Power 3.1
    • Cogeneration 3.2
    • Fuel cell electric vehicles (FCEVs) 3.3
      • Automobiles 3.3.1
        • Criticism
      • Buses 3.3.2
      • Forklifts 3.3.3
      • Motorcycles and bicycles 3.3.4
      • Airplanes 3.3.5
      • Boats 3.3.6
      • Submarines 3.3.7
    • Portable power systems 3.4
    • Other applications 3.5
    • Fueling stations 3.6
  • Markets and economics 4
  • Research and development 5
  • See also 6
  • References 7
  • Further reading 8
  • External links 9


Sketch of William Grove's 1839 fuel cell

The first references to hydrogen fuel cells appeared in 1838. In a letter dated October 1838 but published in the December 1838 edition of The London and Edinburgh Philosophical Magazine and Journal of Science, Welsh physicist and barrister William Grove wrote about the development of his first crude fuel cells. He used a combination of sheet iron, copper and porcelain plates, and a solution of sulphate of copper and dilute acid.[4][5] In a letter to the same publication written in December 1838 but published in June 1839, German physicist Christian Friedrich Schönbein discussed the first crude fuel cell that he had invented. His letter discussed current generated from hydrogen and oxygen dissolved in water.[6] Grove later sketched his design, in 1842, in the same journal. The fuel cell he made used similar materials to today's phosphoric-acid fuel cell.[7] 9.[8]

In 1939, British engineer Francis Thomas Bacon successfully developed a 5 kW stationary fuel cell. In 1955, W. Thomas Grubb, a chemist working for the General Electric Company (GE), further modified the original fuel cell design by using a sulphonated polystyrene ion-exchange membrane as the electrolyte. Three years later another GE chemist, Leonard Niedrach, devised a way of depositing platinum onto the membrane, which served as catalyst for the necessary hydrogen oxidation and oxygen reduction reactions. This became known as the "Grubb-Niedrach fuel cell".[9][10] GE went on to develop this technology with NASA and McDonnell Aircraft, leading to its use during Project Gemini. This was the first commercial use of a fuel cell. In 1959, a team led by Harry Ihrig built a 15 kW fuel cell tractor for Allis-Chalmers, which was demonstrated across the U.S. at state fairs. This system used potassium hydroxide as the electrolyte and compressed hydrogen and oxygen as the reactants. Later in 1959, Bacon and his colleagues demonstrated a practical five-kilowatt unit capable of powering a welding machine. In the 1960s, Pratt and Whitney licensed Bacon's U.S. patents for use in the U.S. space program to supply electricity and drinking water (hydrogen and oxygen being readily available from the spacecraft tanks). In 1991, the first hydrogen fuel cell automobile was developed by Roger Billings.[11][12]

UTC Power was the first company to manufacture and commercialize a large, stationary fuel cell system for use as a co-generation power plant in hospitals, universities and large office buildings.[13]

In recognition of the fuel cell industry and America’s role in fuel cell development, the US Senate recognized October 8, 2015 as National Hydrogen and Fuel Cell Day, passing S. RES 217. The date was chosen in recognition of the atomic weight of hydrogen (1.008).[14]

Types of fuel cells; design

Fuel cells come in many varieties; however, they all work in the same general manner. They are made up of three adjacent segments: the anode, the electrolyte, and the cathode. Two chemical reactions occur at the interfaces of the three different segments. The net result of the two reactions is that fuel is consumed, water or carbon dioxide is created, and an electric current is created, which can be used to power electrical devices, normally referred to as the load.

At the anode a catalyst oxidizes the fuel, usually hydrogen, turning the fuel into a positively charged ion and a negatively charged electron. The electrolyte is a substance specifically designed so ions can pass through it, but the electrons cannot. The freed electrons travel through a wire creating the electric current. The ions travel through the electrolyte to the cathode. Once reaching the cathode, the ions are reunited with the electrons and the two react with a third chemical, usually oxygen, to create water or carbon dioxide.

A block diagram of a fuel cell

The most important design features in a fuel cell are:

  • The electrolyte substance. The electrolyte substance usually defines the type of fuel cell.
  • The fuel that is used. The most common fuel is hydrogen.
  • The anode catalyst breaks down the fuel into electrons and ions. The anode catalyst is usually made up of very fine platinum powder.
  • The cathode catalyst turns the ions into the waste chemicals like water or carbon dioxide. The cathode catalyst is often made up of nickel but it can also be a nanomaterial-based catalyst.

A typical fuel cell produces a voltage from 0.6 V to 0.7 V at full rated load. Voltage decreases as current increases, due to several factors:

  • Activation loss
  • Ohmic loss (voltage drop due to resistance of the cell components and interconnections)
  • Mass transport loss (depletion of reactants at catalyst sites under high loads, causing rapid loss of voltage).[15]

To deliver the desired amount of energy, the fuel cells can be combined in series to yield higher voltage, and in parallel to allow a higher current to be supplied. Such a design is called a fuel cell stack. The cell surface area can also be increased, to allow higher current from each cell. Within the stack, reactant gases must be distributed uniformly over each of the cells to maximize the power output.[16][17][18]

Proton exchange membrane fuel cells (PEMFCs)

In the archetypical hydrogen–oxide proton exchange membrane fuel cell design, a proton-conducting polymer membrane (typically nafion) contains the electrolyte solution that separates the anode and cathode sides.[19][20] This was called a "solid polymer electrolyte fuel cell" (SPEFC) in the early 1970s, before the proton exchange mechanism was well-understood. (Notice that the synonyms "polymer electrolyte membrane" and "proton exchange mechanism" result in the same acronym.)

On the anode side, hydrogen diffuses to the anode catalyst where it later dissociates into protons and electrons. These protons often react with oxidants causing them to become what are commonly referred to as multi-facilitated proton membranes. The protons are conducted through the membrane to the cathode, but the electrons are forced to travel in an external circuit (supplying power) because the membrane is electrically insulating. On the cathode catalyst, oxygen molecules react with the electrons (which have traveled through the external circuit) and protons to form water.

In addition to this pure hydrogen type, there are hydrocarbon fuels for fuel cells, including diesel, methanol (see: direct-methanol fuel cells and indirect methanol fuel cells) and chemical hydrides. The waste products with these types of fuel are carbon dioxide and water. When hydrogen is used, the CO2 is released when methane from natural gas is combined with steam, in a process called steam methane reforming, to produce the hydrogen. This can take place in a different location to the fuel cell, potentially allowing the hydrogen fuel cell to be used indoors—for example, in fork lifts.

Construction of a high-temperature PEMFC: Bipolar plate as electrode with in-milled gas channel structure, fabricated from conductive composites (enhanced with graphite, carbon black, carbon fiber, and/or carbon nanotubes for more conductivity);[21] Porous carbon papers; reactive layer, usually on the polymer membrane applied; polymer membrane.
Condensation of water produced by a PEMFC on the air channel wall. The gold wire around the cell ensures the collection of electric current.[22]

The different components of a PEMFC are;

  1. bipolar plates,
  2. electrodes,
  3. catalyst,
  4. membrane, and
  5. the necessary hardware.[23]

The materials used for different parts of the fuel cells differ by type. The bipolar plates may be made of different types of materials, such as, metal, coated metal, graphite, flexible graphite, C–C composite, carbonpolymer composites etc.[24] The membrane electrode assembly (MEA) is referred as the heart of the PEMFC and is usually made of a proton exchange membrane sandwiched between two catalyst-coated carbon papers. Platinum and/or similar type of noble metals are usually used as the catalyst for PEMFC. The electrolyte could be a polymer membrane.

Proton exchange membrane fuel cell design issues

  • Costs. In 2013, the Department of Energy estimated that 80-kW automotive fuel cell system costs of US$67 per kilowatt could be achieved, assuming volume production of 100,000 automotive units per year and US$55 per kilowatt could be achieved, assuming volume production of 500,000 units per year.[25] Many companies are working on techniques to reduce cost in a variety of ways including reducing the amount of platinum needed in each individual cell. Ballard Power Systems has experimented with a catalyst enhanced with carbon silk, which allows a 30% reduction (1 mg/cm² to 0.7 mg/cm²) in platinum usage without reduction in performance.[26] Monash University, Melbourne uses PEDOT as a cathode.[27] A 2011 published study[28] documented the first metal-free electrocatalyst using relatively inexpensive doped carbon nanotubes, which are less than 1% the cost of platinum and are of equal or superior performance. A recently published article demonstrated how the environmental burdens change when using carbon nanotubes as carbon substrate for platinum.[29]
  • Water and air management[30] (in PEMFCs). In this type of fuel cell, the membrane must be hydrated, requiring water to be evaporated at precisely the same rate that it is produced. If water is evaporated too quickly, the membrane dries, resistance across it increases, and eventually it will crack, creating a gas "short circuit" where hydrogen and oxygen combine directly, generating heat that will damage the fuel cell. If the water is evaporated too slowly, the electrodes will flood, preventing the reactants from reaching the catalyst and stopping the reaction. Methods to manage water in cells are being developed like electroosmotic pumps focusing on flow control. Just as in a combustion engine, a steady ratio between the reactant and oxygen is necessary to keep the fuel cell operating efficiently.
  • Temperature management. The same temperature must be maintained throughout the cell in order to prevent destruction of the cell through thermal loading. This is particularly challenging as the 2H2 + O2 -> 2H2O reaction is highly exothermic, so a large quantity of heat is generated within the fuel cell.
  • Durability, service life, and special requirements for some type of cells. Stationary fuel cell applications typically require more than 40,000 hours of reliable operation at a temperature of −35 °C to 40 °C (−31 °F to 104 °F), while automotive fuel cells require a 5,000-hour lifespan (the equivalent of 240,000 km (150,000 mi)) under extreme temperatures. Current service life is 2,500 hours (about 75,000 miles).[31] Automotive engines must also be able to start reliably at −30 °C (−22 °F) and have a high power-to-volume ratio (typically 2.5 kW per liter).
  • Limited carbon monoxide tolerance of some (non-PEDOT) cathodes.

Phosphoric acid fuel cell (PAFC)

Phosphoric acid fuel cells (PAFC) were first designed and introduced in 1961 by G. V. Elmore and H. A. Tanner. In these cells phosphoric acid is used as a non-conductive electrolyte to pass positive hydrogen ions from the anode to the cathode. These cells commonly work in temperatures of 150 to 200 degrees Celsius. This high temperature will cause heat and energy loss if the heat is not removed and used properly. This heat can be used to produce steam for air conditioning systems or any other thermal energy consuming system.[32] Using this heat in cogeneration can enhance the efficiency of phosphoric acid fuel cells from 40–50% to about 80%.[33] Phosphoric acid, the electrolyte used in PAFCs, is a non-conductive liquid acid which forces electrons to travel from anode to cathode through an external electrical circuit. Since the hydrogen ion production rate on the anode is small, platinum is used as catalyst to increase this ionization rate. A key disadvantage of these cells is the use of an acidic electrolyte. This increases the corrosion or oxidation of components exposed to phosphoric acid.[34]

High-temperature fuel cells


Solid oxide fuel cells (SOFCs) use a solid material, most commonly a ceramic material called yttria-stabilized zirconia (YSZ), as the electrolyte. Because SOFCs are made entirely of solid materials, they are not limited to the flat plane configuration of other types of fuel cells and are often designed as rolled tubes. They require high operating temperatures (800–1000 °C) and can be run on a variety of fuels including natural gas.[35]

SOFCs are unique since in those, negatively charged oxygen ions travel from the cathode (positive side of the fuel cell) to the anode (negative side of the fuel cell) instead of positively charged hydrogen ions travelling from the anode to the cathode, as is the case in all other types of fuel cells. Oxygen gas is fed through the cathode, where it absorbs electrons to create oxygen ions. The oxygen ions then travel through the electrolyte to react with hydrogen gas at the anode. The reaction at the anode produces electricity and water as by-products. Carbon dioxide may also be a by-product depending on the fuel, but the carbon emissions from an SOFC system are less than those from a fossil fuel combustion plant.[36] The chemical reactions for the SOFC system can be expressed as follows:[37]

Anode Reaction: 2H2 + 2O2− → 2H2O + 4e
Cathode Reaction: O2 + 4e → 2O2−
Overall Cell Reaction: 2H2 + O2 → 2H2O

SOFC systems can run on fuels other than pure hydrogen gas. However, since hydrogen is necessary for the reactions listed above, the fuel selected must contain hydrogen atoms. For the fuel cell to operate, the fuel must be converted into pure hydrogen gas. SOFCs are capable of internally reforming light hydrocarbons such as methane (natural gas),[38] propane and butane.[39] These fuel cells are at an early stage of development.[40]

Challenges exist in SOFC systems due to their high operating temperatures. One such challenge is the potential for carbon dust to build up on the anode, which slows down the internal reforming process. Research to address this "carbon coking" issue at the University of Pennsylvania has shown that the use of copper-based cermet (heat-resistant materials made of ceramic and metal) can reduce coking and the loss of performance.[41] Another disadvantage of SOFC systems is slow start-up time, making SOFCs less useful for mobile applications. Despite these disadvantages, a high operating temperature provides an advantage by removing the need for a precious metal catalyst like platinum, thereby reducing cost. Additionally, waste heat from SOFC systems may be captured and reused, increasing the theoretical overall efficiency to as high as 80%–85%.[35]

The high operating temperature is largely due to the physical properties of the YSZ electrolyte. As temperature decreases, so does the ionic conductivity of YSZ. Therefore, to obtain optimum performance of the fuel cell, a high operating temperature is required. According to their website, Ceres Power, a UK SOFC fuel cell manufacturer, has developed a method of reducing the operating temperature of their SOFC system to 500–600 degrees Celsius. They replaced the commonly used YSZ electrolyte with a CGO (cerium gadolinium oxide) electrolyte. The lower operating temperature allows them to use stainless steel instead of ceramic as the cell substrate, which reduces cost and start-up time of the system.[42]

Hydrogen-Oxygen Fuel Cell (Bacon Cell)

The Hydrogen-Oxygen Fuel Cell was designed and first demonstrated publicly by Bacon in the year 1959. It was used as a primary source of electrical energy in the Apollo space program.[43] The cell consists of two porous carbon electrodes impregnated with a suitable catalyst such as Pt, Ag, CoO, etc. The space between the two electrodes is filled with a concentrated solution of KOH or NaOH which serves as an electrolyte. 2H2 gas and O2 gas are bubbled into the electrolyte through the porous carbon electrodes. Thus the overall reaction involves the combination of hydrogen gas and oxygen gas to form water. The cell runs continuously until the reactant's supply is exhausted. This type of cell operates efficiently in the temperature range 343 K to 413 K and provides a potential of about 0.9 V.[44]


Molten carbonate fuel cells (MCFCs) require a high operating temperature, 650 °C (1,200 °F), similar to SOFCs. MCFCs use lithium potassium carbonate salt as an electrolyte, and this salt liquefies at high temperatures, allowing for the movement of charge within the cell – in this case, negative carbonate ions.[45]

Like SOFCs, MCFCs are capable of converting fossil fuel to a hydrogen-rich gas in the anode, eliminating the need to produce hydrogen externally. The reforming process creates CO2 emissions. MCFC-compatible fuels include natural gas, biogas and gas produced from coal. The hydrogen in the gas reacts with carbonate ions from the electrolyte to produce water, carbon dioxide, electrons and small amounts of other chemicals. The electrons travel through an external circuit creating electricity and return to the cathode. There, oxygen from the air and carbon dioxide recycled from the anode react with the electrons to form carbonate ions that replenish the electrolyte, completing the circuit.[45] The chemical reactions for an MCFC system can be expressed as follows:[46]

Anode Reaction: CO32− + H2 → H2O + CO2 + 2e
Cathode Reaction: CO2 + ½O2 + 2e → CO32−
Overall Cell Reaction: H2 + ½O2 → H2O

As with SOFCs, MCFC disadvantages include slow start-up times because of their high operating temperature. This makes MCFC systems not suitable for mobile applications, and this technology will most likely be used for stationary fuel cell purposes. The main challenge of MCFC technology is the cells' short life span. The high-temperature and carbonate electrolyte lead to corrosion of the anode and cathode. These factors accelerate the degradation of MCFC components, decreasing the durability and cell life. Researchers are addressing this problem by exploring corrosion-resistant materials for components as well as fuel cell designs that may increase cell life without decreasing performance.[35]

MCFCs hold several advantages over other fuel cell technologies, including their resistance to impurities. They are not prone to "carbon coking", which refers to carbon build-up on the anode that results in reduced performance by slowing down the internal fuel reforming process. Therefore, carbon-rich fuels like gases made from coal are compatible with the system. The Department of Energy claims that coal, itself, might even be a fuel option in the future, assuming the system can be made resistant to impurities such as sulfur and particulates that result from converting coal into hydrogen.[35] MCFCs also have relatively high efficiencies. They can reach a fuel-to-electricity efficiency of 50%, considerably higher than the 37–42% efficiency of a phosphoric acid fuel cell plant. Efficiencies can be as high as 65% when the fuel cell is paired with a turbine, and 85% if heat is captured and used in a Combined Heat and Power (CHP) system.[45]

FuelCell Energy, a Connecticut-based fuel cell manufacturer, develops and sells MCFC fuel cells. The company says that their MCFC products range from 300 kW to 2.8 MW systems that achieve 47% electrical efficiency and can utilize CHP technology to obtain higher overall efficiencies. One product, the DFC-ERG, is combined with a gas turbine and, according to the company, it achieves an electrical efficiency of 65%.[47]

Comparison of fuel cell types

Fuel cell name Electrolyte Qualified power (W) Working temperature (°C) Efficiency (cell) Efficiency (system) Status Cost (USD/W)
Metal hydride fuel cell Aqueous alkaline solution > -20
(50% Ppeak @ 0 °C)
Electro-galvanic fuel cell Aqueous alkaline solution < 40 Commercial / Research
Direct formic acid fuel cell (DFAFC) Polymer membrane (ionomer) Commercial / Research
Zinc-air battery Aqueous alkaline solution < 40 Mass production
Microbial fuel cell Polymer membrane or humic acid < 40 Research
Upflow microbial fuel cell (UMFC) < 40
Regenerative fuel cell Polymer membrane (ionomer) < 50 Commercial / Research
Direct borohydride fuel cell Aqueous alkaline solution 70 Commercial
Alkaline fuel cell Aqueous alkaline solution 10 – 100 kW < 80 60–70% 62% Commercial / Research
Direct methanol fuel cell Polymer membrane (ionomer) 100 mW – 1 kW 90–120 20–30% Commercial / Research 125
Reformed methanol fuel cell Polymer membrane (ionomer) 5 W – 100 kW 250–300 (Reformer)
125–200 (PBI)
50–60% 25–40% Commercial / Research
Direct-ethanol fuel cell Polymer membrane (ionomer) < 140 mW/cm² > 25
? 90–120
Proton exchange membrane fuel cell Polymer membrane (ionomer) 1 W – 500 kW 50–100 (Nafion)[48]
120–200 (PBI)
50–70% 30–50%[50] Commercial / Research 50–100
RFC – Redox Liquid electrolytes with redox shuttle and polymer membrane (Ionomer) 1 kW – 10 MW Research
Phosphoric acid fuel cell Molten phosphoric acid (H3PO4) < 10 MW 150-200 55% 40%[50]
Co-Gen: 90%
Commercial / Research 4–4.50
Solid acid fuel cell H+-conducting oxyanion salt (solid acid) 10 W - 1 kW 200-300 55-60% 40-45% Commercial / Research
Molten carbonate fuel cell Molten alkaline carbonate 100 MW 600–650 55% 45-55%[50] Commercial / Research
Tubular solid oxide fuel cell (TSOFC) O2−-conducting ceramic oxide < 100 MW 850–1100 60–65% 55–60% Commercial / Research
Protonic ceramic fuel cell H+-conducting ceramic oxide 700 Research
Direct carbon fuel cell Several different 700–850 80% 70% Commercial / Research
Planar Solid oxide fuel cell O2−-conducting ceramic oxide < 100 MW 500–1100 60–65% 55–60%[50] Commercial / Research
Enzymatic Biofuel Cells Any that will not denature the enzyme < 40 Research
Magnesium-Air Fuel Cell Salt water −20 to 55 90% Commercial / Research

Efficiency of leading fuel cell types

Glossary of Terms in table:

  • Anode: The electrode at which oxidation (a loss of electrons) takes place. For fuel cells and other galvanic cells, the anode is the negative terminal; for electrolytic cells (where electrolysis occurs), the anode is the positive terminal.[51]
  • Aqueous solution: a: of, relating to, or resembling water b : made from, with, or by water.[52]
  • Catalyst: A chemical substance that increases the rate of a reaction without being consumed; after the reaction, it can potentially be recovered from the reaction mixture and is chemically unchanged. The catalyst lowers the activation energy required, allowing the reaction to proceed more quickly or at a lower temperature. In a fuel cell, the catalyst facilitates the reaction of oxygen and hydrogen. It is usually made of platinum powder very thinly coated onto carbon paper or cloth. The catalyst is rough and porous so the maximum surface area of the platinum can be exposed to the hydrogen or oxygen. The platinum-coated side of the catalyst faces the membrane in the fuel cell.[51]
  • Cathode: The electrode at which reduction (a gain of electrons) occurs. For fuel cells and other galvanic cells, the cathode is the positive terminal; for electrolytic cells (where electrolysis occurs), the cathode is the negative terminal.[51]
  • Electrolyte: A substance that conducts charged ions from one electrode to the other in a fuel cell, battery, or electrolyzer.[51]
  • Fuel Cell Stack: Individual fuel cells connected in a series. Fuel cells are stacked to increase voltage.[51]
  • Matrix: something within or from which something else originates, develops, or takes form.[53]
  • Membrane: The separating layer in a fuel cell that acts as electrolyte (an ion-exchanger) as well as a barrier film separating the gases in the anode and cathode compartments of the fuel cell.[51]
  • Molten Carbonate Fuel Cell (MCFC): A type of fuel cell that contains a molten carbonate electrolyte. Carbonate ions (CO32−) are transported from the cathode to the anode. Operating temperatures are typically near 650 °C.[51]
  • Phosphoric acid fuel cell (PAFC): A type of fuel cell in which the electrolyte consists of concentrated phosphoric acid (H3PO4). Protons (H+) are transported from the anode to the cathode. The operating temperature range is generally 160–220 °C.[51]
  • Polymer Electrolyte Membrane (PEM): A fuel cell incorporating a solid polymer membrane used as its electrolyte. Protons (H+) are transported from the anode to the cathode. The operating temperature range is generally 60–100 °C.[51]
  • Solid Oxide Fuel Cell (SOFC): A type of fuel cell in which the electrolyte is a solid, nonporous metal oxide, typically zirconium oxide (ZrO2) treated with Y2O3, and O2− is transported from the cathode to the anode. Any CO in the reformate gas is oxidized to CO2 at the anode. Temperatures of operation are typically 800–1,000 °C.[51]
  • Solution: a: an act or the process by which a solid, liquid, or gaseous substance is homogeneously mixed with a liquid or sometimes a gas or solid, b : a homogeneous mixture formed by this process; especially : a single-phase liquid system, c : the condition of being dissolved[54]

For more information see Glossary of fuel cell terms

Theoretical maximum efficiency

The energy efficiency of a system or device that converts energy is measured by the ratio of the amount of useful energy put out by the system ("output energy") to the total amount of energy that is put in ("input energy") or by useful output energy as a percentage of the total input energy. In the case of fuel cells, useful output energy is measured in electrical energy produced by the system. Input energy is the energy stored in the fuel. According to the U.S. Department of Energy, fuel cells are generally between 40–60% energy efficient.[55] This is higher than some other systems for energy generation. For example, the typical internal combustion engine of a car is about 25% energy efficient.[56] In combined heat and power (CHP) systems, the heat produced by the fuel cell is captured and put to use, increasing the efficiency of the system to up to 85–90%.[35]

The theoretical maximum efficiency of any type of power generation system is never reached in practice, and it does not consider other steps in power generation, such as production, transportation and storage of fuel and conversion of the electricity into mechanical power. However, this calculation allows the comparison of different types of power generation. The maximum theoretical energy efficiency of a fuel cell is 83%, operating at low power density and using pure hydrogen and oxygen as reactants (assuming no heat recapture)[57] According to the World Energy Council, this compares with a maximum theoretical efficiency of 58% for internal combustion engines.[57] While these efficiencies are not approached in most real world applications, high-temperature fuel cells (solid oxide fuel cells or molten carbonate fuel cells) can theoretically be combined with gas turbines to allow stationary fuel cells to come closer to the theoretical limit. A gas turbine would capture heat from the fuel cell and turn it into mechanical energy to increase the fuel cell's operational efficiency. This solution has been predicted to increase total efficiency to as much as 70%.[58]

In practice

In a fuel-cell vehicle the tank-to-wheel efficiency is greater than 45% at low loads[59] and shows average values of about 36% when a driving cycle like the NEDC (New European Driving Cycle) is used as test procedure.[60] The comparable NEDC value for a Diesel vehicle is 22%. In 2008 Honda released a demonstration fuel cell electric vehicle (the Honda FCX Clarity) with fuel stack claiming a 60% tank-to-wheel efficiency.[61]

It is also important to take losses due to fuel production, transportation, and storage into account. Fuel cell vehicles running on compressed hydrogen may have a power-plant-to-wheel efficiency of 22% if the hydrogen is stored as high-pressure gas, and 17% if it is stored as liquid hydrogen.[62] Fuel cells cannot store energy like a battery,[63] except as hydrogen, but in some applications, such as stand-alone power plants based on discontinuous sources such as solar or wind power, they are combined with electrolyzers and storage systems to form an energy storage system. Most hydrogen, however, is produced by steam methane reforming, and so most hydrogen production emits carbon dioxide.[64] The overall efficiency (electricity to hydrogen and back to electricity) of such plants (known as round-trip efficiency), using pure hydrogen and pure oxygen can be "from 35 up to 50 percent", depending on gas density and other conditions.[65] While a much cheaper lead–acid battery might return about 90%, the electrolyzer/fuel cell system can store indefinite quantities of hydrogen, and is therefore better suited for long-term storage.

Solid-oxide fuel cells produce exothermic heat from the recombination of the oxygen and hydrogen. The ceramic can run as hot as 800 degrees Celsius. This heat can be captured and used to heat water in a micro combined heat and power (m-CHP) application. When the heat is captured, total efficiency can reach 80–90% at the unit, but does not consider production and distribution losses. CHP units are being developed today for the European home market.

Professor Jeremy P. Meyers, in the

  • Fuel Cell Today – Market-based intelligence on the fuel cell industry
  • Fuel starvation in a hydrogen fuel cell animation
  • Animation how a fuel cell works and applications
  • Fuel Cell Origins: 1840–1890
  • TC 105 IEC Technical standard for Fuel Cells
  • EERE: Hydrogen, Fuel Cells and Infrastructure Technologies Program
  • Thermodynamics of electrolysis of water and hydrogen fuel cells
  • 2002-Portable Power Applications of Fuel Cells
  • Fuel Cell and Hydrogen Energy Association
  • DoITPoMS Teaching and Learning Package- "Fuel Cells"
  • Solar Hydrogen Fuel Cell Water Heating
  • Fuel Cell Technology – One for the Future

External links

Further reading

  1. ^
  2. ^ Nice, Karim and Strickland, Jonathan. "How Fuel Cells Work: Polymer Exchange Membrane Fuel Cells". How Stuff Works, accessed 4 August 2011
  3. ^
  4. ^
  5. ^ Grove, William Robert. "On Voltaic Series and the Combination of Gases by Platinum", Philosophical Magazine and Journal of Science vol. XIV (1839), pp. 127–130
  6. ^
  7. ^ Grove, William Robert. "On a Gaseous Voltaic Battery", Philosophical Magazine and Journal of Science vol. XXI (1842), pp. 417–420
  8. ^
  9. ^ GE's Thomas Grubb (right) and Leonard Niedrach run a fan with a diesel-powered PEM fuel cell in April 1963
  10. ^ PEM Fuel Cell Technology
  11. ^
  12. ^
  13. ^
  14. ^
  15. ^
  16. ^
  17. ^
  18. ^
  19. ^ Anne-Claire Dupuis, Progress in Materials Science, Volume 56, Issue 3, March 2011, pp. 289–327
  20. ^ Measuring the relative efficiency of hydrogen energy technologies for implementing the hydrogen economy 2010
  21. ^ Kakati, B. K., Deka, D., "Effect of resin matrix precursor on the properties of graphite composite bipolar plate for PEM fuel cell", Energy & Fuels 2007, 21 (3):1681–1687.
  22. ^
  23. ^ Kakati B. K., Mohan V., "Development of low cost advanced composite bipolar plate for P.E.M. fuel cell", Fuel Cells 2008, 08(1): 45–51
  24. ^ Kakati B. K., Deka D., "Differences in physico-mechanical behaviors of resol and novolac type phenolic resin based composite bipolar plate for proton exchange membrane (PEM) fuel cell", Electrochimica Acta 2007, 52 (25): 7330–7336.
  25. ^ Spendelow, Jacob and Jason Marcinkoski. "Fuel Cell System Cost – 2013", DOE Fuel Cell Technologies Office, October 16, 2013
  26. ^
  27. ^ a b
  28. ^
  29. ^
  30. ^
  31. ^
  32. ^
  33. ^ Phosphoric acid fuel cell technology
  34. ^
  35. ^ a b c d e f g h "Types of Fuel Cells". Department of Energy EERE website, accessed 4 August 2011
  36. ^ Stambouli, A. Boudghene. "Solid oxide fuel cells (SOFCs): a review of an environmentally clean and efficient source of energy". Renewable and Sustainable Energy Reviews, Vol. 6, Issue 5, pp. 433–455, October 2002.
  37. ^ "Solid Oxide Fuel Cell (SOFC)". FCTec website', accessed 4 August 2011 Archived July 1, 2014 at the Wayback Machine
  38. ^
  39. ^
  40. ^
  41. ^ Hill, Michael. "Ceramic Energy: Material Trends in SOFC Systems". Ceramic Industry, 1 September 2005.
  42. ^ "The Ceres Cell". Ceres Power website, accessed 4 August 2011 Archived December 13, 2013 at the Wayback Machine
  43. ^
  44. ^ Srivastava, H. C. Nootan ISC Chemistry (12th) Edition 18, pp. 458–459, Nageen Prakashan (2014) ISBN 9789382319399
  45. ^ a b c "Molten Carbonate Fuel Cell Technology". U.S. Department of Energy, accessed 9 August 2011
  46. ^ "Molten Carbonate Fuel Cells (MCFC)"., accessed 9 August 2011 Archived July 1, 2014 at the Wayback Machine
  47. ^ "Products". FuelCell Energy, accessed 9 August 2011 Archived January 16, 2013 at the Wayback Machine
  48. ^
  49. ^
  50. ^ a b c d
  51. ^ a b c d e f g h i j "Fuel Cell Technologies Program: Glossary". Department of Energy Energy Efficiency and Renewable Energy Fuel Cell Technologies Program. 7 July 2011. Accessed 3 August 2011.
  52. ^ "Aqueous Solution". Merriam-Webster Free Online Dictionary
  53. ^ "Matrix". Merriam-Webster Free Online Dictionary
  54. ^ "Solution". Merriam-Webster Free Online Dictionary
  55. ^ "Comparison of Fuel Cell Technologies". U.S. Department of Energy, Energy Efficiency and Fuel Cell Technologies Program, February 2011, accessed 4 August 2011
  56. ^ "Fuel Economy: Where The Energy Goes". U.S. Department of Energy, Energy Effciency and Renewable Energy, accessed 3 August 2011
  57. ^ a b "Fuel Cell Efficiency". World Energy Council, 17 July 2007, accessed 4 August 2011 Archived February 9, 2014 at the Wayback Machine
  58. ^ Milewski, J., A. Miller and K. Badyda. "The Control Strategy for High Temperature Fuel Cell Hybrid Systems". The Online Journal on Electronics and Electrical Engineering, Vol. 2, No. 4, p. 331, 2009, accessed 4 August 2011
  59. ^ a b Eberle, Ulrich and Rittmar von Helmolt. "Sustainable transportation based on electric vehicle concepts: a brief overview". Energy & Environmental Science, Royal Society of Chemistry, 14 May 2010, accessed 2 August 2011
  60. ^
  61. ^
  62. ^
  63. ^
  64. ^ Nice, Karim. "How Fuel Processors Work". HowStuffWorks, accessed 3 August 2011
  65. ^
  66. ^ a b c d Meyers, Jeremy P. "Getting Back Into Gear: Fuel Cell Development After the Hype". The Electrochemical Society Interface, Winter 2008, pp. 36–39, accessed 7 August 2011
  67. ^ a b The fuel cell industry review 2013
  68. ^ a b
  69. ^ "Fuel Cell Basics: Applications". Fuel Cells 2000. Accessed 2 August 2011.
  70. ^ "Energy Sources: Electric Power". U.S. Department of Energy. Accessed 2 August 2011.
  71. ^ "2008 Fuel Cell Technologies Market Report". Bill Vincent of the Breakthrough Technologies Institute, Jennifer Gangi, Sandra Curtin, and Elizabeth Delmont. Department of Energy Energy Efficiency and Renewable Energy. June 2010.
  72. ^ U.S. Fuel Cell Council Industry Overview 2010, p. 12. U.S. Fuel Cell Council. 2010.
  73. ^ – gives extensive technical details
  74. ^
  75. ^ World's Largest Carbon Neutral Fuel Cell Power Plant, 16 October 2012
  76. ^
  77. ^
  79. ^ Fuel Cells and CHP Archived May 18, 2012 at the Wayback Machine
  80. ^
  81. ^
  82. ^
  83. ^ "PureCell Model 400: Overview". UTC Power. Accessed 2 August 2011.
  84. ^ "Comparison of Fuel Cell Technologies". Departement of Energy Energy Efficiency and Renewable Energy Fuel Cell Technologies Program. February 2011.
  85. ^ H.I. Onovwiona and V.I. Ugursal. Residential cogeneration systems: review of the current technology. Renewable and Sustainable Energy Reviews, 10(5):389 – 431, 2006.
  86. ^ AD. Hawkes, L. Exarchakos, D. Hart, MA. Leach, D. Haeseldonckx, L. Cosijns and W. D’haeseleer. EUSUSTEL work package 3: Fuell cells, 2006.
  87. ^
  88. ^ Enfarm enefield eneware
  89. ^ "Hydrogen and Fuel Cell Vehicles Worldwide". TÜV SÜD Industrie Service GmbH, accessed on 2 August 2011
  90. ^ Wipke, Keith, Sam Sprik, Jennifer Kurtz and Todd Ramsden. "Controlled Hydrogen Fleet and Infrastructure Demonstration and Validation Project". National Renewable Energy Laboratory, 11 September 2009, accessed on 2 August 2011
  91. ^ a b "Accomplishments and Progress". Fuel Cell Technology Program, U.S. Dept. of Energy, 24 June 2011
  92. ^ Wipke, Keith, Sam Sprik, Jennifer Kurtz and Todd Ramsden. "National FCEV Learning Demonstration". National Renewable Energy Laboratory, April 2011, accessed 2 August 2011
  93. ^ Garbak, John. "VIII.0 Technology Validation Sub-Program Overview". DOE Fuel Cell Technologies Program, FY 2010 Annual Progress Report, accessed 2 August 2011
  94. ^ Brinkman, Norma, Michael Wang, Trudy Weber and Thomas Darlington. "Well-To-Wheels Analysis of Advanced Fuel/Vehicle Systems – A North American Study of Energy Use, Greenhouse Gas Emissions, and Criteria Pollutant Emissions". General Motors Corporation, Argonne National Laboratory and Air Improvement Resource, Inc., May 2005, accessed 9 August 2011
  95. ^
  96. ^ Kubota, Yoko. "Toyota says slashes fuel cell costs by nearly $1 million for new hydrogen car". Reuters, Oct 10, 2013
  97. ^ Ayre, James. "Toyota To Lose $100,000 on Every Hydrogen FCV Sold?",, November 19, 2014; and Blanco, Sebastian. "Bibendum 2014: Former EU President says Toyota could lose 100,000 euros per hydrogen FCV sedan",, November 12, 2014
  98. ^
  99. ^
  100. ^
  101. ^ Lienert, Anita. "Mercedes-Benz Fuel-Cell Car Ready for Market in 2014". Edmunds Inside Line, 21 June 2011
  102. ^
  103. ^ a b "Elon Musk on why Hydrogen fuel cell is dumb (2015)", YouTube, January 14, 2015, at 10:20 of the clip
  104. ^ a b Romm, Joseph. "Tesla Trumps Toyota: Why Hydrogen Cars Can’t Compete With Pure Electric Cars",, August 5, 2014
  105. ^
  106. ^
  107. ^ a b Brian Warshay, Brian. "The Great Compression: the Future of the Hydrogen Economy", Lux Research, Inc. January 2013
  108. ^ "GM CEO: Fuel cell vehicles not yet practical", The Detroit News, 30 July 2011; and Chin, Chris. "GM's Dan Akerson: Fuel-cell vehicles aren't practical… yet". egmCarTech, 1 August 2011, accessed 27 February 2012
  109. ^ Brown, Nicholas. "Hydrogen Cars Lost Much of Their Support, But Why?", Clean Technica, June 26, 2015
  110. ^ "Engineering Explained: 5 Reasons Why Hydrogen Cars Are Stupid", Car Throttle, October 8, 2015
  111. ^ a b Bossel, Ulf. "Does a Hydrogen Economy Make Sense?", 'Proceedings of the IEEE Vol. 94, No. 10, October 2006
  112. ^ Zyga, Lisa. "Why a hydrogen economy doesn't make sense"., 11 December 2006, accessed 2 August 2011, citing Bossel, Ulf. "Does a Hydrogen Economy Make Sense?" Proceedings of the IEEE. Vol. 94, No. 10, October 2006
  113. ^ Romm, Joseph. "Tesla Trumps Toyota Part II: The Big Problem With Hydrogen Fuel Cell Vehicles",, August 13, 2014
  114. ^ Hunt, Tam. "Should California Reconsider Its Policy Support for Fuel-Cell Vehicles?", GreenTech Media, July 10, 2014
  115. ^
  116. ^ Bullis, Kevin. "Q & A: Steven Chu", Technology Review, 14 May 2009
  117. ^ "Steven Chu turns out to be a supporter of Hydrogen Technologies", Autoline.TV at 2.10 min
  118. ^ Motavalli, Jim. "Cheap Natural Gas Prompts Energy Department to Soften Its Line on Fuel Cells", The New York Times, 29 May 2012
  119. ^ "Transportation Fleet Vehicles: Overview". UTC Power. Accessed 2 August 2011.
  120. ^ "FY 2010 annual progress report: VIII.0 Technology Validation Sub-Program Overview".John Garbak. Department of Energy Hydrogen Program.
  121. ^ a b "National Fuel Cell Bus Program Awards". Calstart. Accessed 12 August 2011 Archived October 31, 2012 at the Wayback Machine
  122. ^
  123. ^
  124. ^
  125. ^
  126. ^
  127. ^ Fuel Cell Forklifts Gain Ground
  128. ^ Fuel cell technologies program overview
  129. ^ Economic Impact of Fuel Cell Deployment in Forklifts and for Backup Power under the American Recovery and Reinvestment Act
  130. ^ a b "Global and Chinese Forklift Industry Report, 2014-2016", Research and Markets, November 6, 2014
  131. ^ "Fact Sheet: Materials Handling and Fuel Cells" Archived November 7, 2014 at the Wayback Machine
  132. ^ Hylift
  133. ^ First hydrogen station for fuel cell forklift trucks in France, for IKEA
  134. ^ HyPulsion
  135. ^ HyGear delivers hydrogen system for fuel cell based forklift trucks
  136. ^ "Hydrogen Fueling Stations Could Reach 5,200 by 2020". Environmental Leader: Environmental & Energy Management News,20 July 2011, accessed 2 August 2011
  137. ^ Full Fuel-Cycle Comparison of Forklift Propulsion Systems
  138. ^ Fuel cell technology
  139. ^ Fuel cell forklift
  140. ^
  141. ^
  142. ^
  143. ^
  144. ^ "Horizon fuel cell vehicles: Transportation: Light Mobility". Horizon Fuel Cell Technologies. 2010. Accessed 2 August 2011.
  145. ^ APFCT won Taiwan BOE project contract for 80 FC scooters fleet demonstration
  146. ^ The fuel cell industry review 2012
  147. ^ Burgman_Fuel-Cell_Scooter;
  148. ^ ;
  149. ^ . Boeing. 3 April 2008. Accessed 2 August 2011.
  150. ^ "First Fuel Cell Microaircraft" Archived October 4, 2012 at the Wayback Machine
  151. ^ "Horizon Fuel Cell Powers New World Record in UAV Flight". Horizon Fuel Cell Technologies. 1 November 2007.
  152. ^ "Fuel Cell Powered UAV Completes 23-hour Flight". Alternative Energy: News. 22 October 2009. Accessed 2 August 2011.
  153. ^ "Hydrogen-powered unmanned aircraft completes set of tests" 20 June 2011. Accessed 2 August 2011.
  154. ^ "Lovers introduces zero-emission boat" (in Dutch). NemoH2. 28 March 2011. Accessed 2 August 2011.
  155. ^ "Super-stealth sub powered by fuel cell". Frederik Pleitgen. CNN Tech: Nuclear Weapons. 22 February 2011. Accessed 2 August 2011.
  156. ^ "U212 / U214 Attack Submarines, Germany". Accessed 2 August 2011.
  157. ^ Goodenough, RH; Greig, A; (2008) Hybrid nuclear/fuel-cell submarine. Journal of Naval Engineering , 44 (3) 455 - 471
  158. ^ SFC Energy
  159. ^ Ensol Systems Inc.
  160. ^ "Ballard fuel cells to power telecom backup power units for motorola". Association Canadienne de l'hydrogene et des piles a combustible. 13 July 2009. Accessed 2 August 2011.
  161. ^ India telecoms to get fuel cell power Archived February 9, 2014 at the Wayback Machine
  162. ^ "Cottbus receives new local data center". T Systems. 21 March 2011.
  163. ^ "Fuel Cell Applications". Fuel Cells 2000. Accessed 2 August 2011
  164. ^ DVGW VP 119 Brennstoffzellen-Gasgeräte bis 70 kW. DVGW. (German)
  165. ^
  166. ^
  167. ^ "Alternative Fueling Station Locator". U.S. Department of Energy Energy Efficiency and Renewable Energy Alternative Fuel & Advance Vehicle Center. 14 January 2010.
  168. ^ Berman, Bradley. "Fuel Cells at Center Stage", New York Times, November 24, 2013, p. AU1
  169. ^ Energy Department Launches Public-Private Partnership to Deploy Hydrogen Infrastructure
  170. ^ Goodstein, Steven. "Toyota Motor Corporation (NYSE:TM)’s Mirai Reaches Tesla Motors Inc (NASDAQ:TSLA)’s Driving Range by Providing 312 Miles on a Single Tank",, July 5, 2015
  171. ^ "ECTOS 2003-7", Icelandic New Energy, accessed August 25, 2015
  172. ^ German Government announces support for 50 urban hydrogen refuelling stations
  173. ^ Bundesverkehrsministerium und Industriepartner bauen überregionales Tankstellennetz (German)
  174. ^ Higashi, Tadashi. "Initiative to Promote a Diffusion of Hydrogen Fuel Cell Vehicles", Fukuoka Strategy Conference for Hydrogen Energy, February 1, 2012
  175. ^ "Navigant: fuel cell industry passed $1-billion revenue mark in 2012", Green Car Congress, 12 August 2013
  176. ^ Wesoff, Eric. "Will Plug Power Be the First Profitable Fuel Cell Company?". Greentech Media, October 21, 2013
  177. ^ Fuel cell report highlights continued growth in material handling applications
  178. ^ Latest developments in the Ene-Farm scheme
  179. ^ Tanaka Precious Metals Records Highest Shipment Volume of Fuel Cell Catalysts in FY2011
  180. ^ "Tanaka precious metals constructs dedicated plant for the development and manufacture of fuel cell catalysts",, February 26, 2013, accessed November 16, 2013
  181. ^ Adamson, Karry-Ann and Clint Wheelock. "Fuel Cell Annual Report 2011". 2Q 2011, Pike Research, accessed 1 August 2011
  182. ^ "Solid State Energy Conversion Alliance SECA Cost Reduction". U.S. Dept. of Energy, 31 January 2011, accessed 1 August 2011
  183. ^ "Lower & Lock-In Energy Costs". Bloom Energy, accessed 3 August 2011
  184. ^ Wesoff, Eric. "Bloom Energy Plays the Subsidy Game Like a Pro", April 13, 2011, accessed August 1, 2011 Archived November 26, 2013 at the Wayback Machine
  185. ^ International Platinum Group Metals Association-FAQ Archived January 13, 2015 at the Wayback Machine
  186. ^
  187. ^ Replacement of platinum by iron-sulpher
  188. ^ Fuel cell improvements raise hopes for clean, cheap energy
  189. ^
  190. ^ Cheaper fuel cells
  191. ^ Bio-inspired catalyst design could rival platinum
  192. ^ ACAL Energy System Breaks The 10,000 Hour Endurance Barrier
  193. ^ ACAL poster on Fuel Cell costs and efficiency
  194. ^
  195. ^


See also

  • 2005: triazole to raise the operating temperature of PEM fuel cells from below 100 °C to over 125 °C, claiming this will require less carbon-monoxide purification of the hydrogen fuel.[189]
  • 2008: Monash University, Melbourne used PEDOT as a cathode.[27]
  • 2009: Researchers at the University of Dayton, in Ohio, showed that arrays of vertically grown carbon nanotubes could be used as the catalyst in fuel cells.[190] The same year, a nickel bisdiphosphine-based catalyst for fuel cells was demonstrated.[191]
  • 2013: British firm ACAL Energy developed a fuel cell that it said can run for 10,000 hours in simulated driving conditions.[192] It asserted that the cost of fuel cell construction can be reduced to $40/kW (roughly $9,000 for 300 HP).[193]
  • 2015: Researchers in Imperial College London developed a new method for regeneration of sulfide contaminated PEFCs.[194] They recovered 95–100% of the original performance of a hydrogen sulfide contaminated PEFC. This regeneration method is applicable to multiple cell stacks.[195]

Research and development

Industry groups predict that there are sufficient platinum resources for future demand,[185] and in 2007, research at Brookhaven National Laboratory suggested that platinum could be replaced by a gold-palladium coating, which may be less susceptible to poisoning and thereby improve fuel cell lifetime.[186] Another method would use iron and sulphur instead of platinum. This would lower the cost of a fuel cell (as the platinum in a regular fuel cell costs around US$1,500, and the same amount of iron costs only around US$1.50). The concept was being developed by a coalition of the John Innes Centre and the University of Milan-Bicocca.[187] PEDOT cathodes are immune to monoxide poisoning.[188]

Approximately 50% of fuel cell shipments in 2010 were stationary fuel cells, up from about a third in 2009, and the four dominant producers in the Fuel Cell Industry were the United States, Germany, Japan and South Korea.[181] The Department of Energy Solid State Energy Conversion Alliance found that, as of January 2011, stationary fuel cells generated power at approximately $724 to $775 per kilowatt installed.[182] In 2011, Bloom Energy, a major fuel cell supplier, said that its fuel cells generated power at 9–11 cents per kilowatt-hour, including the price of fuel, maintenance, and hardware.[183][184]

In 2012, fuel cell industry revenues exceeded $1 billion market value worldwide, with Asian pacific countries shipping more than 3/4 of the fuel cell systems worldwide.[175] However, as of October 2013, no public company in the industry had yet become profitable.[176] There were 140,000 fuel cell stacks shipped globally in 2010, up from 11 thousand shipments in 2007, and from 2011 to 2012 worldwide fuel cell shipments had an annual growth rate of 85%.[177] Tanaka Kikinzoku Kogyo K.K. expanded its production facilities for fuel cell catalysts in 2013 to meet anticipated demand as the Japanese ENE Farm scheme expects to install 50,000 units in 2013[178] and the company is experiencing rapid market growth.[179][180]

Markets and economics

Japan has a hydrogen highway, as part of the Japan hydrogen fuel cell project. Twelve hydrogen fueling stations had been built in 11 cities in Japan by 2012.[174] Canada, Sweden and Norway also had planned hydrogen highways.

The first public hydrogen refueling station in Iceland operated from 2003 to 2007. It served three buses in the public transport net of Reykjavík. The station produced its own hydrogen with an electrolyzing unit.[171] The 14 stations in Germany were planned to be expanded to 50 by 2015[172] through its public private partnership Now GMBH.[173]

There were over 85 hydrogen refueling stations in the U.S. in 2010.[167] Some of these have closed, and In November 2013, The New York Times reported that there were "10 hydrogen stations available to the public in the entire United States: one in Columbia, S.C., eight in Southern California and the one in Emeryville".[168] In 2013 the Department of Energy launched H2USA focused on advancing the hydrogen infrastructure.[169] As of July 2015, there were 12 public hydrogen fueling stations in the US, 10 of which were in California.[170]

Fueling stations

  • Providing power for base stations or cell sites[160][161]
  • Distributed generation
  • Emergency power systems are a type of fuel cell system, which may include lighting, generators and other apparatus, to provide backup resources in a crisis or when regular systems fail. They find uses in a wide variety of settings from residential homes to hospitals, scientific laboratories, data centers,[162]
  • telecommunication[163] equipment and modern naval ships.
  • An uninterrupted power supply (UPS) provides emergency power and, depending on the topology, provide line regulation as well to connected equipment by supplying power from a separate source when utility power is not available. Unlike a standby generator, it can provide instant protection from a momentary power interruption.
  • Base load power plants
  • Solar Hydrogen Fuel Cell Water Heating
  • Hybrid vehicles, pairing the fuel cell with either an ICE or a battery.
  • Notebook computers for applications where AC charging may not be readily available.
  • Portable charging docks for small electronics (e.g. a belt clip that charges a cell phone or PDA).
  • Smartphones, laptops and tablets.
  • Small heating appliances[164]
  • Food preservation, achieved by exhausting the oxygen and automatically maintaining oxygen exhaustion in a shipping container, containing, for example, fresh fish.[165]
  • Breathalyzers, where the amount of voltage generated by a fuel cell is used to determine the concentration of fuel (alcohol) in the sample.[166]
  • Carbon monoxide detector, electrochemical sensor.

Other applications

Portable power systems that use fuel cells can be used in the leisure sector (i.e. RVs, cabins, marine), the industrial sector (i.e. power for remote locations including gas/oil wellsites, communication towers, security, weather stations), and in the military sector. SFC Energy is a German manufacturer of direct methanol fuel cells for a variety of portable power systems.[158] Ensol Systems Inc. is an integrator of portable power systems, using the SFC Energy DMFC.[159]

Portable power systems

The U212A is a non-nuclear submarine developed by German naval shipyard Howaldtswerke Deutsche Werft.[155] The system consists of nine PEM fuel cells, providing between 30 kW and 50 kW each. The ship is silent, giving it an advantage in the detection of other submarines.[156] A naval paper has theorized about the possibility of a nuclear-fuel cell hybrid whereby the fuel cell is used when silent operations are required and then replenished from the Nuclear reactor (and water).[157]

The Type 212 submarines of the German and Italian navies use fuel cells to remain submerged for weeks without the need to surface.


The world's first fuel-cell boat HYDRA used an AFC system with 6.5 kW net output. Iceland has committed to converting its vast fishing fleet to use fuel cells to provide auxiliary power by 2015 and, eventually, to provide primary power in its boats. Amsterdam recently introduced its first fuel cell-powered boat that ferries people around the city's famous and beautiful canals.[154]

The world's first certified fuel cell boat (HYDRA), in Leipzig/Germany


There have been several fuel cell-powered unmanned aerial vehicles (UAV). A Horizon fuel cell UAV set the record distance flown for a small UAV in 2007.[151] The military is especially interested in this application because of the low noise, low thermal signature and ability to attain high altitude. In 2009 the Naval Research Laboratory's (NRL's) Ion Tiger utilized a hydrogen-powered fuel cell and flew for 23 hours and 17 minutes.[152] Fuel cells are also being used to provide auxiliary power in aircraft, replacing fossil fuel generators that were previously used to start the engines and power on board electrical needs.[153] Fuel cells can help airplanes reduce CO2 and other pollutant emissions and noise.

Boeing researchers and industry partners throughout Europe conducted experimental flight tests in February 2008 of a manned airplane powered only by a fuel cell and lightweight batteries. The fuel cell demonstrator airplane, as it was called, used a proton exchange membrane (PEM) fuel cell/lithium-ion battery hybrid system to power an electric motor, which was coupled to a conventional propeller.[149] In 2003, the world's first propeller-driven airplane to be powered entirely by a fuel cell was flown. The fuel cell was a unique FlatStackTM stack design, which allowed the fuel cell to be integrated with the aerodynamic surfaces of the plane.[150]


Other examples of motorbikes[143] and bicycles[144] that use hydrogen fuel cells include the Taiwanese company APFCT's scooter[145] using the fueling system from Italy's Acta SpA[146] and the Suzuki Burgman scooter with an IE fuel cell that received EU Whole Vehicle Type Approval in 2011.[147] Suzuki Motor Corp. and IE have announced a joint venture to accelerate the commercialization of zero-emission vehicles.[148]

In 2005 a British manufacturer of hydrogen-powered fuel cells, Intelligent Energy (IE), produced the first working hydrogen run motorcycle called the ENV (Emission Neutral Vehicle). The motorcycle holds enough fuel to run for four hours, and to travel 160 km (100 mi) in an urban area, at a top speed of 80 km/h (50 mph).[140] In 2004 Honda developed a fuel-cell motorcycle that utilized the Honda FC Stack.[141][142]

Motorcycles and bicycles

Most companies in Europe and the US do not use petroleum-powered forklifts, as these vehicles work indoors where emissions must be controlled and instead use electric forklifts.[130][137] Fuel cell-powered forklifts can provide benefits over battery-powered forklifts as they can work for a full 8-hour shift on a single tank of hydrogen and can be refueled in 3 minutes. Fuel cell-powered forklifts can be used in refrigerated warehouses, as their performance is not degraded by lower temperatures. The FC units are often designed as drop-in replacements.[138][139]

A fuel cell forklift (also called a fuel cell lift truck) is a fuel cell-powered industrial forklift truck used to lift and transport materials. In 2013 there were over 4,000 fuel cell forklifts used in material handling in the US,[127] of which only 500 received funding from DOE (2012).[128][129] The global market is 1 million fork lifts per year.[130] Fuel cell fleets are operated by various companies, including Sysco Foods, FedEx Freight, GENCO (at Wegmans, Coca-Cola, Kimberly Clark, and Whole Foods), and H-E-B Grocers.[131] Europe demonstrated 30 fuel cell forklifts with Hylift and extended it with HyLIFT-EUROPE to 200 units,[132] with other projects in France [133][134] and Austria.[135] Pike Research stated in 2011 that fuel cell-powered forklifts will be the largest driver of hydrogen fuel demand by 2020.[136]


The first Brazilian hydrogen fuel cell bus prototype in Brazil was deployed in São Paulo. The bus was manufactured in Caxias do Sul and the hydrogen fuel will be produced in São Bernardo do Campo from water through electrolysis. The program, called "Ônibus Brasileiro a Hidrogênio" (Brazilian Hydrogen Autobus), includes three additional buses.[125][126]

  • 12 fuel cell buses are being deployed in the Oakland and San Francisco Bay area of California.[121]
  • Daimler AG, with 36 experimental buses powered by Ballard Power Systems fuel cells, completed a successful three-year trial in eleven cities, in January 2007.[122][123]
  • A fleet of Thor buses with UTC Power fuel cells was deployed in California, operated by SunLine Transit Agency.[124]

The Fuel Cell Bus Club is a global cooperative effort in trial fuel cell buses. Notable projects include:

As of August 2011, there were a total of approximately 100 [121]


In 2009, Steven Chu, then the United States Secretary of Energy, stated that hydrogen vehicles "will not be practical over the next 10 to 20 years".[115][116] In 2012, however, Chu stated that he saw fuel cell cars as more economically feasible as natural gas prices have fallen and hydrogen reforming technologies have improved.[117][118]

Joseph Romm, the author of The Hype About Hydrogen (2005), devoted two articles in 2014 to updating his critique of the use of fuel cells in cars. He stated that FCVs still had not overcome the following issues: high cost of the vehicles, high fueling cost, and a lack of fuel-delivery infrastructure. "It would take several miracles to overcome all of those problems simultaneously in the coming decades."[113] Most importantly, he said, "FCVs aren't green" because of escaping methane during natural gas extraction and when hydrogen is produced, as 95% of it is, using the steam reforming process. He concluded that renewable energy cannot economically be used to make hydrogen for an FCV fleet "either now or in the future."[104] Greentech Media's analyst reached similar conclusions in 2014.[114]

In 2012, Lux Research, Inc. issued a report that stated: "The dream of a hydrogen economy ... is no nearer". It concluded that "Capital cost ... will limit adoption to a mere 5.9 GW" by 2030, providing "a nearly insurmountable barrier to adoption, except in niche applications". The analysis concluded that, by 2030, PEM stationary market will reach $1 billion, while the vehicle market, including forklifts, will reach a total of $2 billion.[107] Other analyses cite the lack of an extensive hydrogen infrastructure in the U.S. as an ongoing challenge to Fuel Cell Electric Vehicle commercialization. In 2006, a study for the IEEE showed that for hydrogen produced via electrolysis of water: "Only about 25% of the power generated from wind, water, or sun is converted to practical use." The study further noted that "Electricity obtained from hydrogen fuel cells appears to be four times as expensive as electricity drawn from the electrical transmission grid. ... Because of the high energy losses [hydrogen] cannot compete with electricity."[111] Furthermore, the study found: "Natural gas reforming is not a sustainable solution".[111] "The large amount of energy required to isolate hydrogen from natural compounds (water, natural gas, biomass), package the light gas by compression or liquefaction, transfer the energy carrier to the user, plus the energy lost when it is converted to useful electricity with fuel cells, leaves around 25% for practical use."[66][59][112]

Some experts believe that fuel cell cars will never become economically competitive with other technologies[103][104][105][106] or that it will take decades for them to become profitable.[66][107] Elon Musk stated in 2015 that fuel cells for use in cars will never be commercially viable because of the inefficiency of producing, transporting and storing hydrogen and the flammability of the gas, among other reasons.[103] Professor Jeremy P. Meyers estimated in 2008 that cost reductions over a production ramp-up period will take about 20 years after fuel-cell cars are introduced before they will be able to compete commercially with current market technologies, including gasoline internal combustion engines.[66] In 2011, the chairman and CEO of General Motors, Daniel Akerson, stated that while the cost of hydrogen fuel cell cars is decreasing: "The car is still too expensive and probably won't be practical until the 2020-plus period, I don't know."[108] In 2015, Clean Technica listed some of the disadvantages of hydrogen fuel cell vehicles.[109] So did Car Throttle.[110]


In 2014, Toyota introduced its first fuel cell vehicle in Japan, the Mirai, at a price of less than US$100,000,[96] although former European Parliament President Pat Cox estimates that Toyota will initially lose about $100,000 on each Mirai sold.[97] Hyundai introduced the limited production Hyundai ix35 FCEV.[98] Other manufacturers that have announced intentions to sell fuel cell electric vehicles commercially by 2016 include General Motors,[99] Honda,[100] Mercedes-Benz,[101] and Nissan.[102]

As of 2015, two fuel cell vehicles have been introduced for commercial lease and sale in limited quantities: the Toyota Mirai and the Hyundai ix35 FCEV. Additional demonstration models include the Honda FCX Clarity, and Mercedes-Benz F-Cell.[89] As of June 2011 demonstration FCEVs had driven more than 4,800,000 km (3,000,000 mi), with more than 27,000 refuelings.[90] Demonstration fuel cell vehicles have been produced with "a driving range of more than 400 km (250 mi) between refueling".[91] They can be refueled in less than 5 minutes.[92] The U.S. Department of Energy's Fuel Cell Technology Program claims that, as of 2011, fuel cells achieved 53–59% efficiency at one-quarter power and 42–53% vehicle efficiency at full power,[93] and a durability of over 120,000 km (75,000 mi) with less than 10% degradation.[91] In a Well-to-Wheels simulation analysis that "did not address the economics and market constraints", General Motors and its partners estimated that per mile traveled, a fuel cell electric vehicle running on compressed gaseous hydrogen produced from natural gas could use about 40% less energy and emit 45% less greenhouse gasses than an internal combustion vehicle.[94] A lead engineer from the Department of Energy whose team is testing fuel cell cars said in 2011 that the potential appeal is that "these are full-function vehicles with no limitations on range or refueling rate so they are a direct replacement for any vehicle. For instance, if you drive a full sized SUV and pull a boat up into the mountains, you can do that with this technology and you can't with current battery-only vehicles, which are more geared toward city driving."[95]


Element One fuel cell vehicle
Configuration of components in a fuel cell car

Fuel cell electric vehicles (FCEVs)

Delta-ee consultants stated in 2013 that with 64% of global sales the fuel cell micro-combined heat and power passed the conventional systems in sales in 2012.[67] The Japanese ENE FARM project will pass 100,000 FC mCHP systems in 2014, 34.213 PEMFC and 2.224 SOFC were installed in the period 2012-2014, 30,000 units on LNG and 6,000 on LPG.[88]

Co-generation systems can reach 85% efficiency (40–60% electric + remainder as thermal).[35] Phosphoric-acid fuel cells (PAFC) comprise the largest segment of existing CHP products worldwide and can provide combined efficiencies close to 90%.[82][83] Molten Carbonate (MCFC) and Solid Oxide Fuel Cells (SOFC) are also used for combined heat and power generation and have electrical energy efficiences around 60%.[84] Disadvantages of co-generation systems include slow ramping up and down rates, high cost and short lifetime.[85][86] Also their need to have a hot water storage tank to smooth out the thermal heat production was a serious disadvantage in the domestic market place where space in domestic properties is at a great premium.[87]

The waste heat from fuel cells can be diverted during the summer directly into the ground providing further cooling while the waste heat during winter can be pumped directly into the building. The University of Minnesota owns the patent rights to this type of system[80][81]

Combined heat and power (CHP) fuel cell systems, including Micro combined heat and power (MicroCHP) systems are used to generate both electricity and heat for homes (see home fuel cell), office building and factories. The system generates constant electric power (selling excess power back to the grid when it is not consumed), and at the same time produces hot air and water from the waste heat. As the result CHP systems have the potential to save primary energy as they can make use of waste heat which is generally rejected by thermal energy conversion systems.[76] A typical capacity range of home fuel cell is 1–3 kWel / 4–8 kWth.[77][78] CHP systems linked to absorption chillers use their waste heat for refrigeration.[79]


Fuel cells can be used with low-quality gas from landfills or waste-water treatment plants to generate power and lower methane emissions. A 2.8 MW fuel cell plant in California is said to be the largest of the type.[75]

One such pilot program is operating on Stuart Island in Washington State. There the Stuart Island Energy Initiative[73] has built a complete, closed-loop system: Solar panels power an electrolyzer, which makes hydrogen. The hydrogen is stored in a 500-U.S.-gallon (1,900 L) tank at 200 pounds per square inch (1,400 kPa), and runs a ReliOn fuel cell to provide full electric back-up to the off-the-grid residence. Another closed system loop was unveiled in late 2011 in Hempstead, NY.[74]

Since fuel cell electrolyzer systems do not store fuel in themselves, but rather rely on external storage units, they can be successfully applied in large-scale energy storage, rural areas being one example.[69] There are many different types of stationary fuel cells so efficiencies vary, but most are between 40% and 60% energy efficient.[35] However, when the fuel cell's waste heat is used to heat a building in a cogeneration system this efficiency can increase to 85%.[35] This is significantly more efficient than traditional coal power plants, which are only about one third energy efficient.[70] Assuming production at scale, fuel cells could save 20–40% on energy costs when used in cogeneration systems.[71] Fuel cells are also much cleaner than traditional power generation; a fuel cell power plant using natural gas as a hydrogen source would create less than one ounce of pollution (other than CO2) for every 1,000 kW·h produced, compared to 25 pounds of pollutants generated by conventional combustion systems.[72] Fuel Cells also produce 97% less nitrogen oxide emissions than conventional coal-fired power plants.

Stationary fuel cells are used for commercial, industrial and residential primary and backup power generation. Fuel cells are very useful as power sources in remote locations, such as spacecraft, remote weather stations, large parks, communications centers, rural locations including research stations, and in certain military applications. A fuel cell system running on hydrogen can be compact and lightweight, and have no major moving parts. Because fuel cells have no moving parts and do not involve combustion, in ideal conditions they can achieve up to 99.9999% reliability.[68] This equates to less than one minute of downtime in a six-year period.[68]


Type 212 submarine with fuel cell propulsion of the German Navy in dry dock



This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.