A fuel cell is an electrochemical conversion device. Electrochemistry is a branch of Chemistry that studies Chemical reactions which take place in a Solution at the interface of an electron conductor It produces electricity from various external quantities of fuel (on the anode side) and an oxidant (on the cathode side). An anode is an Electrode through which Electric current flows into a polarized electrical device A cathode is an Electrode through which (positive Electric current flows out of a polarized electrical device These react in the presence of an electrolyte. An electrolyte is any substance containing free Ions that behaves as an electrically conductive medium Generally, the reactants flow in and reaction products flow out while the electrolyte remains in the cell. Fuel cells can operate virtually continuously as long as the necessary flows are maintained.
Fuel cells are different from batteries in that they consume reactant, which must be replenished, whereas batteries store electrical energy chemically in a closed system. In electronics a battery is a combination of two or more Electrochemical cells which store chemical Energy which can be converted into electrical energy Additionally, while the electrodes within a battery react and change as a battery is charged or discharged, a fuel cell's electrodes are catalytic and relatively stable. Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst
Many combinations of fuel and oxidant are possible. A hydrogen cell uses hydrogen as fuel and oxygen as oxidant. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Other fuels include hydrocarbons and alcohols. In Organic chemistry, a hydrocarbon is an Organic compound consisting entirely of Hydrogen and Carbon. In Chemistry, an alcohol is any Organic compound in which a Hydroxyl group ( - O[[hydrogen H]]) is bound to a Carbon Other oxidants include air, chlorine and chlorine dioxide. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five Chlorine (ˈklɔriːn from the Greek word 'χλωρóς' ( khlôros, meaning 'pale green' is the Chemical element with Atomic number 17 and Chlorine dioxide is a Chemical compound with the formula ClO2 
In essence, a fuel cell works by catalysis, separating the component electrons and protons of the reactant fuel, and forcing the electrons to travel though a circuit, hence converting them to electrical power. The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J The proton ( Greek πρῶτον / proton "first" is a Subatomic particle with an Electric charge of one positive An electronic circuit is a closed path formed by the interconnection of Electronic components through which an Electric current can flow The catalyst is typically comprised of a platinum group metal or alloy. Another catalytic process takes the electrons back in, combining them with the protons and the oxidant to form waste products (typically simple compounds like water and carbon dioxide).
In the archetypal hydrogen–oxygen proton exchange membrane fuel cell (PEMFC) design, a proton-conducting polymer membrane, (the electrolyte), separates the anode and cathode sides. Proton exchange membrane fuel cells, also known as Proton exchange membrane (PEM fuel cells (PEMFC are a type of Fuel cell being developed for transport An electrolyte is any substance containing free Ions that behaves as an electrically conductive medium An anode is an Electrode through which Electric current flows into a polarized electrical device A cathode is an Electrode through which (positive Electric current flows out of a polarized electrical device This was called a "solid polymer electrolyte fuel cell" (SPEFC) in the early 1970s, before the proton exchange mechanism was well-understood. (Notice that "polymer electrolyte membrane" and "proton exchange membrane" result in the same acronym. Acronyms, initialisms, and alphabetisms are Abbreviations that are formed using the initial components in a phrase or name )
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 is commonly referred to as multi-facilitated proton membranes (MFPM). 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 this example, the only waste product, either liquid or vapor. In Chemistry, a molecule is defined as a sufficiently stable electrically neutral group of at least two Atoms in a definite arrangement held together by Water is a common Chemical substance that is essential for the survival of all known forms of Life. General properties of water vapor Evaporation/sublimation Whenever a water molecule leaves a surface it is said to have evaporated
In addition to this pure hydrogen type, there are hydrocarbon fuels for fuel cells, including diesel, methanol (see: direct-methanol fuel cells) and chemical hydrides. In Organic chemistry, a hydrocarbon is an Organic compound consisting entirely of Hydrogen and Carbon. Diesel or Diesel fuel (ˈdiːzəl in general is any Fuel used in Diesel engines The most common is a specific fractional distillate of petroleum Methanol, also known as methyl alcohol, carbinol, wood alcohol, wood naphtha or wood spirits, is a Chemical compound Direct-methanol fuel cells or DMFCs are a subcategory of proton-exchange fuel cells where the Methanol (CH3OH fuel is not reformed as in the The waste products with these types of fuel are carbon dioxide and water. Carbon dioxide ( Chemical formula:) is a Chemical compound composed of two Oxygen Atoms covalently bonded to a single
The materials used in fuel cells differ by type. The electrode–bipolar plates are usually made of metal, nickel or carbon nanotubes, and are coated with a catalyst (like platinum, nano iron powders or palladium) for higher efficiency. The M acro E xpansion T emplate A ttribute L anguage complements TAL, providing macros which allow the reuse of code across Nickel (ˈnɪkəl is a metallic Chemical element with the symbol Ni and Atomic number 28 See also Graphene, Buckypaper Carbon nanotubes (CNTs are Allotropes of carbon with a nanostructure that can have a length-to-diameter Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst Platinum (ˈplætɪnəm is a Chemical element with the Atomic symbol Pt and an Atomic number of 78 Nano Iron Powder Nano iron powder is an iron powder with granules' sizes ranging on the Nanoscale. Palladium (pronounced \pəˈleɪdiəm\ is a rare and lustrous silvery-white metal that was discovered in 1803 by William Hyde Wollaston, who named it palladium after the Carbon paper separates them from the electrolyte. Carbon paper (originally carbonic paper) is Paper coated on one side with a layer of a loosely bound dry Ink or pigmented coating usually bound with The electrolyte could be ceramic or a membrane. The word ceramic is derived from the Greek word κεραμικός ( keramikos) An artificial membrane, also called a synthetic membrane, is a membrane prepared for separation tasks in Laboratory and industry
A typical PEM 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:
To deliver the desired amount of energy, the fuel cells can be combined in series and parallel circuits, where series yield higher voltage, and parallel allows a stronger current to be drawn. Overpotential is an Electrochemical term which refers to the Potential ( Volts difference between a Half-reaction 's thermodynamically determined Voltage drop is the reduction in Voltage in an Electrical circuit between the source and load If two or more circuit components are connected end to end like a daisy chain it is said they are connected in series. Electrical tension (or voltage after its SI unit, the Volt) is the difference of electrical potential between two points of an electrical Electric current is the flow (movement of Electric charge. The SI unit of electric current is the Ampere. Such a design is called a fuel cell stack. Further, the cell surface area can be increased, to allow stronger current from each cell. Electric current is the flow (movement of Electric charge. The SI unit of electric current is the Ampere.
The principle of the fuel cell was discovered by German scientist Christian Friedrich Schönbein in 1838 and published in the January 1839 edition of the "Philosophical Magazine". Christian Friedrich Schönbein ( October 18, 1799 &ndash August 29, 1868) was a German - Swiss Chemist who is  Based on this work, the first fuel cell was developed by Welsh scientist Sir William Robert Grove in 1845. Sir William Robert Grove PC QC FRS ( 11 July, 1811 &ndash 1 August, 1896) was a British Lawyer The fuel cell he made used similar materials to today's phosphoric-acid fuel cell. Phosphoric acid fuel cells ( PAFC) are a type of Fuel cell that uses liquid Phosphoric acid as an Electrolyte. 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'. GE went on to develop this technology with NASA and McDonnell Aircraft, leading to its use during Project Gemini. Team The Gemini program was managed by the Manned Spacecraft Center Houston Texas under direction of the Office of Manned Space Flight NASA Headquarters Washington This was the first commercial use of a fuel cell. It wasn't until 1959 that British engineer Francis Thomas Bacon successfully developed a 5 kW stationary fuel cell. Francis Thomas Bacon OBE FRS ( December 21, 1904 at Ramsden Hall Billericay, Essex, England &ndash May In 1959, a team led by Harry Ihrig built a 15 kW fuel cell tractor for Allis-Chalmers which was demonstrated across the US 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).
United Technology Corp.'s UTC Power subsidiary 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. United Technologies Corporation (UTC ( is an American multinational conglomerate based in Hartford, Connecticut and is the 20th UTC Power provides On-Site Power Products Transportation Products and Space and Defense Solutions Energy recycling Cogeneration (also combined heat and power, CHP) is the use of a Heat engine or a Power station to simultaneously generate both UTC Power continues to market this fuel cell as the PureCell 200, a 200 kW system.  UTC Power continues to be the sole supplier of fuel cells to NASA for use in space vehicles, having supplied the Apollo missions,  and currently the Space Shuttle program, and is developing fuel cells for automobiles, buses, and cell phone towers; the company has demonstrated the first fuel cell capable of starting under freezing conditions with its proton exchange membrane automotive fuel cell. NASA 's Space Shuttle, officially called Space Transportation System ( STS) is the United States government's current manned Launch A proton exchange membrane or polymer electrolyte membrane (PEM is a Semipermeable membrane generally made from Ionomers and designed to conduct protons
|Fuel Cell Name||Electrolyte||Qualified Power (W)||Working Temperature (°C)||Electrical efficiency||Status||Cost per Watt|
|Metal hydride fuel cell||Aqueous alkaline solution (e. Electric power is defined as the rate at which Electrical energy is transferred by an Electric circuit. Temperature is a physical property of a system that underlies the common notions of hot and cold something that is hotter generally has the greater temperature The efficiency of an entity (a device, component, or System) in Electronics and Electrical engineering is defined as useful Metal hydride fuel cells are a subclass of Alkaline Fuel cells that are currently in the research and development phase In Chemistry, an alkali (from Arabic: Al-Qaly القلي القالي) is a basic, ionic salt of an Alkali metal g. potassium hydroxide)||?||above -20|
(50% Ppeak @ 0°C)
|Electro-galvanic fuel cell||Aqueous alkaline solution (e. Potassium hydroxide is the Inorganic compound with the formula K[[hydroxide OH]] The phrase research and development (also R and D or more often R&D) according to the Organization for Economic Co-operation and Development, refers An electro-galvanic fuel cell is an electrical device used to measure the concentration of Oxygen gas in Scuba diving and Medical equipment g. , potassium hydroxide)||?||under 40||?||Commercial/Research|
|Direct formic acid fuel cell (DFAFC)||Polymer membrane (ionomer)||to 50 W||under 40||?||Commercial/Research|
|Zinc-air battery||Aqueous alkaline solution (e. Direct- formic acid fuel cells or DFAFCs are a subcategory of Proton-exchange fuel cells where the fuel formic acid is not reformed but fed directly to the fuel cell Zinc-air batteries (non-rechargeable and zinc-air Fuel cells (mechanically-rechargeable are electro-chemical batteries powered by the Oxidation g. , potassium hydroxide)||?||under 40||?||Mass production|
|Microbial fuel cell||Polymer membrane or humic acid||?||under 40||?||Research|
|Upflow microbial fuel cell (UMFC)||?||under 40||?||Research|
|Reversible fuel cell||Polymer membrane (ionomer)||?||under 50||?||Commercial/Research|
|Direct borohydride fuel cell||Aqueous alkaline solution (e. Mass production (also called flow production, repetitive flow production, series production, or serial production) is the production of A microbial fuel cell ( MFC) or biological fuel cell is a bio- Electrochemical system that drives a current by mimicking Bacterial interactions Humic acid is one of the major components of humic substances which are dark brown and major constituents of soil organic matter Humus that contributes to Soil chemical A reversible fuel cell ( RFC) is a Fuel cell that can consume chemical A to produce electricity and chemical B and be reversed to consume electricity and chemical B An ionomer is a Polyelectrolyte that comprises Copolymers containing both electrically neutral repeating units and a fraction of Ionized units Direct borohydride fuel cells (DBFCs are a subcategory of Alkaline fuel cells that use a solution of Sodium borohydride for fuel g. , sodium hydroxide)||?||70||?||Commercial|
|Alkaline fuel cell||Aqueous alkaline solution (e. Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature The alkaline fuel cell ( AFC) also known as the Bacon fuel cell after its British inventor is one of the most developed Fuel cell technologies and is the cell g. , potassium hydroxide)||10 kW to 100 kW||under 80||Cell: 60–70%|
|Direct methanol fuel cell||Polymer membrane (ionomer)||100 kW to 1 MW||90–120||Cell: 20–30%|
|Reformed methanol fuel cell||Polymer membrane (ionomer)||5 W to 100 kW||(Reformer)250–300|
|Direct-ethanol fuel cell||Polymer membrane (ionomer)||up to 140 mW/cm²||above 25|
|Direct formic acid fuel cell||Polymer membrane (ionomer)||?||25+||?||Research|
|Proton exchange membrane fuel cell||Polymer membrane (ionomer) (e. Direct-methanol fuel cells or DMFCs are a subcategory of proton-exchange fuel cells where the Methanol (CH3OH fuel is not reformed as in the Reformed Methanol Fuel Cell ( RMFC) or Indirect Methanol Fuel Cell (IMFC systems are a subcategory of proton-exchange fuel cells where the fuel Direct-ethanol fuel cells or DEFCs are a subcategory of Proton-exchange fuel cells where the fuel Ethanol, is not reformed but fed directly to the Proton exchange membrane fuel cells, also known as Proton exchange membrane (PEM fuel cells (PEMFC are a type of Fuel cell being developed for transport g. , Nafion or Polybenzimidazole fiber)||100 W to 500 kW||(Nafion)50–120|
|RFC - Redox||Liquid electrolytes with redox shuttle & polymer membrane (Ionomer)||1 kW to 10 MW||?||?||Research|
|Phosphoric acid fuel cell||Molten phosphoric acid (H3PO4)||up to 10 MW||150-200||Cell: 55%|
|Commercial/Research||$4-$4. Nafion is a sulfonated tetrafluorethylene Copolymer discovered in the late 1960s by Walther Grot of DuPont de Nemours Polybenzimidazole or PBI Fiber (1983 is a Synthetic fiber with an extremely high Melting point that also does not Ignite. A flow battery is a form of Rechargeable battery in which Electrolyte containing one or more dissolved electroactive species flows through a power cell / reactor Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state Phosphoric acid fuel cells ( PAFC) are a type of Fuel cell that uses liquid Phosphoric acid as an Electrolyte. Phosphoric acid, also known as orthophosphoric acid or phosphoric(V acid, is a mineral (inorganic acid having the Chemical formula 50 per watt|
|Molten carbonate fuel cell||Molten alkaline carbonate (e. Molten-carbonate fuel cells ( MCFCs) are high-temperature Fuel cells that operate at temperatures of 600°C and above In Chemistry, a carbonate is a salt or Ester of Carbonic acid. g. , sodium bicarbonate NaHCO3)||100 MW||600-650||Cell: 55%|
|Tubular solid oxide fuel cell (TSOFC)||O2--conducting ceramic oxide (e. Sodium bicarbonate or sodium hydrogen carbonate is the Chemical compound with the formula NaHCO3 A solid oxide fuel cell ( SOFC) is an electrochemical conversion device that produces electricity directly from oxidizing a fuel An oxide is a Chemical compound containing at least one Oxygen atom as well as at least one other element g. , zirconium dioxide, ZrO2)||up to 100 MW||850-1100||Cell: 60–65%|
|Protonic ceramic fuel cell||H+-conducting ceramic oxide||?||700||?||Research|
|Direct carbon fuel cell||Several different||?||700-850||Cell: 80%|
|Planar Solid oxide fuel cell||O2--conducting ceramic oxide (e. Zirconia redirects here For the Sailor Moon character see Dead Moon Circus. The Protonic ceramic fuel cell or PCFC is based on a ceramic electrolyte material that exhibits high protonic conductivity at elevated temperatures A Direct Carbon Fuel Cell (DCFC is a Fuel cell that uses a carbonaceous material as a fuel An oxide is a Chemical compound containing at least one Oxygen atom as well as at least one other element g. , zirconium dioxide, ZrO2 Lanthanum Nickel Oxide La2XO4,X= Ni,Co, Cu. Zirconia redirects here For the Sailor Moon character see Dead Moon Circus. )||up to 100 MW||850-1100||Cell: 60–65%|
The efficiency of a fuel cell is dependent on the amount of power drawn from it. Drawing more power means drawing more current, which increases the losses in the fuel cell. As a general rule, the more power (current) drawn, the lower the efficiency. Most losses manifest themselves as a voltage drop in the cell, so the efficiency of a cell is almost proportional to its voltage. For this reason, it is common to show graphs of voltage versus current (so-called polarization curves) for fuel cells. A typical cell running at 0. 7 V has an efficiency of about 50%, meaning that 50% of the energy content of the hydrogen is converted into electrical energy; the remaining 50% will be converted into heat. (Depending on the fuel cell system design, some fuel might leave the system unreacted, constituting an additional loss. )
For a hydrogen cell operating at standard conditions with no reactant leaks, the efficiency is equal to the cell voltage divided by 1. 48 V, based on the enthalpy, or heating value, of the reaction. In Thermodynamics and molecular chemistry, the enthalpy (denoted as H, h, or rarely as χ) is a quotient or description of For the same cell, the second law efficiency is equal to cell voltage divided by 1. Exergy efficiency (also known as the second-law efficiency or rational efficiency) computes the efficiency of a process taking the second law of thermodynamics into 23 V. (This voltage varies with fuel used, and quality and temperature of the cell. ) The difference between these number represents the difference between the reaction's enthalpy and Gibbs free energy. In Thermodynamics and molecular chemistry, the enthalpy (denoted as H, h, or rarely as χ) is a quotient or description of In Thermodynamics, the Gibbs free energy ( IUPAC recommended name Gibbs energy or Gibbs function) is a Thermodynamic potential which This difference always appears as heat, along with any losses in electrical conversion efficiency.
Fuel cells are not constrained by the maximum Carnot cycle efficiency as combustion engines are, because they do not operate with a thermal cycle. The Carnot cycle is a particular Thermodynamic cycle, modeled on the hypothetical Carnot heat engine, proposed by Nicolas Léonard Sadi Carnot in 1824 and At times this is misrepresented by saying that fuel cells are exempt from the laws of thermodynamics, because most people think of thermodynamics in terms of combustion processes (enthalpy of formation). The standard enthalpy of formation or "standard heat of formation" of a compound is the change of Enthalpy that accompanies the formation of 1 mole of a The laws of thermodynamics also hold for chemical processes (Gibb's free energy) like fuel cells, but the maximum theoretical efficiency is higher (83% efficient at 298K ) than the Otto cycle thermal efficiency (60% for compression ratio of 10 and specific heat ratio of 1. In Thermodynamics, the Gibbs free energy ( IUPAC recommended name Gibbs energy or Gibbs function) is a Thermodynamic potential which Today Internal combustion engines in cars, Trucks motorcycles aircraft construction machinery and many others most commonly use a four-stroke cycle. 4). Of course, comparing limits imposed by thermodynamics is not a good predictor of practically achievable efficiencies. Also, if propulsion is the goal, electrical output of the fuel cell has to still be converted into mechanical power with the corresponding inefficiency. In reference to the exemption claim, the correct claim is that the "limitations imposed by the second law of thermodynamics on the operation of fuel cells are much less severe than the limitations imposed on conventional energy conversion systems".  Consequently, they can have very high efficiencies in converting chemical energy to electrical energy, especially when they are operated at low power density, and using pure hydrogen and oxygen as reactants. In Physics and other Sciences energy (from the Greek grc ἐνέργεια - Energeia, "activity operation" from grc ἐνεργός Electric energy is the potential energy associated with the conservative Coulomb forces between Charged particles contained within a system, where
For a fuel cell operated on air (rather than bottled oxygen), losses due to the air supply system must also be taken into account. This refers to the pressurization of the air and humidifying it. This reduces the efficiency significantly and brings it near to that of a compression ignition engine. Furthermore fuel cell efficiency decreases as load increases.
The tank-to-wheel efficiency of a fuel cell vehicle is about 45% at low loads and shows average values of about 36% when a driving cycle like the NEDC (New European Driving Cycle) is used as test procedure.  The comparable NEDC value for a Diesel vehicle is 22%.
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. Liquid hydrogen (LH2 or LH2 is the Liquid state of the element Hydrogen. 
Fuel cells cannot store energy like a battery, 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. Solar energy is the Light and radiant heat from the Sun that powers Earth 's Climate and Weather and sustains Life Wind Power is the conversion of wind energy into a useful form such as electricity using Wind turbines At the end of 2007 worldwide capacity of wind-powered generators was In chemistry and manufacturing electrolysis is a method of separating chemically bonded elements and compounds by passing an Electric current The overall efficiency (electricity to hydrogen and back to electricity) of such plants (known as round-trip efficiency) is between 30 and 50%, depending on conditions.  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. Lead-acid batteries, invented in 1859 by French Physicist Gaston Planté, are the oldest type of Rechargeable battery.
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. Micro combined heat and power or microCHP is an extension of the now well established idea of Cogeneration to the single/multi family home or small office building When the heat is captured, total efficiency can reach 80-90%. CHP units are being developed today for the European home market.
Fuel cells are very useful as power sources in remote locations, such as spacecraft, remote weather stations, large parks, rural locations, and in certain military applications. Development At the beginning of the 1990s the German Navy was seeking a replacement for the Type 206 submarines Initial study started on a Type 209 The German Navy ( Deutsche Marine ( is the Navy of Germany and part of the Bundeswehr (German Armed Forces A fuel cell system running on hydrogen can be compact, lightweight and has 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.  This equates to less than one minute of down time in a six year period.
A new application is micro combined heat and power, which is cogeneration for family homes, office buildings and factories. Micro combined heat and power or microCHP is an extension of the now well established idea of Cogeneration to the single/multi family home or small office building Energy recycling Cogeneration (also combined heat and power, CHP) is the use of a Heat engine or a Power station to simultaneously generate both This type of 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. A lower fuel-to-electricity conversion efficiency is tolerated (typically 15-20%), because most of the energy not converted into electricity is utilized as heat. Some heat is lost with the exhaust gas just as in a normal furnace, so the combined heat and power efficiency is still lower than 100%, typically around 80%. A furnace is a device used for Heating The name derives from Latin fornax, Oven. In terms of exergy however, the process is inefficient, and one could do better by maximizing the electricity generated and then using the electricity to drive a heat pump. "Available energy" redirects here For the meaning of the term in particle collisions see Available energy (particle collision. A heat pump is a machine or device that moves Heat from one location (the 'source' to another location (the 'sink' or 'heat sink' using work. Phosphoric-acid fuel cells (PAFC) comprise the largest segment of existing CHP products worldwide and can provide combined efficiencies close to 90% (35-50% electric + remainder as thermal) Molten-carbonate fuel cells have also been installed in these applications, and solid-oxide fuel cell prototypes exist. Phosphoric acid fuel cells ( PAFC) are a type of Fuel cell that uses liquid Phosphoric acid as an Electrolyte. Molten-carbonate fuel cells ( MCFCs) are high-temperature Fuel cells that operate at temperatures of 600°C and above A solid oxide fuel cell ( SOFC) is an electrochemical conversion device that produces electricity directly from oxidizing a fuel
Since 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. The Hydra is a 22 person Hydrogen ship, power-assisted by an Electric motor that gets its Electricity from a Fuel cell. This sort of fix restores section edit linkpoints to where they belong Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. In this application, batteries would have to be largely oversized to meet the storage demand, but fuel cells only need a larger storage unit (typically cheaper than an electrochemical device).
One such pilot program is operating on Stuart Island in Washington State. There the Stuart Island Energy Initiative has built a complete, closed-loop system: Solar panels power an electrolyzer which makes hydrogen. The hydrogen is stored in a 500 gallon tank at 200 PSI, and runs a ReliOn fuel cell to provide full electric back-up to the off-the-grid residence. The SIEI website gives extensive technical details.
The world's first Fuel Cell operated and certified passenger ship was the "HYDRA" (see picture). Mr. Christian Machens was the founder of the company "etaing GmbH" and realised this project with a small team of young engineers in Leipzig. It was christened in June 2000 in Bonn. The Fuel Cell System (AFC type, 6,5 kWel net output) was built in Wurzen near Leipzig, the hull was built in Hamburg and it was certified by the Germanischer Lloyd (Hamburg). The boat has transported around 2. 000 persons without any major technical problems. The main advantages of the AFC technology are that the system can start at freezing temperatures (-10°C) and is not sensitive to a salty environment.
The first public hydrogen refueling station was opened in Reykjavík, Iceland in April 2003. For the Greater Reykjavík Area see the Greater Reykjavík Area. Iceland, officially the Republic of Iceland ( ( Ísland or Lýðveldið Ísland ( This station serves three buses built by DaimlerChrysler that are in service in the public transport net of Reykjavík. Daimler AG ( (formerly DaimlerChrysler AG) is a German car corporation (not to be confused with the British car-maker Daimler Motor Company) and The station produces the hydrogen it needs by itself, with an electrolyzing unit (produced by Norsk Hydro), and does not need refilling: all that enters is electricity and water. Norsk Hydro ASA (,) is a Norwegian Aluminium and Renewable energy company headquartered in Oslo. Royal Dutch Shell is also a partner in the project. Royal Dutch Shell plc, commonly known simply as Shell, is a multinational oil company of Dutch and British origins The station has no roof, in order to allow any leaked hydrogen to escape to the atmosphere.
The GM 1966 Electrovan was the automotive industry's first attempt at an automobile powered by a hydrogen fuel cell. The Electrovan, which weighed more than twice as much as a normal van, could travel up to 70mph for 30 seconds. 
The 2001 Chrysler Natrium used its own on-board hydrogen processor. The Chrysler Natrium is a Fuel cell -type Hydrogen vehicle based on the Chrysler Town and Country. It produces hydrogen for the fuel cell by reacting sodium borohydride fuel with Borax, both of which Chrysler claimed was naturally occurring in great quantity in the United States. Borax (from Persian burah) also known as sodium borate, sodium tetraborate, or disodium tetraborate, is an important Boron  The hydrogen produces electric power in the fuel cell for near-silent operation and a range of 300 miles without impinging on passenger space. Chrysler also developed vehicles which separated hydrogen from gasoline in the vehicle, the purpose being to reduce emissions without relying on a nonexistent hydrogen infrastructure and to avoid large storage tanks. Chrysler LLC is an American Automobile manufacturer that has been producing Automobiles since 1925 
In 2005 the British firm Intelligent Energy produced the first ever working hydrogen run motorcycle called the ENV (Emission Neutral Vehicle). MotorCycle is the title of a 1993 album by Rock band Daniel Amos, released on BAI Records. env is a shell command for Unix and Unix-like Operating systems It is used to either print a list of Environment variables The motorcycle holds enough fuel to run for four hours, and to travel 100 miles in an urban area, at a top speed of 50 miles per hour.  Honda is also going to offer fuel-cell motorcycles. () is a Multinational corporation, engine Manufacturer and engineering corporation headquartered in Japan. env is a shell command for Unix and Unix-like Operating systems It is used to either print a list of Environment variables 
There are numerous prototype or production cars and buses based on fuel cell technology being researched or manufactured. The traffic light, also known as traffic signal, stop light, traffic lamp, stop-and-go lights, robot or semaphore, Perth is the capital and largest city of the Australian state of Western Australia. Research is ongoing at a variety of motor car manufacturers. Honda has announced the release of a hydrogen vehicle in 2008. () is a Multinational corporation, engine Manufacturer and engineering corporation headquartered in Japan. A hydrogen vehicle is a Vehicle that uses Hydrogen as its on-board fuel for motive power 
Type 212 submarines use fuel cells to remain submerged for weeks without the need to surface. Development At the beginning of the 1990s the German Navy was seeking a replacement for the Type 206 submarines Initial study started on a Type 209
Boeing researchers and industry partners throughout Europe are planning to conduct experimental flight tests in 2007 of a manned airplane powered only by a fuel cell and lightweight batteries. The Boeing Company is a major Aerospace and defense corporation originally founded by William E Overview Fixed-wing aircraft range from small training and recreational aircraft to Wide-body aircraft and military cargo aircraft. In electronics a battery is a combination of two or more Electrochemical cells which store chemical Energy which can be converted into electrical energy The Fuel Cell Demonstrator Airplane research project was completed recently and thorough systems integration testing is now under way in preparation for upcoming ground and flight testing. The Boeing demonstrator uses a Proton Exchange Membrane (PEM) fuel cell/lithium-ion battery hybrid system to power an electric motor, which is coupled to a conventional propeller. Lithium-ion batteries (sometimes abbreviated Li-ion batteries) are a type of Rechargeable battery in which a Lithium ion moves between the Anode
Not all geographic markets are ready for SOFC powered m-CHP appliances. Currently, the regions that lead the race in Distributed Generation and deployment of fuel cell m-CHP units are the EU and Japan. 
Electrochemical extraction of energy from hydrogen via fuel cells is an especially clean method of meeting our power needs, but not an efficient one, due to the necessity of adding large amounts of energy to either water or hydrocarbon fuels in order to produce the hydrogen. The hydrogen economy is a proposed method of deriving the Energy needed for Motive power (cars boats airplanes buildings or portable electronics by reacting Electrochemistry is a branch of Chemistry that studies Chemical reactions which take place in a Solution at the interface of an electron conductor Additionally, during the extraction of hydrogen from hydrocarbons, carbon monoxide is released. Although this gas is artificially converted into carbon dioxide, such a method of extracting hydrogen remains environmentally injurious. It must however be noted that regarding the concept of the hydrogen vehicle, burning/combustion of hydrogen in an internal combustion engine (IC/ICE) is often confused with the electrochemical process of generating electricity via fuel cells (FC) in which there is no combustion (though there is a small byproduct of heat in the reaction). A hydrogen vehicle is a Vehicle that uses Hydrogen as its on-board fuel for motive power Combustion or burning is a complex sequence of Exothermic chemical reactions between a Fuel and an Oxidant accompanied by the production of The internal combustion engine is an engine in which the Combustion of Fuel and an Oxidizer (typically air occurs in a confined space called a Both processes require the establishment of a hydrogen economy before they may be considered commercially viable, and even then, the aforementioned energy costs make a hydrogen economy of questionable environmental value. Hydrogen combustion is similar to petroleum combustion, and like petroleum combustion, still results in nitrogen oxides as a by-product of the combustion, which lead to smog. Hydrogen combustion, like that of petroleum, is limited by the Carnot efficiency, but is completely different from the hydrogen fuel cell's chemical conversion process of hydrogen to electricity and water without combustion. Exergy efficiency (also known as the second-law efficiency or rational efficiency) computes the efficiency of a process taking the second law of thermodynamics into Hydrogen fuel cells emit only water during use, while producing carbon dioxide emissions during the majority of hydrogen production, which comes from natural gas. Direct methane or natural gas conversion (whether IC or FC) also generate carbon dioxide emissions, but direct hydrocarbon conversion in high-temperature fuel cells produces lower carbon dioxide emissions than either combustion of the same fuel (due to the higher efficiency of the fuel cell process compared to combustion), and also lower carbon dioxide emissions than hydrogen fuel cells, which use methane less efficiently than high-temperature fuel cells by first converting it to high-purity hydrogen by steam reforming. Methane is a Chemical compound with the molecular formula. It is the simplest Alkane, and the principal component of Natural gas. Natural gas is a Gaseous Fossil fuel consisting primarily of Methane but including significant quantities of Ethane, Propane, Although hydrogen can also be produced by electrolysis of water using renewable energy, at present less than 3% of hydrogen is produced in this way.
Hydrogen is an energy carrier, and not an energy source, because it is usually produced from other energy sources via petroleum combustion, wind power, or solar photovoltaic cells. An energy carrier is a substance or phenomenon that can be used to produce mechanical work or heat or to operate chemical or physical processes (ISO 13600 Wind Power is the conversion of wind energy into a useful form such as electricity using Wind turbines At the end of 2007 worldwide capacity of wind-powered generators was A solar cell or photovoltaic cell is a device that converts Solar energy into Electricity by the photovoltaic effect. Hydrogen may be produced from subsurface reservoirs of methane and natural gas by a combination of steam reforming with the water gas shift reaction, from coal by coal gasification, or from oil shale by oil shale gasification. Steam reforming (SR hydrogen reforming or catalytic oxidation, is a method of producing Hydrogen from Hydrocarbons. The water gas shift reaction (WGS is a Chemical reaction in which Carbon monoxide reacts with Water to form Carbon dioxide and Hydrogen Oil shale extraction is an industrial process in which Kerogen &mdasha mixture of organic chemical compounds (including Hydrocarbons found in Electrolysis, which requires electricity, and high-temperature electrolysis/thermochemical production, which requires high temperatures (ideal for nuclear reactors), are two primary methods for the extraction of hydrogen from water. High-temperature electrolysis (also HTE or steam electrolysis) is a method currently being investigated for the production of Hydrogen from water with Hydrogen is commonly produced by extraction from Hydrocarbon Fossil fuels via a chemical path This article is a subarticle of Nuclear power. A nuclear reactor is a device in which Nuclear chain reactions are initiated controlled
As of 2005, 49. 7% of the electricity produced in the United States comes from coal, 19. The United States of America —commonly referred to as the 3% comes from nuclear, 18. Nuclear power is any Nuclear technology designed to extract usable Energy from atomic nuclei via controlled Nuclear reactions 7% comes from natural gas, 6. Natural gas is a Gaseous Fossil fuel consisting primarily of Methane but including significant quantities of Ethane, Propane, 5% from hydroelectricity, 3% from petroleum and the remaining 2. Hydroelectricity is electricity generated by Hydropower, ie the production of power through use of the gravitational force of falling water Petroleum ( L petroleum, from Greek πετρέλαιον, lit 8% mostly coming from geothermal, solar and biomass. Geothermal power (from the Greek roots geo, meaning earth and therme, meaning heat is energy generated by heat stored in the earth or the collection Solar energy is the Light and radiant heat from the Sun that powers Earth 's Climate and Weather and sustains Life Biomass refers to living and recently dead Biological material that can be used as fuel or for industrial production  When hydrogen is produced through electrolysis, the energy comes from these sources. Though the fuel cell itself will only emit heat and water as waste, pollution is often caused when generating the electricity required to produce the hydrogen that the fuel cell uses as its power source (for example, when coal, oil, or natural gas-generated electricity is used). This will be the case unless the hydrogen is produced using electricity generated by hydroelectric, geothermal, solar, wind or other clean power sources (which may or may not include nuclear power, depending on one's attitude to the nuclear waste byproducts); hydrogen is only as clean as the energy sources used to produce it. A holistic approach has to take into consideration the impacts of an extended hydrogen scenario, including the production, the use and the disposal of infrastructure and energy converters.
Nowadays low temperature fuel cell stacks proton exchange membrane fuel cell (PEMFC), direct methanol fuel cell (DMFC) and phosphoric acid fuel cell (PAFC) make extensive use of catalysts. Proton exchange membrane fuel cells, also known as Proton exchange membrane (PEM fuel cells (PEMFC are a type of Fuel cell being developed for transport Direct-methanol fuel cells or DMFCs are a subcategory of proton-exchange fuel cells where the Methanol (CH3OH fuel is not reformed as in the Phosphoric acid fuel cells ( PAFC) are a type of Fuel cell that uses liquid Phosphoric acid as an Electrolyte. Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst Impurities poison or foul the catalysts (reducing activity and efficiency), thus higher catalyst densities are required.  Limited reserves of platinum quicken the synthesis of an inorganic complex very similar to the catalytic iron-sulfur core of bacterial hydrogenase to step in. Platinum (ˈplætɪnəm is a Chemical element with the Atomic symbol Pt and an Atomic number of 78  Although platinum is seen by some as one of the major "showstoppers" to mass market fuel cell commercialization companies, most predictions of platinum running out and/or platinum prices soaring do not take into account effects of thrifting (reduction in catalyst loading) and recycling. Recent research at Brookhaven National Laboratory could lead to the replacement of platinum by a gold-palladium coating which may be less susceptible to poisoning and thereby improve fuel cell lifetime considerably. Brookhaven National Laboratory ( BNL) is a United States national laboratory located in Upton New York on Long Island, and was formally established Gold (ˈɡoʊld is a Chemical element with the symbol Au (from its Latin name aurum) and Atomic number 79 Palladium (pronounced \pəˈleɪdiəm\ is a rare and lustrous silvery-white metal that was discovered in 1803 by William Hyde Wollaston, who named it palladium after the  Current targets for a transport PEM fuel cells are 0. 2 g/kW Pt – which is a factor of 5 decrease over current loadings – and recent comments from major original equipment manufacturers (OEMs) indicate that this is possible. An original equipment manufacturer, or OEM is typically a company that uses a component made by a second company in its own product or sells the product of the second company Also it is fully anticipated that recycling of fuel cells components, including platinum, will kick-in. Recycling involves processing used materials into new products in order to prevent the waste of potentially useful materials reduce the consumption of fresh raw materials reduce High-temperature fuel cells, including molten carbonate fuel cells (MCFC's) and solid oxide fuel cells (SOFC's), do not use platinum as catalysts, but instead use cheaper materials such as nickel and nickel oxide, which are considerably more abundant (for example, nickel is used in fairly large quantities in common stainless steel). A solid oxide fuel cell ( SOFC) is an electrochemical conversion device that produces electricity directly from oxidizing a fuel