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88-601: The concept vehicle is powered by a rechargeable plug-in hybrid hydrogen fuel cell drive train, called HySeries Drive . This power plant system was developed with partial funding from the United States Department of Energy , and is currently being tested on a prototype version of the Ford Edge . The Airstream Concept's wheels are driven by electric motors , which are powered by a lithium-ion battery pack. The Ballard Power Systems hydrogen fuel cell system recharges

176-403: A cathode , and an electrolyte that allows ions, often positively charged hydrogen ions (protons), to move between the two sides of the fuel cell. At the anode, a catalyst causes the fuel to undergo oxidation reactions that generate ions (often positively charged hydrogen ions) and electrons. The ions move from the anode to the cathode through the electrolyte. At the same time, electrons flow from

264-490: A cogeneration power plant in hospitals, universities and large office buildings. In recognition of the fuel cell industry and America's role in fuel cell development, the United States 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). Fuel cells come in many varieties; however, they all work in

352-537: A DC circuit. However, most such circuits have a DC solution. This solution gives the circuit voltages and currents when the circuit is in DC steady state . Such a circuit is represented by a system of differential equations . The solution to these equations usually contain a time varying or transient part as well as constant or steady state part. It is this steady state part that is the DC solution. There are some circuits that do not have

440-407: A DC solution. Two simple examples are a constant current source connected to a capacitor and a constant voltage source connected to an inductor. In electronics, it is common to refer to a circuit that is powered by a DC voltage source such as a battery or the output of a DC power supply as a DC circuit even though what is meant is that the circuit is DC powered. In a DC circuit, a power source (e.g.

528-723: A SOFC system are less than those from a fossil fuel combustion plant. The chemical reactions for the SOFC system can be expressed as follows: 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), propane, and butane. These fuel cells are at an early stage of development. Challenges exist in SOFC systems due to their high operating temperatures. One such challenge

616-450: A battery system to ensure power is maintained for subscriber lines during power interruptions. Other devices may be powered from the telecommunications DC system using a DC-DC converter to provide any convenient voltage. Many telephones connect to a twisted pair of wires, and use a bias tee to internally separate the AC component of the voltage between the two wires (the audio signal) from

704-471: A battery, 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. As of 2019, 90% of hydrogen was used for oil refining, chemicals and fertilizer production (where hydrogen is required for the Haber–Bosch process ), and 98% of hydrogen

792-423: A battery, capacitor, etc.) has a positive and negative terminal, and likewise, the load also has a positive and negative terminal. To complete the circuit, positive charges need to flow from the power source to the load. The charges will then return to the negative terminal of the load, which will then flow back to the negative terminal of the battery, completing the circuit. If either the positive or negative terminal

880-493: A camera view and secondary driver-oriented information, and also allows the front-seat passenger to view DVD movies and work on the Internet. The front seats are captain's chairs that can swivel and rotate to face aft. The rear seats are lounge-like, and includes a 360-degree viewscreen for entertainment, games, Internet access, and as a live camera feed. The seats include four-point safety belts . Fuel cell A fuel cell

968-651: 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. 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

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1056-449: A concentrated solution of KOH or NaOH which serves as an electrolyte. H 2 gas and O 2 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 343–413   K (70 -140 °C) and provides

1144-524: A direct current source . The DC solution of an electric circuit is the solution where all voltages and currents are constant. Any stationary voltage or current waveform can be decomposed into a sum of a DC component and a zero-mean time-varying component; the DC component is defined to be the expected value, or the average value of the voltage or current over all time. Although DC stands for "direct current", DC often refers to "constant polarity". Under this definition, DC voltages can vary in time, as seen in

1232-515: A durability of over 120,000 km (75,000 miles) with less than 10% degradation. In a 2017 Well-to-Wheels simulation analysis that "did not address the economics and market constraints", General Motors and its partners estimated that, for an equivalent journey, 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. Direct current Direct current ( DC )

1320-597: 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. 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,

1408-458: 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%. The high operating temperature is largely due to the physical properties of the YSZ electrolyte. As temperature decreases, so does

1496-403: 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. In the archetypical hydrogen–oxide proton-exchange membrane fuel cell (PEMFC) design, a proton-conducting polymer membrane (typically nafion ) contains the electrolyte solution that separates the anode and cathode sides. This

1584-432: 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. 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. The Japanese ENE FARM project stated that 34.213 PEMFC and 2.224 SOFC were installed in

1672-568: A hydrogen source would create less than one ounce of pollution (other than CO 2 ) for every 1,000 kW·h produced, compared to 25 pounds of pollutants generated by conventional combustion systems. Fuel Cells also produce 97% less nitrogen oxide emissions than conventional coal-fired power plants. One such pilot program is operating on Stuart Island in Washington State. There the Stuart Island Energy Initiative has built

1760-455: A hydrogen-rich gas in the anode, eliminating the need to produce hydrogen externally. The reforming process creates CO 2 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

1848-459: A potential of about 0.9   V. Alkaline anion exchange membrane fuel cell (AAEMFC) is a type of AFC which employs a solid polymer electrolyte instead of aqueous potassium hydroxide (KOH) and it is superior to aqueous AFC. 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

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1936-770: 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 . 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. This equates to less than one minute of downtime in

2024-450: A rear hatch for loading cargo aft. The interior was inspired by spacecraft images and environments portrayed in 2001: A Space Odyssey , according to Ford. It is described as a "lounge atmosphere", meant to provide a relaxing experience while traveling. The instrument panel includes flush-mounted, touch-sensitive controls and a single, multi-function gauge display with primary driving information. A center-mounted dual-view screen provides

2112-425: A requirement, as in enclosed spaces such as warehouses, and where hydrogen is considered an acceptable reactant, a [PEM fuel cell] is becoming an increasingly attractive choice [if exchanging batteries is inconvenient]". In 2013 military organizations were evaluating fuel cells to determine if they could significantly reduce the battery weight carried by soldiers. In a fuel cell vehicle the tank-to-wheel efficiency

2200-401: A six-year period. 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. There are many different types of stationary fuel cells so efficiencies vary, but most are between 40% and 60% energy efficient. However, when the fuel cell's waste heat

2288-411: 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

2376-437: A welding machine. In the 1960s, Pratt & 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 E. Billings. UTC Power was the first company to manufacture and commercialize a large, stationary fuel cell system for use as

2464-572: Is flow batteries , in which the fuel can be regenerated by recharging. 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. In addition to electricity, fuel cells produce water vapor, heat and, depending on the fuel source, very small amounts of nitrogen dioxide and other emissions. PEMFC cells generally produce fewer nitrogen oxides than SOFC cells: they operate at lower temperatures, use hydrogen as fuel, and limit

2552-440: Is an electrochemical cell that converts the chemical energy of a fuel (often hydrogen ) and an oxidizing agent (often oxygen) into electricity through a pair of redox reactions. Fuel cells are different from most batteries in requiring a continuous source of fuel and oxygen (usually from air) to sustain the chemical reaction, whereas in a battery the chemical energy usually comes from substances that are already present in

2640-482: Is an AC device which uses a rectifier to produce DC for battery charging. Most highway passenger vehicles use nominally 12  V systems. Many heavy trucks, farm equipment, or earth moving equipment with Diesel engines use 24 volt systems. In some older vehicles, 6 V was used, such as in the original classic Volkswagen Beetle . At one point a 42 V electrical system was considered for automobiles, but this found little use. To save weight and wire, often

2728-435: Is commonly found in many extra-low voltage applications and some low-voltage applications, especially where these are powered by batteries or solar power systems (since both can produce only DC). Most electronic circuits or devices require a DC power supply . Domestic DC installations usually have different types of sockets , connectors , switches , and fixtures from those suitable for alternating current. This

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2816-427: Is disconnected, the circuit will not be complete and the charges will not flow. In some DC circuit applications, polarity does not matter, which means you can connect positive and negative backwards and the circuit will still be complete and the load will still function normally. However, in most DC applications, polarity does matter, and connecting the circuit backwards will result in the load not working properly. DC

2904-412: Is distributed to a substation, which utilizes a rectifier to convert the power to direct current. The term DC is used to refer to power systems that use only one electrical polarity of voltage or current, and to refer to the constant, zero-frequency, or slowly varying local mean value of a voltage or current. For example, the voltage across a DC voltage source is constant as is the current through

2992-639: Is greater than 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%. In 2008 Honda released a demonstration fuel cell electric vehicle (the Honda FCX Clarity ) with fuel stack claiming a 60% tank-to-wheel efficiency. 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

3080-447: Is mostly due to the lower voltages used, resulting in higher currents to produce the same amount of power . It is usually important with a DC appliance to observe polarity, unless the device has a diode bridge to correct for this. Most automotive applications use DC. An automotive battery provides power for engine starting, lighting, the ignition system, the climate controls, and the infotainment system among others. The alternator

3168-435: Is one-directional flow of electric charge . An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor such as a wire, but can also flow through semiconductors , insulators , or even through a vacuum as in electron or ion beams . The electric current flows in a constant direction, distinguishing it from alternating current (AC). A term formerly used for this type of current

3256-482: Is produced by steam methane reforming , which emits carbon dioxide. 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. The electrolyzer/fuel cell system can store indefinite quantities of hydrogen, and is therefore suited for long-term storage. Solid-oxide fuel cells produce heat from

3344-585: Is referred to 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 types of noble metals are usually used as the catalyst for PEMFC, and these can be contaminated by carbon monoxide , necessitating a relatively pure hydrogen fuel. The electrolyte could be a polymer membrane . Phosphoric acid fuel cells (PAFCs) were first designed and introduced in 1961 by G. V. Elmore and H. A. Tanner . In these cells, phosphoric acid

3432-438: Is said to be the largest of the type. Small-scale (sub-5kWhr) fuel cells are being developed for use in residential off-grid deployment. 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

3520-594: 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. 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

3608-528: 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. Another disadvantage of SOFC systems is the long start-up, making SOFCs less useful for mobile applications. Despite these disadvantages,

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3696-506: Is used as a non-conductive electrolyte to pass protons from the anode to the cathode and to force electrons to travel from anode to cathode through an external electrical circuit. These cells commonly work in temperatures of 150 to 200 °C. 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. Using this heat in cogeneration can enhance

3784-436: Is used to heat a building in a cogeneration system this efficiency can increase to 85%. This is significantly more efficient than traditional coal power plants, which are only about one third energy efficient. Assuming production at scale, fuel cells could save 20–40% on energy costs when used in cogeneration systems. Fuel cells are also much cleaner than traditional power generation; a fuel cell power plant using natural gas as

3872-690: Is used, the CO 2 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 forklifts. The different components of a PEMFC are 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 , carbon – polymer composites etc. The membrane electrode assembly (MEA)

3960-613: The Electrochemical Society journal Interface in 2008, wrote, "While fuel cells are efficient relative to combustion engines, they are not as efficient as batteries, primarily due to the inefficiency of the oxygen reduction reaction (and ... the oxygen evolution reaction, should the hydrogen be formed by electrolysis of water). ... [T]hey make the most sense for operation disconnected from the grid, or when fuel can be provided continuously. For applications that require frequent and relatively rapid start-ups ... where zero emissions are

4048-511: The ionic conductivity of YSZ. Therefore, to obtain the 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

4136-428: The waste heat produced by the primary power cycle - whether fuel cell, nuclear fission or combustion - is captured and put to use, increasing the efficiency of the system to up to 85–90%. 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

4224-448: The DC component of the voltage between the two wires (used to power the phone). High-voltage direct current (HVDC) electric power transmission systems use DC for the bulk transmission of electrical power, in contrast with the more common alternating current systems. For long-distance transmission, HVDC systems may be less expensive and suffer lower electrical losses. Applications using fuel cells (mixing hydrogen and oxygen together with

4312-489: The DFC-ERG, is combined with a gas turbine and, according to the company, it achieves an electrical efficiency of 65%. The electric storage fuel cell is a conventional battery chargeable by electric power input, using the conventional electro-chemical effect. However, the battery further includes hydrogen (and oxygen) inputs for alternatively charging the battery chemically. Glossary of terms in table: The energy efficiency of

4400-493: 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 United States 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. MCFCs also have relatively high efficiencies. They can reach

4488-478: The anode to the cathode through an external circuit, producing direct current electricity. At the cathode, another catalyst causes ions, electrons, and oxygen to react, forming water and possibly other products. Fuel cells are classified by the type of electrolyte they use and by the difference in start-up 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). A related technology

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4576-423: 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

4664-553: The battery. Fuel cells can produce electricity continuously for as long as fuel and oxygen are supplied. The first fuel cells were invented by Sir William Grove in 1838. The first commercial use of fuel cells came almost a century later following the invention of the hydrogen–oxygen fuel cell by Francis Thomas Bacon in 1932. The alkaline fuel cell , also known as the Bacon fuel cell after its inventor, has been used in NASA space programs since

4752-548: 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. The chemical reactions for an MCFC system can be expressed as follows: 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

4840-462: The cell substrate, which reduces cost and start-up time of the system. 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. Like SOFCs, MCFCs are capable of converting fossil fuel to

4928-474: The charging of batteries to large power supplies for electronic systems, motors, and more. Very large quantities of electrical energy provided via direct-current are used in smelting of aluminum and other electrochemical processes. It is also used for some railways , especially in urban areas . High-voltage direct current is used to transmit large amounts of power from remote generation sites or to interconnect alternating current power grids. Direct current

5016-407: The circuit voltages and currents are independent of time. A particular circuit voltage or current does not depend on the past value of any circuit voltage or current. This implies that the system of equations that represent a DC circuit do not involve integrals or derivatives with respect to time. If a capacitor or inductor is added to a DC circuit, the resulting circuit is not, strictly speaking,

5104-597: 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. 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 the current generated from hydrogen and oxygen dissolved in water. Grove later sketched his design, in 1842, in

5192-549: The diffusion of nitrogen into the anode via the proton exchange membrane, which forms NOx. The energy efficiency of a fuel cell is generally between 40 and 60%; however, if waste heat is captured in a cogeneration scheme, efficiencies of up to 85% can be obtained. 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 Sir William Grove wrote about

5280-404: The efficiency of phosphoric acid fuel cells from 40 to 50% to about 80%. Since the proton production rate on the anode is small, platinum is used as a 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. Solid acid fuel cells (SAFCs) are characterized by

5368-447: The electricity into mechanical power. However, this calculation allows the comparison of different types of power generation. The theoretical maximum efficiency of a fuel cell approaches 100%, while the theoretical maximum efficiency of internal combustion engines is approximately 58%. Values are given from 40% for acidic, 50% for molten carbonate, to 60% for alkaline, solid oxide and PEM fuel cells. Fuel cells cannot store energy like

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5456-442: 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. SOFCs are unique because 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 protons travelling vice versa (i.e., from

5544-463: The fuel. According to the U.S. Department of Energy, fuel cells are generally between 40 and 60% energy efficient. This is higher than some other systems for energy generation. For example, the internal combustion engine of a car can be about 43% energy efficient. Steam power plants usually achieve efficiencies of 30-40% while combined cycle gas turbine and steam plants can achieve efficiencies above 60%. In combined heat and power (CHP) systems,

5632-506: 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. A typical capacity range of home fuel cell is 1–3 kW el , 4–8 kW th . CHP systems linked to absorption chillers use their waste heat for refrigeration . The waste heat from fuel cells can be diverted during

5720-462: The ions are reunited with the electrons and the two react with a third chemical, usually oxygen, to create water or carbon dioxide. Design features in a fuel cell include: A typical fuel cell produces a voltage from 0.6 to 0.7 V at a 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 to yield higher voltage , and in parallel to allow

5808-400: The load. At the anode a catalyst ionizes the fuel, 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 an electric current. The ions travel through the electrolyte to the cathode. Once reaching the cathode,

5896-567: The loops of wire each half turn, it caused the flow of electricity to reverse, generating an alternating current . At Ampère's suggestion, Pixii later added a commutator , a type of "switch" where contacts on the shaft work with "brush" contacts to produce direct current. The late 1870s and early 1880s saw electricity starting to be generated at power stations . These were initially set up to power arc lighting (a popular type of street lighting) running on very high voltage (usually higher than 3,000 volts) direct current or alternating current. This

5984-609: 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

6072-512: The metal frame of the vehicle is connected to one pole of the battery and used as the return conductor in a circuit. Often the negative pole is the chassis "ground" connection, but positive ground may be used in some wheeled or marine vehicles. In a battery electric vehicle , there are usually two separate DC systems. The "low voltage" DC system typically operates at 12V, and serves the same purpose as in an internal combustion engine vehicle. The "high voltage" system operates at 300-400V (depending on

6160-485: The mid-1960s 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, trains, boats, motorcycles, and submarines. There are many types of fuel cells, but they all consist of an anode ,

6248-490: 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 a 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 . This

6336-756: The period 2012–2014, 30,000 units on LNG and 6,000 on LPG . Four fuel cell electric vehicles have been introduced for commercial lease and sale: the Honda Clarity , Toyota Mirai , Hyundai ix35 FCEV , and the Hyundai Nexo . By year-end 2019, about 18,000 FCEVs had been leased or sold worldwide. Fuel cell electric vehicles feature an average range of 505 km (314 mi) between refuelings and can be refueled in about 5 minutes. The U.S. Department of Energy's Fuel Cell Technology Program states that, as of 2011, fuel cells achieved 53–59% efficiency at one-quarter power and 42–53% vehicle efficiency at full power, and

6424-428: The raw output of a rectifier or the fluctuating voice signal on a telephone line. Some forms of DC (such as that produced by a voltage regulator ) have almost no variations in voltage , but may still have variations in output power and current. A direct current circuit is an electrical circuit that consists of any combination of constant voltage sources, constant current sources, and resistors . In this case,

6512-493: The recombination of the oxygen and hydrogen. The ceramic can run as hot as 800 °C (1,470 °F). 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

6600-405: 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

6688-504: The same journal. The fuel cell he made used similar materials to today's phosphoric acid fuel cell . In 1932, English engineer Francis Thomas Bacon successfully developed a 5 kW stationary fuel cell. NASA used the alkaline fuel cell (AFC), also known as the Bacon fuel cell after its inventor, from the mid-1960s. In 1955, W. Thomas Grubb, a chemist working for the General Electric Company (GE), further modified

6776-764: 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. Co-generation systems can reach 85% efficiency (40–60% electric and the remainder as thermal). Phosphoric-acid fuel cells (PAFC) comprise the largest segment of existing CHP products worldwide and can provide combined efficiencies close to 90%. Molten carbonate (MCFC) and solid-oxide fuel cells (SOFC) are also used for combined heat and power generation and have electrical energy efficiencies around 60%. Disadvantages of co-generation systems include slow ramping up and down rates, high cost and short lifetime. Also their need to have

6864-459: The thousands of hours. The alkaline fuel cell (AFC) or hydrogen-oxygen fuel cell was designed and first demonstrated publicly by Francis Thomas Bacon in 1959. It was used as a primary source of electrical energy in the Apollo space program. 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

6952-579: The use of a solid acid material as the electrolyte. At low temperatures, solid acids have an ordered molecular structure like most salts. At warmer temperatures (between 140 and 150   °C for CsHSO 4 ), some solid acids undergo a phase transition to become highly disordered "superprotonic" structures, which increases conductivity by several orders of magnitude. The first proof-of-concept SAFCs were developed in 2000 using cesium hydrogen sulfate (CsHSO 4 ). Current SAFC systems use cesium dihydrogen phosphate (CsH 2 PO 4 ) and have demonstrated lifetimes in

7040-451: The vehicle's 336-volt lithium-ion battery pack. With a full load of hydrogen, the range increases another 280 miles (451 km), for a total of 305 miles (491 km). The sole exhaust emission from the operating vehicle is water vapor. The Ford Airstream includes asymmetric doors. The passenger side door is a power clamshell hatch that runs two-thirds the length of the vehicle for loading of passengers and cargo. The crossover includes

7128-512: The vehicle's battery pack as needed, as a portable generator, and the vehicle can also be plugged into an AC source, to recharge between trips. The HySeries Drive delivers the equivalent of a combined city/highway equivalent fuel economy of 41 mpg (U.S.) (5.7 L/100 km). In pure-battery mode, the Ford Airstream Concept is designed to travel about 25 miles (40 km), before the hydrogen-powered fuel cell begins operating to recharge

7216-464: The vehicle), and provides the power for the traction motors . Increasing the voltage for the traction motors reduces the current flowing through them, increasing efficiency. Telephone exchange communication equipment uses standard −48 V DC power supply. The negative polarity is achieved by grounding the positive terminal of power supply system and the battery bank. This is done to prevent electrolysis depositions. Telephone installations have

7304-515: Was galvanic current . The abbreviations AC and DC are often used to mean simply alternating and direct , as when they modify current or voltage . Direct current may be converted from an alternating current supply by use of a rectifier , which contains electronic elements (usually) or electromechanical elements (historically) that allow current to flow only in one direction. Direct current may be converted into alternating current via an inverter . Direct current has many uses, from

7392-540: 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

7480-406: Was followed by the widespread use of low voltage direct current for indoor electric lighting in business and homes after inventor Thomas Edison launched his incandescent bulb based electric " utility " in 1882. Because of the significant advantages of alternating current over direct current in using transformers to raise and lower voltages to allow much longer transmission distances, direct current

7568-407: Was produced in 1800 by Italian physicist Alessandro Volta 's battery, his Voltaic pile . The nature of how current flowed was not yet understood. French physicist André-Marie Ampère conjectured that current travelled in one direction from positive to negative. When French instrument maker Hippolyte Pixii built the first dynamo electric generator in 1832, he found that as the magnet used passed

7656-477: Was replaced over the next few decades by alternating current in power delivery. In the mid-1950s, high-voltage direct current transmission was developed, and is now an option instead of long-distance high voltage alternating current systems. For long distance undersea cables (e.g. between countries, such as NorNed ), this DC option is the only technically feasible option. For applications requiring direct current, such as third rail power systems, alternating current

7744-408: 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

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