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Unit -V New Energy Sources Unit -V New Energy Sources Hydrogen as a Renewable Energy Source : Sources of hydrogen Fuel for vehicles Hydrogen Production Direct Electrolysis of Water Thermal Decomposition of water Biological and Biochemical methods of hydrogen Production Storage of hydrogen gaseous Cryogenic and metal hydride: Fuel cell Principle of working Construction and Applications. Hydrogen as a Renewable Energy Source Hydrogen is the most abundant substance within the universe, making up 3/4 of all matter. The sun still being in the early stages of it’s life is made up of 75% hydrogen. Millions of years ago Hydrogen reacted to produce Helium and all the energy was emitted to space, but a small amount was captured on Earth by plants that had died and have now become the fossil fuels that are now the basis of today’s leading world industry. Exists in nature, an invisible gas which is extremely flammable, can produce secondary energy Hydrogen.. A Plentiful Element existing freely in nature an invisible, extremely flammable gas highly reactive and essential in many chemical and biological processes not an energy source, but rather an energy carrier from which a secondary form of energy must be created Why Hydrogen? Why Now? 1. Hydrogen production is already large a) It is used to synthesize ammonia for fertilizer production b) It is used in high-pressure hydro-treating petroleum in refineries 2. Transportation and energy-intensive processes depend on oil, which is a finite, non-renewable energy source 3. Hydrogen promises to lead “better, faster, more efficient, environmentally clean transportation designs. 4. Clearly, hydrogen has the potential of being a powerful energy source!!! 5. IN FACT, Hydrogen has the highest heat of combustion of ANY known SUBSTANCE. 6. Used in rockets, space shuttle, small batteries, etc 7. High energy, low emission = TANTILIZING for fuel in cars and other Sources of hydrogen Sources that Hydrogen can be extracted from: Natural Gas, Water, Coal, Gasoline, Methanol, Biomass Other sources being researched include the uses of solar energy, photosynthesis, decomposition, and fuel cells themselves can tri-generate electricity, heat, and hydrogen. Sources of hydrogen Where can we get hydrogen? Reaction of metal with Acid • On that Day I demoed Sodium Metal and Water Na(s) + H2O(l) -> NaOH + H2 • More commonly (a metal w/ Sulfuric acid) Zn(s) + H2SO4 -> H2(g) + ZnSO4 Electrolysis • Demoed the bubbling that occurs at an electrode surface. Remember the light bulb. H2O(l) -> H2 + ½ O2 (reverse reaction of combustion) » Same amount of energy NEEDS TO BE INPUTED – Discussed feasibility Sources of hydrogen (Cont’d) Hot steam over pure carbon (coke) Input 131 kJ/mol H2O + C(s) -> H2(g) + CO(g) CO is carbon MONOXIDE!! Hot steam over methane (natural gas) Input 165 kJ/mol H2O + CH4 -> 4 H2 (g) + CO2(g) CO2 = Greenhouse gas Fuel for vehicles (Hydrogen Vehicles) Stores energy more efficiently than batteries Burns twice as efficiently in a fuel cell as gasoline does in an engine Doesn’t rely on any fossil fuel It’s only waste product is water Other Modes of Hydrogen Transport Hydrogen Production H is difficult and costly to compress, store, and transport; it has one of the lowest energy densities of any fuel, 1/3rd of any natural gas. Hydrogen has major safety issues; it’s flammable over a wide range of concentrations and is very easily ignited. Hydrogen is one of the most leak prone gases, set to a strict set of regulations and standards. Currently in US at 8 billion kg (energy equivalent of 8 bil/gal. of gasoline), Americans consumed 180 bil/gal. gasoline in 2000, hydrogen demand is growing. Hydrogen Production Direct Electrolysis of Water Electrolysis is a process that splits Hydrogen from water, which results in no emission but is very expensive at present, It accounts for only 4-5% of Hydrogen production in the United States today, due mostly to the greater cost. •Electrolysis of water Hydrogen Challenger •Production of hydrogen from water requires large amounts of energy and is uncompetitive with its production from coal or natural gas. Potential electrical energy supplies include hydropower, wind turbines, or photovoltaic cells. Usually, the electricity consumed is more valuable than the hydrogen produced so this method has not been widely used. Other potential energy supplies include heat from nuclear reactors and light from the sun. Hydrogen can also be used to store renewable generated electricity when it is not needed (like the wind blowing at night) and then used to meet power needs during the day or to fuel vehicles. The storable quality of hydrogen helps make hydrogen an enabler of the wider use of renewables,[3] and internal combustion engines. •High pressure electrolysis •When water is pressurized and then electrolysis is conducted at those high pressures, the produced hydrogen gas is pre-compressed at around 120–200 bar (1740–2900 psi).[4] By pre-pressurising the hydrogen in the electrolyses energy is saved as the need for an external hydrogen compressor is eliminated, the average energy consumption for internal compression is around 3%.[5] The energy required to compress water is very much less than that required to compress hydrogen gas. •High-temperature electrolysis •When the energy supplied is in the form of heat (originating from solar thermal, or nuclear), the best path to the production of hydrogen is through high-temperature electrolysis (HTE). In contrast with low-temperature electrolysis, HTE of water converts more of the initial heat energy into chemical energy (hydrogen), potentially doubling efficiency to about 50%. Because some of the energy in HTE is supplied in the form of heat, less of the energy must be converted twice (from heat to electricity, and then to chemical form), and so the process is more efficient. •HTE processes are generally only considered in combination with a nuclear heat source, because the other nonchemical form of high-temperature heat (concentrating solar thermal) is not consistent enough to bring down the capital costs of the HTE equipment. Research into HTE and high-temperature nuclear reactors may eventually lead to a hydrogen supply that is cost-competitive with natural gas steam reforming. HTE has been demonstrated in a laboratory, but not at a commercial scale. Hydrogen Production Thermal Decomposition of water 1. Thermal decomposition of water • Thermal decomposition, also called thermolysis, is defined as a chemical reaction whereby a chemical substance breaks up into at least two chemical substances when heated. At elevated temperatures water molecules split into their atomic components hydrogen andoxygen. For example, at 2200 °C about three percent of all H2O molecules are dissociated into various combinations of hydrogen and oxygen atoms, mostly H, H2, O, O2, and OH. Other reaction products like H2O2 or HO2 remain minor. At the very high temperature of 3000 °C more than half of the water molecules are decomposed, but at ambient temperatures only one molecule in 100 trillion dissociates by the effect of heat. • Thermal water splitting has been investigated for hydrogen production since the 1960s.[15] The high temperatures needed to obtain substantial amounts of hydrogen impose severe requirements on the materials used in any thermal water splitting device. For industrial or commercial application, the material constraints have limited the success of applications for hydrogen production from direct thermal water splitting and with few exceptions most recent developments are in the area of thecatalysis and thermochemical cycles. Nuclear-thermal decomposition of water • Some prototype Generation IV reactors, such as the HTTR, operate at 850 to 1000 degrees Celsius, considerably hotter than existing commercial nuclear powerplants. General Atomics predicts that hydrogen produced in a High Temperature Gas Cooled Reactor (HTGR) would cost $1.53/kg. In 2003, steam reforming of natural gas yielded hydrogen at $1.40/kg. At 2005 gas prices, hydrogen cost $2.70/kg. Hence, just within the United States, a savings of tens of billions of dollars per year is possible with a nuclear-powered supply. Much of this savings would translate into reduced oil and natural gas imports. • One side benefit of a nuclear reactor that produces both electricity and hydrogen is that it can shift production between the two. For instance, the plant might produce electricity during the day and hydrogen at night, matching its electrical generation profile to the daily variation in demand. If the hydrogen can be produced economically, this scheme would compete favorably with existing grid energy storage schemes. What is more, there is sufficient hydrogen demand in the United States that all daily peak generation could be handled by such plants Nuclear-thermal decomposition of water contd… • Recent research on the hybrid thermoelectric Copper-chlorine cycle has focused on a cogeneration system using the waste heat from nuclear reactors, specifically the CANDU supercritical water reactor.Electrolysis of water is the decomposition of water (H2O) into oxygen (O2) and hydrogen gas (H2) due to an electric currentbeing passed through the water. In chemistry and manufacturing, electrolysis is a method of separating chemically bonded elements and compounds by passing an electric current through them. One use of electrolysis of water or artificial photosynthesis (photoelectrolysis in a photoelectrochemical cell) is to produce hydrogen. Recently, researchers have shown that water splitting can be broken into two discrete steps using polyoxometalate based redox mediators.[2] • Power to gas production schemes, the excess power or off peak power created by wind generators or solar arrays is used for load balancing of the energy grid by storing and later injecting the hydrogen into the natural gas grid. Biological and Biochemical methods of hydrogen Production • Biological hydrogen production (algae) • The biological hydrogen production with algae is a method of photobiological water splitting which is done in a closed photobioreactorbased on the production of hydrogen as a solar fuel by algae. Algae produce hydrogen under certain conditions. In 2000 it was discovered that if C. reinhardtii algae are deprived of sulfur they will switch from the production of oxygen, as in normal photosynthesis, to the production of hydrogen. Photosynthesis • Photosynthesis in cyanobacteria and green algae splits water into hydrogen ions and electrons. The electrons are transported over ferredoxins. Fe-Fehydrogenases (enzymes) combine them into hydrogen gas. In Chlamydomonas reinhardtii Photosystem II produces in direct conversion of sunlight 80% of the electrons that end up in the hydrogen gas. Light-harvesting complex photosystem II light-harvesting protein LHCBM9 promotes efficient light energy dissipation. The Fe-Fehydrogenases need an anaerobic environment as they are inactivated by oxygen. Fourier transform infrared spectroscopy is used to examine metabolic pathways Biological and Biochemical methods of hydrogen Production Contd… • • • • • • • • • • Truncated antenna The chlorophyll (Chl) antenna size in green algae is minimized, or truncated, to maximize photo biological solar conversion efficiency and H2 production. The truncated Chl antenna size minimizes absorption and wasteful dissipation of sunlight by individual cells, resulting in better light utilization efficiency and greater photosynthetic productivity by the green alga mass culture. Bioreactor design issues Restriction of photosynthetic hydrogen production by accumulation of a proton gradient. Competitive inhibition of photosynthetic hydrogen production by carbon dioxide. Requirement for bicarbonate binding at photosystem II (PSII) for efficient photosynthetic activity. Competitive drainage of electrons by oxygen in algal hydrogen production. Economics must reach competitive price to other sources of energy and the economics are dependent on several parameters. A major technical obstacle is the efficiency in converting solar energy into chemical energy stored in molecular hydrogen. Attempts are in progress to solve these problems via bioengineering Challenges of using hydrogen • Even though, hydrogen is an attractive alternative to hydrocarbon fuels such as gasoline in mobile applications. However, the storage of hydrogen in these applications still remains a problem and and scientists have to come up with applicable, light, affordable, and safe method for storing hydrogen in such applications. Hydrogen storage options • Storage as gas under pressure (250-350 bar) • Cryogenic storage as liquid hydrogen (temp –253 0C ) • Storage as metallic hydrides • Carbon adsorption and glass microsphere storage techniques (under development) 1 methods -Storage of hydrogen gaseous • If we succeed in producing H2 cheaply, we are still faced with the questions: – How do we store it? – How do we transport it • 1 gram occupies about 12 liters – If stored as gaseous state, large heavy walled containers will be necessary! This eliminates the benefits of H2 as a fuel (high energy/low mass ratio) • Liquefied at -250oC – A lot of energy would be required!! 2 methods -Storage of hydrogen gaseous • Adsorption of H2 onto activated carbon • Use of Li metal. – Li is highly reactive metal – Reaction of H2 gas can reduce the volume of 12 liter to about 4-5 ml. Here is the chemistry: Li(s) + ½ H2(g) -> LiH(s) Q: Ok … how do we get it back when we need it A: Drop Lithium hydride (LiH) into water LiH + H2O -> H2 + LiOH Produces Hydrogen gas Compressed hydrogen • the most straightforward option at this time • offers the simplest and least expensive method for onboard storage of hydrogen • The refilling time of compressed hydrogen tanks is also similar to that of gasoline tanks. Problems • Low energy density (One way to increase the fuel stored in the container is to increase pressure, but this requires more expensive storage containers, increasing compression costs ) • hydrogen has a tendency to leak because of its small size. Seals and valves on the containers need to be designed to prevent leaks. If a fuel cell vehicle is stored in a closed garage, hydrogen that has leaked out could accumulate and increase the risk of fire or explosion.in addition to the explosion could happen from cars accidents on the road Problems • Does not liquefy until (~-253 0C) Which cost energy • 40% of energy can be lost(25 percent of LH2 boiled off during refueling and 1 percent lost per day for onboard storage.) • requires excellent insulation of storage containers; otherwise, left for a period of time, the storage tanks could become depleted Bonded hydrogen (Metal hydride) • Since heat is required to release the hydrogen, this method avoids safety concerns surrounding leakage that can be a problem with compressed hydrogen and LH2. In fact, metal hydrides are one of the safest methods for storing hydrogen. Problems • Heavy weight. (One major obstacle to this method is that the metal compounds used to attract the hydrogen tend to be very heavy resulting in only 1.0 to 1.5 percent hydrogen by weight) • Some of the metals used for hydrides are very expensive. There are less expensive options but they are impractical for use in fuel cell vehicles as these cheaper metals require extremely high temperatures to release the hydrogen Vehicles requirements of H2 • A modern, commercially available car optimized for mobility and not prestige with a range of 400km burns about 24 kg of petrol in a combustion engine; to cover the same rage by electric car with a fuel cell 4kg hydrogen is needed (Louis Schlapbach & Andreas Zuttel) Volume of 4kg hydrogen compacted in different ways, with size relative to the size of a car • Cryogenic and metal hydride: Background of metal hydride • the last century, scientists discover that Pd metal occluded large amount of H2 at ambient pressure and temperature. However, it was not very useful because of issues associated with the cost and low capacity of hydrogen storage. The recent discovery of hydrogen sorption by intermetallic compounds created great hopes and stimulated research and development worldwide of using the metal hydrides as a new alternative for storing and delivering pure hydrogen that can be very useful for fuel cell technology Metal hydrides material • Hydrogen is a highly reactive element and has been shown to form hydrides and solid solutions with thousands of metals and alloys. Figure beside shows the family tree of hydriding alloys and complexes Family tree hydriding alloys and complexes Metal hydride elements • For PEM fuel cell vehicular applications the range is 0-100 0C and 1-10 atm. This is based on the possibility of using the waste heat from the fuel cell to release the hydrogen from the metal hydride. In the last century Pd was used to store H2. However, it is no longer used because it is very expensive, doesn’t hold much hydrogen, and requires heating above 100 0C to release that hydrogen. Today Vanadium (V) and Niobium (Nb) are well known elements for storing hydrogen in the range of practical applications Van’t Hoff lines (desorption) for elemental hydrides. Box indicates 1–10 atm, 0–100°C ranges Metal Hydride Alloys • Scientists have been required to combine strong hydride forming elements (A) with weak hydride elements (B) to form alloys (especially intermetallic compounds) that have the desired intermediate thermodynamic affinities for hydrogen • there are some conditions should be considered of choosing these alloys as metal hydrides: 1-Temperature and pressure of hydride and dehydride 2-Hydrogen storage capacity of the alloys 3-Rate of absorption and desorption 4-Ease of activation 5-Poisoning by impurities 6-Cost and availability • Typically there are three type of bonding between metals and hydrogen: Ionic, Covalent, and Metallic Metallic hydride • Ionic, Covalent types of bonding are not very practical in mobile applications because they require extremely high temperature in order to liberate H2 . Where as the metallic type bond offers the necessary behavior for hydrogen storage systems (In the metallic hydrides, the hydrogen acts an electron accepter, the hydrogen atom accept the electron from the conduction band of the metal and fill its first orbital ) • The conventional metal hydride alloy families to be described here are the AB5, AB2, and AB intermetallic compounds Problems of metal hydrides • Low mass density is the general weakness of all known metal hydrides working near room temperature. There are intermetallic compounds and alloys can form hydrides up to 9 mass% hydrogen but they are not reversible within the required range of temperature and pressure. Table beside shows the mass density of the well-known compounds and alloys Intermetallic compounds and their hydrogen-storage properties • The other common problem of storing hydrogen is the impurity and the most problematic impurities are: CO, CO2, NH3, H2S, CH4 and O2. These impurities reduce the storage capacity and also could cause poisoning, retardation, or reaction. Table beside shows the effect of impurities on metal hydride Poisoning = Rapid loss of H-capacity with cycling Retardation = Reduction in absorption/desorption kinetics without significant loss in the ultimate capacity Reaction = Bulk corrosion was leading to irreversible capacity loss Liquefied Hydrogen • Could perform better in an accident • high energy density of liquid hydrogen • Increase available space • Reduce environments effect Fuel cell (Principle of working, Construction and Applications) What is fuel cell? A Fuel cell is a electrochemical device that converts chemical energy into electrical energy • Every fuel cell has two electrodes, one positive and one negative, called, respectively, the cathode and anode. The reactions that produce electricity take place at the electrodes • In all types of fuel cell, hydrogen is used as fuel and can be obtained from any source of hydrocarbon. • The fuel cell transform hydrogen and oxygen into power, emitting water as their only waste product. electric 39 • Every fuel cell also has an electrolyte, which carries electrically charged particles from one electrode to the other, and a catalyst, which speeds the reactions at the electrodes. • A single fuel cell generates a tiny amount of direct (DC) electricity. current • A converter is used to produce AC current • In practice, many fuel cells are usually assembled into a stack. Cell or stack, the principles are the same. • In 1932, Francis Bacon developed the first successful used hydrogen, oxygen, an alkaline electrolyte, and electrodes. FC. He nickel 40 1. Anode Parts of a Fuel Cell • Negative post of the fuel cell. • Conducts the electrons that are freed from the hydrogen molecules so that they can be used in an external circuit. • Etched channels disperse hydrogen gas over the surface of catalyst. 2. Cathode • • • • Positive post of the fuel cell Etched channels distribute oxygen to the surface of the catalyst. Conducts electrons back from the external circuit to the catalyst Recombine with the hydrogen ions and oxygen to form water. 3. Electrolyte • Proton exchange membrane. • Specially treated material, only conducts positively charged ions. • Membrane blocks electrons. 4. Catalyst • • • • Special material that facilitates reaction of oxygen and hydrogen Usually platinum powder very thinly coated onto carbon paper or cloth. Rough & porous maximizes surface area exposed to hydrogen or oxygen The platinum-coated side of the catalyst faces the PEM. 2.A fuel cell configuration 1. A fuel cell consists of two electrodes namely an anode and a cathode and sandwiched around an electrolyte. 2. An electrolyte is a substance, solid or liquid, capable of conducting oving ions from one electrode to other. (+) (-) Anode Cathode Electrolyte 42 3. Types of fuel cells There are different types of fuel cells, differentiated by the type of electrolyte separating the hydrogen from the oxygen . The types of fuel cells are: • • • • • • Alkaline fuel cells (AFC) Direct methanol fuel cells (DMFC) Molten carbonate fuel cell (MFFC) Phosphoric acid fuel cells (PAFC) Polymer electrolyte membrane fuel cells (PEMFC) Solid oxide fuel cells (SOFC) 43 44 4. Principle, construction and working of H2-O2 fuel cell Principle: The fuel is oxidized on the anode and oxidant reduced on the cathode. One species of ions are transported from one electrode to the other through the electrolyte to combine there with their counterparts, while electrons travel through Fuel the external circuit producing the electrical current. Fuel Electrons (e-) Cations (+ve) Anions (-ve) Oxidant Electrolyte Permeable Anode Oxidant Permeable Cathode 45 Working The Fuel gas (hydrogen rich) is passed towards the anode where the following oxidation reaction occurs: H2 (g) = 2H+ + 2eThe liberated electrons from hydrogen in anode side do not migrate through electrolyte. Therefore, they passes through the external circuit where work is performed, then finally goes into the cathode. On the other hand, the positive hydrogen ions (H+) migrate across the electrolyte towards the cathode. 46 At the cathode side the hydrogen atom reacts with oxygen gas (from air) and electrons to form water as byproduct according to: The overall cell reaction is fuel + oxidant product + Heat H2 + 1/2 O2 +2e - H2O + Heat 47 Fuel Cell Stack 48 Operation of Fuel Cell 49 Fuel Cell Energy Exchange http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/electrol.html The liberated electrons from the hydrogen are responsible for the production of electricity. The water is produced by the combination of hydrogen, oxygen and liberated electrons and is sent out from the cell. The DC current produced by fuel cell is later converted into AC current using an inverter for practical application. The voltage developed in a single fuel cell various from 0.7 to 1.4 volt. More power can be obtained by arranging the individual fuel cell as a stack. In this case, each single cell is sandwiched with one another by a interconnect. Therefore, electricity power ranging from 1 kW to 200 kW can be obtained for domestic as well as industrial application. 51 Electrical power production by fuel cell Hydrogen Oxygen Rotating shaft connected to generator for electricity production 52 Polymères Electrolyte Membrane (PEM) Fuel Celles H2-O2 Fuel Cell or Polymer electrolyte membrane (PEM) fuel cells—also called proton exchange membrane fuel cells—deliver high power density and offer the advantages of low weight and volume, compared to other fuel cells. PEM fuel cells use a solid polymer as an electrolyte and porous carbon electrodes containing a platinum catalyst. They need only hydrogen, oxygen from the air, and water to operate and do not require corrosive fluids like some fuel cells. They are typically fueled with pure hydrogen supplied from storage tanks or onboard reformers. Alkaline Fuel Cells Alkaline fuel cells (AFCs) were one of the first fuel cell technologies developed, and they were the first type widely used in the U.S. space program to produce electrical energy and water onboard spacecraft. These fuel cells use a solution of potassium hydroxide in water as the electrolyte and can use a variety of nonprecious metals as a catalyst at the anode and cathode. High-temperature AFCs operate at temperatures between 100°C and 250°C (212°F and 482°F). However, newer AFC designs operate at lower temperatures of roughly 23°C to 70°C (74°F to 158°F). AFCs high performance is due to the rate at which chemical reactions take place in the cell. They have also demonstrated efficiencies near 60 percent in space applications. Phosphoric Acid Fuel Cells Phosphoric acid fuel cells (PAFCs) use liquid phosphoricacid as an electrolyte—the acid is contained in a Teflon-bonded silicon carbide matrix—and porous carbon electrodes containing a platinum catalyst. The chemical reactions that take place in the cell are shown in the diagram to the right. The phosphoric acid fuel cell is considered the "first generation" of modern fuel cells. It is one of the most mature cell types and the first to be used commercially, with over 200 units currently in use. This type of fuel cell is typically used for stationary power generation, but some PAFCs have been used to power large vehicles such as city buses. Solid Oxide Fuel Cells Solid oxide fuel cells (SOFCs) use a hard, non-porous ceramic compound as the electrolyte. Since the electrolyte is a solid, the cells do not have to be constructed in the plate-like configuration typical of other fuel cell types. SOFCs are expected to be around 50-60 percent efficient at converting fuel to electricity. In applications designed to capture and utilize the system's waste heat (co-generation), overall fuel use efficiencies is 80-85 percent. Solid oxide fuel cells operate at very high temperatures—around 1,000°C (1,830°F). High temperature operation removes the need for precious-metal catalyst, thereby reducing cost. It also allows SOFCs to reform fuels internally, which enables the use of a variety of fuels and reduces the cost associated with adding a reformer to the system. SOFCs are also the most sulfur-resistant fuel cell type; they can tolerate several orders of magnitude more sulfur than other cell types. In addition, they are not poisoned by carbon monoxide (CO), which can even be used as fuel. This allows SOFCs to use gases made from coal. Hydrogen Fuel Cell Efficiency 40% efficiency converting methanol to hydrogen in reformer 80% of hydrogen energy content converted to electrical energy 80% efficiency for inverter/motor – Converts electrical to mechanical energy Overall efficiency of 24-32% 5. Advantage, disadvantage and applications Advantages • Zero Emissions: a fuel cell vehicle only emits water Therefore, no air pollution occurs. vapour. • High efficiency: Fuel cells convert chemical energy directly into electricity without the combustion process. As a result, Fuel cells can achieve high efficiencies in energy conversion. • High power density: A high power density allows fuel cells be relatively compact source of electric power, beneficial application with space constraints. to in 58 • Quiet operation: Fuel cells can be used in residential or built-up areas where the noise pollution can be avoided. • No recharge: Fuel cell systems do not require recharging. Disadvantages • It is difficult to manufacture and stores a high pure hydrogen • It is very expense as compared to battery 59 Applications 1. Portable applications • They used in portable appliances and power tools • They can be used in small personal vehicles • They are used Consumer electronics like laptops, cell phones can be operated • They can be used in Backup power 60 Applications 1. Portable applications • They used in portable appliances and power tools • They can be used in small personal vehicles • They are used Consumer electronics like laptops, cell phones can be operated • They can be used in Backup power 61 2. Transportation applications • They can be used for transport application in the following areas, • Industrial transportation • Public transportation • Commercial transportation (truck, tractors) • Marine and Military transportation 62 3. Power distribution application • Fuel cells can be used for the distribution of various fields such as, power in • Homes and small businesses • Commercial and industrial sites • Remote, off-grid locations (telecom towers, weather stations) 63 Problems regarding hydrogen fuel cells •Lack of hydrogen infrastructure •Need for refueling stations •Lack of consumer distribution system •Cost of hydrogen fuel cells •2009 Department of Energy estimated $61/kw •Honda FCX Clarity costs about half a million dollars to make •Carbon cost of producing hydrogen •Problems with HFC cars •Short range (~260 miles) •Warm up time (~5 minutes) Thanks ………..