Term paper Hydrogen Fuel Cell
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Hydrogen Fuel Cell
Author Utsav Mone 1st Year MBA Vinod Gupta School of Managment IIT-Kharagpur [email protected]
Abstract Since long we are looking forward to unconventional sources of energy. We have started using many such sources but the cost of energy generation has not reduced to the point that they can substitute conventional sources. Many trails are going on in different direction out one is Hydrogen fuel cell. Fist such cell was developed in 1955 but economics never let this source to come into picture. But with recent developments going on, now this source of energy is coming back as good candidate among rest of unconventional energy sources. In this report we are analysing how much impact these developments can bring in economics of energy sector. What are current trends and new possibilities which lead me to visualise a new reality in the area of business and technology.
Introduction Conventional sources of energy are not going to last very long, since long time we are searching for unconventional sources of energy, and this search is going on. We have got many substitute of conventional energy, many technological breakthroughs took place. We saw sun as a major source of energy. As per the calculation the amount that sun was dissipating in one second entire human civilization has not used that energy till now. Silicon was an abundant element on earth and photovoltaic cells to generate can be manufactured this material, but till now we could not make solar energy an economical source of energy. There are many issues involved in this that we will discuss in this paper. In 1813 Rivaz thought that in the whole universe Hydrogen is an abundant element can we use it for our energy. He came with auto-mobile with this engine, fuelled by hydrogen gas. Unlike oil and petroleum, hydrogen as a combustive fuel presents the many advantage like; wide range of flammability, small quenching distance, low ignition energy, high auto ignition temperature, very low density or in other words light weight, high flame speed, high diffusivity and. These all things made it a very good substitute for consideration as a good source and of its application in an internal combustion engine. Although enthalpy of combustion for hydrogen is 286 kJ/mol still due to other issues like combustion engine efficiency and economic reasons, hydrogen is not a good substitute in combustion engines. Whatever efforts we make if economic viability is not in our favour even big technological inventions dont get realised by the world. One such episode took place when in 1838 the principle of the fuel cell was discovered by a German scientist named Christian Friedrich Schnbein. His principle was published in some scientific magazines of the time. From his study Sir William Robert Grove took inspiration and he introduced first fuel cell in 1839. This year is regarded as the birth date of the fuel cell, we know Sir William Robert Grove as Father of the Fuel Cell. Since then any technological advancements keep on taking place but fuel cell was never seen as substitute for mass energy. Its application was limited to scientific experiments only. In 1955 a chemist working for the General Electric Company (GE) named W. Thomas Grubb, further modified the design of original fuel cell by the use of sulphonated polystyrene ion-exchange membrane as the electrolyte. Then many other modifications took place and GE went on developing this technology with McDonnell Aircraft and NASA. This lead to use of fuel cell in an esteemed project called Project Gemini. It is said that it was
the first commercial use of a fuel cell. But economy was not in favour of fuel cell. Since then with every new technological advancement the usage and importance of fuel cell increased. And now with recent developments the fuel cell appears to be ahead of all green energy substitutes. Now a days economic viability cannot be estimated very easily as complex technological advancement in one field are not sufficient to create a big change it needs to be backed by many other technological changes. Hydrogen economy is the term coined by John Bockris which now many see as something which has the potential to modify and re-define the business and economic landscape of the world. In this paper now we will see what fuel cell is and what are the technological advancement which took place in recent year which if supported by mass production will make fuel cell very economical.
What is Fuel Cell? Most of the sources of energy that we see are combustible which leads to pollution hydrogen was one such substance that if burned lead to water not any greenhouse gas. This was a green substance but when we try to convert this energy into electrical energy there comes inefficiency of conversion which finally makes it a costly source of energy. Fuel cell is something very similar to battery but the unlike normal battery the chemicals are not part of battery, in fuel cell you let the chemical go inside a cell which provides conducive conditions for reaction to take place then the products of reaction come out of cell. A fuel cell is an electrochemical cell that converts a source fuel into an electric current with the help of electrolyte, catalyst and different types of cathode and anode materials. A fuel cell transforms the chemical energy liberated during the electrochemical reaction of hydrogen and oxygen to electrical energy unlike direct combustion of hydrogen and oxygen gases which lead to production of thermal energy. Fuel cell generates electricity inside a cell through reactions between a fuel and an oxidant, which is triggered in the presence of an electrolyte. The reactants mainly hydrogen or other hydrocarbons flow into the cell and the reaction products mainly water flow out of it, while the electrolyte remains within cell.
At the Anode:
At the cathode:
Overall reaction Fuel cells can operate continuously as long as the necessary reactant (hydrogen or hydrocarbons) and oxidant flows are maintained without bothering about electrolyte. Fuel cells are different from
conventional electrochemical cell batteries mainly in terms thermodynamically closed and open system. In case of fuel cell it consumes reactant from an external source and the flow has to be maintained. While in case of batteries it stores electrical energy in the form of chemicals and hence it represents a closed system.
Many combinations of fuels and oxidants are possible in fuel cells. A hydrogen fuel cell uses hydrogen as its fuel and oxygen as its oxidant. The oxidants are either oxygen or chlorine and chlorine dioxide. In case of oxygen it can be supplied either directly from air or pure oxygen by special arrangements. There are other cells that use hydrocarbons and alcohols as fuel.
Classification of Fuel Cell The main classification of fuel cells is based on fuel or oxidants used, or temperature range (construction), material of cathode and anode, type of electrolytic material used. Following are some popular fuel cell used.  Following classification are not rigid as one fuel cell under a classification at the same time can be under other classification.
1) SOFC - Solid oxide fuel cell 2) MCFC - Molten carbonate fuel cells 3) AFC - Alkaline Fuel Cells 4) PEFC - Proton exchange fuel cells 5) PAFC -Phosphoric Acid Fuel Cells 6) RFC -Regenerative Fuel Cells 7) DAFC Direct Alcohol fuel cell.
1) SOFC It use solid oxide or ceramic as electrolyte. Its main advantages are high efficiency, long-term stability, fuel flexibility, low emissions, and relatively low cost. While disadvantages are high operating temperature which results in longer start-up times and mechanical and chemical compatibility issues.
2) MCFC - Molten carbonate fuel cells are used for industrial and military applications. MCFCs use an electrolyte composed of a molten carbonate salt mixture suspended in a porous, chemically inert ceramic matrix of beta-alumina solid electrolyte. Due to its high temperature operation range non-precious metals can be used as catalysts at the anode and cathode, reducing costs.
3) AFC - is one of the most developed fuel cell technologies and is the one cell that flew Man to the Moon. NASA has used alkaline fuel cells since the mid-1960s including the moon missions. It is among most fuel efficient fuel cell, it consumes hydrogen and pure oxygen
4) PEM - Polymer Electrolyte Membrane also known as Proton exchange fuel cells are most popular fuel cells. It uses a solid polymer as an electrolyte and porous carbon electrodes containing a platinum catalyst A stream of hydrogen is goes to the anode side of the membrane electrode assembly (MEA) where it is catalytically split into protons and electrons.
5) PAFC - The electrodes of PAFC are made of carbon paper coated with a finely dispersed platinum catalyst. It is not affected by carbon monoxide impurities in the hydrogenstream. Since phosphoric acid solidifies at a temperature of 40 C, it makes start-up difficult. Platinum make s them expensive to manufacture.
6) RFC - Regenerative fuel cell or reverse fuel cell runs in reverse mode, which consumes electricity and chemical to produce another chemical. By definition and theoretical understanding, the process of any fuel cell could be reversed however standard fuel cells operated backwards generally do not make very efficient systems unless they are purpose-built to do so.
7) This fuel cell was largely overlooked because its efficiency was below 25%. In 1999 there was a marked shift away from developing the PEFC in favour of the DAFC after which several companies around the world started working on DAFC. In this type of fuel cell, either methyl or ethyl alcohol is not reformed into hydrogen gas but is used directly in a very simple type of fuel cell. Its operating temperature of 50-100C is ideal for tiny to midsiz e applications. Its electrolyte is a liquid alkaline or a polymer material. Most companies pursued the PEFC because of its higher efficiency and power density. There has been tremendous progress since 1999 now efficiencies of the DMFC are much higher and predicted efficiencies in the future may be as high as 40%
Name of Fuel Cell Electrolyte Working
Metal hydride fuel cell
Aqueous alkaline solution
-ve 20 to 0
Direct formic acid fuel cell Polymer membrane (ionomer) < 40
Zinc-air battery Aqueous alkaline solution < 40
Regenerative fuel cell Polymer membrane (ionomer) < 50
Direct borohydride fuel cell Aqueous alkaline solution 70
Alkaline fuel cell Aqueous alkaline solution < 80 Efficiency 6070%
Direct methanol fuel cell Polymer membrane (ionomer) 90120 Efficiency 2030%
Direct-ethanol fuel cell Polymer membrane (ionomer) > 25
Proton exchange membrane fuel cell
Polymer membrane (ionomer) 50120 (Nafion) Efficiency 5070%
Phosphoric acid fuel cell Molten phosphoric
acid (H3PO4) 150-200 Efficiency 55%
What new is coming? June 2010 - Mani Narayanasamy, Vice-President - R&D, Ingsman India, an energy and fuel cell research company provides technology for defence organisations for military applications, is very optimistic about use of fuel cell. September 2010 - P. Ragunathan, Head, Fuel Cell Section, Heavy Water Division Bhabha Atomic Research Centre (BARC), Trombay says Hydrogen is the fuel for the future. September 2010 - Mr. Green head UK Energy Programme Engineering and Physical Sciences Research Council EPSRC and the Department of Science and Technology (DST) declared that they would soon call for joint projects worth 6 million in next generation, environment-friendly fuel cell technologies. October 2010 - Murali Arikara, Executive Vice-President - Emerging Markets, Intelligent Energy, U.K. stated that fuel cell technology has a huge market. He says Currently in India market of diesel generators running the cell-phone towers is that of $ 2 billion. Increase in diesel price will push the cost factor higher. A hydrogen-powered car could be ten times costlier than a car with an internal combustion engine. Scientists like Anthony Kucernak are precisely on it. A professor of Chemical Physics at Imperial College in London, Mr. Kucernak is a principal investigator in 11 EPSCRC projects. His Flexible Fuel Cell was rated one out of 13 proposals and Alkaline Polymer Electrolyte Fuel Cells rated one out of 55 proposals considered by EPSCRC. 
What is that which making so much movements in world of fuel cell? Let us see.
Developments in world of fuel cell are leading to new diagnostic techniques to help optimise cost and lifetime of fuel cell systems. Many changes are looking at a new geometry of fuel cells. The ability to support new catalysts and supports which reduce the cost, increase durability, improve the performance and increase the stability of catalysts systems is important. We know that for any commercial purpose single cell is of no use. To generate voltage we need to arrange many fuel cells in a series. Similarly to generate required current you need to arrange cell in parallel system. When cells are arrange in series the current from series becomes function of weakest performing cell. Therefore current geometrical design of common fuel cells was not fault tolerant, and for smooth functioning it required that all components should operate in an ideal manner. As the weakest link in the fuel cell chain dictates performance and reliability it is necessary to identify such cells for high reliability. In this direction Prof Kucernak is working on flexible fuel cell technology to remove this problem Flexible fuel cell concept given by Mr Kucernak This concept requires to design a fuel cell stack so that we can "switch out" bad units and allow the fuel cell to continue operation. Such a fuel cell stack would then show fault tolerance and resilience to adverse environmental and internal influences. Indeed it might even be possible to check poorly performing electrodes, and repair them so that they can work normally. In a nut-shell the purpose of this project is to radically redesign fuel cells operation. As per the project we can integrate the power control electronics directly with the fuel cell. Not much detail are available but we can say that this configuration will allow us to have much greater control of the fuel cell operation as compared to the configuration used almost exclusively everywhere else. Project claims that we can achieve significant space savings and a decrease in the cost of the controlling electronics. In order to produce this new type of fuel cell, requirement is that a very tight coupling between both Chemistry and Chemical Engineering aspects should come up. The development of new types of electrodes is guided by some subtle concepts of chemistry associated with the production of 'through-membrane' connectors. The integration of electrodes into a stack requires a radically different type of housing. Such work must be carefully guided by modelling and simulation tools, and the results need to be fed back to optimise the electrodes design. What we require is a close cooperation between both chemists and engineers in order to ensure the success of the project. In recent developments the research team is getting assistance by four collaborating external partners. These collaborators will assist the teams for developing fuel cell system and representing a balanced team representing the development chain a technology transfer company. Imperial Innovations Ltd will manage the commercialisation of this work out of Imperial. Applied intellectual Capital, an applications developer will define the market and establish precise operational requirements. SPC Technologies Ltd, materials supplier / developer will supply sample materials for use as flow fields and sealant material and will also contribute expertise on the processing of porous plastics. The Defence Science and Technology Laboratory will test the robust lightweight design against requirements for infantry missions.
Other New possible areas A new fuel cell system, based on alkaline conducting membranes is an important area in reducing the total cost of fuel cells and developing new markets. My opinion is that getting cheaper alkaline is very much possible and research in this direction is progressing.
In DMFC issue of fuel crossing over from the anode to the cathode without producing electricity was one problem that has been resolved. There were concerns about the poisonous aspects of methanol but it is replaced by ethanol. Now I believe that getting ethanol is not economically difficult task, as many companies are working on developing cheaper technology to get ethanol from plants just one development in this direction will lead to a big change. So we can see that any of the above development can trigger a huge change in world of energy.
Pure platinum alternative promises breakthrough in fuel cell technology In direction of reduction in cost of fuel cell one direction is reducing the cost of material used. In this direction with the help of nanoparticles technology has achieved a big success. One of the most expensive elements used in most fuel cells is platinum, but now researchers have created a unique core and shell nanoparticle that uses far less platinum then required before. At the same time it performs more efficiently and lasts longer than commercially available pure-platinum catalysts at the cathode end of fuel cell reactions. The oxygen reduction reaction which takes place at the cathode of fuel cell creates water as its only waste and if it is then up to 40 percent of a fuel cells efficiency is lost. Due to many reasons platinum has always been the catalyst of choice for this reaction for many researchers, but it is expensive, and the reaction causes it to break down over time. The core-shell nanoparticle developed by researchers at Brown University and Oak Ridge National Laboratory addresses both of these problems of cost and decay. The team at Laboratory created a five-nanometer palladium (Pd) core and encircled it with a shell consisting of iron and platinum (FePt). The trick was in moulding the shell that would retain its shape and it require the smallest amount of platinum to pull off an efficient reaction. The team has created a iron-platinum shell by decomposing iron pentacarbonyl and reducing platinum acetylacetonate to result in a shell that uses only 30 percent platinum. Researchers claim that they expect to be able to make thinner shells and use even less platinum. The researchers demonstrated for the first time that they could consistently produce the unique core-shell structures with low use of platinum. In laboratory tests, the palladium/iron-platinum nanoparticles combination generated 12 times more current than commercially available pure-platinum catalysts at the same catalyst weight. The output also remained consistent over 10,000 cycles of experiment, which is at least ten times longer than commercially available platinum models that begin to deteriorate after 1,000 cycles. The iron-platinum shells created by team varied in width from one to three nanometres. It was found in laboratory tests that the one-nanometre shells performed best. The next step is to scale them up for commercial use at low prices, and researchers are confident well be able to do that.
Mazumder and Shouheng Sun, professor of chemistry at Brown University, think that palladium core increases the catalytic abilities of iron platinum has something to do with the transfer of electrons between the core and shell metals. They are studying why the palladium core increases the catalytic abilities of iron platinum. To that end, they are trying to use metals that are chemically more active than palladium as the core to confirm the transfer of electrons in the core-shell arrangement. They will study its behavioural importance to the catalysts function.
What else fuel cell can offer? The beauty of system lies in the fact that it is very much compatible with other technologies as well. Australian scientists with an aim of enabling solar power to be tapped as an economic source of energy have claim they will be able to build solar power driven hydrogen generating titanium oxide ceramics. They say that using special titanium oxide ceramics that harvest sunlight and split water to produce hydrogen fuel, it will then be a simple engineering exercise to make an energy-harvesting device with no moving parts and emitting no greenhouse gases or pollutants. Hydrogen fuel cell is compatible with other technology. Main cost driving factor in case of hydrogen fuel cell. Researchers of University of Wisconsin claim they have developed a more efficient and less polluting way to convert hydrocarbons into hydrogen. The efficiency of any fuel cell is dependent on the amount of power drawn from it. Since it supplies almost fix voltage drawing more power means drawing more current, which increases the losses in the fuel cell. As a general rule, the more the power drew, lower the efficiency. Most losses manifest themselves as a voltage drop in the cell which is undesired, so the efficiency of a cell is almost proportional to its voltage. For this reason, it is very important to study polarization curves of fuel cell and its performance on graphs of voltage versus current. A typical fuel cell running at 0.7 Voltage 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 mainly heat. Also depending on the fuel cell system design, some fuel might leave the system un-reacted, constituting an additional loss. But we see that modern designs do not allow this loss any more. For a hydrogen cell operating at standard conditions with no reactant leaks (modern design) , the efficiency is equal to the cell voltage divided by 1.47 V, based on the enthalpy, or heating value, of the reaction. For the same cell, the second law efficiency is equal to cell voltage divided by a standard s voltage which varies with fuel used, and quality and temperature of the cell. The difference between these numbers (Second law results and practical results) represents the difference between the reaction's enthalpy and Gibbs free energy. This difference always appears as heat, along with any losses in electrical conversion efficiency but in this paper we will see how this loss can be used as advantage of fuel cell. Fuel cells do not operate on a normal thermal cycle. Cells are not constrained, as combustion engines are, in the same way by thermodynamic limits, such as Carnot cycle efficiency. 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 but the laws of thermodynamics also hold for chemical processes (Gibbs free energy) like fuel cells as well. The maximum theoretical efficiency is also higher in case of chemical processes. Theoretical efficiency of hydrogen oxygen
reaction 298K is approximately 83%. While Otto cycle thermal efficiency is about 60% for compression ratio of 10 and specific heat ratio of 1.4. Comparing limits imposed by thermodynamic laws is not a good predictor of practically achievable efficiencies but it gives future possibilities. Also, if propulsion is the goal, electrical output of the fuel cell has to still be converted into mechanical power which will lead to another efficiency drop. It is batter that we use hydrogen engines for mechanical energy requirements. The claim 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 so overall fuel is more efficient is very correct.
Improving efficiency One big issue that we kept on talking in this paper about fuel cell was that it dissipates high amount of heat. When many high powered hydrogen fuel cells are kept together they dissipates so much heat that separate cooling systems are needed to make sure that fuel cell will work fine. As we saw in earlier table that different types of cell work in different rage as the temperature ranges go beyond the limit the efficiency of cell gets effected and in many cases it erosion of plates or it can get completely dysfunctional. This cooling system was causing another cost factor which was not in favour of fuel cell. But after all heat was also a source of energy, it could have been used in some other form. This thought can lead to devising of new high power fuel cell system along with heat generator. Heat dissipated from such cells could be used to heat water and generation of steam. Infect this idea has started getting implemented. By research results it is found that high temperature fuel cell can be used as a heat source in conventional heat engine i.e. gas turbine system. In this case the ultra high efficiency of more than 70% is predicted. But in my opinion instead of gas turbine systems if we can directly use this heat that will be batter, like as a supply of hot water in industries, hotels and residential houses.
What is the economic potential of the idea? Efficiency above hydrogen based ICE: Reiterating that efficiency of Carnot cycle cannot go high even theoretically also when this mechanical power is converted into electrical power there comes efficiency factor which makes use of hydrogen based or any other fuel based electric generation highly costly. In case of electrochemical process these losses can be reduced to great extent. When we compare the costs of different energy sources we find that point to point comparison is not straightforward for the many reasons, but still we can make out some advantages of fuel cell. The cost of finance: It is critical to renewable energy sources. Energy sources that utilize fossil fuels have both upfront costs and ongoing costs (i.e. the cost of purchasing oil, gas), which means that a substantial part of their total costs are spread over time also as time goes due to increase in prizes of fuel ongoing cost increases. On the other hand renewable energy typically incurs a high upfront cost, but sees extremely low ongoing costs. This means that running cost over the life of the equipment/capital investment can vastly enhance the economics of renewable energy. Making perditions of cost of hydrogen is very difficult.
Value of Dispatchability: Fuel cells energy supply is dispatchable, it means the energy supply is guaranteed or predictable. The more predictable source is, the higher its advantages. Fossil fuel driven power plants as well as nuclear power falls under category of dispatchable, but renewable energy sources alone are generally not. To make an accurate comparison, the renewable energy sources must be configured with a means of energy storage (i.e. batteries or hybrid systems, renewable energy etc). Fit with load curve: An energy source that produces at the time of high demand (over a period of 24 hour) has greater value to both the Utility and the Customer. Periods of peak demand are the most expensive time because the Utility has to have that capacity available, yet that same capacity will remain idle during other parts of the day. Solar Energy does fit with daily load peaks of evening and nights. In winter use of heater, geyser peaks demand which solar energy is not aligned with. While in summer air conditioning is required where solar energy sources works fine. Since we know that solar power cannot work 24Hr a day it has to use some other support like battery for storing the power. Now challenges associated with maintaining battery becomes part of the solar power system. But in case of fuel cell there are no such constraints of capability and demand. Advantage of source guarantee: Problem with most of the unconventional sources of energy is that source availability is not guaranteed all time. It is not necessary that wind will flow round the year in identified area nor sun is present in night time or even many times in day time. This reason leads to use of another technology to accompany for all practical reasons. With solar power you need storage (usually battery storage) and these additional overheads leads to increase in the cost of production. But this is not the case with fuel cell as availability of fuel can be guaranteed. Support from other technology is not required in fact fuel cell can very well replace battery systems used along with solar power systems as suggested by Australian scientist about solar power driven hydrogen generating titanium oxide ceramics technology. Distributed generation advantages: A distributive generation can reduce or avoid the necessity to build new transmission/distribution lines or upgrade existing ones. Such system can be configured to meet peak power needs. It can diversify the range of energy sources in network and thus increase the reliability of the grid network used. It can be configured to provide premium power, when coupled with uninterruptible power supply (UPS) in batter way. This distributive system is well-suited to the use of those energy technologies which can be located close to the user and can be installed in small increments to match the load requirement of the customer. Fuel cells are such technology which gives an additional edge above other unconventional sources of energy. Concentrated solar power generations systems, wind power houses, nuclear power plants cannot be installed near location of use, they have to be installed in appropriate locations for many reasons. Fuel cells have no such constraints thus it can avail all the advantages that distributed generations systems gives. Other reasons: Today's Photovoltaic devices can convert only 7%-17% of light energy into electric energy (batter then early Photovoltaic devices which converted about 1%-2%). Other disadvantage of solar power is panels require quite a large area for installation, relies on the location of the sun.
The biggest question is from where we will get Cheap Hydrogen? Cost of hydrogen fuel is the major driving factor in visualization of hydrogen economy. Hydrogen occupies big share of abundance of elements on earth too including water, air and crust. What we need is just a technology to produce it cheaply. Here I have discussed some or possible technologies.
Ammonia is one of the cheap sources of hydrogen but with increasing use of fertilizers cost of ammonia is increasing. The hope in this direction is alcohol and alkaline generated from plants. Researchers at GE say they've come up with a prototype version of an easy-to-manufacture apparatus that they believe could lead to a commercial machine able to produce hydrogen for less than $3 per kilogram -- a quantity roughly comparable to a gallon of gasoline -- down from today's $8 per kilogram. That could make it economically practical for future fuel-cell vehicles that run on hydrogen. It uses fairly simple technologies: water is mixed with potassium hydroxide electrolyte and made to flow past a stack of electrodes. Electricity causes the water molecules to split into hydrogen and oxygen gases. Commercial-scale quantities of hydrogen can be extracted far more cheaply from natural gas. Another new process uses nanostructured catalyst in presence of sunlight to generate inexpensively and efficiently hydrogen for fuel. Nanoptecks innovative way to make hydrogen from water using solar energy is unique research in its direction. The company says that its process is cheap enough to compete with the cheapest approaches used till now. Nanoptek Maynard, who has been developing this new technology in part with grants from NASA and the Department of Energy (DOE), completed its first venture-capital round, raising $4.7 million that it has used to install its first pilot plant. The technology uses Titania, a cheap and abundant material, to capture more energy from sunlight. The absorbed energy releases electrons, which split water to make cheap hydrogen. John Guerra says that other researchers have used Titania to split water in the past, but Nanoptek researchers found a way to modify Titania to absorb more sunlight, which makes the process much cheaper and more efficient. It was known since the 1970s that Titania can catalyze reactions that split water but was never tried for improving efficiency. While Titania is a good material for the purpose because it is cheap and doesn't degrade in water, it only absorbs ultraviolet light, which represents a small fraction of the energy in sunlight.
Who are the current players in this area? Government and research organizations were the key players in upcoming technology but now there is surge of new companies which are taking lead in this technology. Almost all the leading automobile companies of the world have now become current players in this area. Honda, Toyota, Rolls-Royce, Nissan and Mercedes are just few to name. Toshiba, Oorja Protonics, Altergy Systems, Ingsman, Ballard Power Systems, Bloom Energy, ClearEdge Power, Dantherm Power, FuelCell Energy, Hydrogenics, IdaTech, Nuvera Fuel Cells, P21 GmbH, Plug Power, ReliOn, UTC Power and many more large player in current market.
Figure - A Mercedes-Benz O530 Citaro powered by hydrogen fuel cells, in Brno, Czech Republic.
Fig Right: Sheraton San Diego's clean and quiet fuel cells are located next to the hotel's tennis courts. 
Fig Left: Energy fuel cells at Gills Onions 
Fig Right: Fuel cells power Pepperidge Farms Bloomfield, Connecticut bakery 
Any applications where concept is tried?
Vehicle and backup power applications Commercially available PEM fuel cell systems are capable to support these applications and offer several potential advantages over current technologies, longer runtimes, including lower emissions, lower O&M requirements, and other productivity enhancement advantages. Users are looking for alternatives to batteries to increase runtime and productivity, across the various specialty vehicle markets analyzed. Users want to and reduce safety risks, and for opportunities to reduce O&M costs associated with their ICE vehicles which makes fuel cell a good substitute.
Forklifts applications When forklifts were operated under conditions of near continuous use, fuel cell vehicles were significantly less expensive than similar battery-powered systems from a lifecycle cost perspective. Advantages of PEM fuel cell systems operating under such conditions include constant voltage delivery, rapid refuelling eliminating time and cost of replacing batteries, fewer repairs due to fewer moving parts, increased productivity by eliminating battery recharging time, and elimination of battery storage/changing room and associated costs.
Airport ground support equipment Recent federal and state air quality regulation and federal incentive programs are driving airlines to use low emission alternatives to ICE, and batteries are well-positioned to gain market share in this area. As PEM fuel cells are to compete effectively in this market, they have to be more cost effective than battery systems. Also quick entry to market will be required along with an affordable source of hydrogen available. The US Department of Energys Office of Energy Efficiency and Renewable Energy (EERE) is focused on the development of hydrogen fuel cell vehicles by 2015. Department realizes that there will likely be a lengthy transition period so they are focused on identifying market opportunities for Proton Exchange Membrane (PEM) fuel.
Biggest challenges that may cause these ideas to fail Many researches claim that oil and gas giants never want technological progress in this filed. Cheap supply of fuel is the most important thing that is to be considered for economic viability. If upcoming technologies fail to reduce the cost of it hydrogen economy will remain a concept. Lack of practical hydrogen distribution system: Even if we get hydrogen at cheap rates as we are optimistic but distribution system is very risky. High cost of hydrogen storage is hurdle in progress. Fuel cell are not able to take heavy loads shocks, they are still not very successful in use in heavy load vehicles like cranes
Summary We see that fuel cell have changed a lot in the recent past. These changes are like a new turning point in developments of fuel cell. Now it is not just area where governmental organizations are doing research. Now commercial applications have also come up and this will increase the flow of money for more research. As commercial organization sees benefits of fuel cell it will trigger more research in area of cheap availability of hydrogen and once commercially cheap hydrogen is available Hydrogen economy will not remain just a vision.
References  Fuel Cell History document by George Wand  http://en.wikipedia.org/wiki/Fuel_cell  http://www.benwiens.com/energy4.html  Newspapers and Magazines mainly from The Hindu  Research Atlas: Research Register-EP/G041792/1 at http://ukerc.rl.ac.uk  Journal of the American Chemical Society and http://www.gizmag.com  January 2008, Kevin Bullis and http://www.technologyreview.com  The Business Case for Fuel Cells: Report by Sandra Curtin and Jennifer Gangi  http://www.solarbuzz.com/DistributedGeneration.htm  http://www1.eere.energy.gov/hydrogenandfuelcells/fuelcells/fc_types.html#fc