Honda may employ fuel cell technology where electricity generated from a hydrogen-oxygen chemical reaction powers the vehicle; Ford and BMW have invested in hydrogen direct injection technology to power their vehicles. Hydrogen is often cited as the energy carrier of our future. With regards to hydrogen powered internal combustion (IC) engines, the direct injection (DI) combustion concept looks set to offer a lot of opportunities for further improvements. The Institute of Internal Combustion Engines and Thermodynamics at Graz University of Technology is carrying out extensive research in the area of Hydrogen Direct Injection in close cooperation with BMW, Munich. Westport Innovations Inc., which since 1995 has been engaged in the research, development, and marketing of high-performance engines and fuel systems which use gaseous fuels such as compressed natural gas (CNG), liquefied natural gas (LNG), hydrogen, and hydrogen-enriched compressed natural gas (HCNG), has been developing proprietary injector technology that enables injection of hydrogen at high pressure directly into the combustion chamber of an internal combustion engine. Combustion of a lean mixture of hydrogen and air is initiated by a hot surface or spark ignition. The approach completely eliminates backfiring, and enables much higher power density compared to current spark-ignited hydrogen engines that use external mixture formation. The H2DI engine can be optimised to achieve diesel like performance (high torque/power) and fuel efficiency. Emissions of nitrogen oxides (NOx) can be reduced to very low levels. Emissions of other toxic pollutants and greenhouse gases (carbon dioxide) are nearly zero. Ford started investigating the benefits of hydrogen direct injection for reciprocating engines with Westport in 2003. Ford in collaboration with Westport recently announced a project to develop and demonstrate an advanced direct injection fuel system for vehicles powered by high-efficiency, high performance engines operating on pure hydrogen. Dr Michael Gallagher, Westport's President and Chief Operating Officer, said that the U.S. Department of Energy (DOE) would also be teaming with Westport and Ford on the further development of Westport's hydrogen direct injection (H2DI) technology.The two-year development program will be divided into two phases. Phase one will define advanced fuel system requirements including the design of fuel injectors. Phase two will incorporate the design and manufacture of new prototype fuel systems. The Government of Canada has contributed $250,000 during phase one. Both the Government of Canada and the U.S. DOE have recognised that hydrogen-fuelled internal combustion engines can help enable the deployment of functional hydrogen powered vehicles, especially work vehicles, which consume large quantities of fuel. This will allow users and technology providers to gain experience with hydrogen infrastructure while operating large numbers of low-cost early production vehicles.Dr Gallagher added that West-port's H2DI technology has been in testing at Ford, and has shown the potential to provide high power and engine torque with diesel-like efficiency and very low emissions. "Early data indicates the strong potential for a truly green vehicle combining great efficiency characteristics with extremely low air pollutants and zero greenhouse gas emissions at the tailpipe. This technology has the potential to be commercially available a lot sooner and more cost-effectively than other hydrogen automotive technologies." The new collaboration builds on several years of work between Ford Research and Westport starting in 1999 with natural gas engines. The development work for the next generation hydrogen engine program will take place in Westport's technology centre in Vancouver, Ford's test facilities in Dearborn, Michigan and the Department of Energy's Pacific Northwest National Laboratory (PNNL) in Richland, Washington. PNNL will participate in the development program under funding already allocated by DOE's FreedomCAR and Vehicle Technologies Program. PNNL research will focus on modeling the effects of hydrogen on component performance with the goal of extending the life of injection components so that no maintenance is required in the normal life of the engine.The development of a practical fuel injection system for hydrogen is a key objective to Ford's strategy in making low cost hydrogen internal combustion engine technology commercially available to the market within the next few years. It's been almost a decade after scientists found out that hydrogen could replace petrol and diesel as the fuel for transport. Various methods of using hydrogen as a fuel have been tried out and polished. While direct hydrogen direct injection is looked upon as new approach towards employing hydrogen as a fuel, companies like Honda have already ventured deep into the fuel cell arena with vehicles like the FCX. In fuel cell technology, hydrogen and air are used to generate electricity. The 2005 FCX demonstrates Honda's revolutionary fuel-cell technology and is considered the world's most advanced fuel-cell vehicle (FCV) in regular (daily) use. The car is powered by an electric motor running on electricity generated by a fuel stack, which uses hydrogen as its energy source. The unique technology used in FCX allows its motor to be powered with electricity generated from a hydrogen-oxygen chemical reaction, thereby producing water vapour as the only emission. With a maximum output of 80 horsepower, FCX's acceleration is ideal for city driving. Honda's second-generation fuel-cell vehicle, the 2005 FCX is the first to be powered by a Honda designed and manufactured fuel-cell stack. While debate on which of the two hydrogen technologies will come out to be practical, it is a fact that H2 engines pose unique combustion challenges. Combustion anomalies such as pre-ignition and knock create operational challenges. These challenges are especially prevalent when the engine is operating under high-speed/high-load conditions. However, hydrogen possesses several characteristics that offer significant advantages. The wide flammability limits of hydrogen provide the opportunity to run the engine without a throttle, increasing efficiency. The high flame speed of hydrogen offers the chance to increase the power output of the engine without increasing its size. As mentioned earlier, the researchers at the Technical University of Graz, Austria, are addressing these challenges. They are striving to acquire more detailed information over the high end of the engine's operating range. By using imaging tools and other standard engine measurement devices on a Ford single-cylinder DI H2 engine, they are optimising operation and identifying the root causes of combustion anomalies. With ultraviolet imaging, the team is capturing OH* chemiluminescence inside the engine while running at high speeds and loads. (OH* emits photons in the ultraviolet spectra, caused by the chemical reaction of H2 and O2 in the air, and that light can be captured with specialised optics)1. Furthermore, researchers are taking a multiple-injection approach to reduce or eliminate combustion problems while simultaneously reducing nitrogen oxides (NOx) emissions in the engine.The BMW H2R is powered entirely by the clean-burning process of liquid-hydrogen combustion. The H2R features a 6.0-litre, V12 hydrogen-powered engine. In the H2R, the injection valves have been integrated into the intake manifolds, as opposed to injecting fuel directly into the combustion chambers. Liquid hydrogen does not lubricate the way gasoline does, so the H2R uses altered valve seat rings that compensate for this. To maximise power and efficiency, hydrogen is injected into the intake manifold as late as possible, so the injection valves have been redesigned, as well. The H2R made an ideal test bed for the forthcoming hydrogen-powered BMW 7 Series. It pushed the envelope of what had previously been thought possible with such a dual fuel vehicle. However, some significant changes had to be made to the engine in the standard 760i to make a hydrogen-powered one viable.While work continues on the hydrogen combustion technology at Graz, Austria, and manufacturers like BMW are taking a different approach towards hydrogen combustion, the University of South Carolina's Mechanical Engineering Department is investigating the feasibility of utilising liquid hydrogen fuel in the compression-ignition (CI) diesel power cycle. The diesel engine has a long history of use in industrial, automotive, and maritime applications, and, as the price of diesel fuel is expected to continue to increase, the need for alternative energy sources grows. The Department of Mechanical Engineering, BMW, and Siemens are working cooperatively in an effort to find solutions to help curb the demand and dependency on fossil fuels. Specifically, this research program has the aim of discovering the necessary modifications to convert existing diesel engines to run efficiently on liquid hydrogen fuel and utilise advanced injector technology.The use of alternative fuels in CI engines is not a new concept. Many typical diesel engines have been modified to run off natural oils and other alternative fuels. Unfortunately most of these alternative fuels are not practical enough to devote supporting technologies to optimise the power cycles using these fuels. Hydrogen does however offer several benefits that make it clearly one of the best choices for advanced alternative fuel combustion reactions for the CI engine.Due to their high torque and power curves, diesel CI engines are currently in service across the globe. As the economy shifts its dependency from fossil fuel sources to alternative fuel sources, there is a great demand to utilise a fuel, which will allow for these current CI engines in service to remain in service with a minimal downtime for conversion to an alternative fuel source. This research at the University of South Carolina aims to investigate these changes to current diesel CI engines, which would allow efficient operation using liquid hydrogen as an alternative energy source.