Fuel Cell ApplicationsTransportation | Portable Power | Stationary Power | Military & Space | Fuel Cell Research in Australia | Further Information | References |
When using fuel cells, hydrogen is applicable to both stationary and portable applications. Fuel cells are able to produce energy continuously and efficiently whilst not producing harmful emissions.
In the transport industry, hydrogen can be used to fuel cars, buses, trains, boats and planes. In the electricity industry, utility-scale units are being developed as well as units suitable for distributed generation with each home meeting their own energy needs. The commercial and industrial sectors are already starting to use hydrogen and fuel cells to produce their electricity and heat requirements through the co-generation.
Hydrogen fuel cells may replace the rechargeable battery in mobile phones, laptops and portable music players, with many prototypes and some commercial products already becoming available. In fact, hydrogen could be applicable to almost any energy requirement. In its purest form, the Hydrogen Economy would encompass all areas of the energy industry and even open up some new areas. Hydrogen fuel is applicable to an infinite number of applications.
The many different types of fuel cells allow the user to match their fuel cell’s characteristics to better suit the energy services required (see Table 1).
Table 1 A simplified reference for Fuel Cell comparisons (courtesy of the US Department of Energy).
There are a variety of applications for fuel cells due to the wide range of system types and sizes (1W to over 1MW). Generally, fuel cells can be used for one of the following four applications:
- Portable power
- Stationary power
- Military and Space applications
Methanol and other fuels such as natural gas can be used but may need reforming. The first General Motors car to run on methanol, the Opel Zafira was designed to produce almost zero sulphur dioxide (SO2), nitrogen oxides (NOx) emissions and 50% less carbon dioxide than an internal combustion engine. The latest incarnation of the Zafira, the HydroGen 3, runs on pure hydrogen (see Figure 1).
Hydrogen may be preferred as the fuel for cars if some storage issues can be overcome. Current storage systems are bulky and heavy and may not be practical on such a small-scale. Also, hydrogen is usually stored at high pressure, which is also a problem. Recent developments in the hydrogen storage field are seeing the introduction of new lightweight materials being produced that are able to store hydrogen at lower pressures. Due to these recent technological developments, there has been an increase in fuel cell cars are being produced by car manufacturers (see Figure 2).
Buses powered by fuel cells are in current operation in many cities. In 1995, Ballard Systems tested fuel cell powered buses in Vancouver and Chicago. Further trials have been conducted in Europe, California and in Western Australia (see Figures 3 and 4). A number of businesses collaborated on the project, including EvoBus (a subsidiary of Daimler-Chrysler), Ballard Power Systems and BP. The trial in Western Australia will undergo an independent evaluation programme by Murdoch University to further the development of hydrogen and fuel cell technology. The evaluation aims to identify opportunities for industry development in Western Australia and investigate government and private sector systems that will facilitate the future introduction of associated technologies.
Hydrogen is the preferred fuel used for buses due to the zero exhaust emissions. Initial systems were large, consuming around one-third of the vehicle space, making buses the most appropriate application for domestic transport. With improvements in power density, smaller systems are being introduced.
Hydrogen fuel cells may replace the rechargeable battery in mobile phones, torches, laptops and portable music players, with many prototypes and some commercial products already becoming available (see Figures 5 & 6). In fact, hydrogen could be applicable to almost any energy requirement.
Fuel cells have potential applications for wide-scale use in a number of portable electronic devices, particularly in personal devices such as laptop computers, mobile phones, video cameras and stereos. Fuel cells have some significant advantages over batteries for these applications. Potentially a fuel cell could last three times longer than a battery of equivalent size and the fuel cell could be replenished more quickly using fuels such as hydrogen or methanol than batteries can be recharged .
There are currently many fuel cells available that have been developed for use as small (less than 5 kW) power supply systems, portable commercial, residential, or remote generators, or as a back-up power supply system (see Figure 7).
In general there are three types of stationary fuel cell applications:
- Stand-alone Power Systems (SPS) or Distributed Power Systems
- Industrial or Commercial Systems
- Utility Systems
Stand-alone or Domestic Systems
Stand-alone power systems (SPS) are one of the main areas where sustainable energy systems are viable because of the large cost of providing power to these areas. Fuel cells could be an option in the areas where small-scale generation is required. Similarly, urban residential areas could take advantage of a distributed and continuous power supply. Companies such as Plug Power manufacture fuel cell systems able to produce up to 5 kW of electricity and 9 kW of thermal energy, which is sufficient for domestic applications. The excess heat could be used for water or space heating, which will further reduce energy use. Hydrogen and natural gas are typical fuels for applications of this size.
Uninterruptible Power Supply (UPS) Systems
UPS systems are one of the fastest growth areas for fuel cell technologies. Fuel cells are used as backup power supplies if the primary power system fails, and are often used in important services, such as telecommunications, banking, and military uses. If the primary power source fails (i.e. the electricity grid goes down in a storm), and no power is available from this primary source, the fuel cells can then take over to provide power to maintain such services. Battery systems have been used for many years to provide backup power to essential services, however the lifespan of such technologies is relatively short. Fuel cells have the advantage that they can provide power for as long as required, with refillable storage systems and standby fuel allowing ample time for the primary power source to be repaired. Plug Power’s 5 kW GenCore® UPS hydrogen fuel cell system, tripled the number of orders received in 2005, to more than 300 and reduced the GenCore® direct material cost by more than 25 percent from 2004 levels. Plug Power also began field-testing its next generation continuous run fuel cell system at Robins Air Force Base in Georgia and secured and executed against contracts with Honda R&D for Phase III of the Home Energy Station and more general research topics.
Industrial or Commercial Systems
On a large scale (greater than 10kW) fuel cells may also be an option for electricity and heat generation (also called co-generation). Large commercial buildings or industrial sites require significant amounts of electricity, water heating, space heating and/or process heat. Fuel cells combined with a heat recovery system may be able to meet some or all of these needs as well as the possibility of providing a source of purified “chemical” water (HSW). Phosphoric Acid Fuel Cells have been used to provide stationary power for a number of commercial and industrial sites including the 200 kW unit at the Yonkers Waste Treatment Plant, New York. This site uses reformed methane (extracted from sewage) as the fuel for the system. For a list of Fuel cell installations in New York State click here.
Some other examples of fuel cells in applications of this scale are:
· The 1 MW system (five 200 kW fuel cells) at the US Postal Service Anchorage Mail Handling Facility (Alaska, USA), which provides all the site’s electricity needs, half of the hot water requirements and feeds electricity back into the traditional grid.
· The 1 MW (single fuel cell) in King County generates electricity using methane gas from a sewage treatment. Wastewater-solid digesters at the treatment plant and a fuel cell power plant produces up to 1 MW of electricity, or enough to serve 800 households (see Figure 8).
· The 10 MW proposed system for Long Island Power Authority (LIPA) is due for commercial operation in June 2006 (see Figure 9). The successful existing West Babylon fuel cell “farm” is an example of large-scale grid connected fuel cells, also operated by LIPA (see Figure 10).
Large units needed for large-scale power generation are not currently in demonstration, although research continues into such units. The largest individual units are limited to 200 – 250 kW. However these units are stacked together to form large systems (such as the US Postal Service Facility previously described).
The Fuel Cell Energy Inc has demonstrated a 2 MW system in California (see Figure 11). The plant uses Molten Carbonate Fuel Cell (MCFC) technology. The company offers fuel cells for stationary applications of sized 1.5 – 3 MW. Solid Oxide Fuel Cells may also have the potential to provide power of this size with the US Department of Energy and Siemens Westinghouse successful conclusion of a 220 kW SOFC co-generation system combining the fuel cell with a gas microturbine. They are also planning new MW sized fuel cells and gas turbine hybrids using coal derived gases with over 50% electrical efficiency with greater than 90% CO2 capture. These systems are proposed to be scalable to sizes of greater than 100 MW.
NASA has used fuel cells for providing power and drinking water for their Space Shuttle fleet since the 1960’s. Polymer Electrolyte Membrane (also called Proton Exchange Membrane) fuel cells (PEMFC) were first used in the Gemini missions, and the Apollo Missions in the 1960’s used alkali fuel cells (AFC’s) for the moon landings and now all space fuel cells are PEMFC’s.
The US Army has used a number of different fuel cells for a number of applications. Alkali fuel cells were used for mobile radar sets, Molten Carbonate Fuel Cells (MCFC’s) were tested at the Mobility Equipment Research and Development Centre (MERDC) running on the army’s “combat gasoline” using a reformer as well as testing Phosphoric Acid Fuel Cells (PAFC’s) because of their ability to use readily available fuels. The US army also use accumetric solid oxide fuel cells (SOFC) as power supplies in the field because of their efficiency and durability in combat situations. One of the newest additions is a 188 kW (2 stacked cells) military truck, which is being evaluated until mid 2006 for near-future deployment (see Figure 12).
The Chicken and Egg Dilemma
There is a serious question mark over what comes first: the technology to utilise hydrogen or the infrastructure to deliver it? There is not likely to be development of wide-spread hydrogen delivery systems without enough uses to require such systems. Similarly, consumers are unlikely to buy products that run on hydrogen if there is no convenient way of providing the hydrogen. The fossil fuel industry has already faced and overcome these challenges and this will make it hard for hydrogen to displace fossil fuels. This may however also offer some valuable lessons.
The technology to run the Hydrogen Economy is not developed to a level that makes it competitive with traditional technologies. There are continual improvements and it is envisaged that the potential of the hydrogen-fueled technologies will be superior to fossil fuel technologies. However, this is not yet a reality and major technical issues need to be addressed, such as hydrogen storage, fuel cell costs and system durability.
Economic and Political Barriers
The economic barriers facing the Hydrogen Economy are similar to those facing renewable energy sources. They are seen as having a large risk associated with them and finding financial backing is difficult at acceptable interest rates. Coal, oil and gas are recognised commodities and are viewed as much safer investments. There are large subsidies and incentives for the fossil fuel industry whilst the environmental benefits of a Hydrogen Economy are not considered in dollar terms.
Governments, particularly the United States and Australia, are lobbied heavily by the fossil fuel industry and they will continue to provide incentives for the growth of these industries. Changing to an economy based on hydrogen would require a major shift in the view of such countries. However, countries like Iceland and Germany have already made this shift aiming to have a sustainable energy economy. Iceland’s current electricity is sourced from geothermal and hydroelectric power and it plans to have all its transport run on hydrogen over the next 30 years with a view to exporting hydrogen to the rest of Europe (Dunn, 2001). Germany also aims to have 100% of its electricity grid sourced from renewable technologies in the near future with a large roll-out in renewable infrastructure.
There will be a considerable cost associated with establishing a Hydrogen Economy. At present fuel cells are expensive to produce, using expensive materials and not having large scale manufacturing procedures. Without developments in these areas it will be difficult to make fuel cells commercially viable. Major new infrastructure will be required and once again, this will be expensive. Large amounts of money are already invested in energy infrastructure and in current economic climates it will be difficult to shift these investments to a Hydrogen Economy. Fossil fuels will remain less expensive to produce and it may take some time before hydrogen is competitive with the fossil fuels on an economic level.
One of the major barriers to the use of hydrogen is the perceived safety risk. There is a strong association between hydrogen and the infamous Hindenberg disaster. Whilst recent evidence has pointed to the materials used to build the zeppelin as the cause of the fire, the image of the burning airship remains vivid and helps to maintain the perception that hydrogen is an unsafe fuel (Thomas and Zalbowitz, Hydrogen aus). In fact, hydrogen may be safer than the fuels we are currently comfortable with. Hydrogen disperses quickly and storage tanks are no more prone to explosion than petrol or gas tanks. Hydrogen burns far more quickly than petrol and in one direction rather than spreading like a petrol fire (Thomas and Zalbowitz, Hydrogen aus).
Standards and Legal Frameworks
The early introduction of international standards for all countries is important in avoiding unnecessary extra costs such as redesign as a consequence of diverging standards and safety requirements. Standardisation would also simplify the international trading of hydrogen technology. In this vein, the International Organisation for Standardisation (ISO) has established a technical committee for hydrogen technology. In March 1999 the first hydrogen standard was published and many more standards will inevitably be established (Bellona, 2002).
Western Australia's first fuel cell was installed at Research Institute for Sustainable Energy’s (RISE) Renewable Energy Systems Test Centre (ResLab) at Murdoch University in 2003. This small 5 kW alkaline system was designed to prove the concept in a RAPS test facility with a 30 kW wind turbine. The prototype alkaline fuel cell system was replaced with a commercial 5 kW PEM fuel cell in late 2004. The most recent fuel cell successfully tested at ResLab was a 1.2 kW alkaline fuel cell in January 2006.
The Fuel Cell Bus Trial
The Perth Fuel Cell Bus Project (Ecobus) involved operating three fuel cell buses in the Perth public transport system for a period of three years (2004-2007). These buses operated on normal bus routes in Perth, Western Australia for three years and used 250 kW PEM fuel cells. The trial ended in September 2007 and various options are currently being considered to conduct trials for the next-generation of fuel cell vehicles. Murdoch University developed a Memorandum of Understanding with the Department of Planning and Infrastructure of the Government of Western Australia to undertake a number of research projects associated with this trial. RISE was involved in two of the research projects from the Perth Fuel Cell Bus Trial that were under the supervision of Dr Trevor Pryor. These were:
- The Bus Operations Project
This project involved a PhD student and focused on the operation of the buses and how the data obtained would impact the cost-benefit analysis of the project. A cost-benefit analysis was conducted on the operation of fuel cell buses compared to diesel and natural gas buses. Regular data was collected on the operation of the buses and the data was then fed into the larger CUTE (Clean Urban Transport for Europe) project, of which the Perth trial was a part.
- The Life Cycle Assessment (LCA) Project
Involved an MPhil student and focused on applying the GaBi software to undertake a series of scenario analyses. The LCA model for this work was developed and a number of scenarios were investigated.
The CSIRO is also active in solar-hydrogen production by water-splitting research. They aim to engineer materials with appropriate optical, electronic and chemical properties for use as photocatalysts in efficient and cost effective photoelectrochemical cells. Their current research encompasses the areas of materials science, plasma and thin film physics, electrochemistry and analytical chemistry. The main areas of research are:
- Synthesis and modification of suitable semiconducting materials using a range of techniques (Flame Pyrolysis, Filtered-Arc Deposition, Oxidative Annealing, Sol-gel Preparations, Ball Milling, and Nanostructuring.
- Materials characterisation of materials using different analytical techniques (X-ray Diffraction Spectroscopy (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), UV-Visible Spectroscopy, Electrical Measurements, Electrochemical Measurements, and Impedence spectroscopy).
Also CSIRO's, Dr Sukhvinder Badwal and his research team are developing a compact, lightweight PEM fuel cell that could power a laptop computer for up to 24 hours, or a mobile phone for up to a month, before requiring a recharge. One year into the project, Badwal’s team in Clayton, Victoria, has developed working prototypes of both hydrogen and methanol powered micro fuel cells, and aims to commercialise them in 2007.
Ceramic Fuel Cells Ltd
Australia is also home to Ceramic Fuel Cells Ltd, a world leader in the development of solid oxide fuel cells. Australia is competing with multinational companies in a fuel cell market predicted to be worth billions of dollars worldwide. Ceramic Fuel Cells Ltd has developed a solid oxide fuel cell stack the size of a 2 litre milk carton that produces 1.5 kilowatts, enough power to meet the needs of a typical household. The company has also demonstrated a larger, 5 kilowatt unit, operating it continuously for 200 hours. These solid oxide fuel cells promise to achieve a very efficient conversion of fossil fuels to electricity, while producing only very low levels of pollutants. Currently Ceramic Fuel Cells Ltd have a pre-commercial 1 kW SOFC microgenerator called NetGen that integrates a domestic hot water system to produce electricity and heat.
UNSW'S Solar Hydrogen Program
The UNSW team's particular expertise is in photosensitive oxide semiconductors. UNSW's research program aims for the development of a commercial (i.e., practical and inexpensive) device for the production of hydrogen from photolysis of water using solar energy. The UNSW hydrogen generating device can be marketed internationally and has no moving parts, so maintenance is minimal. Offers to be involved in UNSW's research are coming from the US, Europe and Asian countries (UNSW, 2008).
RISE Information Portal - Information regarding renewable energy resources, technologies, applications, systems designs and case studies.
For further information on hydrogen, see the RISE Information Portal File on Hydrogen.
For further information on fuel cells, see the RISE Information Portal File on Fuel Cell Technology.
H2 Stations.org - Hydrogen Filling Stations Worldwide
Ballard Power Systems - For an excellent animation on the operation of fuel cell vehicles and further commercialisation of vehicles.
Ford Motor Company - For information on their Innovative Engines and Fuel Technology.
General Motors – How fuel cells work.
UNSW, 2008. “Solar hydrogen - energy of the future” (Online)
http://www.unsw.edu.au/news/pad/articles/2004/aug/Solar_hydrogenMNE.html (Accessed 2 December 2008).