The transition from fossil-intensive energy system today toward the potential emergence of hydrogen and electricity (the “hydricity” age), as virtually emissions-free energy carriers of the future, has spurred increasing interest from scientific, entrepreneurial and policy communities as of recently encompassing the full range from optimistic to sceptical views. In 2002, the European Community has identified hydrogen technologies and systems as one of the pillars of the energy policy toward achieving the sustainability transition. The development of these technologies should not be exclusively a task of international research initiatives. From a strategic point of view it is important for Austrian private and public organizations and energy companies to participate actively in research, development and deployment of hydrogen technologies and in this way gain experience and know-how.
The long-term goal is to produce both hydrogen and electricity from renewables, fossil energy sources in conjunction with carbon dioxide capture and storage and from nuclear energy to the extent that its social acceptability can be achieved. Today, virtually all hydrogen is produced from fossil energy sources and used as chemical feedstock rather than as an energy carrier. One of the great advantages of hydrogen as a future emissions-free energy carrier is that it can be produced in principle from all primary sources of energy. The high cost of renewables is generally inhibiting their use for hydrogen production. There are also other competing uses of renewables such as generation of electricity and heat. Large-scale hydropower may become one of the first non-fossil sources of hydrogen in the future. It is likely that hydrogen would be produced in the future in both large-scale centralized and smaller, on-site decentralized facilities. Primary energy sources particularly suitable for centralized, large-scale production of hydrogen include natural gas and coal, in conjunction with carbon dioxide capture and geological storage, nuclear energy, large hydropower plants, high-temperature solar power and large off-shore wind parks. Energy sources particularly suitable for decentralized production of hydrogen include natural gas steam reforming, biomass gasification followed by steam reforming or future biogenetic processes for direct conversion into hydrogen, and hydrolysis of excess electricity produced from a range of intermittent (local and on-site) renewables such as wind and photovoltaic.
Like electricity or natural gas, hydrogen is an energy carrier that requires elaborate transportation and distribution infrastructures. It is conceivable that in the more immediate future hydrogen will continue to be transported compressed or as a liquid in containers. However, development of elaborate transport infrastructures is unavoidable if hydrogen is to become an important energy carrier in the long run. A first step in this direction could be the addition of hydrogen to methane (“hythane”) in current natural gas pipelines. This could provide for a more evolutionary transition to ever larger use of hydrogen as an energy carrier.
Fuel cells are considered to be very promising technology for conversion of chemical energy forms into electricity because they can achieve very high efficiencies especially in cogeneration schemes. As such, fuel cells are also considered to be a key hydrogen technology. Fuel cells are a relatively mature technology in the sense that they have been used for a long time in special niche applications such as space travel. However, the costs of fuel cells are very high compared to competing prime movers such as the internal combustion engine. This implies that large cost reductions need to be realized in the future. These could emerge from various synergies and technological learning effects associated with their initial deployment in niche markets and later on through widespread diffusion and adoption. The first fuel cell applications could be portable devices such as mobile phones and laptops and once they become more competitive also vehicles, first cars and specialized fleets and eventually possibly also private automobiles. Various stationary applications for cogeneration of electricity and heat might also constitute in parallel some of the first fuel cell applications. For instance, hydrogen might become a realistic source of power for a wide range of electronic devices in a few years because batteries are very costly and have lower energy densities compared with fuel cells. Stationary applications in households and commercial sector might become attractive within next decades. In contrast, hydrogen vehicles will no doubt take much longer time to diffuse even though they are most discussed by media and the public as a promising solution to a wide range of environmental challenges including the global climate change. Widespread diffusion of hydrogen vehicles will not only require an enormous reduction of fuel cell costs, but also the development of new hydrogen distribution infrastructures throughout the world. It is for these reasons that this would constitute the ultimate stage in the global transition toward the hydrogen economy of the more distant future and last many decades.