Hydrogen economy

The hydrogen economy is a proposal for the distribution of energy by using hydrogen. Hydrogen (H₂) gives off energy when it is combined with oxygen, but the hydrogen itself has to first be produced, which requires more energy than is released when it is used as a fuel.

To use hydrogen as a fuel, it first has to be generated by electrolysis of water or another method. A reduction in carbon dioxide emission would only be achieved if the energy used to split the water is obtained from non carbon-based sources.

Some futurists promote hydrogen as potential fuel for motive power (including cars, boats and airplanes), the energy needs of buildings and portable electronics. They believe a hydrogen economy could greatly reduce the emission of carbon dioxide and therefore play a major role in tackling global warming. Countries without oil, but with renewable energy resources, could use a combination of renewable energy and hydrogen instead of fuels derived from petroleum, which are becoming scarcer, to achieve energy independence.

In the context of a hydrogen economy, hydrogen is an energy carrier, not a primary energy source (see nuclear fusion for an entirely separate discussion of using hydrogen isotopes as an atomic energy source). Nevertheless, controversy over the usefulness of a hydrogen economy has been confused by issues of energy sourcing, including fossil fuel use, global warming, and sustainable energy generation. These are all separate issues, although the hydrogen economy affects them all (see below).

Proponents of a world-scale hydrogen economy argue that hydrogen can be an environmentally cleaner source of energy to end-users, particularly in transportation applications, without release of pollutants (such as particulate matter) or greenhouse gases at the point of end use. A 2004 analysis asserted that "most of the hydrogen supply chain pathways would release significantly less carbon dioxide into the atmosphere than would gasoline used in hybrid electric vehicles" and that significant reductions in carbon dioxide emissions would be possible if carbon capture or carbon sequestration methods were utilized at the site of energy or hydrogen production.

Critics of a hydrogen economy argue that for many planned applications of hydrogen, direct distribution and use of energy in the form of electricity, or alternate means of storage such as chemical batteries, fuel plus fuel cells, or production of liquid synthetic fuels from locally-produced hydrogen and CO₂ (see methanol economy), might accomplish many of the same net goals of a hydrogen economy while requiring only a small fraction of the investment in new infrastructure. Hydrogen has been called the least efficient and most expensive possible replacement for gasoline (petrol) in terms of reducing greenhouse gases. A comprehensive study of hydrogen in transportation applications has found that "there are major hurdles on the path to achieving the vision of the hydrogen economy; the path will not be simple or straightforward". The Ford Motor Company has dropped its plans to develop hydrogen cars, stating that "The next major step in Ford’s plan is to increase over time the volume of electrified vehicles".

Recent publicly describing the use of low cost materials and manufacturing processes challenge the popular critique. Hydrogen (renewable hydrogen) can be produced from renewable sources, thus enabling the intermittent and excess power generated to be stored for applications in transport, homes and businesses, thereby making off-grid wind and solar sources economic.

The term hydrogen economy was coined by John Bockris during a talk he gave in 1970 at General Motors (GM) Technical Center.