Hydrogen economy, electricity and fuel cells

First coined in 1970 by John Bockris, a Texas A&M professor, “hydrogen economy” is an ideal scenario in which all energy needs of the humankind are met by hydrogen. If we look at the history of energy use, there has always been a gradual switch toward the energy sources with lower carbon content. Thus, many researchers and scientists believe that it is only a matter of time before widespread adoption of hydrogen fuel takes place making realization of the hydrogen economy.

Though hydrogen is being widely accepted as the energy carrier of the future, there are various factors, ranging from technological to political, which will decide the fate of hydrogen in near term. Development of cost-competitive, efficient and safe technologies for the production, storage, distribution as well as end use of hydrogen obviously plays the crucial role. Besides, the importance of policy support in national and international level cannot be ignored. In fact, move toward the ideal hydrogen economy seems possible only when there is sufficient investment in infrastructure build-up and incentives are provided in terms of targets, regulations, standards, grants, etc.

Hydrogen vs. electricity

It is important to evaluate the future of hydrogen with respect to its competitors. Though currently there are many competing options, in the long term hydrogen will have to compete only with electricity because electricity potentially offers the same benefits with respect to greenhouse gas reduction, energy security and reduction of local air pollution. But it is argued that hydrogen and electricity should not be viewed as competitors, rather they are complementary to each other to satisfy all energy needs of modern civilization.

Hydrogen and electricity are closely interacting energy carriers. On the one hand, hydrogen can be produced from electricity via electrolyzers and on the other hand, reverse process can be employed to produce electricity from hydrogen with the help of fuel cells. This interchangeability is promising particularly to use hydrogen as a storage medium for electricity from intermittent renewable energy sources such as solar and wind. Moreover, hydrogen could be produced from off-peak electricity and stored for later use, e.g. as a transportation fuel. This results in effective utilization of existing electrical capacity where there are significant diurnal and/or seasonal fluctuations in supply to demand ratio.

Hydrogen and fuel cells

Fuel cell technology is often associated with hydrogen or hydrogen economy. Of course, fuel cells are one of the key elements in the hydrogen economy but the beauty of fuel cell technology is that not all fuel cells require pure hydrogen as fuel. Fuel cells like SOFC (solid oxide fuel cell) and MCFC (molten carbonate fuel cell) can run with straight hydrocarbon fuels such as natural gas offering a number of benefits over conventional energy conversion systems (as discussed in my first post). Thus, it is not hydrogen economy that will boost fuel cell technology but the vice versa is true.

Also, fuel cells are generally perceived as only the replacement of IC engines in automobiles. Though R&D in some fuel cells, especially PEFCs (polymer electrolyte fuel cells), is primarily focused on vehicular applications, utility of fuel cells ranges from large scale stationary power generation to portable electronic devices.

Commercial use of fuel cells in automobiles, stationary power plants as well as domestic CHP systems has already started. Despite the fact that fuel cell systems are currently not cost-competitive with conventional systems, R&D efforts are continually being made to reduce their cost and it would not be an optimistic illusion to expect fully cost-competitive fuel cell systems in the market within next few years!