|Future transportation will require a broad portfolio of fuel technologies. Click to enlarge.|
Using hydrogen and fuel cells in transport and power generation could halve global carbon dioxide emissions by 2050 but major challenges need to be overcome—and more private and public investment needs to be made—according to a new report by the International Energy Agency (IEA).
But even under the most optimistic conditions, hydrogen will support just 30% of the global stock of vehicles by 2050, according to the IEA study, Prospects for Hydrogen and Fuel Cells. As a result, transportation will require a mixed portfolio of fuel technologies, including biofuels and synthetic fuels.
The IEA study suggests that hydrogen and fuel cells can have a significant role in the energy system if current targets for reducing their costs can be met and if Governments give high priority to policies for reducing CO2 emissions and oil dependence.
In the next few decades, hydrogen costs would need to be reduced three- to ten-fold and fuel cell costs by ten- to fifty-fold. Substantial improvements are also needed in hydrogen transportation and storage, and fuel-cell performance. At same time, the report argues, governments need to implement decisive policies and incentives to promote emission savings and diversify the energy supply.
Under the most favorable conditions, hydrogen fuel cell vehicles would enter the market around 2025 and power 30% of the global stock of vehicles by 2050—the equivalent of about 700 million vehicles.
The oil saving would then be equivalent to some 13% of global oil demand (or 5% of the global energy demand). Because the fuel cell efficiency is more than twice that of combustion engines, the energy needed to fuel these hydrogen vehicles would be less than 3% of the global energy demand, according to the IEA researchers.
Under these conditions, the collective impact of hydrogen and other emerging technologies could halve global CO2 emissions by 2050.
However, hydrogen and fuel cell vehicles will only play a significant role under these favorable assumptions. If less optimistic assumptions are considered for technology development and policy measures, hydrogen and fuel cell vehicles are unlikely to reach the critical mass that is needed for mass market uptake. Competing fuels with lower infrastructure costs, such as biofuels and synthetic fuels derived from coal and gas, would play a larger part.
The report also concludes that deployment of a hydrogen infrastructure now would be premature, as some of the key technical issues that are still being worked on—such as fuel cell operating conditions and hydrogen on-board storage—may have a considerable impact on the choice of technologies for hydrogen production, distribution, and refuelling.
Given that natural gas and coal are likely to remain the lowest-cost sources of hydrogen for many years to come, the report notes that:
...large-scale CO2 capture and storage, already of the highest importance to mitigate emission in the power sector, is also a vital step towards the wider use of hydrogen.