Therefore, if greenhouse gas emissions are to be curbed within the next 20 years, improving mainstream gasoline and diesel engines and expanding the use of hybrids is most progressive path to pursue, the study recommends. Continuing to work on today's gasoline engine and its fuel can cut energy use and emissions by a third compared to today's vehicles by 2020, the study says.
However, work on the hydrogen fuel cell should not be stopped. Hydrogen fuel-cells are still "the only major fuel option identified to date", says John B. Heywood, Director of MIT's Laboratory for 21st-Century Energy and co-author of the study. But the hydrogen will have to be produced without making greenhouse gas emissions, which at this moment is still too expensive.
In November last year, a similar report was issued by the British Institute for European Environmental Policy. It will take at "least 30 years" before mass-market use of hydrogen fuel cells produces a carbon benefit, the experts estimated. Based on economic considerations, McKinsey's latest report on fuel cell technology, too, concludes that the internal-combustion engine "will still be installed in 90 percent of all new vehicles sold in developed economies in 2015 and remain dominant in new vehicles for at least another decade after that, both as a stand-alone technology and as an integral part of hybrids."
