“When the aircraft engine reduces its engine thrust by 1,000 pounds — that’s a turning point, a big deal,” Mr. Wolf said. “So we recognize that, if one engine at a time would need to reduce power to achieve that, the number of engines that would need to be stripped out to achieve those same levels of reduction could be exponentially greater, so we need to really focus on, first of all, clean-burning fuel alternatives.”
One technology that’s receiving a lot of attention is fuel cells. Some commercial airliners like Japan Airlines’s All Nippon Airways, which uses fuel cells made by General Electric Co., already use the technology in smaller aircraft. (China’s state-owned airline Air China is one of the largest carriers in the world using such a technology. The Hong Kong-based conglomerate Swire Pacific Ltd. recently announced a U.S. project with General Electric to develop a commercial-scale fuel cell.) The general benefit of the technology is that it produces much more power from a smaller amount of fuel.
There are also inherent advantages for consumers that can help shift toward alternatives.
Hydrogen could deliver a host of benefits to airlines. A 2016 study by Tel Aviv University suggested that it has the potential to dramatically lower emissions and other serious problems. According to the study, if 10 percent of fleet flights were made using fuel cells, those reductions could generate a carbon benefit of roughly 1.8 million tons per year. That could reduce the greenhouse gas emissions across the world by a quarter, according to the study.
But that means it’s way too early to tell whether the fuel cells and hydrogen can be a part of the solution to the problem of rising emissions and more fuel-efficient airplanes.