Aerospace giant Embraer has predicted that a regional airliner powered by hybrid technology will reach operational capability before hydrogen fuel cell development matures.
In an update on the company's futuristic Energia program delivered this week, Embraer said that hybrid power was less complex and would be technologically ready sooner than power trains relying on electric engines fed from hydrogen fuel cells.
Embraer announced the four-plane Energia family in November last year, of which the smaller hybrid-electric version was predicted to be ready by 2030. With the aviation industry committing itself to a goal of zero carbon emissions by 2050, the Brazilian manufacturer has dedicated itself to the task.
"Climate change is a crisis that is threatening our peace and security, our economic well-being and our way of life," said Arjan Meijer president and CEO Embraer Commercial Aviation.
"I believe the aviation industry is one of the industries that has really embraced the sustainability challenge. It set itself the goal of being net-zero by 2050, and here at Embraer we have embraced the target."
Embraer said the Energia family is being developed in collaboration with the aviation industry and that studies showed significant potential for new, sustainable aircraft. The company identified four main trends driving aviation towards sustainable technologies:
- increased pressure to "de-carbonise"
- growth in regional air travel
- volatile aviation fuel prices
- congestion in urban areas.
The company stressed that sustainable aircraft will also needed to make economic sense as well as have enough range to to match operator demands, use existing airports and runways, and be able to operate in conditions up to 39,000 feet and in temperatures as low as -69oC.
If aircraft manufactuers can meet those conditions, Embraer is predicting a demand for 4000 new aircraft for fleet replacement by 2035 with another 3000 on top of that due to operators electing to retire existing airframes early to adopt the new technologies instead.
"We're exploring and evaluating a number of new technologies to accelerate the deployment of zero-emission regional aircraft," Meijer said.
"Smaller aircraft are going to be the first platforms on which new propulsion systems will be introduced, simply because we can apply those systems more easily on a small scale before we put them gradually on bigger and bigger aircraft in the future.
The Energia project studied 20 different concepts, which Embraer has narrowed down to only four: hybrid electric, fully electric, sustainable aviation fuel (SAF) and hydrogen combusion fuel cells.
Luis Carlos Affonso senior vice president Engineering, Technology Development and Corporate Strategy said the company would focus on the technologies that would become operational first.
"Hydrogen, battery-electric and hybrid-electric technologies allow us to frame the future of sustainable aviation," he said, "and given the need to peak carbon dioxide emissions ... it is our responsibility to pursue the deployment of these technologies with the fastest possible route that makes them viable.
"Therefore our journey to a full-sustainable future aircraft fleet will likely start with smaller commuter regional aircraft, which, by their specific mission characteristics, may be developed earlier, delivering a truly sustainable solution."
Embraer's research showed that hybrid-electric engines burning jet fuel and SAF using small batteries would be simpler to develop that hydrogen fuel cells for aircraft in the 19-30 seat range. This would reduce carbon emissions but not eliminate them completely.
The company predicts that hybrid technology could be running in regional aircraft by 2030. The design concept is for two rear-mounted tractor propellers and a whole new wing.
Hydrogen fuel cells will eliminate carbon emissions, but the technology requires a heat exchanger installed in the airframe, which is large and heavy.This would mean a large air intact for the exchanger mounted at the base of the vertical stabiliser.
Embraer says it will prove the technology on small aircraft first before scaling it up for use on large aeroplanes.
Such a system is not expected to be operational before 2035.