Hybrid Electric Flight Pioneer Ampaire Ground Tests Dimensional Energy e-Fuel

by Tony Harrington (GreenAir) Electric aviation pioneer Ampaire has partnered with Dimensional Energy, an emerging power-to-liquid producer, to perform a ground test of a hybrid-electric powertrain using 100% e-SAF created by converting carbon dioxide captured from the atmosphere. The two US-based companies performed the test using an Ampaire Eco Caravan, a Cessna Grand Caravan commuter plane retrofitted with an Ampaire AMP-H570 AMP Drive propulsion system. Dimensional Energy specialises in power-to-liquid production, blending captured CO2 with green hydrogen to create syngas, which is then to converted to low carbon liquid e-fuel. Ampaire has also announced the acquisition of Magpie Aviation, whose autonomous tow aircraft can be used to meet electric planes during flight and tow them for part of their journey, enabling the e-planes to conserve battery power and extend their flight range, before descending under their own power.

Ampaire and Texas-based Dimensional Energy are both backed by global climate investment platform Elemental Excelerator and have significant advance orders for their products. The propulsion company says its AMP-H570 hybrid electric propulsion systems can reduce by 50-70% the fuel burn and emissions of conventional Pratt & Whitney PT6 turboprop engines usually used to power the short-haul Cessna Caravan.

Dimensional’s customers include United Airlines Group, which has not only ordered 300 million gallons of the e-SAF but also invested in the fuel start-up in 2022. Ampaire said the ground test using Dimensional’s 100% ASTM D7566 SAF “exceeded expectations” and progressed the powertrain’s development.

The Dimensional Energy process involves extracting CO2 from the air with giant fans, then combining it with green hydrogen, produced by using renewable electricity to split water into hydrogen and oxygen. The syngas this creates is converted via the Fischer-Tropsch process into variations of liquid fuel including SAF or renewable diesel for road and sea transport. READ MORE

Excerpt from Robb Report: Dimensional has finalized its chemical process, run the pilot plant, built a larger test plant in Vancouver and started construction on its first commercial plant, in Niagara Falls, N.Y. That facility is scheduled to begin producing three million gallons of fuel a year starting in 2027. “It’s all progressed very naturally,” Salfi says. “We’re an overnight success story . . . eight years in the making.”

Before Dimensional and its competitors—Air Company, Infinium, and Twelve—emerged, the concept of Sustainable Aviation Fuel (SAF) had become a type of catchall solution for aviation’s race to be carbon neutral by 2050. It is, in many ways, a myth.

Enter Gen 3, also known as eSAF or Power-to-Liquid (PtL), offering a promise that seems almost too good to be true—which, to an extent, it is. The production process uses existing, above-ground carbon, but burning the resulting fuel emits carbon, so SAF doesn’t reduce atmospheric carbon. It only allows planes to operate at net-carbon neutral.

While it’s possible to pull carbon directly from the air, all the current makers of eSAF take CO2 from factories with high emissions, such as concrete, steel, and ethanol production facilities. “Piping those exhaust streams directly into our system is the most efficient approach,” says Gregory Constantine, CEO of Air Company in Brooklyn, N.Y., another eSAF producer. “Also, it allows for the highest greenhouse gas emissions reductions.”

Other players in the field include California based Twelve, in Berkeley, and Infinium, in Sacramento. Each of the four have slight operational differences but all undertake the same basic task—making synthetic aviation fuel from CO2, water and green energy. An IATA report estimated that eSAF will eventually account for 65 percent of aviation’s push to carbon neutrality, so those four companies may not be alone for long.

Air Company’s Constantine, who allows that his long-term plan is licensing the technology to “existing infrastructure players,” says: “We need more people involved, more ideas and more solutions to emerge. We don’t want to be the only ones doing this because of the size of the market. It’s about getting to scale.”

Scale. That’s the one word that comes up repeatedly when talking eSAF. Everyone’s chasing the concept, but a realistic solution remains distant. The fuels should become commercially available within three years, but the manufacturers say it’ll be five to 10 years before they’re in broad use. At least any growth spurt won’t be slowed by infrastructure concerns. Unlike earlier forms, the new SAF doesn’t need to blend with traditional fuel to run in existing engines, and it’s compatible with current distribution systems.

“It’s a tremendous opportunity because it bridges the gap between those in oil and gas today and the exact talent pool we need for production,” Salfi says. “So it’s not about switching out one form of infrastructure for another but about leveraging the trillions of dollars of intellectual and physical capital already existing to transition to a less carbon-emissive economy. We view this sector as a job-creating force.”

But that force still needs to overcome a large obstacle—the interrelated issues of money and power. “It’s going to come down to economics,” says Kevin Noertker, CEO of Ampaire, a builder of hybrid-electric aircraft who has worked with eSAF. “It’ll be hard to achieve full-scale adoption if they’re charging a premium. Aviation has historically been very price sensitive.”

Currently, eSAF costs about twice as much as standard aviation fuel, although, “when oil prices shot up, it closed the gap,” says Sincock. Still, the carbon-neutral fuels are working through a classic chicken-egg loop—the price is high because there isn’t enough renewable energy, but the expansion of renewables takes time because it’s expensive.

“Scaling takes years,” Sincock says. “The production process is electric intensive, which is a huge cost to the producers. As the supply of green electric increases and the cost approaches the cost of traditional energy, the price of the fuel will come down.”

That need for cheap and abundant clean energy is why Dimensional has set both its Vancouver and Niagara Falls facilities along rivers, where they can tap into steady hydroelectric electricity, and why Twelve has made a similar choice with the commercial facility it is building in Moses Lake, Wash. As Air Company’s Constantine says, “We’re starting in places where low-cost green power is available.” READ MORE