A hydrogen-powered plane

From TriplePundit

The clean energy revolution means more than simply replacing fossil fuels with low-carbon alternatives. Clean technology can also provide extra benefits for companies in terms of productivity, comfort and convenience. A case in point is the hydrogen plane startup ZeroAvia. The company has just emerged from “stealth” mode to offer the world’s first commercial aircraft with a hydrogen fuel cell powertrain as its exclusive means of locomotion.

ZeroAvia’s business model is based on the premise that its hydrogen fuel cell powertrain will reduce the cost of flight on small, 10-20 seat aircraft, targeting short-haul journeys of up to 500 miles.

With the ability of the company's hydrogen plane to compete on cost for passengers against large conventional jets, ZeroAvia is anticipating that business travelers will be attracted by the opportunity to fly into smaller regional airports.

Ideally, the increased flexibility in choice of destinations will reduce the potential for delayed flights and long security lines that often bedevil larger airports.

Hydrogen fuel cell passenger cars have been slow to take off, partly due to their relatively high cost and lack of a mature fuel distribution network for motorists.

Those two issues are not significant barriers for ZeroAvia’s hydrogen fuel cell aircraft, however.

The company is anticipating a per-flight cost savings of about 50 percent for its powertrain compared to conventional jet aircraft. Higher power train efficiency is one key difference. Lower fuel and maintenance costs will also factor in.

To help reduce costs farther, ZeroAvia has adopted a “power-by-the-hour” engine lease model commonly used in the aircraft industry, in which customers pay only for the hours that they use the powertrain. The cost of fuel and maintenance will be picked up by ZeroAvia as part of the lease.

Hydrogen fuel cells produce no airborne pollutants. The only emission is water, resulting from the interaction of hydrogen with oxygen in the fuel cell.

Still, the supply chain for hydrogen is front-loaded with pollutants and environmental impacts because the primary source for hydrogen today is natural gas.

Air Liquide has committed to decarbonizing hydrogen production for energy-related applications through its Blue Hydrogen initiative.

For its short-term goal, the company has pledged carbon-free production for at least 50 percent of hydrogen in the energy category by 2020 -- in other words, by next year. Biogas, water-splitting (using electricity sourced from renewables) and carbon recycling are the three main pathways identified by the company.

Air Liquide’s timetable for renewable hydrogen improves the prospects for ZeroAvia to reduce its supply chain emissions.

ZeroAvia is looking at the year 2022 to introduce its new fuel cell aircraft to the market, and earlier this year Air Liquide announced it would ramp up carbon-free hydrogen production at an existing facility just across the border from the U.S. in Canada.

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Brown hydrogen is made from coal, blue hydrogen from natural gas and green hydrogen via electrolysis using green electricity.  The supporters of a hydrogen economy say that supporting blue hydrogen will lead to economies of scale which will then allow the introduction of green hydrogen.  For example, this page from Oz gas producer Woodside. 

I'm not altogether convinced.  The problem with blue hydrogen is not economies of scale.  It's cost, because the chemical bonds between oxygen and hydrogen in the form of water are so strong it requires lots of energy to break them apart during electrolysis.   ZeroAvia's relative cheapness, I suspect, depends on blue hydrogen, not green. 

That's doesn't mean ZeroAvia's project is completely pointless.  Green hydrogen produced by renewable electricity that would otherwise be curtailed because there is surplus electricity in the grid is cheap.  Curtailment will increase rapidly as we increase the percentage of renewables in the grid.  And it may be possible that the CO₂ produced as a by-product of the production of blue hydrogen could be dissolved in water and pumped into basalt where it turns into rock.  On the other hand, compressing and delivering the CO₂ to far-off locations increases the cost and energy usage.

For now, blue hydrogen is more efficient and much less polluting than petroleum or jet-fuel, so it is half a step forward.  Air Liquide's commitment to producing 50% green hydrogen as part of its total hydrogen production is good news.  Progress comes from small steps, as long as they're all in the same direction.