February 6, 2023
Etihad’s ‘Greenliner’ reveals a glimpse of a extra sustainable future for aviation
(CNN) — Whereas some delegates eventually week’s COP27 local weather convention had been criticized for arriving by personal jet, others arrived in Egypt aboard flights that had been described as being emission-free, as they had been powered absolutely by sustainable aviation gas.

The flights had been a part of a program referred to as “Greenliner,” run by Etihad Airways, the nationwide provider of the United Arab Emirates, as a testbed for sustainable air journey options.

Business aviation accounted for simply over 2% of worldwide CO2 emissions in 2021, which suggests it could be a modest contributor to local weather change. However the quantity does not inform the entire story, as air journey impacts the local weather in additional advanced methods than simply carbon emissions, and its impression is predicted to rise sooner or later, as increasingly more individuals will need to fly.
Whereas renewable power and electrical autos supply clear pathways to decarbonize sectors like energy and street transport, it is much less easy for the aviation trade.
Consequently, the trade isn’t on observe to fulfill its web zero goal by 2050, and is banking on two thirds of that transition coming from sustainable aviation gas (SAF). It is made out of waste merchandise and may curb emissions by 80% on common — however it presently accounts for simply 1% of worldwide jet gas utilization. One thing wants to vary, quick.

That is why SAF is without doubt one of the key components of the “Greenliner” program. “It is primarily a name to motion,” says Mariam AlQubaisi, head of sustainability at Etihad. “The thought took place in late 2019 to launch a message to the trade: let’s attempt every little thing potential to decarbonize.” This system relies across the Boeing 787 Dreamliner, however Etihad has the same initiative, referred to as Sustainable50, devoted to the Airbus A350. Since its launch, Greenliner has championed the adoption of SAF and tackled points resembling plastic waste and inefficient flight routes.

Etihad's "Sustainable50" Airbus A350.

Etihad’s “Sustainable50” Airbus A350.


The “Greenliner” moniker is usually used to discuss with a selected 787 plane, which AlQubaisi calls this system’s “mascot.” Unsurprisingly, it is painted inexperienced — which she says is a manner pre-empting accusations of greenwashing.

“Any venture any airline would launch will all the time be scrutinized below the umbrella of greenwashing,” she explains. “Portray the plane inexperienced was a technique to problem that and say it’s devoted to a goal. We’re proudly owning as much as our emissions: We’re saying sure, we’re a serious emitter — however we’re doing one thing about it.”

A fast repair

Etihad ferried delegates to Sharm El Sheik in Egypt, the place COP27 passed off, by including a stopover to its common Washington Dulles to Abu Dhabi service. The flight was described as “emission-free” as a result of being powered completely by SAF — however confusingly, the planes really used conventional jet gas.

The obvious absurdity highlights challenges with each SAF infrastructure and speaking inexperienced initiatives. The airplane did not have SAF on board as a result of present rules prohibit business flights from utilizing greater than 50% SAF, as not all engines are licensed for larger concentrations. Plus, not all airports have the infrastructure to make use of it, and the inexperienced gas should come from a manufacturing facility comparatively near the airport to keep away from canceling out the discount in flight emissions with these coming from transportation.

So, Etihad bought sufficient SAF to energy the flight and delivered the gas to Los Angeles Worldwide Airport, which has the mandatory infrastructure and amenities. There, the SAF was built-in into the airport’s refueling system with conventional gas, and utilized by whichever plane had been refueling that day. This technique is named “E-book & Declare,” and it is presently the one manner for a flight to assert it is utilizing 100% SAF. The emissions are merely offset elsewhere, reasonably than on one particular flight.

Etihad's "Greenliner" program tests out sustainable initiatives on this Boeing 787 Dreamliner.

Etihad’s “Greenliner” program checks out sustainable initiatives on this Boeing 787 Dreamliner.


AlQubaisi calls it a “fast repair” till rules change, however for SAF to change into extra widespread, extra progress is required. “The worth of SAF is 4 to 5 occasions that of typical jet gas and it is restricted in provide. Solely two our bodies are allowed to certify it, so till we’ve got extra and till governments intervene to incentivize manufacturing, SAF will proceed to be restricted,” she says.

Etihad has used SAF extensively in a sequence of “EcoFlights,” which make use of the provider’s 787 and A350 fleet to evaluate new sustainability initiatives. These culminated within the airline’s most environmentally pleasant flight ever, a London Heathrow to Abu Dhabi service on October 23, 2021. The flight, Etihad says, achieved a 72% general discount in emissions by utilizing 38% SAF (by way of “E-book & Declare”) and adopted a number of different measures, resembling decreasing single-use plastic by 80% and delivering baggage by way of electrical tractors.

It was additionally the primary business flight to check a novel technique to fight emissions, by utilizing navigation and synthetic intelligence to keep away from the formation of contrails. These are vapor trails that type when ice crystals coalesce across the exhaust gasses emitted by plane engines, and lead to short-term clouds that entice warmth, contributing considerably to the warming impact of air journey. However modifying the airplane’s route or altitude might help dramatically. “The warming you are avoiding by merely including a bit extra time to the journey is as much as 60%, if no more,” says AlQubaisi. “What’s good about that is that it is performed by way of particular algorithms that make the system change into smarter the extra we use it.”

A greener future?

Etihad’s “EcoFlights” have trialed a spread of applied sciences and methods aimed toward decreasing emissions, resembling an optimized climb and a steady descent, last-minute engine start-up, taxi procedures utilizing a single engine, and washing the engine with a particular foam that improves effectivity by decreasing the build-up of deposits.


Good navigation might help to scale back a single flight’s carbon footprint.


Many of those methods have since made it into on a regular basis operations, and in recognition of those efforts Etihad was named “Environmental Airline of the Yr 2022” on the annual Airline Rankings awards. In line with Geoffrey Thomas, Airline Rankings’ editor-in-chief, Etihad has proven “clear management within the push for sustainable flight.”

There’s nonetheless rather a lot to be performed, AlQubaisi says: “That is an trade that has had free rein on air pollution for a few years and it is about time we come clean with our accountability to decarbonize.”

The important thing to reaching a greener aviation is everybody working towards it, she provides: “Hopefully you will hear of extra airways becoming a member of the Greeliner program, as a result of it does not matter who does it first — what issues is who does it higher.

“We are able to do higher collectively, as a result of sustainability isn’t an space for competitors, it is an space for collaboration.”

Leave a Reply