Flight path set for net zero greenhouse emissions writes Graham Skellern.

The self-piloted fan-powered Cora.

Over the past decade Air New Zealand has improved its aviation fuel efficiency by more than 20 per cent. The national air carrier wants to do better, even though further improvements will become tougher.

Air New Zealand, a founding member of the Climate Leaders Coalition, is determined to demonstrate climate change leadership in New Zealand and other destinations it flies to.

Advertisement

It is focused on minimising emissions by using fuel more efficiently and exploring new commercial solutions and technology to stabilise its carbon gas emissions by 2020 and help the environment.

The company says it wants to play its role in an ultra-low carbon economy towards a world of net zero greenhouse gas emissions in the second half of this century.

"We recognise the aviation industry's emissions are significant — at least 2-3 per cent of global emissions — but improvements in emission levels are counteracted by continuing growth in demand for travel," the company says.

Air New Zealand emits more than 3.5 million tonnes of carbon dioxide into the atmosphere every year. This year its carbon footprint (greenhouse gas emissions) rose 3 per cent — mainly due to a 5 per cent increase in its network capacity. But it achieved a 1.1 per cent improvement in aviation fuel efficiency compared with 2017.

The company says aviation fuel efficiency is the most significant way of reducing its carbon footprint, far outweighing other factors such as ground fleet fuel use and stationary energy reductions.

Air New Zealand has this year been trialling and implementing more efficient departure climb profiles on the Boeing 777 and Boeing 787-9 aircraft and will roll out the procedure to the A320 fleet.

It is also trialling more accurate and efficient navigation procedures, especially the approach paths into domestic airports. This reduces the distance flown and can allow for continuous lower-powered descents, therefore decreasing the amount of fuel required.

Air New Zealand's primary ground fuel project is reducing the use of the Auxillary Power Unit (APU), the small engine that runs mechanical systems, such as electrical supply and air conditioning when an aircraft is on the ground with its main engines turned off. The APUs operating at Auckland Airport for the jet fleets ran for 4200 hours per month, consuming more than 600,000kg of fuel and emitting an average of 2000 tonnes of carbon dioxide emissions each month.

In July 2017 Air New Zealand introduced a new process of connecting to an alternative ground power source, enabling the APU to be switched off soon after gate arrival. This required the co-operation of 1000 pilots, 500 ramp employees and 140 engineers to work collaboratively.

The target was to reduce APU fuel burn in the year to June 2018 by 675,000kg or 2100 tonnes of carbon dioxide emissions. In the first 10 months the company exceeded this target by more than 20 per cent, saving 2 million kg of fuel and 6300 tonnes of carbon dioxide emissions.

This year Air New Zealand extended the APU initiative to Christchurch and Wellington airports, and its overall Carbon Reduction Programme reached 3.63 million kg of fuel, representing a saving of 11,468 tonnes of carbon dioxide emissions.

Air New Zealand believes every action counts. Other emissions reduction initiatives include continued renewal of the fleet to more fuel-efficient aircraft (the average fleet age is 7.5 years), efficient flight planning and lighter weight baggage containers to save weight and fuel.

The company plans to have 100 per cent of belt loaders electric by the end of 2019 — the loaders transfer baggage and cargo to and from the aircraft — and all baggage tugs will be electric by the end of 2020. Two electric tugs capable of pulling wide-body aircraft — the first of their type in the Asia-Pacific region — began operating this year. Air New Zealand has two electric container loaders in action (the only ones in Australasia) and intends to replace a further 30 of 56 by the end of 2020.

The company says the challenge is ensuring the airport infrastructure enables sufficient electric charge to run the vehicles for a full day — and it is working with the airport and ground handling companies.

Air New Zealand is investigating the supply of bio-jet, a biomass derived jet fuel, to reduce operating costs and environmental impact.

It looked overseas for supply and found that bio-jet fuel production globally is in its infancy with several development plants under construction.

So Air New Zealand formed a consortium with Refining NZ, Scion and Auckland Airport to build a commercially viable business case and work with government to develop bio-jet production capability in New Zealand.

Perhaps the most exciting prospect is Air New Zealand's partnership with Zephyr Airworks, and bringing the world's first autonomous, emissions-free electric air taxi service to this country.

Zephyr has been testing its unmanned aircraft called Cora at a private airport in Canterbury since October last year. Cora, self-piloted through software, takes off vertically and is powered by 12 electric fans that together produce 522,000 watts, or 700hp. It travels up to 177km/h and is silent in cruise mode.

The agreement between Air New Zealand and Zephyr signalled the intention to form a long-term relationship and make autonomous electric air travel a reality for New Zealanders.

Air New Zealand chief executive Christopher Luxon said at the time of the announcement: "The airline is committed to embracing new technologies that make life easier, as well as understanding the potential of cleaner energy solutions for travel."

Climate change challenge:
The world must hold the increase in the global average temperature to well below 2 degrees celsius pre-industrial levels by peaking global greenhouse gas emissions as soon as possible or face a potentially irreversible threat to human societies and the planet.

Global aviation contributes at least two per cent of global emissions and rising.

Air NZ's 2030 goal:
Stabilise emissions through carbon neutral growth post-2020 in a way that simultaneously drives significant environmental, social and economic benefits.