Mon 12 July 2010 – A new initiative has been launched to reduce carbon emissions from aircraft ground operations and improve local air quality and noise at major airports in the UK. The Aircraft on the Ground CO2 Reduction (AGR) Programme has been developed by BAA, the UK’s largest airport operator, through the Sustainable Aviation coalition. Guidelines and practical action steps for airports, airlines, air navigation service providers and ground handling companies have been drawn up to capture best practices to cut emissions from aircraft auxiliary power units (APUs) and taxiing operations. The programme was launched at the recent Environmental Conference held by the UK Airport Operators Association (AOA).

 

The 72 AOA member airports have been invited to sign up to a 12-month period, examining how best to implement the programme’s action steps and further develop the aviation industry’s understanding of and ability to manage CO2 emissions on the ground. So far, 15 airports – including BAA’s Heathrow, Stansted, Edinburgh, Glasgow, Aberdeen and Southampton – have joined the programme, which together make up 70% of all UK passenger traffic.

 

“Airports have an important role to play in reducing the environmental impact of aviation,” commented AOA Chairman Ed Anderson. “This new, exciting scheme will complement the existing great work being done by airports across the country and enable all to share best business practice going forward. It’s not a case of competition, as the industry must work together to take action on environmental challenges.”

 

Identification of the action steps has been facilitated through a ‘trial case’ at Heathrow Airport with the help and support of the Clinton Climate Initiative, which oversaw and project managed technical studies feeding into the final programme. Sustainable Aviation stakeholders involved in developing the programme included airlines British Airways, bmi and Virgin Atlantic, as well as aero engine manufacturer Rolls-Royce, NATS, ADS and Entec.

 

Heathrow’s carbon footprint was used to provide context to the development of the programme, which showed a total CO2 inventory of 2.1 million tonnes in 2008, with 0.6 million tonnes (30%) coming from aircraft on the ground.

 

The programme’s focus is on steps to reduce CO2 emissions from aircraft ground movements by broadly reducing emissions from aircraft taxiing and reducing the use of APUs whilst aircraft are being prepared on stand for departure or following arrival.

 

Taxiing under certain conditions can be completed with one or more of aircraft engines (as appropriate) not operating. If an engine can be shut down during the taxi-in or, on a departure, is not started after pushback until the aircraft is in an advanced stage of the taxi-out for takeoff, then such a procedure, under current operating procedures, has the potential to reduce fuel burn and CO2 emissions significantly. For taxi-in operations a saving of between 20-40% per aircraft movement has been estimated.

 

APUs are small gas turbines normally mounted in the rear fuselage of most transport category aircraft. They are used to power electrical systems on board, to run air circulation and conditioning systems and to supply bleed air for starting main engines before or during push back.

 

The use of aviation jet fuel in APUs is both expensive and inefficient. In many cases, the electrical and air conditioning loads normally supplied by an APU can be better supplied instead by ground based systems, which use grid electricity generated at a higher efficiency and thus have a much lower carbon intensity, lower NOx emissions and will in general offer a much lower running cost.

 

The exact potential for savings is complex, says the programme study, and dependent on a multitude of factors ranging from the availability of ground based systems at an airport, weather conditions and the flight schedules and local operating procedures in place. This large number of variables makes an exact calculation of saving potential problematic but the programme has looked at the evidence elsewhere.

 

A European study found that airports are realizing emissions reductions through the use of fixed electrical ground power (FEGP) and pre-conditioned air instead of APUs of up to 40%, with a potential to go further in the future. Another study found that a Boeing 747 APU used roughly six times more fuel than a ground power unit (GPU) supplying the same load, which in turn generates more CO2 than FEGP.

 

The potential CO2 savings from reduced engine taxiing and APU substitution have been modelled using the Heathrow footprint by the Clinton Climate Initiative. If Heathrow is taken as representative the results suggest that UK airports today are delivering efficiency savings in the order of 20% per movement versus a ‘do nothing’ scenario. Calculations carried out for Heathrow show that initiatives already taking place at the airport are saving approximately 100,000 tonnes of CO2 per annum.

 

The study also looked at the potential for greater efficiency improvements in the future and concluded that these were significant, although detailed airport-by-airport studies are required to confirm this potential.

 

For the BAA group, Heathrow’s Director of Operations, Colin Wood, said: “The UK aviation industry is leading the world in our collective work to pioneer new procedures and technologies that will improve our environmental performance. As part of this work, the new AOA guidance provides a clear framework for airport operators to address targeted areas of operations by encouraging measurement of current practice, planning to deliver results and a system of review.”

 

Manchester Airport Group, which operates four regional UK airports, was a contributor to the development of the programme. Penny Coates, Managing Director, Regional Airports Division, commented: “We welcome the introduction of the supporting guidelines, which we will apply at our airports. We believe that the programme provides a clear, evidence based and pragmatic approach to ensure that we continue to bear down on the environmental impacts of all aspects of aircraft operation.”

 

IATA has estimated that the global savings potential from aircraft ground operations are in the order of 6 million tonnes CO2 annually.

 

 

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