Spring 2023

GPUs go green

A Guinault GPU in a maintenance hangar with an Air France KLM aircraft

Aircraft’s auxiliary power units burn fuel and can be blamed for producing a significant proportion of the harmful emissions created at airports and airfields. Traditionally, the ground power units (GPUs) that have been used in their stead have been fuelled by diesel, but the move towards electric GPUs is gathering pace; besides being greener, these are also much quieter, and arguably more cost efficient

At Saint-Cyr-en-Val, France-headquartered GPU, air-conditioning unit (ACU) and air start unit (ASU) supplier Guinault, producing environmentally friendly equipment is a high priority, just as using greener GPUs is a priority for its customers. “If reducing the carbon footprint might have been a strategic positioning for companies in the past, the environment has now become a pillar in purchasing decisions’ processes and airport stakeholders’ priorities,” says the company’s CEO, Lionel Clermont.
“In this trend, the reduction of auxiliary power unit (APU) usage on the airport ramp has become a sine qua non condition for airports willing to contribute the reduction of the carbon footprint. Today, APU OFF projects are now often driven by environmental departments.”
Guinault’s APU OFF offering relates to the provision of APU substitution solutions that enable minimal use of expensive and emission-creating aircraft APUs when an aircraft is on the ground.
Guinault customises its commercial offer to ensure the shutdown of auxiliary power units wherever possible, with options taking into account variables such as the type of aircraft that might be involved, its configuration, airline operator processes and so on.
Auxiliary turbine engine-powered APUs are power hungry, more expensive to run than the electric motors or diesel engines of ground units and, crucially in today’s world, very environmentally unfriendly. Indeed, notes Clermont: “The use of APUs represents 30 to 50% of the carbon emissions of an airport (landing and take-offs excluded).
“APU OFF has been Guinault’s mission since the establishment of the company in 1949. Forced to acknowledge that the APU consumes an average of 100 to 400 litres of fuel at each aircraft turnaround, continuing to run the aircraft turbines during aircraft parking represents an environmental and financial shortfall for airlines, airports and ground handlers. The only alternative to the APU is using external solutions: GPUs and ACUs.”
Clermont continues: “Guinault’s expertise allows any aircraft stakeholder the possibility to switch off the APU whatever the level of infrastructure available. We prioritise the electric GPU and PCA [pre-conditioned air] for minimising carbon emissions on the ramp. However, the company also reminds its customers that when existing ramp facilities prevent them from using grid-powered equipment, a diesel- or battery-powered solution still allows them to turn off an APU and hence reduce the carbon footprint on the ramp by at least 80%.”
Guinault’s in-house expertise offers it the flexibility to meet all its customer needs, Clermont says. “Its historical record as a manufacturer and supplier of GPUs and PCAs to airlines gives it a unique experience of aircraft’s electrical and cooling requirements.
“We also innovate according to evolving industry requirements: digital engineering has therefore been placed at the centre of our research and development (R&D). We are investing to develop more efficient and more connected ways to optimise ground operations with the help of artificial intelligence (AI).”

Sensitive and critical equipment
“As GPUs and ACUs are actually plugged into aircraft, they are the most sensitive and critical GSE used around an aircraft,” Clermont suggests. “And as a manufacturer of these systems, Guinault understands that any of its customers should be supported by one of its experts, anywhere, at any time.
“Developing our own telemetry system has allowed us to fulfill that need. Plus, the AI Guinault is developing is aimed at anticipating equipment breakdowns and monitoring GPU and ACU units remotely for faster and more efficient technical support.”
Finally, he notes, to match increasing global demand for APU OFF solutions, Guinault is currently ramping up production while nevertheless minimising the carbon footprint of its manufacturing processes. It is building new, partially self-powered facilities with a 2,000m² solar farm at its 20,000m² production and operation plant at Saint-Cyr-en-Val, near Orléans.

ITW GSE ramps up its battery GPU offering
Rune Lind Pedersen, strategic marketing manager for GPU and PCA system supplier ITW GSE – part of the Illinois, US-headquartered conglomerate Illinois Tool Works (ITW) – confirms that it is working on a number of improvements to its product line at the moment, including further promoting its battery GPU offering.
“This coming year is going to be a big one for us,” he says, “both in terms of the strategy of the business and new product development.”
Key to the product portfolio’s evolution will be ITW GSE’s innovative Intelligent Power Management (IPM) technology, which is hosted in its PCA 3500 product. IPM is responsible for monitoring power use and needs of both a GPU and PCA at an aircraft gate and can distribute power dynamically as demand changes. ITW GSE is actually rethinking the complete airport gate power system to bring GSE together within a single, ‘smarter’ power infrastructure environment, Pedersen says.
With the 3500 PCA as ‘the beating heart of the gate’, ITW GSE can connect GPUs, chargers and other auxiliary equipment to the 3500, enabling it to monitor and share power as necessary, thereby expanding the functionality of the gate without adding costly infrastructure.
“We have had great initial success with IPM,” Pedersen confirms. “It’s really starting to take off.”
Meanwhile, ITW GSE’s 7400 battery-powered eGPUs will form an integral part of what will be a very environmentally friendly as well as cost-effective offering, says Pedersen. Demand for its 7400 is continuing to gain yet further momentum, he notes, pointing by way of example to a recent order by the UK’s defence and aerospace manufacturing giant BAE for 40 of its 7400 eGPUs – the largest single order yet placed for these systems.
The units will support the Royal Air Force’s Typhoon multi-role aircraft at a number of RAF stations, and, says Pedersen, in line with the RAF’s desire to operate an environmentally healthy working environment for its personnel as far as is possible, these eGPUs mean lower emissions and less noise at any airfield.
The 7400 eGPUs also represent a significant cost saving over their lifetime compared to older, less efficient diesel equivalents, he adds, a not inconsiderable benefit to their operators.
US GSE operators are also enthused by the environmental value of electric GPUs, Pedersen believes, and this is driving demand there for the green eGPUs that ITW GSE produces at its Palmetto, Florida plant (its other major manufacturing facility is in Odense, Denmark). The likes of carriers DHL and United as well as fixed-base operator (FBO) Signature Air have all purchased ITW GSE eGPUs, for instance.
Programmes in America, such as the state of California’s Clean Off-Road Equipment (CORE) that offers financial inducements for businesses and government agencies to acquire emissions-free off-road equipment, have spurred demand for eGPUs, Pedersen says.
He notes that, while the European market for fixed GPUs and PCA units has certainly picked up from the dark days of the Covid pandemic that devastated the aviation industry, and there are signs of this in the Far East as well, the US market appears to be leading the way. There, the recovery of flying passenger numbers has been accompanied by a growing commitment among purchasers to invest in new GSE as major airport projects get under way (some of these programmes having been postponed under the impact of Covid).
The US is also a big market for ITW GSE’s new 3500 PCA unit. San Diego, Philadelphia and Syracuse airports have all acquired the 3500 in recent times and, in general, “2022 was a great year for our sales and production teams in Florida,” Pedersen declares.
Orders for PCAs and ITW GSE power coils have also come in from various markets, including major European air hubs such as Rome’s Fiumicino Airport and Amsterdam Airport Schiphol in the Netherlands.

Going green is one of the biggest priorities of the Alvest Group, which is dedicated to the design, manufacture and distribution of products for the aviation industry. Indeed, the group, which includes the well-known GSE brands of TLD, Smart Airport Systems (SAS), Sage Parts, AERO Specialties and service provider Alvest Equipment Services (AES), has a mission to ‘provide the highest quality products and solutions to the aviation industry, and to help it become greener and leaner’.
Many of the businesses within the group are active in the GPU market. TLD produces a range of diesel units as well as its environmentally friendly lithium-powered GPU-409-iBS model and, notes the chief operating officer of TLD Group, Erwan Jalil: “The second generation of Li-ion battery GPUs will be available in 2023, on the back of a strong success with the first generation which was launched in 2021.”
Of the ever-growing momentum in the industry towards greener GPUs, he highlights the regulatory driver. For example, “Regulation in Europe is forcing the transition to electric GPUs from 2025 (when no more sales of diesel GPUs will be allowed) to 2030 (when no more operations involving diesel GPUs will be allowed).”
The good news, he notes, is that, “The economics of electric GPU are quite favourable, with a payback of the additional upfront cost typically within two to three years. So they will definitely become mainstream in Europe, and the rest of the world will follow gradually in the years beyond.”
TLD has seen a general recovery in the GPU market over recent times. In fact, says Jalil: “Other than in China, demand is back to pre-pandemic levels.”
Meanwhile, at Boise, Idaho, US-headquartered AERO Specialties, director of sales and service Pete Johnson reports “continuing good sales of our hybrid JetGo models”. AERO Specialties manufactures and distributes high-quality GSE, both new and refurbished, and amongst its product lines is the JetGo 28V DC diesel/electric hybrid GPU.
Yves Crespel, director of communication for the Alvest Group, says the commonality of batteries used across the full range of the group’s electric GSE enables great circularity, with all the environmental, social and governance (ESG) benefits that brings, as well as significant cost benefits, particularly through the re-use option that commonality allows.
“In other words, an operator of TLD eGSE can simply recycle five-to-seven-year-old batteries from heavy-duty applications (from a baggage tractor or pushback tractor, for instance) to lighter eGPU applications, effectively getting the eGPU batteries for free,” he says.
As for the group’s plans for GPU product additions or improvements, he promises further development of its GPU range in terms of power and features.