Grounded aircraft require reliable power and air conditioning, yet airports are typically sourcing this energy from grossly inefficient on-board generators. Future Airport speaks to Andrea Zimmermann, deputy CEO of Swiss firm IST-Edelstahl-Anlagenbau, about how ground-based power and preconditioned-air systems are the way forward.

What makes the IST-Edelstahl-Anlagenbau Aircraft Ground Energy System (AGES) unique?

Andrea Zimmermann: During their time on the ground, stationary aircraft require 400Hz of electrical power. Depending on the ambient environmental conditions, they may also require preconditioned air (PCA) for heating and cooling of the cabin. Traditionally, this energy is provided by an auxiliary power unit (APU) located at the rear of the aircraft. As a result of the unit’s poor efficiency, just 8-14%, the APU is a major contributor to pollutant emissions and airport noise. IST offers AGES, the first complete system for the power and PCA needs of grounded aircraft.

AGES represents the world’s only complete, high-quality, highly efficient ground-based power and PCA system. The 400Hz generators provide uninterrupted power supply to the aircraft on the ground prior to the safe shutdown of their engines after docking. The provision of conditioned air, available from a central or a stationary so-called point-of-use (POU) air handling unit, ensures the conditioning of the aircraft’s air, enhanced hygiene and increased passenger comfort.

Many ground power supply systems are totally outdated with regard to the current state of technology and generate environmental unfriendly emissions that can easily be avoided – not unlike those of APU operation. The airport, airlines and environment benefit from the use of AGES. APU fuel consumption is significantly reduced, as are CO2 and NOx emissions, and the noise level on the apron and its surroundings drops significantly. By using stationary systems that provide power and PCA, airports can make fuel savings of up to 90% – excluding grey energy – in comparison with the fuel consumption of a traditional APU.

What else does the company offer that makes it stand out from its competitors?

IST specialises in process engineering plants for a wide variety of industries, such as chemical and pharmaceutical, nutrition and beverage, medical technology and more. These companies have very high demands on the quality, hygiene standards and sustainability of the products – just as airports and airlines have high demands on energy supply systems.

IST can supply complete system solutions manufactured in stainless steel from the initial planning stage all the way through to engineering, manufacturing, installation and service. IST provides its clients with comprehensive, innovative, tailor-made products and system-based solutions. As a Swiss producer, the company has also committed itself to the ‘Swiss Quality’ standard of excellence.

What are the advantages of using stainless steel for power supply systems?

An investment in a power supply system is very high, so it must be ensured that the system meets the highest quality requirements, provides the necessary performance and is durable. IST has specialised in the processing of stainless steel for more than 40 years.

The IST-manufactured and initially patented stainless steel telescopic tube, for example, is the only PCA tube in the world that consistently demonstrates a well-above-average service life. It is extremely stable, robust and essentially maintenance-free. Since the first installation of telescopic tubes and hose reels at Airport Zurich in 2000, for example, no maintenance or replacement has been necessary, thus incurring no costs, and the components still look like new.

Making a power supply system using stainless steel will result in a very long product life compared with mild steel on account of its great resistance to corrosion; structures made from stainless steel will therefore last many times the normal life. Stainless steel is probably more expensive to buy in the beginning, but it is cheaper in the long run since it lasts, and incurs little or no maintenance and repair costs.

When the total life-cycle costs are considered, stainless steel is therefore often the least expensive material option. Furthermore, as a result of the exemplary smooth surfaces that can be achieved through the use of stainless steel, pressure losses are reduced to a minimum.

In addition to these qualities, stainless steel has also become an important product in terms of sanitation because of its suitability for environmental stress as well as its hygienic qualities. It complies with the highest hygiene standards, has an exceptionally smooth and inert surface to which bacteria cannot adhere, and it resists denting, nicking and scratching under the most stressful and robust operating conditions.

What are the benefits of using a complete PCA system from one contractor, such as IST, rather than integrating components from various sources?

As a general contractor, IST provides its clients with a complete system from a single source. Customers only have one contractor that takes over the responsibility of the system, and guarantees quality, costs and performance. As the number of interfaces is reduced, the associated coordination effort is minimised.

Efficient and reliable operation at high technical availability is a key factor for the successful operation of a stationary system. Therefore, AGES has to deliver the required performance, even in hot and humid conditions.

For the airport, it is less important to know the performance of the air conditioner, or the temperature and pressure losses in the air distribution system; much more important is the overall performance of the system as a whole and the assurance that the aircraft can be conditioned accordingly. This can only be guaranteed by implementing energy systems as a complete system.

What are IST’s goals in collaborating with Seven-Air, the leading Swiss heating, ventilation and air-conditioning supplier?

The aim of this cooperation was the development and distribution of a highly efficient PCA unit for preconditioned air supply for aircraft on ground. The newly developed non-subfreezing POU air-conditioning unit is designed for moderate climatic regions. The plant is a stand-alone application, weather-proofed and simply requires electrical energy from the airport. The new system design, with integrated chilled water for air cooling, allows excellent control even at partial load with the smallest air flows. This increases comfort and minimises operational costs.

For countries with hot and humid weather conditions, IST has developed a subfreezing PCA unit. This AGES unit is based on new technology that continuously supplies the aircraft with cold and dry air according to Airbus’s specifications, specifically for the A380 and is more energy efficient than conventional equipment thanks in part to its integrated energy-recovery system.

So what’s next for IST?

IST is developing a flexible hose system. The first prototype was completed in June 2016 and will be installed at a European airport for testing purposes. In contrast to the hose reel, the new system is much more flexible: the hose length can vary depending on the aircraft and be adapted accordingly. The new retriever is constructed so that hose wear is minimised. We are planning to launch the new product in the latter half of 2016, after testing is complete.