Most of us accept that, with the burning of fossil fuels and the large-scale use of energy, nearly every form of transport has an impact on the environment.
The air transportation industry accounts for 2% of total global emissions and is making great efforts to reduce its CO2 emissions. Similarly, many airports have begun to examine and optimise all of their processes with respect to their environmental impact. They are developing strategies to minimise their carbon footprint.
Of the air transportation industry’s total emissions, airports – presently facing the challenge of a growing numbers of passengers, escalating security needs, energy costs and mandated emission targets – account for around 5%.
With an ever-increasing number of airports realising that being energy efficient can lead to cost-savings on a large scale and, just as importantly, that environmental compatibility can go hand in hand with improved competitiveness, the figure could even come down in the years’ ahead.
Inside the airport terminal building
Vital to its commercial success, the airport’s interior environment should make people feel safe, secure and comfortable.
Within the terminal building, where the main use of energy is by systems moving passengers and their baggage and those maintaining the internal environment, opportunities exist for the implementation of various energy-saving measures.
The growth of direct digital control (DDC), and global standards for the interface of IP-based products, are bringing about improvements in communication, operational and energy efficiency.
This sort of control is used by intelligent building management systems (BMS), which can now provide optimal control of heating, ventilating, air-conditioning (HVAC) and lighting systems.
By picking up data from sensors throughout the airport, the systems switch on only those devices needed. With continuous monitoring of power consumption levels, trend analysis can identify further potential energy savings.
It also gives operators the flexibility to adjust schedules, set points and overall control strategies to suit the changing needs of a growing airport.
Ventilation and lighting systems
Demand-controlled ventilation is one such approach particularly suited to the airport environment that ensures the terminal is ventilated cost-effectively whilst maximising indoor air quality.
The number of passengers can fluctuate quite significantly within the building, so the measurement of air quality throughout different parts is critical for providing adequate fresh air for passengers’ comfort. Mixed gas sensors detect the presence of oxidizable (combustible) gases to establish when areas are occupied, along with odours or ‘volatile organic compounds’ perceived by people as ‘stale’ air.
Patterns throughout zones such as passenger gates, retail areas, restaurants, bars and check-in areas – where numbers fluctuate the most – can be monitored and ventilation controlled.
When occupancy is high, levels of fresh air are increased. When no occupancy is detected, ventilation and heating or cooling can be kept to a minimum.
Savings can be achieved with lighting levels, too. Energy-efficient lamps are widely available, as is LED lighting technology, which can be controlled with reference to indoor lighting-levels such as ‘indoor’, ‘shop’, ‘mood’, ‘street’ and ‘garage’.
As with ventilation control, lights can be programmed according to usage or, when occupancy is not detected, turned off altogether.
Baggage handling systems
Perhaps not surprisingly, conveyor belts and escalators are airport processes that are heavy users of electrical power. Components of the systems can be improved, and consequent energy savings can be made.
In a system that has inefficient controls logic, a simple software upgrade can bring about substantial immediate savings. But if savings are to be optimised on belt conveyor systems, changes are best done at the ‘end-of-life’ of the existing belts, with savings of 25% possible when low-friction belts are substituted for torn belts.
As 95% of the life-cycle costs of a motor is taken up in the energy it uses, replacing old drives can also produce savings of 40% when modern gearboxes and motors are used. With the use of variable speed drives, the baggage system can be run at load-dependent speeds, bringing about lower energy and maintenance costs.
It is possible also to reduce energy consumption of IT systems by upgrading and updating both software and hardware.
It is usual these days for any workplace, including airports, to have numerous individual workstations and servers running at a fraction of their computing capacity. Instead of having various computers running single applications, one powerful server might be able to run all applications simultaneously.
This application and desktop ‘virtualisation’ can achieve energy savings of up to 80% and would facilitate the implementation of redundant and back-up concepts whilst offering more dynamic load sharing.
Smarter software solutions that focus on integrating airport processes can optimize functions such as resource management, fleet management, airport operations and collaborative decision-making.
This approach can be extended to encompass safety, security, building management and flight information functions in a single command and control programme. Fire, intrusion, access control, video surveillance, public announcement and flight information systems along with heating, ventilating, air-conditioning and energy usage are all effectively controlled and monitored together with an overview displayed in a user-friendly way on a single screen.
The advantages of a combined solution would be immediately apparent should any emergency occur. But with this high-level integration, energy usage can also be monitored and controlled.
For example, instead of using video surveillance solely for security purposes, it could also be used for intelligent crowd management whereby heating, ventilating and lighting levels are adjusted appropriately by operators and reduced wherever possible.
Energy production on-site
The on-site generation of power is also becoming more commonplace at airports. Compared to a typical set-up of several boilers, chillers and electrical generators, the use of a modern, gas-fired, combined heat and power (CHP) plant with heat recovery, along with district heating and cooling, can improve overall efficiency by more than 50%.
Solar power is also, of course, an option – with the installation of photovoltaic (PV) panels being particularly suitable for airports. For those based in countries with government-supported, feed-in tariffs for PV panels, returns on investment are sometimes feasible within six to seven years, depending on the tariffs, the financing costs and the yield.
Airports of the future
Green airports make economic sense as well as environmental sense. However, the green and efficient airport of the future is about much more than merely optimising performance in problem areas, even though individual solutions can bring about substantial reductions in CO2 through the use of renewable energies.
It is about utilising architecture, technology, and logistics for environmental compatibility with products and systems featuring health-friendly, recyclable materials and low resource consumption.
A greater level of integration of systems in the future will bring greater levels of intelligence. More efficient technologies and higher energy savings will offset initial investments more quickly and deliver measurable efficiency gains in costs and operations, as well as an improved customer experience.
Furthermore, with the need for growing transparency, in the future, airports will be required to compile data from relevant sensors and systems and to report on improvements achieved.
In effect, they will have little choice whether to invest in the new technologies or not, their only choice being which ones yield the highest benefits, both in terms of return and social responsibility for their own specific requirements.