Sustainable development is becoming more and more recognised in every sector these days. Air transport, like other sectors, is also acknowledging the importance of this kind of development by considering different methods, technologies, concept, strategies and operational procedures. Thus, airports as a component of the air transport system are going through a process called “greening.” Greening, in this context, refers to medium- to long-term mitigation of the airports’ environmental and social impacts under conditions of their continuous constrained or unconstrained growth. In this article, a greening concept called “Eco-Airport” will be discussed (Janic, 2011).
According to the International Civil Aviation Organization (ICAO), an Eco-Airport is an airport that is implementing measures to conserve the environment and to produce a healthy environment in and around the airport. In other words, an Eco-Airport is a sustainable airport that contributes to the development of a low-carbon society, a recycle-oriented society and a society which co-exists with nature.
The Necessity of Eco-Airports
Airports are the face of the country and foreign visitors get their first impression of the country they visit from this place. An Eco-Airport can improve the image of a country due to being the main gateway of the country. This has turned into a trend in recent years and countries such as the U.S.A., Japan and India are creating guidelines for Eco-Airports in their respective countries.
Simultaneously, the cost of operation is reduced by saving energy. The reduction of operation costs is done through utilising different technologies and techniques that increase the efficiency of the process (ICAO, 2013). Therefore, Eco-Airports have an ecology (image of a country) and economy (energy saving) impact.
The Eco-Airport Procedure
Generally, there are two major steps in the procedure:
- The government formulates an “Eco-Airport Guideline”
- The Eco-Airport Council of each airport formulates an annual environmental plan and takes initiatives
Promoting Eco-Airports by enforcing regulation is not the same as other regulations such as aircraft noise reduction. The regulations for Eco-Airports should be accompanied by grand efforts of environmental measures. In other words, all parties concerned need to cooperate with each other to come up with an environmental plan which specifies certain environmental targets. These targets differ from airport to airport because of the different size, location and climate that each of them have. Achieving these targets are not only essential for the development of the airports but also addressing global and regional environmental concerns (Nishiyama, 2014).
For example, in a Plan-Do-Check-Act (PDCA) cycle, an environmental target could be the reduction of emitted CO2 by a certain amount within a period of time. In order to attain this target, actions such as LED adoption, using an alternative source for fuel or energy production and less idling of vehicles could be implemented. Figure 1 illustrates a PDCA cycle for an Eco-Airport council.
Fig. 1 – PDCA Cycle for Eco-Airport Council of Each Airport (Nishiyama, 2014).
As mentioned earlier, most environmental targets lead to an increase in efficiency. Some efforts could be done immediately. For instance, actions such as saving water, recycling, less idling of engines and turning unnecessary lights off have no initial costs; whereas efforts like establishing solar power plant, recycling plant, rooftop gardening, LED lighting and recycling water have an investment cost besides the operating cost and need more time for implementation.
International Passenger Terminal of Haneda Airport: A Successful Case Study
Tokyo is currently one of the world’s leading advanced environmental cities. Haneda International, which is one of the two primary airports of Tokyo, has improved energy efficiency and reduced CO2 emissions. To fulfill these two targets, various measures are taken into consideration. These measures are divided into two categories: that of “efficient production of energy” and “efficient use of energy,” both of which are explained briefly below (TIAT, 2015).
Efficient Production of Energy
Efficient energy production helps in reducing CO2 emissions significantly. At Haneda International’s new passenger terminal, energy production is done through renewable energies such as solar and geothermal energy rather than conventional sources.
The reason for using solar is that shading is rare at the airport because high-rise buildings are not near it. This makes the airport a suitable site for installing solar power generation facilities. Thus, 1042 kW of solar panels are installed on the rooftop of the terminal and 10 kW of solar panels are integrated into the construction material to generate electricity. The annual power generated from photovoltaics is about 1.10 million kWh which is equivalent to the annual consumption of 220 households.
Geothermal energy is used for air conditioning. Unlike air temperature, the underground temperature remains constant throughout the year. Geothermal energy recovery pipes are embedded inside the pile foundation of the supply and treatment facility buildings in order to recover geothermal energy by using a heat pump. By using the difference between underground and ambient temperature, air conditioning systems consume less energy. The refrigeration capacity is about 176 kW, which is approximately equivalent to the power of 60 units of household air conditioners.
A distributed power generation system called gas co-generation is used at Haneda International to generate electricity onsite using environmentally friendly city gas. The heat generated during the electricity production process is used for air conditioning and heating water. By doing so, the system will have a high energy efficiency. If the power was to be supplied by a thermal power plant – for which the primary energy source would be oil, coal or natural gas – a 60% loss in the form of transmission losses and unused heat energy would have occurred. However, using a gas co-generation system would significantly increase the efficiency from 40% to around 70-85%. The loss is only about 15-30%, which consists of waste heat that is difficult to use. The annual power generated by the gas co-generation system is about 7 million kWh. The power that is generated is equivalent to the annual consumption of 1,400 households.
Efficient Use of Energy
The efficient use of energy is encouraged to conserve energy and does not concern the way the energy is produced. In most cases, the efficient use of energy requires less investment than energy production. Due to this characteristic, it could be applied at a faster rate.
A lot of measures have been applied at Haneda International’s new passenger terminal. For example, the thermal load is reduced by implementing a ceiling ventilation system. The system prevents the entrance of heat with the flow of air. An insulation and shading system is used to reduce the load of solar radiation. Low-E, double-pane window glass is installed to reduce solar radiation from the sun and reduce the heat input and radiation through the window glass. The double pane window glass provides higher insulation performance and thus can reduce the energy loss from cooling and heating. This system removes about 81% of solar radiation heat.
While insulating, the heat island effect is prevented as well. To achieve this, plants are planted on the rooftop and on the walls of the airport. Green rooftops increase air condition efficiency in both winter and summer. The plants soften the solar heat in the summer and keep heat inside the building envelope in winter. Green walls also alleviate temperature changes inside the terminal and reduce the heat island effect. The other advantage of greening is improving landscape and creating a pleasant atmosphere.
Furthermore, a reduction of lighting load is achieved through illumination control by using natural lighting and light sensors. Top-lights and high-side light techniques are utilised to use natural lighting as much as possible and reduce wasteful energy. Fluorescent lamps are replaced by LEDs, which reduce the energy consumption drastically and, at the same time, have a longer lifespan. LEDs are not only used for lighting but also for information panels and guide signs. All these make LEDs very cost effective.
Other than energy, water is also conserved by recycling wastewater. Rainwater, water discharged from the kitchen and other miscellaneous wastewater is treated and recycled as grey-water. The grey-water is then used for flushing toilets at the terminal.
Figure 2 shows the energy system used at Haneda and all the measures aimed at improving energy efficiency, cost effectiveness and the reduction of CO2 emissions.
Fig. 2 – Haneda Energy System (TIAT, 2015).
Conclusion
Global aviation accounts for 11% of all transport CO2 emissions. International flights create about 62% of these emissions with domestic flights representing the remaining 38% (ICAO, 2010). Therefore, a model like the Eco-Airport could play a vital role in reducing CO2 emissions. Implementing it, though, might be challenging, especially in developing countries as it requires sufficient funding, state of the art technology and perhaps an incentive from policy makers.
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References:
- ICAO (2013). Aerodromes Operations & Planning – Working Group (AOP/WG/1). Bangkok: International Civil Aviation Organization.
- ICAO (2010). Environment Report 2010: Aviation & Climate Change. Montreal: International Civil Aviation Organization.
- Janic, M. (2011). Greening Airports. London: Springer.
- Nishiyama, T. (2014). “Eco-Airport” In Japan. Ministry of Land, Infrastructure, Transport & Tourism (MLIT), Civil Aviation Bureau (CAB). Montreal: International Civil Aviation Organization.
- TIAT (2015). Haneda Airport International Passenger Terminal – Eco-Airport Guide Book. Tokyo: JCAB.