Athens International Airport: Powered by the sun

Towards the end of 2011, the sun rose to shine for the first time on the newly inaugurated Photovoltaic (PV) park at Athens International Airport (AIA), the largest unified PV installation at an airport worldwide.

AIA’s PV park is expected to contribute significantly to the airport’s target of reducing its carbon footprint. The production of approxi – mately 11 million ‘green’ KW annually, corresponds to almost nine per cent of the airport’s electricity needs and will reduce CO2 emissions by 11,000 tonnes per year, for a period of at least 25 years.

The inauguration of the PV park marked the end of AIA’s efforts to introduce renewable energy sources at the airport. However, before AIA considered adding energy producing facilities within its strategy, it had to tackle the issue of energy efficiency. An important energy manage – ment process was initiated in 2002 which targeted the reduction of energy consumption at the airport. The airport had to run on the absolute minimum energy required, without comp ro – mising the high level of services offered to our passengers and partners.

Through the application of an active handson energy management process, a number of targeted actions reduced the airport’s electricity consumption by more than 25 per cent in 2002 compared to figures in 2003. These actions included locating and eliminating unrecorded or wasted energy outputs, using a real-time central monitoring/controlling system to synchronise power-consuming equipment to operate in the most efficient way, ensuring that no energy was consumed without cost-allocation and replacing older technology with newer more efficient devices. All of these initiatives resulted in the reduction of both costs and ultimately carbon emissions. For its energy saving actions and programmers, AIA gained international recognition, receiving the European Commission’s GreenLight Award in 2004.

The 8MW PV facility has been developed on a 160,000m2 area within the airport site, off of the eastern runway. The land used for the project had no alternative use due to its location on the airside section of the airport which is restricted to runway-related improvements only. Many airports face the question of what – if anything – can be done with the sizeable and sometimes vast arid land that they are obliged to maintain on the airside. With careful consideration of health and safety and operational and development aspects, PV installations can prove to be the most opportune exploitation of this otherwise baron land. When factoring in the fact that airports are villages (sometimes cities) which are energydependent, on a 24/7 basis, it makes sense to combine the energy-demand with energyproduction capabilities.

The operation of AIA, as with most airports, peaks during the daytime and reaches a low at night. The PV park works exactly the same with production peaks towards midday and stops at sunset, making the decision to incorporate the park a wise choice. Furthermore, in the case of the Athens Airport, this correlation also exists on a seasonal level. In the summer, as the airport’s electricity needs rise, so does the production of the PV park, thus contributing peak power when it is most needed.

The energy produced from the park is fed to the airport’s electrical grid. It is generally deemed more logical and efficient to produce the required energy as close to the point of consumption as possible. This reduces transmission costs and losses on a local and national level. It also creates an alternative power source other than that of the national utility. This diversification of an airport’s power sources ensures both increased redundancy and more manageable power. Depending on a power source’s design criteria, power demand to power production ratio and the airport power grid, quality may also be improved, reducing voltage fluctuations.

The main components of the PV Park are the 28.740 PV panels each creating 280W of power (Made by Suntech), the 12 inverters each have a peak power of 630KW (made by SMA), over 270km of cabling and a sophisticated on-line system that monitors the park (purposedeveloped by Biosar Energy).

The PV panels are south facing and are installed on fixed structures. Every day the PV park welcomes the sun in order to produce anywhere between 20-50,000KW, depending on the season. The PV panels are of the highest quality and convert the sunlight to electrical DC current. They are constructed to withstand strong winds and hail and have a very low reflectivity factor (much lower than most objects to be found in an airport).

The Inverters, in turn, receive the DC current and convert it to AC power, at a rate of 97-98 per cent efficiency. In addition, they monitor all the PV panels, in real-time, in order to provide infor – mation to the monitoring system, thus enabling AIA to be aware of and promptly correct any dysfunctions that may take place. This ensures optimal production at all times of the year. The 400V of AC power exiting the inverters is then upscaled to 20KV and fed into the AIA grid.

In order to reach the stage of imple – mentation, AIA studied PV technology and its possible application in the airport for a number of years. In 2004, AIA installed and operated a pilot photovoltaic unit, of five KW, for research purposes. The airport had to undergo a rigorous process of studies and approvals by the competent authorities, including the Hellenic Civil Aviation Authority, which lasted for four years. This process is extremely important in order to guarantee that the proven safe operation of the airport is not compromised.

The final investment amounted to approxi – mately €20 million and was completely selffunded. It was the outcome of an international tender process which placed more than 10 companies from around the globe in competition for the optimal outcome, both in terms of quality and economic rate of return. The implementation was finally awarded to Biosar Energy, a company specialising in large PV installations. The actual construction was concluded in six months. Today, the park is visible by almost all passengers who fly in and out of Athens International Airport.

AIA’s energy strategy is focused on costeffective smart-energy concepts and is thus, fully aligned with the company’s actions against climate change. In terms of energy-production, AIA aims to further reduce its dependence on traditional forms of energy by adopting green alternatives, through a series of specific plans and actions.

Currently AIA are looking at energy production through gas-fired co-generation plants, through biomass/biogas and windgenerators. Co-generation uses one energy source to produce two energy outputs, namely electricity and heating or chilling. Biomass/Biogas plants use the abundant bio-degradable waste and sewage sludge in order to produce biogas which is then used to create electricity. All of the above primary sources (natural gas, waste, wind) are readily available 365 days a year at the airport.

It makes no sense to produce power in order to consume it irresponsibly, AIA is constantly investigating the market for new technology which can be applied to energy consumption also. To that end, power improvement and energy efficiency projects are also under way making sure that the Athens International Airport is constantly on the edge of technology and pays its greatest respects to the environment.

About the author

Dimitris Dolapsakis joined Athens International Airport S.A in 2000. He has completed his studies in both Engineering and Economics. He has worked in banking, hotel construction, resort management and different manufacturing sectors, in countries such as the US, Argentina, France, Morocco and finally Greece.