Photovoltaic solar energy is one of the world’s fastest growing businesses today. It is an industry that it is constantly attaining greater efficiency and increased competitiveness.
We must therefore ask ourselves what impact this industry is having on the world of aeronautics in general and airports in particular.
Airport managers should begin broaching the possibility of including photovoltaic solar energy facilities in their master plans and analyse whether they are feasible or not at their airports.
To start off with, it should be pointed out that an airport environment is ideal to house a photovoltaic facility because its electricity consumption is high and it tends to have a lot of land available for the facility (including building roofs). Furthermore, the energy produced is directly consumed at the infrastructure itself and there is therefore no need to transmit it over large distances. To sum up, this kind of energy can significantly reduce an airport’s operating costs.
These facilities, however, have a series of conditioning factors which airport managers have to take into account when planning a photovoltaic facility at their airport, which are as follows:
- Physical easements. Panels may not infringe any of the physical easements laid down by ICAO. Neither may panels be installed on any runway or taxiway safety areas. This issue does not usually involve too many problems in the design stage due to the panels’ shape.
- Glare. The issue of glare is perhaps the one which worries an airport manager most when it comes to setting up a project of this kind. This is due to the fact that is has a direct impact on operational safety.
Firstly, it should be mentioned that photovoltaic panels are designed to absorb light, not reflect it. It is therefore deemed that only 3% of the light is reflected, a very similar percentage of that of a calm lake adjacent to the airport.
At this point, it should be highlighted that the FAA has made software available to analyse in the design stage the potential impact of glare. This software is called “Solar Glare Hazard Analysis Tool” (SGHAT) and it was developed” by the DOE’s Sandia National Laboratories.
This program analyses where and when glare may be produced over the course of the year and, should it be the case, whether it could cause eye damage or lesions.
Two points are analysed: The control tower and the aircraft’s approach trajectory from two miles back until contact is made. As a matter of fact, the FAA has established some criteria to determine whether glare is considered as unacceptable (though merely as a guideline, not a regulation). These include: for the tower, any glare that may cause eye damage is not allowed, and as for the approach trajectory, the reflection should not reach the point where it could dazzle the pilot and cause him/her to suffer a temporary loss of vision.
Despite the reluctance of airport managers because of this issue, it should not be considered as a significant concern when it comes to taking a decision if the design is properly conceived.
- Communications system interferences. Panels should not be placed near any radio communications facility, since they could reflect or block the signal.
Nor should they be placed near the approach trajectory because plates release heat at sunset and said heat could be picked up by aircraft and cause unexpected signals.
Moreover, these systems do not emit electromagnetic waves which can produce interferences.
In any case, an analysis of how communications may be affected should be conducted during the design stage. Whether the facility will be approved or not depends on the competent authorities.
Before setting up this kind of facility, each airport manager should conduct its own feasibility study, which ought to consider at least the following aspects:
- Land available for the facility, which also analyses the availability of building and hangar roofs.
- Electric power that is expected to be generated. In order to do so, factors like the climate, days of sunshine, the plates’ orientation, shadows or the area available should be taken into account.
- Analysis of the airport’s electricity consumption. For instance, there are many airports in the world which are seasonal; in other words there are periods of the year in which passenger numbers double or triple. Hence, electricity consumption would not be constant. The possibility of selling any excess energy to the general grid in the period of less activity could be broached. To achieve this, it should be taken into account that the in-house grid has to comply with the parameters of the general grid of the country in question. This may involve an increase in the initial investment. Moreover, the price at which that energy would be sold should be taken into account.
- Electricity price study. Among other matters, historical data of price behaviour in the country in question or national and international political factors which may affect the price in the short, medium and long term should be analysed.
- Any possible government policies on renewable energy, possible aid or, on the contrary, any possible taxes, such as is currently the case in countries like Spain.
- Analysis of facility’s return on investment. It should be taken into account that these facilities involve a significant initial investment. However, maintenance costs are minimal during their operational life. According to some studies, they amount to 0.02% of initial investment. The useful life of a photovoltaic plate tends to be 20 years or more.
This then is the theory, but is a project of this kind really viable at an airport today. The answer is yes. A series of examples that demonstrate it follow.
Cochin International Airport, CIA.
This is a medium-sized airport which handles 7.7 million passengers a year situated in the state of Kerala in India.
This airport was the first one in the world to be completely powered by solar energy after photovoltaic plates were installed. It is equipped with 46,000 panels covering 17.4 hectares which generate 52,000 kW/day, though the system can generate up to 52,000 kW/day. The airport consumes approximately 48,000 kW/day (the excess is sold to the general grid).
Denver International Airport, DEN.
Two projects were carried out at this airport at the same time. The first of these entered into operation in July of 2008 and generates 2 MW. The second entered into operation in December of 2009 and generates 1.6 MW. This airport pioneered the use of solar energy at US airports and has been of great help for the development of similar facilities at other airports.
These are just two examples, but there are many more, particularly at small airports, around the world. This is the case of Galapagos Airport, whose ecological philosophy is exemplary. The same can be said of George Airport, a small airport which handles 560,000 passengers a year. It is located in South Africa and was the second airport in the world after the above-mentioned CIA to be fully powered by photovoltaic energy.
Lastly, what about regulations? Are there any specific regulations for this kind of facilities? At the moment, there are none.
The FAA has drawn up a guideline entitled “Technical Guidance for Evaluating Selected Solar Technologies on Airports”, which is not mandatory. As is mentioned on its cover, this guideline is currently under review and therefore subject to possible modifications in the future.
As for European EASA regulations, reference is only made in point GM1 ADR-DSN.M.615, where it is stated that an operational safety study should be conducted that takes glare into account in the descent, landing and taxiing phases.
For its part, the ICAO only refers to this issue in Doc. 9157, Part 5, Electrical Systems, which discusses an airport’s power sources. In this regard, one of the possible scenarios covered in said document would be power supplies from a local generating plant (which covers the generation of photovoltaic energy) and from a distribution system outside the airport (publicly or privately owned). Thus, airports are urged to be equipped with at least one alternative source of power.
In any event, whether this type of facilities are approved or not resides in the competent authorities and, logically enough, operational safety is given priority over any other kind of consideration.
To conclude, I believe airport managers should begin broaching the possibility of including photovoltaic solar energy facilities in their master plans and analyse whether they are feasible or not at their airports. Firstly, because of the significant economic savings they could entail in their operations and, secondly, due to their environmental responsibility, a commitment we should all make.
I would finally like to end this article with a quote from Thomas Edison: “I’d put my money on the sun and solar energy. What a source of power! I hope we don’t have to wait until oil and coal run out before we tackle that. I wish I had more years left.”