Power source

Solar panels beside runway

A number of airports are looking at solar power to reduce the carbon footprint of their infrastructure. Gary Mason reports.

Solar panels beside runwayAirports are very heavy users of power and with the global drive to make the aviation industry more sustainable, organisations are increasingly looking towards new technologies to reduce the power consumption of the buildings and other infrastructure, which is often operating 24 hours a day the whole year round.

One of these areas is Airfield Ground Lighting (AGL) where the introduction of LED (light-emitting diode) technology is powering a revolution in the way systems operate.

The LED revolution

Morand Fachot from the Geneva-based International Electrotechnical Commission (IEC) says that new technologies  – mostly in the field of LED – are leading the way in terms of providing more sustainable sources of AGL.

“After years of gradual improvements thanks to new technologies and requirements, AGL is now on the threshold of a revolution with the introduction of LED (light-emitting diodes) across all AGL installations.

“Airfield lighting is a tough environment submitted to shocks and vibrations and great changes in temperatures (frost or intense heat of the sun and surrounding tarmac) that requires very robust installations. Current AGL is mainly provided by incandescent lamps using a filament. These suffer from a number of weaknesses, in particular a relatively short average life as filaments are burnt after 1,000 to 2,000 hours.”

He says that another drawback of incandescent lamps is their poor spectral emission, which can prove confusing in specific weather conditions or on certain stretches of runways or taxiways.

By contrast, LED airfield lighting solutions, which first appeared in 2002 and are being adopted by an ever expanding number of airports, present significant advantages on their incandescent counterparts, in particular as regards their average life (between 30,000 and 60,000 hours at least), lower operating and maintenance costs (by as much as 70 per cent), power savings of between 60 and 85 per cent (including power line losses), and better light spectrum characteristics.

Initially limited to certain systems owing to technical limitations, LED lighting products have greatly improved in recent years and are now being introduced across the entire AGL environment.

But the LED revolution is also paving the way for other technologies to be introduced into the AGL environment such as solar power. LED systems replacing conventional incandescent lighting products can now be combined with solar PV cell technology, which means that expensive cabling and trenching is no longer required. This can result in significant savings on installation, running and maintenance costs for airports.

Since 2010, there have been Solar Series Elevated Runway Guard Lights (ERGL) units installed at UK airports such as Southampton and Leeds Bradford.

Nick-named “Wig Wags” the flashing lights cost £25,000 in total and are used at junctions between the runway and taxiways.

Southampton was the first UK airport to install the lights which are also used by the US Air Force in Afghanistan. As the number of aircraft and vehicle movements increased within the airport over the years, regular reviews of signals, signs and markings were undertaken.

An airport spokesperson said: “We’ve been able to minimise the environmental footprint and maintenance costs.”

The five units, supplied by Systems Interface, use solar panels to convert sunlight into electricity and ensure the lights operate 24 hours a day.

Their batteries can store enough energy to permanently operate the lights for up to 120 days without any solar charging.

The lights have also been installed in areas of the airport where there is no access to power supplies, saving the £170,000 cost of laying cables.

As the lights are 100% solar powered, the airport has been been able to minimise the environmental footprint and maintenance costs by using a renewable energy light source. We’ve been able to install them in the more remote areas of the airport, where there is no access to power supplies. This has saved the airport over £170,000 of installation costs to lay electrics to these areas.”

Southampton Airport’s vision to become ‘Europe’s leading regional airport’ has provided the motivation for a number of innovate investments in recent years. But some airports are going further still in the use of alternative and greener power sources. Cochin International Airport has a huge array of reflective solar panels near the runway which powers the airport’s entire energy requirements.  The airport commissioned the German company Bosch to build a vast 45-acre solar plant on unused land near the international cargo terminal.

The 46,000 panels generate on average slightly more than the roughly 48,000-50,000 kilowatts of power that the airport requires per day. Surplus energy is fed into the wider electricity grid which the airport relies upon for night time lighting requirements and the rainy season.

The $9.3 million cost of the installation is expected to be re-couped in less than six years by not having to pay electricity bills. Airport management also estimates the solar plant will avoid more than 300,000 metric tons of carbon emissions from coal power over the next 25 years.

Indian Civil Aviation Minister Ashok Gajapathi Raju visited Cochin in January and told reporters that authorities have directed other airports around the country to start using at least some solar power.

Located in the southern state of Kerala, Cochin is now the first airport in the world to run completely on solar power.

The airport started with a small pilot project by installing a solar energy plant with 400 panels on its rooftop in 2013. When that experiment succeeded, it decided to go all the way.

The airport’s managing director VJ Kurian says it was the huge power bills that prompted them to look at greener solutions.

The airport, which is the seventh busiest in India handling more than 1,000 flights a week, consumes nearly 48,000 units costing 336,000 rupees ($5,160; £3,364) every day.

Mr Kurian says airports across the country have approached him to learn more about the “Cochin model”. A team from Liberia is also interested to learn more about harnessing the sun’s energy.

The installation of the solar plant took around six months to complete.

The airport is looking to inaugurate a new international wing comprising nearly 1.5m sq ft which will require more energy than what the existing plant is generating.

Additional solar panels will have to be set up if the authorities wants to hang onto the “first fully solar powered airport” tag.

Complex systems

AGL systems are characterised by a diversity of light units, each one with its own set of requirements and technical specifications, spread out over a relatively large area. They cover:

  • approach lights, which guide aircraft in flight during the landing phase and comprise centreline, crossbars and supplementary approach lights;
  • runway lights, which direct aircraft after they land or as they take off. They include runway guard, threshold, centreline, edge, touch-down zone, runway end and stopway lights, among others;
  • taxiway lights that give indications to crews as they manoeuvre to / from parking positions from / to runways, with centreline, edge, stop-bar, intermediate holding position lights;
  • apron lights, used in areas set aside for aircraft parking, servicing and loading;
  • manoeuvring and visual docking guidance systems;
  • signage that provides direction and information to taxiing aircraft and airport vehicles to help prevent runway incursions.
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