India’s pursuit of clean and green energy uptake has spread across all infrastructure sectors including railways, airports and educational institutions as the country strives to achieve its Intended Nationally Determined Contributions through the installation of 100 GW of solar power capacity by 2022. The government is actively promoting innovative distributed solar generation installations in spaces such as lakes, ponds, canal tops, railway coaches, stations and airports. In this respect, airports hold significant potential for solar power generation due to the availability of large, flat and shadow-free areas such as rooftops of terminals and hangars, car parks and buffer land around runways. The solar power generated on airport premises can complement the massive power requirement of the terminals, leading to reduced electricity bills, especially through net metering. Moreover, the increase in air-conditioning load coincides with the highest generation during peak summer months, thereby compensating for the spurt in power demand.

The aviation industry, which is highly carbon intensive and heavily dependent on oil and gas for flight operations, can look to reduce its carbon footprint and contribute to the achievement of the country’s clean energy targets by embracing solar power technology. The low gestation period, limited infrastructure requirement and shorter period for return on investment (four to five years) are some of the other factors that make a strong case for solar power generation at airports.

In July 2016, the Airports Authority of India (AAI) announced plans to expand its installed solar power capacity to about 150 MW, with 50 MW targeted to be deployed in Phase I (by 2016). To this end, AAI signed an MoU with the Solar Energy Corporation of India for installing solar power capacity at AAI-operated airports. At the time of the announcement, about 5.4 MW of solar capacity was already under operation at 16 airports across the country and 30 MW was in the pipeline. According to the Ministry of New and Renewable Energy, a total capacity of 12.6 MW was installed at 29 AAI-operated airports as of March 2017. Meanwhile, airports developed in partnership with AAI, such as the Indira Gandhi International Airport (IGIA) (operated by Delhi International Airport Limited [DIAL]) and Cochin International Airport (operated by Cochin International Airport Limited [CIAL]) have also been expanding their solar power portfolio.

Key solar power developments at Indian airports.

Cochin International Airport

In August 2015, Cochin airport made it to the headlines by becoming the first airport in the world to be run entirely on solar power. The net metering system generates between 50,000 kWh and 60,000 kWh of electricity per day for its operations and supplies the excess power to the grid in the afternoon. At night, the airport buys back power from the grid, making it power-neutral. The airport commissioned 1.1 MW of solar capacity in 2013 and scaled this up to 13.1 MW within the next two years.

CIAL’s 12 MW plant was installed by Bosch Limited, while the solar modules were provided by Renesola and the 1 MW capacity inverters by ABB India. It is spread over an area of 45 acres and can generate 18 million kWh of electricity annually and is expected to cut down the airport’s carbon footprint by 300,000 metric tonnes (mt) over the next 25 years. In addition, the airport has a solar car park with charging facilities for electric vehicles. The roof of this car park is fitted with 2.5 MW of solar power capacity.

IGIA

In 2014, DIAL set up 2.14 MW of solar capacity at IGIA in New Delhi. It was the first airport in the world to be registered under the clean development mechanism of the United Nations Framework Convention on Climate Change. In 2016, with the addition of a 5.7 MW plant, the airport’s total solar capacity increased to 7.84 MW. At present, solar energy from this combined capacity accounts for 9 per cent of the airport’s total power supply.

IGIA is one of the few airports to have installed solar panels on land parcels on the airside, which is normally locked under various statutory rules and regulations. To ensure that there is no impact on flight movement due to these panels, DIAL had conducted a computer-aided solar glare analysis for 365 days prior to the installation. In addition, non-reflective solar panels were used to reduce any glare effect. The airport expects annual energy savings of Rs 82 million and a reduction in its carbon imprint by 10,602 mt by generating solar power on its premises.

Netaji Subhas Chandra Bose International Airport

The Netaji Subhas Chandra Bose International Airport in Kolkata currently consumes a minimum of 10-11 MW of electricity. In February 2016, a 2 MW rooftop solar plant was installed at the airport by Vikram Solar. In addition to providing clean energy, the plant generates carbon credits and accounts for Rs 21.5 million annually in savings in energy bills. In December 2017, AAI commissioned another 15 MW of solar capacity at the airport. This project was developed by Sterling & Wilson with expected energy savings worth Rs 180 million per year. The project, which cost Rs 900 million, will meet the power requirements of the terminal building while any excess electricity will be sold to the Calcutta Electric Supply Corporation. AAI expects to start generating revenues from the solar plant after six years of operations.

Rajiv Gandhi International Airport

With the success of solar power plants at the Cochin and Delhi airports, GMR Hyderabad International Airport Limited (GHIAL) followed suit and commissioned a 5 MW solar plant in 2016. The plant can generate up to 25,000 kWh of electricity per day. GHIAL has formulated a plan to scale up its solar capacity to 30 MW by 2022. Built at an approximate cost of Rs 250 million, the plant will help reduce the airport’s grid-based power demand by 30 per cent. As a result, it will help avoid the consumption of 12 mt of coal and 76,800 litres of water per day, while reducing 71,000 mt of carbon emissions.

Key challenges

The glare from solar panels can disturb aircraft operations. Thus, the installation of solar panels is not only structurally challenging but also a safety hazard. To prevent this, it is generally recommended that the solar modules be placed on the rooftops of terminals and away from the runways. Shadow and glare analysis, therefore, becomes crucial while designing a solar plant at an airport. The panels used near runways should essentially be anti-glare and be regularly checked to ensure that their anti-reflective coating is maintained. Moreover, the module structure should be able to withstand high wind speeds. Such preventive measures often result in cost and time overruns, making project development even more challenging.

Outlook

As specified in the government’s clean energy development agenda, AAI is actively contributing towards global carbon reduction by reducing its own emissions. With solar power reaching grid parity across the country, this is increasingly becoming a viable solution for large electricity consumers who wish to cut down on their electricity costs and reduce emissions.

With reduced capital and operational costs of solar power, many airports have announced detailed expansion plans of their existing solar power capacities. DIAL plans to set up 12.84 MW of capacity by 2018 and 20 MW by 2020, which would account for 25 per cent of its total energy consumption. CIAL recently released a tender for the installation of an additional 9.9 MW of solar capacity at multiple locations within the airport premises. This is a part of CIAL’s plans to augment its solar capacity to 30 MW by 2019.

Civil aviation minister P. Ashok Gajapathi Raju has reportedly stated that as of December 2017, 90 MW of solar capacity has been installed at AAI-operated airports across the country. In addition, 45 MW of solar capacity has been installed at various private airports. He also mentioned that a new target of 200 MW of installed solar capacity could be achieved in the coming years if net metering connections are made available at airports. The shift in centre and state policies for solar capacity addition, combined with growing international and national interest for funding solar power projects in India, is likely to help surpass the targets for airports. Meanwhile, better research and development of anti-glare solar modules is needed in order to use the large swathes of unutilised land available at airport premises.