Energy consumption is a major cost component for operating an airport. With increasing passenger traffic at airports, the cost of energy consumption too is rising. In 2018-19, the Airports Authority of India (AAI) consumed 467 MUs of energy and incurred a cost of Rs 4.16 billion. Two key airports – Chennai and Kolkata – consumed the maximum of 83 and 90 million units of electricity, respectively, together constituting 37 per cent of AAI’s total energy consumption. In light of this, energy management and conservation measures are required to be taken up to generate large dividends and save costs.
Penetration of renewable energy
Many airports across the country have started relying on renewable energy for meeting their energy requirements. Kolkata airport, for instance, has installed a 15 MW solar power plant. This transition from conventional power sources to green energy has not only helped in environment protection but has also resulted in generating economic benefits.
Apart from this, initiatives such as design and construction of new terminal buildings as per GRIHA ratings and installation of equipment as per the Energy Conservation Building Code (in all new terminal buildings) and deployment of star-rated appliances are being taken. The national LED programme, Unnat Jyoti by Affordable LEDs, and the Airport Carbon Accreditation certification have also been introduced to incentivise airports to rely on renewable energy sources.
Modes of sourcing solar power
AAI has huge potential for setting up solar power plants on large unused tracts of land at operational and non-operational airports. However, the mode of sourcing has to be selected for ensuring adequate savings. These modes are net metering and sourcing through captive power plants.
Under the net metering mode, solar power generated at a plant completely offsets consumption at the distribution company’s prevailing unit rate. Further, power of up to 1 MW or a threshold fixed as per contractual demand, whichever is lower, can be generated. However, generation and consumption of power has to be at the same place, and this is a major limitation considering that none of AAI’s load centres have spare land.
Sourcing through captive solar power plants is another alternative that offers monetary benefits in the form of elimination of the cross-subsidy charge, among other charges. Some states also give exemption from transmission and distribution charges within their region under this mode. In addition, it overcomes the limitation of location (posed by net metering) as power can be generated at one station and be transmitted to other stations for interstate or intra-state consumption. However, for interstate consumption of power, banking or energy storage is not allowed and power generated during the day has to be consumed within the scheduled time of day. Currently, an 8 MW captive power plant is being developed at Hubballi Airport.
Savings
Though a solar power plant involves an initial capital cost of Rs 45 million per MW, power generation tariff is cheaper at Rs 2 per unit against an average commercial power tariff of Rs 9 per unit charged by state distribution companies. Considering this, reliance on solar or wind power plants is essential. But, based on the mode of power sourcing, the savings might vary.
For instance, through the net metering mode, airport operators accrue savings of Rs 7 per unit, considering the conventional power tariff to be an average of Rs 9 per unit. With captive power plants, savings might be in the range of Rs 3.70 per unit (for interstate consumption) or Rs 5.50 per unit for intra-state consumption. In addition, with captive power plants, the cross-subsidy charge that otherwise increases the landed cost of power by Rs 2 per unit is eliminated. However, in the case of captive plants, wheeling and transmission charges are to be borne by the airport operator.
The way forward
Airports already have the resources in the form of large tracts of land along the runway which is a no-construction zone to meet operational safety requirements. This land can be used for installation of solar power plants to generate clean energy. Considering this, airports may be allowed to generate solar energy up to their total units of consumption under the net metering mode instead of the only up to the present cap on capacity. This will help airports become self-reliant in terms of energy production.
Apart from this, other energy efficiency measures like optimising the loading and operation cycle of transformers to minimise losses, introducing insulated-gate bipolar transistor-based technology, using variable frequency drives for operation of motors to reduce power consumption, and replacing old equipment with efficient star rated-equipment need to be taken.
Based on inputs from Anil Kumar Sharma, Executive Director, AAI, at a recent India Infrastructure conference