Clean Route

Transport sector ramps up renewables deployment

The green energy revolution is unfolding on a global scale, with utilities, ind­­ustries and even commercial es­ta­blishments opting to make the switch fr­om conventional to renewable energy. India is also witnessing a major migration of consumers from grid power to renewables gi­ven the attractive cost economics of dep­loying solar and wind power. The country’s transport sector has been a front runner in sourcing renewable power for meeting its partial or total energy requirements.

Typically, solar panels are mounted on the premises of metro stations, railway stations, airports, ports as well as in parking sp­aces and toll booths on highways. While on-site solar power deployment – on the ground, rooftops, canal tops and car parking structures – is the common route for renewable energy procurement, other methods such as group captive, open acc­ess and procurement from the ex­changes are also gaining uptake across solar as well as other renewable energy te­chnologies such as wind, waste-to-en­ergy (WtE) and small-hydro power.

There are several reasons for this transition to green power. First, renewable energy, especially solar or wind power, is quite cheap when compared to power sourced from discoms. Moreover, commercial us­ers pay exorbitantly high tariffs as comp­a­red to residential consumers. Thus, meeting their energy requirements throu­gh renewables helps bulk power consumers such as airports and metro rail au­thorities to reduce their power bills and operating costs significantly.

Second, with the global thrust on climate change and the policy initiatives of the central and state governments, various transport authorities and corporations have devised their own green strategies. Many of them have set targets for decarbonisation and are working towards them diligently. Some are required to meet renewable purchase obligations or other mandates for reducing the conventional power use in their energy mix.

Third, power reliability and quality continue to be concerns, especially in smaller towns and cities, and power cuts impact smooth operations. The use of diesel generators is both costly and polluting. In this scenario, renewable power systems can help in lighting highways, and enabling the smooth functioning of toll booths and hundreds of small and big railway stations across the country.

Fourth, with a huge customer base of corporate and industrial clients ready to opt for renewable power solutions, many de­velopers have entered this market with a variety of cost-effective procurement op­tions. While some models require custo­mers to bear the capital cost and take ow­nership of assets, a few models free them of such responsibilities. Customers just pay the energy use charge at contracted tariffs, and developers finance, own, install and operate the projects, whether on-site or offsite. Other attractive models such as the lease model and the deferred payment model are also gaining popularity.

This article explores the growth of renewables’ use across different transport segments – metro rail, airports, railways, ports and roadways – and presents the outlook for the future…

Metro rail systems

Urban metro rail systems require huge volumes of high quality power for their vast operation networks comprising many me­tro stations, depots, parking spaces and other premises, as well as high sp­eed trains running at frequencies of minutes. With route extensions and train additions, the power consumption of metro rail networks will continue to increase and so will their energy bills. Thus, to reduce their op­e­rational expenses, metro rail corporatio­ns across the country have started us­ing solar power and other renewables extensively. Along with the deployment of solar projects at depots, metro stations, parking spaces, and other buildings and workshops, they are now procuring rene­wable energy through open access.

The Delhi Metro Rail Corporation (DMRC) is leading the way in the open access segment, with rapid strides being taken towards greening its operations. As of January 2020, it had already installed 43 MWp of solar power projects at various locations including station roofs, parking spaces and depots, mainly on the RESCO model. Further, it procures 2 MW of power from the Ghazipur WtE project. Moreover, in April 2019, DMRC started procuring 345 MUs of solar power from the Rewa Ultra Mega Solar Park in Madhya Pradesh. This remains a landmark deal till date as DMRC became the first commercial consumer of its scale and size to procure solar power from another state throu­gh the open access route.

Moving rapidly towards its solar power goals, DMRC issued a tender in October 2021 to set up 2 MW of rooftop solar capacity under the RESCO model. The project will have a 25-year fixed tariff with a maximum tariff of Rs 4 per kWh. In addition, the metro rail corporation earned Rs 195 million in 2021 from the sale of 3.55 million carbon credits, accumulated over a six-year period from 2012 to 2018 in its quest for increased energy efficiency. It also provides CDM consultancy services to other Indian metro systems, helping them collect carbon credits from their projects.

Apart from DMRC, many other metro rail corporations, including those of Chennai, Mumbai, Kochi, Hyderabad and Benga­luru, have taken encouraging steps to deploy renewable energy projects on their premises and reduce their power bills. For instance, in February 2021, Amp Energy India commissioned a 7.8 MW solar plant for Larsen & Toubro’s metro rail project with a 25-year PPA signed between the two parties. This solar project will power 24 stations and two depots in Hyderabad city, and will help meet 15 per cent of Hyderabad Me­tro Rail’s total electricity consumption.

Then, in August 2021, Bengaluru Metro Rail Corporation Limited anno­un­ced its plans to partner with private co­mpanies to explore the potential of solar energy at its various facilities including all stations envisaged under Namma Metro’s Phase II, Phase II-A (Outer Ring Road), and Phase II-B (Connecting Airport) projects. More recently, in January 2022, Kochi Metro Rail Limited (KMRL) commissioned a solar plant of 824.1 kWp at its Mu­tton depot. The metro rail corporation has commissioned 8.1 MWp of solar projects till date with another 3.1 MWp under deployment. This newest addition helps KMRL to meet 42 per cent of its power needs on its own.


Airports, with massive tracts of shadow-free land and huge rooftop spaces of lar­ge terminals, workshops and other buildings, are ideal for solar power installations. Airports operate 24×7, 365 days in a year, and thus have huge power requirements. They are also suitable candidates for the procurement of offsite renewable energy. Many airports across the country have started increasing the share of re­newables in their energy mix to green their operations, become power self-reliant, reduce operating costs and offset their carbon emissions. Solar systems have been installed at the Delhi, Kochi, Benga­luru, Thiruvananthapuram, Hyderabad, Chennai, Trichy, Calicut, Vijayawada, Tiru­pati, Dibrugarh, Gaya and Gondia airports, among others.

An Indian airport that made headlines ac­ross the globe for its clean energy initi­ati­ves is the Cochin International Airport Limi­ted. In 2018, it received the Uni­ted Na­tion’s prestigious Champion of the Earth Prize for going carbon-neutral. With 40 MWp of solar power capacity, it became the world’s first airport to be completely powered by solar. It also commissi­oned a 452 kWp floating solar project in January 2021. Keeping up the mo­men­t­um, it is developing a 12 MWp plant at Payyannur in Kannur district. It has also en­tered the hydropower space with a small-hydro project on the Iruvazhinji river. It won the project from the state power de­p­ar­tment under the build-own-operate-transfer mo­d­el for a period of 30 years.

Another airport that has been in the news for significantly reducing its carbon footprint is Bengaluru’s Kempegowda Inter­na­tional Airport (KIA), which attained net energy-neutral status during 2020-21. KIA procures roughly 50 MUs of solar power from a mix of on-site and offsite projects. It procures 10 MUs of solar power from its on-site projects, which include 503 kW of solar rooftop capacity on utility buildings, 440 kW in the car parking area, 3,350 kW on the cargo and office buildings and 2,500 kW of ground-mounted capacity at the airside. It also procures 20 MUs of wind power through an open acc­ess arrangement.

In other developments, in March 2021, NTPC Vidyut Vyapar Nigam invited bids fr­om consultants to assess the potential and feasibility of ground-mounted and rooftop solar capacities for airports managed by the Airports Authority of India (AAI). The sites listed were Aurangabad, Kangra, Tiruchirapalli, Madurai, Prayagraj, Leh, Salem, Tuticorin, Amritsar and Jabal­pur. Further, GMR Hyderabad Interna­tional Airport Limited (GHIAL) completed its second phase 5 MW solar power plant in July 2021, taking its total solar power capacity to 10 MW. This newest solar po­w­er addition will help GHIAL cover 50 per cent of its total energy requirements.


One of the world’s largest railway networ­ks in terms of size, Indian Railways (IR) accounts for more than 2 per cent of the country’s total power consumption and spends more than Rs 100 billion on its electricity bills each year. It is now working towards reducing its consumption of conventional energy sources that are finite as well as polluting, and is opting for renewable energy sources that are clean and cost effective. With its rail network spread across the length and breadth of the country and stations in almost every city, town and village, IR has vast reserves of land to deploy renewable energy projects on a massive scale. In fact, it aims to become a net zero carbon emitter by 2030 and has been taking many steps in recent years to decarbo­nise its operations and become greener.

As part of its efforts, IR has commissioned 119.98 MW of solar plants comprising 113.28 MW of rooftop solar and 6.7 MW of ground-mounted projects, as of March 2021. Solar projects have be­en set up at railway stations across the country including Varanasi, Katra, New Delhi, Jaipur, Kol­kata, Howrah, Guwahati. Further, IR plans to set up solar projects on its vacant land parcels and on land along railway tracks. Two pilot projects – 2 MW at Diwana and 1.7 MW at Bina – have al­ready been commissioned successfully. In fact, the Bina solar project is a unique project as it feeds solar power directly to IR’s traction system at 25 kV. Further, a 50 MW ground-mounted solar project is being implemented at Bhilai. IR has also tied up 400 MW of power from the Rewa Ultra Me­ga Solar Project in Madhya Pradesh. To further deploy large-scale solar power, Ra­il­way Energy Management Company Limited has been mandated to initially un­dertake 1.4 GW of solar projects on railway land in three phases.

Apart from solar power, IR is deploying wind power projects. It has commissioned 103.4 MW of wind capacity as of March 2021 spread across Tamil Nadu, Rajas­than and Maharashtra. Furth­er, to better manage peak demand and optimise the consumption of conventional and renewable power, it is planning to procure round-the-clock renewable power and has planned a storage-based solar pilot project. As per a recent announcement, IR plans to invite me­ga tenders for about 40 GW of renewable energy in the next two to three years to move closer to its clean energy goals.


Like airports, urban metro rail and railways, efforts are on to decarbonise Indian ports as well. The government undertook the Green Ports initiative in 2016 to im­pro­ve the environmental performance of these ports through a host of measures in­cluding the deployment of renewable power projects to fulfil their energy re­quirements. Ports at Visakhapatnam, New Mangalore, Mormu­gao, Chennai, Cochin and other ports  have already installed some renewable po­wer capacity. However, there is significant sco­pe to scale up this capacity. Thus, according to a September 2021 announcement, there is a plan to increase the share of re­newable energy to 60 per cent of the total power demand at ev­ery major port from less than 10 per cent at present.


Unlike airports, metro rails, railways or ev­en ports, the energy consumption of roadways is quite distributed. Power is mainly required for street lighting and toll booths; there are no other buildings that consume power. Hence, decarbonising energy use here is quite simple – using solar lights wherever possible and deploying rooftop solar panels or a small ground-mounted solar installation near the toll booth complex. This work has already begun, and the majority of the expressways and important highways use solar lights. Moreover, at some toll booths, solar power projects are being set up. These initiatives now need to be ramped up across the country in every town and city and not just highways to truly make a difference.

Key challenges and outlook

With extensive networks, large premises and infrastructure, and high power requ­irements, transport corporations present an ideal case for making the renewable energy transition. Unlike other commercial or industrial consumers, these organisations are safeguarded to some extent from approval delays, bureaucratic hurdles and discom reluctance, thereby making implementation easier. Thus, it is critical that these energy guzzlers deploy re­newable power projects to reduce their carbon footprint, further expand the distributed renewables market, and set an example for other bulk consumers. Going forward, the role of these organisations will evolve with the growth of emerging segments such as electric vehicles, green hydrogen and biofuels, and they should devise strategies accordingly.

The good news is that these companies are already moving at a rapid pace to decarbonise their operations. The country’s transport sector is surely on its way to a greener future.

By Khushboo Goyal


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