Solar push for Railways

Indian Railways can reduce its carbon dioxide emissions by 239 tonnes per year per train by fixing solar panels atop coaches

By Megha Prakash
Published: Friday 15 August 2014


The railways' decision to experiment with solar energy to electrify train coaches can substantially reduce its carbon footprint, say researchers. Union railway minister D V SadanandaGowda in June announced a Rs 7-crore pilot project to electrify 30 train coaches with solar power. The solar-powered coaches will start plying within six months on the Delhi-Uttar Pradesh and Delhi-Haryana routes.

A team of researchers from Indian Institute of Science in Bengaluru calculate that installing photovoltaic panels atop coaches can reduce 239 tonnes of carbon dioxide emissions per year per train, which is roughly equal to the annual emissions of 50 cars in the city. On an average, 11,000 trains ply in India every day. The researchers say the Railways can save close to Rs 60 lakh annually on each train by shifting to solar panels. Their paper on the use of solar energy to fuel railway coaches is scheduled to be published in Current Science journal.

Lead researcher Sheela K Ramasesha and her team calculated the energy consumption pattern of a train with 19 Linke Hofmann Busch (LHB) coaches, which are used in superfast trains such as Rajdhani, Shatabdi and Durunto. The Railways plan to introduce LHB coaches in all the trains in the coming years.

They found that to make a 1,800 km trip, a rake (comprising of 19 LHB coaches) consumes 3,000 litres of diesel for auxiliary energy needs such as lighting and cooling. “Assuming that the rake makes 188 trips in a year, our calculations indicate that 90,804 litres of diesel can be conserved every year, with a saving of Rs 59,93,064, by putting solar panels on the train,” says Ramasesha.

The researchers suggest that the estimated price of an LHB rail coach with a solar power generation system is 4 per cent higher than the price of the present LHB coaches. The investment would be recovered within two-three years, they say.

Talking about the feasibility of the project, the paper says, “It is clear that the energy that can be harnessed during sunshine hours is much more than the requirements of the train even during the shorter days of winters.” The researchers, as a result, suggest the installation of batteries to store excess energy to be used at night.

Technology troubles

While the Railways’ move to go green is positive, researchers say introducing solar panels in trains will not be easy. For one, it will be a constructional challenge to install the panels on curved train rooftops. “The solar panels need to be manufactured specially based on the dimensions suitable for mounting. We have submitted a design proposal to officials at the Railway Coach Factory in Kapurthala,” says ShravanthVasisht, one of the researchers. “We are waiting to get a nod from the Railways authorities to test our design,” he adds.

Going green

The Delhi Metro has set up a 500 kilowatt peak (kWp)-capacity solar plant at the Dwarka Sector 21 metro station. Power generation is expected to start soon. The Delhi Metro is now planning three more solar power plants at AnandVihar ISBT station, PragatiMaidan station and at the residential complex in PushpVihar. The combined capacity of the three plants will be 250 kWp


The Indian Railways is planning to generate 1 MW solar power at the New Delhi railway station by installing solar panels on the roofs of platforms. Once operational, around 25 per cent of the energy requirements at the station can be met just by solar power


Gujarat launched the world's first solar power project on a canal in April 2012. Once operational, the project on the Narmada branch canal in Mehsana district will generate 1.6 million units of electricity every year

Sunil Dayal, a Delhi-based expert on solar power technology, points out another problem. He says the rooftop solar modules will have to survive extreme weather conditions such as rain, dust storms and snow. Besides the obvious wind pressure that will be created during the motion of the train, the panels will be exposed to sand and dust particles, especially in difficult geographical locations. “For example, dust particles in Rajasthan are coarse and they may settle in huge quantities. In that case, the module’s efficiency is lost by three per cent and the panels will require frequent cleaning,” Dayal says.

He warns that cleaning the solar modules will be an arduous task. “While cleaning these modules, extra caution has to be taken to avoid eroding the thin film of semiconductors used in them. Though recent advances such as water pump suction system have been made towards maintaining solar panels, they are extremely expensive,” he says.

The other major challenge will be storing the surplus energy. Though efforts are being made by numerous groups across the globe, an efficient battery model is still a dream. There are two ways to use the solar energy; one is through a grid system and the other is by using stand-alone photovoltaic power systems. The grid system, without a battery, can supply electricity between sunrise and sunset. “The other option of a stand alone system that uses a battery support to store energy will increase the cost, which might make the project uneconomical,” says Dayal.

The problems, though difficult, can be tackled, the researchers believe. They say the Railways can learn a lot from the Shimla-Kalka toy train named Himalayan Queen, which is the first train to successfully use solar power. Each of its coaches is fitted with 100-Watt solar panels, each of which cost Rs 1.25 lakh. The panels generate enough electricity to meet the coaches’ lighting needs for two days. The use of solar panels has also made the coaches lighter by 500 kg and reduced the frequency of maintenance.

How solar power fares on tracks
Despite constructional hurdles, going solar will be profitable for the Railways
483 litres of diesel can be saved during a 40-hour trip if a train with 19 coaches is fitted with solar panels

90,804 litres of diesel can be saved per train per year if they are fitted with solar panels. On an average, a train makes 188 trips a year

239 tonnes less Co2 will be emitted by each train per year if the Railways introduces solar panels on trains. The Co2 amount is roughly what 50 cars emit in a year

26 million tonnes less Co2 will be emitted by the Railways if all of the 11,000 trains are fitted with solar panels

Source: Indian Institute of Science, Bengaluru

The grey side

Wind speed The solar panels will be exposed to high wind speeds as trains move at a speed of 100-150 km/hr

Electric field Trains usually have electric lines above them. The magnetic field created by the lines might interfere with the solar power system

Cleaning The panels will require regular cleaning which might erode the thin film of semiconductors used in them

Weather Extreme weather conditions such as rains, dust storms and snow might destroy the solar panels

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