The Telegraph
Friday , June 20 , 2014
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Solar roof for trains to save fuel

New Delhi, June 19: Scientists have asked the railways to consider installing rooftop solar power panels on train coaches to meet their electricity needs and curb the country’s diesel consumption and carbon dioxide emissions.

Researchers from the Indian Institute of Science, Bangalore, have sent their proposal to the Rail Coach Factory at Kapurthala, Punjab, after showing through a theoretical study that solar panels can save up to 90,000 litres of diesel per rake per year.

They have estimated that a single rake — made up of five air-conditioned coaches, 12 other coaches, a pantry car and two power cars — relying on rooftop solar panels and making 188 forty-hour trips during a year could reduce carbon dioxide emissions by 239 tonnes.

Their study has indicated that the additional cost of the solar panels could be recovered within three years.

“Given our huge oil imports, every possible option to reduce dependence on oil must be explored — this is one such option,” Jayaraman Srinivasan, professor at the Divecha Centre for Climate Change at the IISc and a co-author of the study, told The Telegraph.

The study, accepted for publication in the journal Current Science, published by the Indian Academy of Sciences, examined the feasibility of installing solar photovoltaic panels that convert sunlight into electricity on a type of rail coach produced at the RCF, Kapurthala.

While the train coaches would be pulled by conventional diesel-run power cars, the solar panels are intended to provide all the internal electricity needs for lights and fans on both AC and non-AC coaches.

“The cost of solar photovoltaic panels has rapidly come down — we’re in a period of time when this idea can be tested for economic viability,” said Sheela Ramasesha, a materials scientist at the Divecha Centre who led the study.

The researchers relied on estimates by the new and renewable energy ministry that present-day solar photovoltaic panels would cost Rs 90 per watt. This would increase the cost of the rail coach retrofitted with rooftop solar panels by four per cent.

“We’re assuming 15 hours of sunshine during a 40-hour trip,” said M. Shravanth Vasisht, an electrical engineer and research fellow at the Divecha Centre. The excess energy generated by the solar panels could be stored in batteries for use during cloudy days or during the night.

But the idea doesn’t appear to have impressed railway engineers, who have questioned the stability and functioning of the solar panels on rooftops of fast-moving trains.

“A train moves at speeds exceeding 100kmph --- how are they going to fix the solar panels? This will be a big challenge,” Paramanand Singh, chief design engineer at the RCF, told this newspaper.

The researchers say they are trying to collaborate with railway engineers to select appropriate solar panels that could fit on rail coach rooftops and tolerate the vibrations and other forces they would encounter during high-speed runs.