The Indian Railways is one of the biggest consumers of diesel in the country. However, they have now started fitting solar panels on a few non-AC coaches on a trial basis. According to the Railways, one such train is going to save an impressive 90000 litres of precious imported diesel per year and help to reduce the carbon footprint by 200 tonnes a year.
Such a ‘solar powered’ coach can produce 17 units of electricity in a day, a number which is very low considering the total energy requirement in a train. It is important to note that current technology cannot power the entire train by placing solar panels on the top.
Currently, the power produced by solar panels on the top of the trains is sufficient to power the lights and mobile charging points. A 3000 HP train consumes a huge amount of power, somewhere around 20kWh per km. The entire surface of a train coach is 40 m2 and even if it is completely covered, it still won’t be able to power the air conditioners.
Is There A Better Alternative?
Yes. Instead of having solar panels on train rooftops, it is better to have stand alone ones on other fixed places, such as on the roofs of stations and on the top of railway buildings where the panels can get maximum sunshine. While a train is moving, it receives direct sunlight only for about 15 hours in a 40 hours journey. Also, it passes through the shade of trees, wrong angle of inclination and other obstructions that reduce the efficiency of solar power. The electricity from station and other rooftops can be fed into the track grid, or consumed at the stations itself. Considering the railways have a lot of real estate, they can easily generate megawatts or even gigawatts of electricity easily.
So Is This Just Good Publicity?
No, any reduction in fossil use is always welcome. A practical problem is that only 34 percent of the tracks in India are electrified – which means diesel is the major driver. It costs the railways INR 20 per kWh to produce energy from diesel. The solar panels would cost nearly INR 4 lakhs for a coach and the money will be recovered within 3 to 4 years. Putting up panels on top of buildings would be more efficient, and while it won’t reduce the diesel use directly, it can offset the carbon use.
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