India's first solar-powered train makes its debut

India's diesel-powered train network has a new kid on the block. The gas-guzzling Indian Railway system has just debuted its first solar-powered train, called the Diesel Electric Multiple Unit (DEMU). It will operate in the city of New Delhi.
The train will still be pulled by a diesel locomotive; the solar panels will only power passenger comfort systems, such as lights, information displays and fans. Even so, Indian Railways estimates that just one train with six solar-panel equipped cars will save 21,000 liters (5,547 gallons) of diesel fuel per year, at a cost savings around Rs12 lakh (almost $20,000).
Indian Railways is the largest rail network in Asia, running around 11,000 trains daily. The service moves roughly 13 million passengers every day. That translates to incredibly large fuel bills; in 2015, the service spent Rs16,395 crore ($2.5 billion) on diesel. They've been trying to reduce their fuel consumption, in part by more reliance on solar energy; the hope is that it will save them Rs41,000 crore ($6.31 billion) over the next 10 years.