State-owned Indian Railways launched the country’s first solar-powered train with rooftop solar panels that power the lights, fans, and information display systems inside passenger cars. Although the train will still be drawn by a diesel-powered locomotive, a set of 16 solar panels atop each car will replace the diesel generators that typically power these appliances. The Railways estimate that a train with six solar-powered cars will save approximately 5,548 gallons of diesel every year, worth around $18,000.

Quartz says that the rooftop solar system was developed by Noida-based Jakson Engineers, under the direction of the Indian Railways Organization for Alternate Fuels. “It is not an easy task to fit solar panels on the roof of train coaches that run at a speed of 50 miles per hour. Our engineering skills were put to a real test during the execution of this rooftop solar project for Indian Railways,” Sundeep Gupta, vice-chairman and managing director of Jakson Engineers

Indian Railways has ambitious plans for solar: by 2020, the state-run transportation network plans to generate around 1,000 megawatts of solar power, which could be scaled up to 5,000 megawatts by 2025.