And, like solar panels placed on land or rooftops, the panels must be cleaned regularly as electricity production declines if dust collects on top of them. The operation and maintenance of canal-top projects is a big challenge, as ramps have to be built to enable cleaning, says Jolly. Some companies use sprayers and robots to clean the panels in remote areas. “Because canal-top plants are spread over large areas and cannot be protected by boundary walls or fencing, security concerns are major – cameras may have to be installed to monitor pilferage,” adds Gensol Engineering’s Payal Saxena.

The meandering nature of the canals also imposes restrictions. To maximise the absorption of energy, the solar panels should face south, but the canal’s direction cannot be dictated.  Solar panels also act as an obstruction to repair the canals or remove silt, and very often trees along the canal have to be cut down as the areas have to be shadow-free.

So far, eight Indian states have commissioned canal solar projects. “These innovative projects can provide cheap and consistent electricity to millions of farmers and improve their profits,” says Jolly. And there is more potential to maximise renewable power from India’s canals, if solar farms above were combined with hydro-power from below, as researchers such as Sabah Usmani, an analyst at the Environmental Defense Fund, have suggested.

With their water-cooled efficiency, and mutual benefits for the canals that run beneath, it looks likely that these snaking, glittering solar canals will become a much more common sight in India.

—

The emissions from travel it took to report this story were 0kg CO2. The digital emissions from this story are an estimated 1.2g to 3.6g CO2 per page view. Find out more about how we calculated this figure here.

—

Join one million Future fans by liking us on Facebook, or follow us on Twitter or Instagram.

If you liked this story, sign up for the weekly bbc.com features newsletter, called “The Essential List”. A handpicked selection of stories from BBC Future, Culture, Worklife, and Travel, delivered to your inbox every Friday.