A city located in the Bay of Bengal in East India reports has cut its energy bill by about INR 5.5 million (US $) after upgrading 96,000 streetlights to LEDs, reported The Times of India.

The seemingly large number of streetlight retrofit makes up nearly 38.63% of Chennai’s 248,467 traditional CFL and high pressure sodium streetlights, which has been replaced by local authorities since 2014. Bimonthly streetlight energy consumption was cut from 11.59 million units to 9.9 million units, according to Chennai Corporation compiled data.

In power hungry states such as Tamil Nadu, the new LED lights have conserved 1.6 million units of electricity bimonthly.

"This translates to a total savings of 820,000 units every month. The power consumption would be further reduced once the INR 3.22 billion project to install 110,000 LED streetlights in the expanded areas is completed by next March," said a senior corporation official.

The same official went on saying Chennai had installed nearly doubled the number of LED streetlight installations compared to other city governments in India. "The expanded areas of the corporation have the maximum LED lights (61,379) compared to those in the core city limits (35,329)," he said. The city also sent in a detailed project proposal to install another 30,000 LED streetlights that will cost INR 1.46 billion.

The streetlights in the city are kept on for an average of 12 hours per day, and the LED installations could help the city cut energy consumption by nearly 40% compared to sodium vapor lamps, said experts. The LED lights are estimated to have a life cycle of 40,000 hours.