The Indian city Delhi has one of the largest compressed natural gas (CNG) vehicle fleets in the world. Walking around the streets of Delhi you can see buses and three-wheeled motorized rickshaws that run on CNG all around you. When did this all happen?
Back in the summer of 1998, the Indian Supreme Court ordered that all commercial passengers vehicles have to be converted to CNG, including taxis, buses and three-wheelers. CNG is a cleaner-burning fuel compared to gas and diesel.
After much controversy and protests, the shift happened, and as of 2007, Delhi had 90,000 CNG vehicles. (I will update this if I get newer stats). The switch to CNG was accompanied by a retirement of old commercial vehicles and an increase in the number of buses.
Years after the switchover, studies have found the conversion of commercial gas and diesel consuming vehicles to CNG vehicles has overall helped to reduce air pollution in Delhi (though in comparison to the U.S. it seems mighty smoggy here this week). However, the conversion of the three-wheelers to CNG hasn’t seemed to help that much and has potentially increased certain types of emissions because of the use of old and inefficient tech, says the researchers at Resources for the Future.
The findings (from the 2007 study) suggest that Delhi can help upgrade the CNG three-wheelers with newer tech to reverse that trend. At the same time those learnings can show other cities that they need to make sure the most efficient tech is used for CNG, or the benefits can be negated. T. Boone Pickens must be proud.