Carbon credits are measured in terms of reduction of carbon dioxide by adequate measures. "This is the first time in the world that the UNFCCC has registered a project based on regenerating braking technology (RBT)," DMRC Chief Public Relations Officer Anuj Dayal said.

Under the RBT system, whenever a train applies brake, 30 per cent of the energy released by it is conserved and is used by the train coming from behind. The total amount of energy thus conserved can be converted into financial terms — Certified Emission Reduction (CER). "DMRC can now claim 400,000 CERs for a 10-year crediting period. This translates to Rs 1.2 crore per year for 10 years," Dayal said.

It took over a year for DMRC to get itself registered as it had to go through several procedures. The entire project was carried out with the support of Japan Carbon Finance Ltd which provided $95,000.