Delhi Metro has earned more than Rs2 crore by either directly reducing or causing to reduce carbon emission in the environment in the past few years.
From the sale of 82,000 Certified Emission Reductions (CERs), commonly called carbon credits, from the Japan Finance Carbon Ltd, the Metro received the money for years 2008 and 2009. It earned Rs1.07 crore on the sale of 39,000 CERs for 2008, and Rs1.33 crore on the sale of 43, 000 CERs for 2009.
"We were the first railway project in the world to be registered by the United Nations under the Clean Development Mechanism (CDM) which enabled us to claim carbon credits," said Anuj Dayal, spokesperson, Delhi Metro Rail Corporation (DMRC).
The Delhi Metro earns CERs for the use of regenerative braking system in its trains. This was the first time in the world that the United Nations Framework Convention on Climate Change (UNFCCC) had registered a project based on regenerative braking.
Under the regenerative braking process, whenever trains on the Metro network apply brakes, three phase-traction motors installed on these trains act as generators to produce electrical energy which goes back into the Over Head Electricity (OHE) lines, Dayal said.
The regenerated electrical energy that is supplied back to the OHE is used by other accelerating trains in the same service line, thus saving overall energy in the system as about 30% of electricity requirement is reduced.
A Germany-based validation organisation TUV NORD which conducted an audit on behalf of UNFCCC certified in 2009 that DMRC had stopped the emission of 90,004 tonnes of carbon dioxide from 2004 to 2007 by adoption of regenerative braking systems in the Delhi Metro trains.
The officials said that money earned from the sale of CERs will be used to offset the additional investment and operation costs incurred due to the implementation of the project activity, to stimulate research and development activities by DMRC to develop technology to reduce emission of green house gases and to give extensive training to train operators for optimum regeneration.