Delhi Metro has earned Rs 19.5 crore from sale of 3.55 million carbon credits which it had collected over a period of six years, in its bid towards gaining greater energy efficiency, DMRC authorities said on Sunday.

The Delhi Metro Rail Corporation (DMRC) has been a pioneer in India in quantifying climate change benefits from its operations. It has a number of dedicated projects to its credit oriented towards energy efficiency, it said in a statement.

The DMRC has earned a commendable Rs 19.5 crore from the sale of 3.55 million carbon credits which it had collected over a period of six years from 2012 to 2018, it said.

In 2007, Delhi Metro became the first metro or railway project in the world to be registered by the United Nations under the Clean Development Mechanism (CDM) which enabled Delhi Metro to claim carbon credits for its Regenerative Braking Project, officials said.

The CDM is a project-based green house gas (GHG) offset mechanism under the Kyoto Protocol allowing the public and private sector in high-income nations the opportunity to purchase carbon credits from greenhouse gas emissions-reducing projects in low or middle-income nations as part of their efforts to meet international emissions targets under the Kyoto Protocol, the DMRC said.

CDM projects generate emissions credits called Certified Emission Reductions (CERs), which are then bought and traded. One CER is equal to one ton of CO2(eq) emission reduced. The CDM helps to deliver sustainable development benefits to the host country, the statement said.

The CDM projects are managed by The United Nations Framework Convention on Climate Change (UNFCCC), an entity established to combat "dangerous human interference with the climate system", it said.

Since 2015, Delhi Metro has also been providing CDM consultancy services to other metro systems in India, enabling them to earn carbon credits from their project.

Already Gujarat Metro, Mumbai Metro and Chennai Metro etc. Have registered their projects under the Delhi Metro's Program of Activities (PoA) project enabling them to earn carbon credits and contribute to India's Intended Nationally Determined Contribution (INDC) in compliance with the Paris Agreement, it added.

For the period 2012-18, combined GHG emission reduction achieved from all the CDM and Gold Standard projects was 3.55 million carbon credits.

The sale of carbon credits accrued from CDM and Gold Standard projects in the period 2012-18 has generated a revenue of Rs 19.5 crore to the DMRC. The total revenue generation from CDM and Gold Standard projects since inception has been Rs 29.05 crore, it said.