The New York State Metropolitan Transportation Authority (MTA) is a public transportation agency that serves the metropolitan area of New York City. The MTA operates a network of buses, subways, commuter trains, and other transit services that connect millions of people each day. The MTA is one of the largest transportation systems in the world, with a budget of over $18 billion and more than 70,000 employees.

In recent years, the MTA has made a concerted effort to reduce its carbon footprint and transition to renewable energy sources. The agency has set ambitious goals for decarbonisation and has implemented a number of initiatives to achieve these goals.

One of the key strategies that the MTA has pursued is the adoption of corporate power purchase agreements (PPAs) for renewable energy. A corporate PPA is a contract between a company and a renewable energy provider that guarantees a fixed price for a certain amount of renewable energy over a set period of time. By entering into these agreements, the MTA is able to secure a reliable source of renewable energy while also supporting the growth of the renewable energy industry.

The MTA has signed several corporate PPAs for renewable energy in recent years. In 2018, the agency signed a 20-year agreement with a wind farm in upstate New York that will provide enough energy to power all of the MTA's subway and commuter rail systems. The wind farm is expected to begin operations in 2020 and will generate 1.4 million megawatt-hours of electricity per year.

In addition to corporate PPAs, the MTA has also implemented a number of other initiatives to reduce its carbon footprint and promote renewable energy. The agency has installed solar panels on the roofs of several of its facilities, including the Coney Island Maintenance Facility and the Jamaica Maintenance Facility. These solar panels generate a significant amount of renewable energy and help to reduce the MTA's reliance on fossil fuels.

The MTA has also implemented a number of energy efficiency measures to reduce its overall energy consumption. The agency has installed energy-efficient lighting systems, HVAC systems, and other equipment in its facilities, which has helped to reduce energy consumption by more than 10% in recent years.

The MTA has also invested in the development of new technologies and infrastructure to support decarbonisation and renewable energy. The agency has launched a pilot program to test electric buses on several of its routes, and has also invested in the development of new battery storage technologies to support the integration of renewable energy into the grid.

Overall, the MTA's efforts to promote decarbonisation and renewable energy are an important step towards a more sustainable future for New York City and the surrounding region. By adopting corporate PPAs, investing in renewable energy infrastructure, and implementing energy efficiency measures, the MTA is demonstrating its commitment to reducing its carbon footprint and promoting a cleaner, more sustainable transportation system.