Last week, the New York Metropolitan Transportation Authority (MTA) and New York Power Authority (NYPA) unveiled an advanced rooftop-mounted solar thermal array that heats hot water used to wash subway cars at New York City Transit's Coney Island Overhaul Shop and Maintenance Facility.

By lessening MTA's need for electricity, the array will lower the agency's power bill by $94,000 and cut 86 tons of carbon dioxide (CO₂) emissions per year.

The solar thermal system consists of 48 panels that are mounted on the building's roof. They capture the radiant heat from the sun and transfer it to water in interconnected pipes. The system functions as a water heater for domestic and other hot water use at the facility. The water is used for cleaning and washing trains during their scheduled maintenance and for domestic-use needs by staff.

Installation of the solar thermal array cost $550,000, which was financed by NYPA with the help of a $150,000 grant from the New York State Energy Research and Development Authority (NYSERDA).

The solar thermal project, which began in November, is part of a more than $1.1 million NYPA- and NYSERDA-funded energy efficiency upgrade for the Coney Island Facility, which also includes the installation of high-output fluorescent fixtures that are more efficient, last longer and provide better illumination than the light sources they replaced, saving the MTA $76,000 per year.

Altogether, the MTA and NYPA have partnered on 85 energy projects for a savings of nearly $5.7 million a year and annual reduction of greenhouse gas emissions of more than 34,000 tons.