The New York City subway systems and a Hudson River railroad line used lower voltage direct current (DC) electrification, but for longer distances that would mean high transmission losses or frequent and closely spaced substations.

The plant was built by Westinghouse in 1907 in Mission Style, and was located where the Mianus River empties into the Cos Cob Harbor of Long Island Sound.

The plant used coal-fired steam turbines, and the three-phase alternators supplied single-phase power at 11 kV 25 Hz directly to the catenary.

They also supplied power to the New York Central's Port Morris generating station to compensate the NYC for power consumed by New Haven trains on the NYC's third-rail supplied line to the Grand Central Terminal within the city limits.

[citation needed] Part of the site is now a public park, and a plaque commemorating the plant is located at the nearby Cos Cob Railroad Station.