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WHAT WE DO > Transmission improvements

Convertible Static Compensator


In the summer of 2004, we completed the installation at our Marcy Substation of the Convertible Static Compensator (CSC)—the first device in the world with the capability of instantaneously shifting power in the same substation from a heavily loaded transmission line to one with spare capacity. By permitting more electricity to be carried on existing transmission lines (it can permit total increases of close to 200 megawatts—enough to serve about 200,000 homes—statewide), the CSC has enhanced the reliability and efficiency of the New York State power system.

Photo of circuit breaker

A circuit breaker at the Marcy substation, where we installed the world's most advanced transmission control device.

With much of New York State’s electric generating capacity in the north and west and its heaviest consumer demand in the New York City area, transmission bottlenecks can impede efficient and economical power transfers. Completion of the CSC has strengthened voltage support on the transmission system, permitting increased power flows during periods of greatest statewide electricity use.

The CSC is largely contained in a gymnasium -sized building at the Marcy Substation which is the hub of our transmission system, encompassing more than 1,400 circuit-miles, or about one-third of the state's high voltage transmission facilities.

We invested $41 million in the CSC, with additional funding for the $54 million project from EPRI, the electricity industry's science and technology development organization; Siemens Transmission and Distribution and more than 30 electric utilities and independent system operators in the United States, Canada and New Zealand.

The CSC is the latest in a series of transmission control technologies known as FACTS (Flexible Alternating Current Transmission Systems) that have been developed by EPRI in cooperation with the Power Authority and several other utilities.