The New York Power Authority (NYPA) said Oct. 7 it has upgraded the first of 12 pump-turbines at the Niagara Hydroelectric Power Plant’s Lewiston Pump-Generating Plant (LPGP) as part of a 10-year, $460m life extension and maintenance program that started last year.
The upgrade is in line with Gov. Andrew Cuomo’s emphasis on “modernizing the state’s electric power system to optimize its performance and reliability,” said NYPA President and CEO Gil C. Quiniones.
The modernization at Lewiston provides for the upgrade of the facility’s 12 pump-turbines and the replacement of generator step-up transformers, which date back to 1961 when the Niagara plant went into service. The next pump-turbine unit is scheduled to be taken out of service later this month.
Replacement of the decades-old equipment will enable the pumped-storage facility to run more efficiently, a NYPA spokesperson said.
Lewiston provides electricity during periods of peak power demand, supplementing the output of the Robert Moses Niagara Power Plant, the main generating facility.
Together, the Moses plant and Lewiston combine for a net dependable capability of 2,441 megawatts (mw), making the Niagara plant the largest generating facility in the state and one of the largest in the country.
The work at Lewiston will overhaul one pump-turbine every eight-to-nine months, ensuring that 11 of the 12 units remain available for operating throughout the project.
Work on the plant’s refurbishing includes contract awards to Ferguson Electric of Buffalo, the largest electrical contractor in Western New York.
Pumped-storage facilities like Lewiston store water as potential energy during off-peak hours for later use. At night or on weekends, when electricity demand is low, the pumped-generating plant’s reversible pump-turbine generating units operate as pumps, transporting water from the Niagara project’s forebay up to the Lewiston plant’s 22-billion-gallon upper reservoir, which is approximately 70 to 120 feet higher in elevation.
Surplus electricity from the Moses plant is used to power the pumps to push water into the Lewiston Reservoir during the off-peak times.
During the daytime, when electricity use peaks, the pumps are reversed and become generators allowing Niagara River water to be used to produce electricity twice, with the same water flowing through the Lewiston pump-turbines and then the generating units at the Moses plant.
Lewiston is one of two major pumped storage facilities in New York State—the other being the Blenheim-Gilboa Pumped Storage Hydroelectric Power Plant, in the northern Catskills, another NYPA facility. In May 2010, the Power Authority completed a four-year overhaul of that facility.
More than 70% of the electricity NYPA produces is renewable hydropower.