The hydroelectric project, in the northern Catskills, was returned to service following an outage to facilitate preliminary work on the last of four pump-turbine generators to undergo refurbishing.

“The equipment improvements at the Blenheim-Gilboa project will contribute to the continued efficiency and effectiveness of this key generating facility,” NYPA President Richard M. Kessel. Said. “Our engineering, site personnel and project management staffs have done a commendable job in their carrying out of the Life Extension and Modernization Program and keeping it on schedule and budget. The work will maximize the electricity output from the water harnessed by the project and ensure that this clean generating facility continues to provide reliable service for decades ahead.”

Three of four pump-turbine generating units were returned to service earlier this month following the project’s shutdown in mid-September to permit replacement of a spherical valve on the pump-turbine generating unit that is currently being refurbished. In order to replace the valve, which controls the flow of water into the pump-turbine generator, the water level in the project’s upper reservoir on top of Brown Mountain had to be lowered The reservoir, on Kingsley Road in the Town of Gilboa, has since been refilled to its five-billion-gallon capacity.

NYPA began the Blenheim-Gilboa LEM in September 2006 when the first of the four pump-turbine generating units was taken out of service for refurbishing. Since then, the process has been repeated three times, in the fall of 2007, 2008 and 2009.

Each of the refurbished generating units has a maximum capacity of approximately 290MW, compared to the replaced units that were rated at 260MW. At the conclusion of the LEM program, scheduled for June 2010, it is projected that Blenheim-Gilboa will be capable of producing approximately 1160MW from the same amount of water.

In addition to the LEM at Blenheim-Gilboa, NYPA is currently conducting a similar program at its St. Lawrence-Franklin D. Roosevelt power project in Massena, with that initiative expected to be complete by 2013. NYPA also completed a 15-year upgrade of its Niagara power project, near Niagara Falls, in late 2006.