The New York Power Authority (NYPA) has approved a major contract for new computer monitoring and control equipment for the Blenheim-Gilboa pumped storage project in Schoharie County, in anticipation of a major programme to modernise and extend the life of the hydroelectric facility.

NYPA conducted a competitive review of proposals from several companies before selecting Siemens Power Transmission and Distribution of San Jose, Calif.ornia, for purchase of the supervisory control and data acquisition (SCADA) equipment. Siemens, which submitted the low bid, will deliver the equipment prior to the start of the four-year, US$135MLife Extension and Modernisation (LEM) programme, which is scheduled to officially begin in September 2006.

The amount expended by NYPA for the new monitoring and control equipment is not to exceed US$875,000, under the terms of the trustees’ authorisation of the Siemens contract.

The existing SCADA equipment needs to be replaced in order to have an up-to-date expandable system for handling additional requirements from the LEM program.

Blenheim-Gilboa’s operators use SCADA to monitor and control not only the operation of the 1,040,000kW project but also the facility’s 345kV switchyard, transmission system stations in central New York, and several small hydro facilities by rivers and reservoirs in the area.

The LEM program will involve renovation of Blenheim-Gilboa’s four turbine- generators, with the first unit to be completed by May 2007. The programme will include replacement of many of the major mechanical and electrical components, and maintenance and repairs to virtually all other parts.

After the first turbine-generator, the work on the remaining three units will occur in successive years, in 2007, 2008 and 2009. The schedule calls for the entire project to be completed in May 2010.

The work on each unit will require that the water level of the project’s upper reservoir, on top of Brown Mountain, be reduced each fall to permit replacement of spherical valves that control the flow of water into the power house.

Blenheim-Gilboa produces power during periods of peak power demand by drawing water from Schoharie Creek and recycling it between two large reservoirs. More than three-quarters of the facility is underground.

The project has been in operation since 1973.