Cornell University Electrical Substation

Cornell University owns and operates an electric distribution system which supplies a load of over 30 MW.  Prior to this project, all power was purchased at 13.2 kV from New York State Electric & Gas (NYSEG).  The University was paying a premium for 13.2 kV delivery.  Since power costs are lower at higher delivery voltages, Cornell University determined that it could save close to $1 million/yr if it changed its delivery voltage to 115 kV. Since NYSEG would not sell the substation which supplied Cornell, Cornell elected to construct a new substation. O'Brien & Gere assisted Cornell with project planning and provided design, construction management, and construction inspection service. 

The logical site for the new substation was adjacent to NYSEG's existing substation. This site was reasonably hidden from view and accessible to both transmission and distribution lines. The steep terrain — 20 ft drop in 100 ft over portions of the site — however, was not ideal for substation construction. A gas-insulated substation was not practical due to cost and maintenance concerns;  a high-bay lattice design was not acceptable because of aesthetic concerns; therefore, a compact, low-profile design was the only acceptable alternative.

Methods used to decrease space and cut and fill requirements included the following:

• careful attention to site, equipment, and access road orientation
• installation of a 115 kV tie bus between the legs of the incoming dead-end towers
• use of vertical style circuit switches with integral disconnect switches
• placement of service disconnect switches and metering transformers on incoming dead-end towers
• the completed substation required a site of 124 ft by 154 ft, and this included space for a future third transformer bay

Elements of the project are listed in the table below: