Electric Distribution Systems
Electric Distribution Systems originated in 1895 when the UNC Physics Department, directed by the UNC Board of Trustees, built a power generator to service the dorms for student safety. Over time, the system was expanded to include all of the campus buildings, as well as the cities of Chapel Hill and Carrboro. About 30 years ago, the portion of the distribution system servicing Chapel Hill and Carrboro was sold to Duke Power, now Duke Energy.
Today, Electric Distribution Systems receives power from the both the local utility provider, Duke Energy, and the UNC Cogeneration Facility. The electricity from both sources is delivered to three substations, each having a supply transformer rated at 20/27/33 MVA (million-volt-amperes) with a summer peak rating of 43.3 MVA. The supply transformers and the related University-owned switchgear have a combined capacity of 84 megawatts, which is roughly the equivalent to the peak power demand of 8,600 all electric homes. In 2008, the capacity of the system will increase to approximately 234 mVA (200,000 kilowatts) with the replacement and addition of transformers at the substations. A planned improvement in reliability is added through the use of Gas Insulated Switchgear (GIS) at each substation. This specially insulated switchgear provides the means to enclose the necessary switchgear inside housings that are insulated with a special gas. The additional capacity is to provide significant improvement in system reliability and to also provide some redundancy in the event of any system problem or failure while allowing for continual growth and expansion of the University power system.
