Electric Distribution Systems originated in 1895 when the UNC Physics Department, directed by the Board of Trustees, built a power generator to service the dorms for student safety. Over time, the system was expanded to include all campus buildings, as well as the cities of Chapel Hill and Carrboro. In 1976, that portion of the system providing service to Chapel Hill, Carrboro and some nearby rural areas was sold to Duke Power, now Duke Energy.

Today, Electric Distribution Systems receives power from both the local utility provider, Duke Energy, and the UNC Cogeneration Facility. The electricity from both sources is delivered to three substations, all three of which were recently expanded and upgraded. Since completion of these upgrades, the substations have total transformation capacity of 250 megawatts, or approximately enough to power 26,000 homes. (See System Demand and Capacity for more information.) Each substation is connected to Duke Energy with 100KV gas insulated switchgear (GIS). These are the first installations of GIS on the Duke Energy System. This switchgear technology uses sulphur hexafluoride gas as an insulating medium, which greatly reduces the area required for the substation. These substation upgrades provide significant improvement in system reliability and redundancy in the event of system problems or failures, while allowing for continued growth and expansion of the University power system.

The University operates its own electric distribution system extending from the substations to each of the individual buildings serviced. This network consists of 820 electric and telecommunications manholes, tied together with 39 miles of duct bank, containing 68 miles of underground cable and operating at a voltage of 12,470 volts. This power delivery is controlled using 49 high speed automatic switches and 162 manual switches serving 406 transformers. (Some older parts of campus are still served from an overhead power line system, 5 miles in total length.)

Electric Distribution Systems is also responsible for the installation, operation and maintenance of all 2,739 lights in the University’s roadway, parking lot and area lighting systems.

System Design and Capacity

Substation No. of Circuits Power Demand Total Capacity
Manning 17 30 MW 100 MW
Cameron 18 35 MW 100 MW
South 9 15 MW 50 MW
Total 44 80 MW 250 MW

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