How We Get Electricity To You
Greenville Utilities purchases electric power from the North Carolina Eastern Municipal Power Agency (commonly just called "the Power Agency"). The Power Agency jointly owns generation facilities with Progress Energy. Progress Energy maintains the transmission facilities needed to get the power supply to Greenville and 31 other municipally-owned utilities in eastern NC, which in turn distribute electricity to their customers.
All of the electricity we purchase is sent to our Point of Delivery (POD) substations. Our Greenville 230 kV Point of Delivery substation, equipped with three transformers, is located on Mumford Road. Our second Point of Delivery substation (the Greenville 230 kV West substation on MacGregor Downs Road), serves as a back-up for the Mumford Road substation. It has one transformer and the capacity to carry 80-100% of GUC's load if necessary.
How is our Electricity Distributed?
Our supply of electricity is sent to us through transmission lines. These transmission lines are high voltage power lines that transport electricity at 230 kV over long distances. Transmission substations are located at major load centers, such as Greenville/Pitt County. The transmission substations, such as POD substations, reduce the voltage for transmission over shorter distances at lower capacities.
Once the voltage is reduced to 115kV at the point of delivery substation, it is distributed throughout Greenville/Pitt County over five transmission circuits. These circuits are typically located on top of the larger poles approximately 60 feet above the ground. If a storm causes a problem with one of the circuits, the other circuits can "backfeed" electricity, restoring power in a short period of time.
The five transmission circuits provide power to Greenville Utilities' 17 substations. At each of these distribution substations, transformers reduce voltage to 12.5 kV. There may be four, five, six, seven or eight circuits leaving these substations to provide power in a designated area.
The power lines that leave these substations are called primary distribution circuits, feeder circuits or three-phase circuits. These lines are located at the top of poles about 40 feet above the ground. They have been designed to distribute power evenly on each phase. These feeder lines also have the ability to be "backfed" by other circuits (either from the same substation or from one nearby). These are the power lines commonly seen paralleling the road throughout the county.
Once again, the voltage on these primary distribution circuits will be transformed to a lower, more usable level. This is done through distribution transformers, the gray cylindrical devices seen on top of the poles of power circuits installed on the poles. The voltage gets reduced for residential, commercial and industrial use.