For a cooperative like Suwannee Valley Electric Cooperative (SVEC), which does not generate its own electricity, substations play a critical role in making sure that the power we purchase can be used by our consumer-members.
How Substations Work
SVEC’s power is generated by Seminole Electric Cooperative and transmitted over long distances to our service area. To make the trip with as little energy loss as possible, transmission lines operate at a very high voltage. The first step in making that electricity useful for our consumer-members is reducing the voltage. That’s where substations come in.
“The primary function of a substation is to step the voltage from the transmission lines down to the voltage we use on our distribution lines to deliver power to our consumer-members,” says Daniel Carver, field equipment specialist for SVEC.
Electricity enters the substation from the transmission lines, passing through a transformer that reduces its voltage. It then is metered and regulated to a constant voltage. After that, it travels through a series of switches and circuit breakers that protect the transformer and isolate certain sections of the substation for repairs.
Finally, the electricity leaves the substation via the cooperative’s distribution lines to be carried to SVEC consumer-members.
Carver has made a career out of understanding the workings of substations and maintaining them to ensure members have reliable service. Along with Journeyman Lineman Jodi Hughes, he is responsible for the monthly inspections and testing SVEC does on substations and the high-voltage equipment in them.
The most common problems in substations are the result of flawed or degraded connections in these different components. When a faulty connection exists, it tends to heat up due to increased resistance. SVEC works to stay ahead of these issues by using infrared cameras to identify areas of overheating.
“It gives us the ability to locate hot spots we can’t see with the naked eye,” Carver says. “If we find an issue, we can address it before it turns into an outage and causes inconvenience to our members. We try to be proactive.”
SVEC performs infrared inspections on its substations twice each year. Carver and Hughes also conduct inspections of relays and other substation equipment on a monthly basis.
However, Carver emphasizes that he and Hughes are able to work safely with substation equipment because they are qualified to do so and have decades of experience in the electric industry. No unauthorized person should ever enter an electrical substation, as the high-voltage electricity poses a serious safety hazard.
“It’s not a playground for people to come in and explore,” Carver says. “We’ve had people cut their way into the fences to steal copper and other items. It’s really a dangerous environment that only trained personnel should be in.”
During An Outage
During large outages, SVEC often first checks to see if the problem is with equipment in the substation.
The transmission lines leading into SVEC’s substations are owned by Duke Energy and Florida Power & Light, while the power itself comes from Seminole Electric Cooperative. When the lines are damaged, SVEC must wait for them to be fixed before we can deliver the electricity to our consumer-members.
Each substation serves hundreds of consumer-members, which is why SVEC regularly performs maintenance on the equipment in each one. During an outage, the cooperative may first need to repair damage to a substation before power can be restored to a large number of people.