This is the third and final column about the regulations that keep order in the day-to-day operation of electric utilities.
At a few spots along the Ohio River, power lines cross from Kentucky to another state. Those thick cables could be hundreds of miles from your home, but they play a key role in helping your local utility provide reliable, affordable electric service to you.
Your home is within a service territory with borders that are defined by state law. Your local co-op utility buys the power it sends to you from a larger power supply utility.
But where does that power come from? It might be from a source within Kentucky. But it could be from somewhere else.
Within Kentucky, local electric cooperatives buy power for their member-owners from three power supply utilities. In the east, 16 local utilities distribute power purchased from East Kentucky Power Cooperative. In the west, three local co-ops rely on Big Rivers Electric Corporation for their power. In the southwest, five Kentucky co-ops buy the electricity they distribute to their members from the Tennessee Valley Authority.
Prepared for the unexpected
Each of the three power suppliers has its own power plants. The mix might include a coal power plant, a natural gas power plant, a hydroelectric dam, and perhaps some nontraditional resources such as landfill gas power plants, wind turbines, or solar arrays. These varied resources can usually supply enough power (plus a little extra on standby) to meet Kentucky consumers’ needs.
But all the resources don’t all run all of the time. The mix of operating units is always changing. Weather conditions might knock one resource out for a while. Scheduled maintenance work or emergency repairs might shut down a power source for a few months or a few hours. When everything is working smoothly, even though various units are going on and off, your electric service remains steady and reliable.
However, a power supplier must always be prepared for the unexpected and be ready to find replacement power—and find it fast.
That’s why East Kentucky Power’s Spurlock power plant near Maysville has a set of bulk power lines that go across the river to the Zimmer and Stuart power plants that are owned and operated by other utilities in southern Ohio.
Denver York, vice president for System Operations at EKPC, says, “Years ago those kinds of interconnections arose from the viewpoint that we can provide more reliable service if we hook together. We said, ‘When my plant fails, yours can pick up, and if yours fails, mine can pick up.'”
Known as “free-flowing” interconnections, these power lines are capable of moving enough electric power in either direction to meet the needs of hundreds of thousands of homes in Kentucky or Ohio.
Sharing resources for reliable service is not the only reason for these interconnections. They also help keep the cost of electricity low. Sometimes it makes economic sense for a power supplier to buy some power from a distant resource if the price for that electricity is substantially lower than its own cost would be.
Finding the best deal
During the last century, controllers at each utility spent hours making one-to-one phone calls to each other checking whose generators were running or would be available soon, and discussing prices.
It was a workable system, but not perfect. Sometimes the utility with the most generators running couldn’t find anyone who needed any extra power. Sometimes a utility with low-cost
power to sell could not add it to the bulk transmission lines because those lines were already too crowded.
Since the Energy Policy Act of 1992, and continuing with orders issued during the next two decades by the Federal Energy Regulatory Commission, the decision-making process for moving power through transmission lines has changed.
Two new federally mandated organizations now help coordinate the action.
Regional transmission organizations help generating utilities and transmission line owners plan ahead to meet federal reliability standards, determine interconnection points for the big power lines, and coordinate other long-term physical details.
As a result, more interconnections are being added to the bulk power system to provide added pathways for electricity to move between more power supply utilities in all states.
And there’s another innovation. Instead of various independent utilities constantly making phone calls back and forth, new regional authorities called independent system operators now play the role of a centralized marketplace. Each ISO matches up buyers and sellers of power within a region on a minute-to-minute basis. That should make it easier to send the lowest cost electricity to you.
Regulating electric utilities in Kentucky
Connections for Kentucky’s generation and transmission utilities stretch out in all directions.
East Kentucky Power Coop-erative participates in the PJM Interconnection, which includes utilities in parts of 13 northeastern states and the Washington, D.C., area.
Big Rivers Electric Corporation is a member of the Midcontinent Independent System Operator that provides bulk power management services in parts of 15 Midwestern states and a portion of Canada.
The power plants and transmission lines within the vast Tennessee Valley Authority system crisscross seven Southern states