On a wall of screens at the Columbus offices of Buckeye Power, the electricity supplier for Ohio’s 24 electric cooperatives, computer screens show graphs rippling in real time, painting a picture of the lives of the 400,000 co-op members around the state.
On one of the screens, a line representing members’ overall electricity usage begins to climb as early risers turn on lights and coffee makers, then more steeply as small businesses open, office buildings fill, and air conditioners deal with the afternoon sun. Later, that line ascends again as people pop dinner in the oven and relax in front of the TV.
Buckeye Power system operations staff constantly monitor members’ electricity usage so they can make generation adjustments and ensure grid balance.
In front of those screens at Buckeye Power, the system operations team watches it all unfold, for the most part just as had been predicted the night before, then gets to work on the all-important forecast for the next day. The basic question team members must answer is both simple and complicated: How much electricity will our members need?
They feed that forecast to PJM, the regional transmission organization charged with balacing supply with demand across 13 states, including Ohio. PJM then determines which power plants across the region are best-suited to fill that anticipated demand, both reliably and economically.
The near-term dance
“One of the most basic elements of the electric grid is that it always has to be in balance,” says Kara Smith, director of market operations at Buckeye Power. “Electricity has to be produced in the same moment it’s consumed. PJM puts everyone’s forecasts together and then tells us how much we will need to operate our generation facilities to make sure the amount being generated across the grid matches the amount being used — minute by minute, second by second.”
While PJM uses the forecasts to make sure the grid is in balance, Buckeye Power also uses them to inform its buying and selling decisions on the open markets. That’s why getting that next-day forecast as accurate as possible is critical for keeping electricity not just reliable but also affordable for members around the state.
The biggest factor in that daily forecast is weather. But it’s not just temperature. Humidity, wind speed, cloud cover, and even the timing of a storm front all play roles in what types of generation get scheduled. A sudden heatwave can send air-conditioning demand surging. A pop-up storm may flatten what would otherwise be a peak.
Weekends, of course, look different from weekdays, and holidays rewrite the script entirely. A Monday morning in October behaves differently from one in July, and an Ohio State University home football game can cause a noticeable spike in demand on what might otherwise be a low-usage fall Saturday.
And during the solar eclipse in April 2024, usage patterns went entirely haywire —day literally turned to night, and generation facilities everywhere had to make adjustments.
Looking into the future
Co-ops, however, also need to look further down the road in their forecasting as their leaders make decisions that will affect their members for years and even decades to come.
Long-term load forecasting looks less at weather and more at broader questions that will determine how and when to make larger capital investments.
Co-ops do a deep-dive forecast of their energy needs at least annually, and usually they’ll try to make projections at least 20 years into the future, says Kevin Zemanek, vice president of operations at Buckeye Power. “Those reviews look at everything from new laws and regulations to new and emerging technologies to potential sources of funding, and more.”
Population growth is a starting point. If a co-op stands to gain a significant number of members because of a new housing development, for example, its overall demand will rise. New factories being planned or commercial parks all bring new load and shape a co-op’s long-term plan.
Then there are technological shifts. Will electric vehicle use move more into the mainstream with memebrs? Co-ops need to plan for that. They’re also wrestling with how to deal with potentially significant loads that will come along with new data centers on their lines. Those are both examples why those long-term forecasts need that annual check-up.
“Five years ago, no one was really predicting the effect that data centers would have on the grid and on electricity demand,” says Buckeye Power President and CEO Craig Grooms. “Then for a while, there was a lot of speculation that they might need more electricity than the grid could provide. Now that everyone’s getting a better handle on what the actual demand is going to look like, co-ops are able to make plans that will protect their current members from some of the costs that data centers bring with them.”
Always the bottom line
Accurate near-term forecasts keep the grid stable minute by minute, preventing blackouts and ensuring that supply meets demand efficiently. They also can lower costs by reducing the need for expensive last-minute power purchases. Long-term forecasts help co-ops make informed, thoughtful investment decisions when they’re needed, and not before. For members, that all translates into more stable rates.
“Our cooperatives absolutely have enough power available to serve their members’ needs right now and for years to come,” Grooms says. “At the same time, you don’t build a power plant overnight. Decisions co-op leaders make today are purely about serving their members — today and tomorrow, but also 10, 15, 20 years from now, and they take that responsibility very seriously.”
