How does CLMS work?

Cooperative consumer-members, through Allegheny, own a significant portion — nearly 70% — of the generation resources that power their homes and businesses.

This includes the Raystown Hydroelectric Plant in Huntingdon County and a 10% share of the Susquehanna Steam Electric Station, a nuclear plant in Luzerne County. Allegheny has also secured long-term power purchase agreements for hydroelectric energy from the New York Power Authority. These carbon-free resources ensure cooperative members enjoy stable electric rates at the lowest cost possible.

The remaining energy is purchased on the open market. The cost of that extra electricity is based on the amount of electricity called for, or “demanded,” at a particular time of day. “Peak demand” refers to those periods when electric consumers collectively use the most electricity. Generally, electricity prices are higher during those peak-demand periods.

As a result, the price of electricity is partially based on how much power your local electric cooperative requires during the five hottest, most humid days each summer. Reducing the amount of power your cooperative uses on those days, as well as during other times throughout the year, can stabilize electric costs.

CLMS works by shifting when electricity is used — from times of peak demand to off-peak hours. As a result, Allegheny’s generation costs are lower, which in turn reduces power costs to local cooperatives and, ultimately, the cost to members of every cooperative. In 2024, the CLMS program reduced purchased power costs by approximately $5.3 million, bringing total savings to more than $170 million since the program began.

Currently, more than 42,000 load control receivers (LCR) are installed on appliances in the homes of electric cooperative consumer-members. These members volunteer to have an LCR installed on a particular appliance, such as a heat pump or hot water heater. Meanwhile, Allegheny staff monitors real-time electricity demand. When demand reaches an extremely high level, a load management operator sends a signal to the LCRs, which temporarily cut power to the appliances they are connected to, reducing demand across a cooperative’s service area.

Historically, hot water heaters have yielded the biggest bang for your buck in the CLMS program, with 91% of LCRs installed on these appliances. The program is set up so volunteers typically are not even aware the control has been activated. Because larger water heaters retain heat for a long period of time, cooperative members should not notice when they are off for a few hours. Water heaters are generally grouped according to capacity and household size with the goal being no group is turned off longer than the storage capacity and needs of the family allow.

Usually equipped with ample insulation, water heaters are akin to batteries in terms of energy use; they can be switched off, which won’t impact the heated water inside, and then switched back on when demand is lower. Electric thermal storage (ETS) units and dual-fuel home heating systems are other common candidates for LCRs.

“Initially, the program was just for water heaters, but later it was expanded to central air, heat pumps and then ETS units. Then as technology allowed, we were able to control more loads through an interruptible subpanel that controlled everything attached to it,” says Brian Shearer, senior staff engineer at Gettysburg-based Adams Electric Cooperative. “Any kWhs used from that panel are at a reduced rate for our members, regardless of how many times we enter control.

“For example, March and April we only had to enter control one day each month, but members still benefitted from a reduced rate and limited interruptions.”

Ted and Bonnie Wacchaus, Adams Electric members in York Springs, have been participating in the cooperative’s load control program — U-$hift, U-$ave — for as long as they can remember. In 1969, they moved into a century-old home that required more than $500 worth of oil to heat year-round. As oil costs rose, they knew they needed to make their home more efficient.

“We have always been very aware of our energy use, so when Adams offered the U-$hift, U-$ave program, it was a no brainer for us,” explains Ted, a retired state worker. “Almost 60% of our high-demand items — an ETS, three water heaters, a hot tub and even our dryer — are on load control. We’re both retired and have a very livable situation with a lower, more stable electric bill.”
 

A SWITCH THAT SAVES: Brian Shearer, senior staff engineer at Gettysburg-based Adams Electric Cooperative, stands beside a water heater equipped with a load control receiver. When members volunteer to have these systems installed in their homes, it helps the cooperative manage purchased power costs and offer stable rates. (Photo courtesy of Adams Electric Cooperative)
 

Keeping up with the times

For decades, energy use across the grid showed distinct peaks and valleys. Today, however, end-use electrification — a term that describes the use of electricity over fossil fuels to power things, such as appliances, tools, and vehicles — is growing. More people are working from home, too. That makes load management trickier.

“That’s one thing that has changed over the past three to five years: The consumers’ energy usage curve is much flatter than before,” says Todd Sallade, PREA/Allegheny vice president – power supply & engineering, “and it makes the load operators’ jobs more challenging when trying to determine a peak.”

To keep pace with the evolving demands on the grid, CLMS is receiving upgrades of its own.

“We are currently in the process of converting to radio frequency (RF), which will replace the original powerline carrier system to activate load controls,” says Chris Weller, load management supervisor for REA Energy Cooperative in Indiana, Pa. “The RF will allow two-way communication, essentially letting load control receivers send data back to the control center.”

Near-real-time data enables cooperatives to find patterns that help to better predict loads, allowing for tighter control periods and more precise measurement of a control period’s effectiveness, says Phil Stern, manager of technical services at Somerset Rural Electric Cooperative. Incidentally, two-way communication helps cooperatives manage outages more efficiently simply by seeing where electricity is and isn’t being used.

As the CLMS program nears its 40th anniversary, Tony Vincik, PREA/Allegheny manager, energy management systems, is imagining new opportunities to help cooperatives control load.

“In 2023, there were approximately 20,000 internet-connected thermostats in co-op territory,” says Vincik, who joined PREA/Allegheny in 2008 and will be retiring soon. “Can we find a way to control those without inconveniencing our members? Can we discharge batteries on peak and charge at night? Would members allow devices to limit electric vehicle charging until nighttime?

“There’s a lot of possibilities out there,” he adds, “we just have to be willing to try it and see if it will work.”

Taking the reins from Vincik is CLMS Supervisor Brian Smith, who joined the cooperative family in 2020. When Smith first came on board, his task was “simple,” he says: Don’t miss a peak — although that’s not always easy.

“We enter control periods according to the available, real-time load data provided by PJM, but we work with our members to tailor our operations to meet their needs,” Smith says. “We provide all the facts of the load as it stands, give them an estimated start and stop time, and let them make the decision as to when and how they control.”