Electric Cooperatives place a high value on load management to reduce purchased power costs for their membership. Since most co-ops purchase power from Generation & Transmission Cooperatives or Investor-owned power plants, there is a big incentive to control peak demand each month.

While many utilities have relied on controlling heavy appliances as the primary method for short-term load reduction, Central Georgia EMC (CGEMC) is casting a wider net to ensure they reliably and cost effectively hit their peak management goals.

“We take a very targeted approach to when and how we reduce system load, and we use the methods necessary to hit our peak-shaving goals,” said Chris Mitchell, Director of Field Services at CGEMC. 

Mitchell, along with Landis+Gyr Solutions Director Chris Patton, shared some of these strategies in a presentation with attendees of NRECA’s TechAdvantage conference in Nashville, TN. 

CGEMC is located in Jackson, GA, and serves a 14-county service territory that includes agricultural and commercial customer loads. However, it’s located in a growth corridor 50 miles south of Atlanta which means suburban development is also spurring load growth and driving planning for future demand management. 

One of the reasons for their success to date is CGEMC’s practice of controlling appliance loads only when necessary. This means customers who receive a bill credit to participate in load management rarely drop out, since appliances such as air conditioners and water heaters are only controlled a handful of times per year.

However, with added residential growth and changing load patterns due to shifting weather patterns, the utility is experiencing a shift from summer peaking to winter peaking. Responding to changes such as this requires rethinking which loads to target as many of their traditional DR programs were not usable in winter months. As Mitchell pointed out, “We’re not going to mess with a member’s hot water on a cold winter day.”

The utility has implemented a broad range of demand reduction options, but is also preparing to test new strategies, such as a residential generator program and EV charger management. Currently, it has tested submetering EV chargers that serve utility fleet vehicles and have successfully disconnected the chargers during peak events. 

In addition to traditional HVAC and water heater control programs, the utility has been using their Gridstream AMI network from Landis+Gyr to support a dynamic voltage reduction program. Using voltage studies at the feeder and circuit level, combined with near real time voltage reads from bellwether meters, the utility is able to confirm available headroom to reduce voltage from controlled regulators at the substation during peak events. It is currently exploring ways to get further savings using voltage reduction.

Irrigation load control presents another opportunity for the utility and is typically an easy sell to farmers as a way to reduce their operational costs.

Finally, the utility offers real-time pricing (which reflects the rising cost per kWh during peak) to in many cases drive dramatic peak-time reductions as commercial customers will go on generator or other power sources during the highest cost periods.

In the future, CGEMC intends to continue taping into grid edge data to uncover new and better demand management strategies. DERMS might also play an increased role in better integration of distributed resources such as residential and commercial solar, battery storage, and generators. Of course, reducing power costs is not the only benefit of improving demand flexibility. As higher demand puts pressure on generation resources, it also strains distribution infrastrucutre. Deferral of new “wires” projects at a time of equipment supply shortages is a sizable bonus.

“Working closely with our technology partners, such as Landis+Gyr, is crucial for our planning process,” said Mitchell. “We put a lot into demand flexibility because it’s a proven way to reduce operational costs while still providing reliable service for our members.”