PJM system operators took over management of the East Kentucky Power Cooperative system at midnight Saturday, adding almost 3,100 MW of generation and 2,800 miles of transmission to the RTO.

While PJM is a summer-peaking system, EKPC’s demand peaks in the winter. “The diversity of demand between EKPC and other PJM members and the resources they bring will strengthen reliability and have economic benefits not only for EKPC but throughout the region we serve,” said PJM President and CEO Terry Boston.

East Ken­tucky, which joined PJM as an Other Sup­plier in 2005, esti­mates it will save almost $132 mil­lion over the next decade by tak­ing advan­tage of PJM’s economies of scale and gen­er­a­tion diversity.

“Our organizations have put a lot of hard work into this integration,” EKPC CEO Anthony “Tony” Campbell said in a statement. “This move will help EKPC to operate more efficiently and economically.”

The biggest sav­ings will come from reduced reserve require­ments. East Ken­tucky main­tains a 12% reserve mar­gin. By join­ing the summer-peaking PJM, it will be able to reduce its reserve to 2.8%, allow­ing it to sell the dif­fer­ence in the capac­ity market. The inte­gra­tion also will result in more eco­nom­i­cal gen­er­a­tion dis­patch, as the coop replaces its higher cost gen­er­a­tion with cheaper PJM power.

East Ken­tucky said its move was prompted by increas­ing trans­mis­sion con­straints with poten­tial coun­ter­par­ties and fed­eral envi­ron­men­tal reg­u­la­tions, which made it expen­sive to con­tinue oper­at­ing as an inde­pen­dent con­trol area and bal­anc­ing author­ity. The coop has inter­con­nec­tions with TVA, Duke Energy, Amer­i­can Elec­tric Power and Louisville Gas and Elec­tric Co./Kentucky Util­i­ties Co.

EKPC is owned by 16 distribution cooperatives that serve 1.1 million people in 87 counties across Kentucky.