At various times throughout the year--especially during the air conditioning and irrigation months--an above average amount of electricity is used by NPPD customers. To provide the extra electricity needed during this peak usage period, NPPD uses three gas turbine driven "peaking units." The units located in Hallam and Hebron can generate 52,000 kilowatts each and the unit at McCook 51,000 kilowatts of power. All three of the units are capable of firing on distillate oil. One unit is normally fired on natural gas.

When running at full capacity, each unit uses up to 5,000 gallons of oil per hour or 650 thousand cubic feet of gas per hour. The peaking units are started by remote control and can be activated and running at full power in only seven minutes. Although these units only operate a few hours of the year, they are an important part of NPPD's ability to deliver electricity to customers when they need it most.