Gas Turbine Units

Construction

Sunflower constructed the S4 gas turbine unit in 1976 and the S5 gas turbine unit in 1979. The total cost of construction for each unit was approximately $2 million.

Operation

The S4 and S5  units are gas-fired turbine generators each capable of outputting 55 megawatts. The units operate much as a typical jet aircraft engine. Natural gas is injected at high-pressure into the combustion cylinders where it is ignited causing the shaft to spin. The shaft is connected to a General Electric turbine generator that produces the electric power. Sunflower’s transmission network carries the electricity to its member cooperatives and to non-member power customers. Sunflower uses these plants for peak generation needs.

Black Start

In the event of a total blackout of the electric grid and the tripping of all generation sources, electricity will be needed to re-fire the generating plants across the region. Towards this end, Sunflower constructed their S3 gas turbine generator in 1973. This unit operates as all other gas turbine generators except it is totally self-contained and can start itself under such circumstances.

The generator's 14 megawatt capacity will be used as the electromotive power required to start the S4 and S5 gas turbines. These units in turn will be used to re-fire Holcomb Station and all other generators in the area.