S2 is a natural gas-fired boiler and steam turbine facility. S2 has a nameplate of 98 megawatts. The unit operates by utilizing pipeline quality natural gas, which is combusted in the furnace. The intense heat released inside the furnace is absorbed by pure water circulating inside steel tubes, a process that converts the water into steam. Steam is directed into the unit’s steam turbine, causing its rotor to spin at high-speed, turning the generator and producing electric power. The unit was built in 1973.
The S4 and S5 units are simple-cycle, gas-fired turbine generators. S4 and S5 each have a nameplate rating of 71 megawatts, and were built in 1976 and 1979. The units operate similar to a typical jet aircraft engine. Natural gas and air are injected at high pressure into the combustion cans where it is ignited, creating high temperature and high-velocity gas, which is blown through the turbine, causing the shaft to spin. The turbine shaft is connected to a generator that produces the electric power.
Sunflower’s transmission network carries electricity produced at the Garden City Complex to the bulk electric system where the power flows to the market. The Garden City facility is used for system peaking and intermediate needs.