In typical power systems, the base load generation capacity consists of large centralised coal and/or nuclear power plants alongside combined cycle gas turbines (CCGT), with long ramp-up and ramp-down times. The intermediate load is traditionally often handled by combined cycle gas turbines. Reserve and peaking capacity are often based on less efficient smaller generating units which are expensive to operate.
The new Flexicycle™ solution combines the advantages of a flexible simple cycle plant with the superb efficiency of a combined cycle plant, in a unique way. The Flexicycle™ power plants can be optimised for different outputs in the 100 to 500 MW range. The power plant solution is based on gas fired combustion engines and steam turbine combined cycle. Each engine is equipped with waste heat recovery steam generator. The power plant has one common steam turbine with condenser. The power plant cooling is typically arranged so that the combustion engines are cooled with closed loop radiators and the steam cycle with cooling towers.
Flexicycle power plant
500 MW Flexicycle™ power plant based on 24 units of Wärtsilä 18V50SG generating sets and steam turbine combined cycle.
The Flexicycle™ power plant solution’s two in one characteristic makes it a very competitive solution to take care of a grid system’s intermediate load. Depending on the power system’s capacity mix, the Flexicycle™ power plant can also be the best choice for base load generation, thanks to the high combined cycle efficiency.
In the Flexicycle™ concept, the unique dynamic features of combustion engines are maintained as the combined cycle can be shut on and off individually for each generating set. Features like fast synchronisation and ramp times as well as flexibility enabled by multiple independent units, make the power plants outstandingly well suited to support grid systems requiring flexibility due to daily load fluctuations, or having a significant installed base of wind or other non-dispatchable power.