The on-going privatization of electricity generation across the world, competition, and demand by shareholders for higher profits, stricter regulations on environmental impacts and the increasing penetration of non-dispatchable energy have resulted in an increasing need for larger energy generators to operate as non base-load units. As a result, Natural Gas-Fired Combined Cycle (NGCC) Power Plants are increasingly being subjected to load-following and/or cyclic operation. However, cyclic operation introduces new types and higher rates of damage, and hence can result in reduced performance and increased maintenance and repair costs.In this study, the effect of increased plant cycling on plant performance is studied and estimates are provided of the costs and the basic causes of cost impacts through top down statistical analysis so that utilities can better understand the true economic implications of these modes of operation. The study is intended to provide better information for decision-making around dispatching of units and the economics of investing in them with a view to reducing costs through improvements in operating, inspection, and maintenance procedures.
Keywords: Power Plants, NGCC, Thermal, Cycling, Two Shift