As more intermittent renewable generation is added to utility portfolios, traditional baseload power plants have been adopting more flexible operations to balance out the variable generation of renewables. Generation that was previously considered base load has to adjust power output as needed to make up for shortfalls (as renewables go off-line) and surpluses on an hourly basis. The plants required to operate flexibly incur a real—yet difficult to quantify—cost of cycling, including efficiency losses, increased component damage, and reduced component life. These factors are important to understand for O&M planners tasked with developing efficient and reasonable future budget estimates, as the capital-intensive nature of the industry requires accurate long-term forecasts.
The key result of this report is a parametric study of the relative damage incurred through cycling a representative plant, derived from a proprietary modeling tool informed by review and meta-analysis of long-term economic forecasts and public plant operations data to determine inputs. Using this model, a framework was generated to place boundaries around the extent of those factors and how they might change in the coming years. From this, a series of potential scenarios for a hypothetical representative power plant was built and evaluation performed to generate estimates of component damage for the unit. These results show how different situations change the expected cycling damage and how this impacts the variable O&M costs associated with increased flexibility. This information can be applied to sites in the EPRI-member fleet as a starting point for making long-term plans including the expected degree of O&M budget growth due to the factors identified.