VALUE ANALYSIS OF INTERMITTENT GENERATION SOURCES FROM THE SYSTEM OPERATIONS PERSPECTIVE

The objective of this study is to determine the economic and operational impact on energy cost of incorporating large photovoltaic (PV) and wind energy conversion systems (WECS) into the electric utility generation mix. In most cases, PV and WECS power outputs are subtracted from the utility load with the expectation that conventional generation would meet the residual load. This approach is valid for small penetration levels and/or for PV and WECS facilities connected near load centers. However, several constraints such as thermal generation characteristics, fuel supply and delivery, spinning reserve requirements, and hydro availability are not adequately represented in this process. To determine the optimal value of large-scale PV and WECS applications, a new methodology that would take into account the forth-mentioned constraints as well as a more global penetration is being developed. The proposed methodology also handles constrained combustion turbines and hydro power plant generation. While PV systems are considered as a prototype to test the methodology, WECS and other renewable energy sources can be handled similarly. Performance analysis shows that hydro availability, generation mix and characteristics, spinning reserve requirements, maintenance schedule, PV power output dynamics, and load variations influence the economic and operational value of large-scale PV generation. Results indicate that while high hydro availability increases PV penetration levels, high ramping rates can also significantly increase penetration levels.