The amount of solar photovoltaic (PV) generation added to electric utility grids in the Southwest has been growing and is expected to be robust. Until recently, renewable generation has not significantly altered the operation of, or required major expansion to, the electric grid. However, there is increasing concern that the variable power produced by large-scale PV generation will strain the ability of the current grid to deliver the power reliably.
The territory served by NV Energy’s southern Nevada system is well suited for large-scale PV systems. Due to the large number of pending interconnection requests, the Company in early 2010 submitted an application to the Public Utilities Commission of Nevada (PUCN) requesting approval for funding to evaluate the impacts of PV. The PUCN issued a Compliance Order approving a study of large-scale PV, and subsequently approved a second study to determine how much distributed PV generation (DG) could be installed on NV Energy’s existing distribution system (December 2010 DG Study). The PUCN accepted the EG study’s findings that NV Energy’s distribution system alone is not a limiting factor for new DG capacity, and agreed with the Company’s recommendation that DV should be evaluated as part of the large-scale PV Study.
This study quantifies the impact of variable PV generation output on NV Energy’s system operations, including balancing reserve requirements, and the ability of the existing generation fleet to accommodate increasing amounts of large-scale PV and DG. Because the level of detail in this study exceeds that in earlier industry studies, new and innovative methods were developed to estimate PV output and to perform the technical and economic evaluation.