Report Says Western Grid Can Weather Disturbances Under High Renewable Penetrations

Dec. 22, 2014

A new report finds that with good system planning, sound engineering practices, and commercially available technologies, the Western Interconnection can withstand the crucial first minute after grid disturbances with high penetrations of wind and solar on the grid.

The report by NREL and General Electric Energy Consulting is titled The Western Wind and Solar Integration Study Phase 3 (WWSIS-3) - Frequency Response and Transient Stability.  

The report covers the third phase of the Western Wind and Solar Integration Study, one of the largest regional solar and wind integration studies to date, which explores whether large amounts of wind and solar energy can be integrated into the Western electric power system. The first phase examined the operational impact of up to 35% penetration of wind, photovoltaic (PV), and concentrating solar power (CSP) energy on the electric power system. The goal was to understand the effects of and investigate mitigation options for the variability and uncertainty of wind and solar. The study found that these levels of wind and solar could be integrated if certain operational changes could be made, such as intra-hour scheduling and balancing area coordination. Phase 2 of the study examined the impacts of fossil-fueled cycling on emissions and wear-and-tear costs. It found that cycling did not significantly reduce the emissions benefits or avoided fuel savings that come from wind and solar. Phase 3 of the study focused on reliability and stability.

Large-scale transient stability and frequency response are critical to grid reliability, particularly for the Western Interconnection, which has a long history of dynamic performance constraints on its operation. The new report specifically addresses the dynamic performance of the Western Interconnection with high penetrations of renewable energy.

Read the executive summary and full report.

—Kelly Yaker