WECC has released the Long-Duration Energy Storage assessment which examined how—with 12-hour duration energy storage—an 80–90% clean energy future with high electrification load can be achieved and what effect this might have on the reliability of the BPS.

Anchor Data Set

Impact of High Distributed Energy Sources (DERs). The assessment identifies potential reliability risks associated with a high penetration of distributed energy resources in the Western Interconnection. As DERs become more widely used across the interconnection, they begin displacing other generation sources. This change in the makeup of the resources at the distribution level could lead to system impacts at the grid level if not adequately studied and assessed during system planning.

The Western Interconnection’s bulk power system (BPS) has experienced challenges due to extreme weather events becoming more frequent and intense. Furthermore, the changing resource mix with higher renewable penetration adds more variability to the system. Climate change has emphasized the need to study extreme events, which can co-occur like extreme heat and wildfires, causing widespread impacts on the BPS.

The study shows that unforeseen changes in system load caused by sudden changes in temperature and unpredictable generation output from high variability resources could create significant reliability challenges. The study also examines how storage technologies may help mitigate those challenges.

WECC’s Planning Department, in conjunction with the Studies Subcommittee, has completed the second of five WECC-wide studies to analyze potential reliability risks. The second study, 2040 Clean Energy Scenarios, asked “What are the implications of approaching a near-100% clean energy portfolio in the Western Interconnection by 2040?”

WECC’s Planning Department, in conjunction with the Studies Subcommittee, has completed the first of five Western Interconnection-wide studies to analyze potential reliability risks. The first study, Changes in System Inertia, investigated two questions:

• What is the potential minimum amount of inertia needed to prevent a large generation outage from causing underfrequency load shedding?

• What other reliability issues could occur with low system inertia?