By: Ramsey Ayass, Director, Energy Resources – West/Central

The Western Interconnection, a vast geographic area encompassing several American states and Canadian provinces, plays a crucial role in ensuring a reliable Bulk Electric System (BES). At the heart of this network is the Western Electricity Coordinating Council (WECC), a non-profit corporation approved by the Federal Energy Regulatory Commission (FERC) as the Regional Entity for the Western Interconnection. In this blog post, we explore case studies in the Western Interconnection, as well as services available in the region.

Case Study: Feasibility Study for Offshore Wind in CAISO 

The Bureau of Ocean Energy Management (BOEM), which is tasked with regulating offshore energy development, designated the Humboldt Call Area as a Wind Energy Area (WEA) in 2018. This WEA begins 21 miles offshore of the city of Eureka in northern California and is approximately 132,369 acres in size. For this project, EPE identified the best options for interconnection and evaluated proposed projects by the California Independent System Operator (CAISO), California Public Utilities Commission (CPUC) and Pacific Gas & Electric (PG&E).

Option 1

Option 2

Option 3

Option 4 involved an HVDC route to another Point of Interconnection (POI) south of Humboldt.

EPE performed a feasibility study, which included creating a project schedule, a cost estimate, and a timeline, in order for the project to be able to enter Queue Cluster 15. EPE also ​determined potential interconnection facilities and network upgrades, including Reliability Network Upgrades (RNUs) and Deliverability Network Upgrades (DNUs).

Case Study: Morro Bay Wind Energy Area

In 2021, BOEM announced a second WEA, the Morro Bay Wind Energy Area. The Morro Bay WEA comprises approximately 376 square miles off California’s central coast and has the potential to generate enough energy to supply more than 1,000,000 homes.

For this project, EPE examined interconnection at various POIs along the Central California coast, compared high voltage direct current (HVDC) vs. high voltage alternating current (HVAC) generator tie line (gen tie) options, and performed a feasibility study with various alternatives. EPE also assisted with the submission of several offshore and onshore interconnection requests during the CAISO Cluster 15 window in April 2023. EPE produced a project schedule for each submission, including estimated posting amounts and an interconnection timeline.

Unlocking the Future: RNUs, DNUs, IFs, MCR and MCE

As projects in the Western Interconnection grow, EPE has supported clients in the WECC regions within CAISO by walking them through each type of network upgrade. We explained how the upgrades are determined, how they will impact the project, as well as the cost allocation and “reimbursability” of each upgrade. A description of each network upgrade is provided below:

  • Interconnection Reliability Network Upgrades (IRNU) are RNUs at the Point of Interconnection to accomplish the physical interconnection of the Generating Facility to the CAISO Controlled Grid.
  • General Reliability Network Upgrades (GRNU) include all RNUs that are not IRNUs.
  • Local Delivery Network Upgrades (LDNU) are transmission upgrades or additions that are identified by the CAISO in the GIDAP interconnection study process in order to relieve a Local Reliability Constraint.
  • Area Delivery Network Upgrade (ADNU) are network upgrades that increase Transmission Plan Deliverability in order to relieve an Area Deliverability Constraint.
Power Engineering, Regulatory Compliance and Energy Consulting in the WECC Region

Services offered by Electric Power Engineers within the WECC region include, but are not limited to:

  • Full transmission and area-wide analyses
  • Generation interconnection requests
  • General consulting and interconnection support
  • Owner’s Engineer services
  • Feasibility studies
  • Energy Market Analysis
  • NERC compliance services
  • CAISO deliverability studies
  • CAISO NRI Process support
  • Load interconnections and modeling
  • Distributed generation services.

For more information on EPE’s services, or for help navigating the WECC region, please contact us to schedule a consultation.