Transmission and Renewable Resource Needs in Northern California

The multi-agency Renewable Energy Transmission Initiative (RETI) 2.0 began in September 2015 with two objectives. First, to address Governor Brown’s call for California to reduce its greenhouse gas emissions 40 percent below 1990 levels by the year 2030. Second, to help the state comply with Senate Bill 350, which requires 50 percent of the energy sold in the state be generated by “qualified” renewable resources by 2030.

RETI 2.0 included a high-level, non-regulatory review of renewable energy potential in California and the west. It also developed an overview of the potential transmission needs, as well as environmental and land use issues that must be addressed in order to meet California’s policy objectives. A draft RETI 2.0 Plenary Report, intended to frame and inform future transmission planning proceedings, was issued December 16, 2016. A final RETI 2.0 Plenary Report was issued on February 23, 2017. Among the challenges facing California is that the evolving California electricity marketplace is seeing an increase in congestion on key transmission pathways. In northern California, RETI 2.0 results confirm that congestion on the California-Oregon Intertie (COI) is a limiting factor to interconnecting more energy resources, especially renewables. The California-Oregon Transmission Project (COTP) and two other 500-kV facilities comprise the COI, which connects the electric grids of Oregon and California.

The Transmission Agency of Northern California (TANC), is the project manager of the COTP and an active participant in the RETI 2.0 process. TANC’s position is that maximizing access to renewable and low or carbon-free resources in the Pacific Northwest is integral to meeting the state’s future power needs. Furthermore, in considering options for California to meet its energy policy goals, the location and utilization of existing transmission lines and corridors should be given priority.

RETI 2.0 divided the state into Transmission Assessment Focus Areas (TAFAs) to consider both renewable development areas and transmission needs. What’s clear is that geographic resource diversification is vital—simply locating the majority of the renewable resources in the southern California will not be a sustainable solution to helping California reach its policy mandates. In fact, RETI 2.0 concluded that the desert region is likely to emerge as a serious impediment to meeting California’s goals because the area would require more than 100 miles of new transmission infrastructure to interconnect more energy