The Pacific Northwest’s power supply is expected to be close to adequate through 2019. The Council estimates that the likelihood of a power supply shortage (more commonly referred to as the loss of load probability or LOLP) in that year is 6 percent, slightly higher than the 5 percent maximum standard adopted by the Council in 2011. By 2021, however, after the planned retirements of the Boardman and Centralia-1 coal plants (1,300 megawatt combined capacity), the LOLP rises to about 11 percent.
The Council’s adequacy assessment only counts existing resources and planned resources that are already sited and licensed for operation in the year assessed. There are other planned resources that appear in utility long-term strategies that are not counted because they do not meet this criterion. It should also be noted that this is a regional assessment and does not reflect the constraints and special needs of individual utilities. Each utility must make its own assessment of adequacy.
Between 2017 and 2019, regional demand, net of targeted energy efficiency savings, is expected to grow annually by about 130 average megawatts (0.6 percent per year). Energy efficiency savings assumed for this analysis are the 350 average megawatts per year from the Council’s Sixth Power Plan. Achieving these savings is critical to adequacy. For example, if the region were to only acquire half of the targeted savings, the 2019 LOLP would grow to over 7 percent. Having a better understanding of the hourly shape of efficiency savings would also improve the accuracy of our assessments.
Since the last adequacy assessment (7 percent LOLP for 2017 released in December 2012), Portland General Electric has proceeded with plans to acquire 667 megawatts of new dispatchable generation. An additional 267 megawatts of new wind nameplate capacity is also expected. The gains in new generation are somewhat offset by reduced capability of standby resources: demand-side actions and emergency resources used only during shortages. The assumption about the availability of winter peak-hour imports from California was also increased from 1,700 to 2,500 megawatts based on an analysis of California loads and resources for 2019.
Actions to bring the 2019 and 2021 power supplies into compliance with the Council’s standard may include various types of new generating resources or demand reduction programs. For example, adding 400 megawatts of dispatchable generation by 2019 would bring the LOLP back to 5 percent. Alternatively, lowering the 2019 annual load by about 300 average megawatts (via additional energy efficiency savings) would do the same. Looking ahead to 2021, Portland General Electric is expected to define a Boardman replacement strategy in its next integrated resource plan, and other Northwest utilities show a combined 1,800 megawatts of planned new generation over the next 10 years that is not included in this assessment.
