The Pacific Northwest’s power supply is expected to be adequate through 2020. However, with the planned retirements of four Northwest coal plants by July of 2022, the system will no longer meet the Council’s adequacy standard and will have to acquire nearly 1,400 megawatts of new capacity in order to maintain that standard.
The Boardman and Centralia 1 coal plants (1,330 megawatts of nameplate capacity) are scheduled to be retired by December of 2020. With these retirements, the regional power supply’s LOLP rises from just under 5 percent in 2020 to 10 percent in 2021. In this scenario, the region will have to acquire a little more than 1,000 megawatts of new capacity to maintain adequacy. This capacity shortfall should be made up with most cost effective and implementable resources, which may include additional energy efficiency, demand response programs and new generating resources. The Council’s power plan can provide very useful information toward developing the most cost effective mix of replacement resources.
The Colstrip 1 and 2 coal plants (307 megawatts of regionally committed nameplate capacity) are to be retired no later than July of 2022. However, should they be retired earlier – say at the same time at the Boardman and Centralia plants – the resulting LOLP for 2021 grows from 10 percent to 13 percent. In this scenario, the region would have to acquire almost 1,400 megawatts of new capacity to maintain adequacy.
The amount of replacement capacity will grow, however, if load growth rises more rapidly than expected or if the out-of-region market supply decreases. In a high load growth scenario, for example, the required amount of new capacity needed to maintain adequacy would double.
These results are not surprising and, in fact, Northwest utilities have already begun to develop replacement resource strategies. Currently about 550 megawatts of new generating capacity is planned for development by 2021. The Council will reassess the adequacy of the regional supply next year, which undoubtedly will include additional planned resources.