also see Dec 4, 2012 press release
In 2010, as a part of its Sixth Power Plan, the Council reported that the region’s power supply was on the cusp of becoming inadequate by 2015. Based on an assessment prepared by the Resource Adequacy Forum, the plan noted that relying only on existing resources and targeted energy efficiency savings would result in a 5 percent likelihood of a shortfall, which is right at the limit the Council adopted in 2008. This result is consistent with the plan’s finding that energy efficiency could meet most but not all forecasted load growth.
In this updated assessment, the forum concludes that the likelihood of a shortfall in 2017 has increased to 6.6 percent. This means that the region will have to acquire additional resources in order to maintain an adequate power supply, a finding that supports acquisition actions currently being taken by regional utilities.
Between 2015 and 2017, regional electricity demands, net of planned energy efficiency savings, are expected to grow by about 300 average megawatts. Since the last assessment, 114 megawatts of new thermal capacity, about 1,200 megawatts of new wind capacity and about 250 megawatts of small hydro and hydro upgrades have been added to the analysis. Also, a Northwest utility has contracted to purchase 380 megawatts of capacity from an independent power producer, which shifts this in-region generation from the market supply to firm resource status. Meanwhile, availability of the winter California market is assumed to decrease from 3,200 to 1,700 megawatts, mainly due to the retirement of coastal water-cooled thermal power plants.
The majority of potential future problems are short-term capacity shortfalls. The most critical months are January and February and, to a lesser extent, August. This is a different result from the 2015 assessment, which indicated that August was the most critical month. The major reason for this shift is the use of an updated streamflow record, which contains 10 more years of historical flows, new irrigation withdrawal amounts and various updates to reservoir operations both in the U.S. and Canada. The net result yields a higher average streamflow in August, thus improving summer adequacy.
The forum analyzed two different approaches to lowering the likelihood of a shortfall in 2017 back down to the 5 percent limit. Results show that adding 350 megawatts of additional dispatchable generation capacity or lowering the 2017 annual load by 300 average megawatts would bring the likelihood of a shortfall back down to the 5 percent limit. Demand response may also be a viable option but was not analyzed.
It should be noted that this assessment is not a substitute for a comprehensive resource acquisition plan. The optimal amount and mix of new resources needed to provide an adequate, efficient, economic and reliable regional power system is determined by the Council’s power plan. This assessment also does not fully reflect constraints and needs of individual utilities within the region. Thus, these results should be viewed as a conservatively lower bound on regional needs for new resource capacity.
