The Western Electricity Coordinating Council is seeking comments on a draft report on long-term transmission planning.
The draft report summarizes a technical workshop hosted by the Western Electricity Coordinating Council’s Reliability Assessments Committee on Oct. 6, 2022, in response to the Federal Energy Regulatory Commission’s Notice of Proposed Rulemaking on transmission planning, Building for the Future Through Electric Regional Transmission Planning and Cost Allocation and Generator Interconnection (RM21-17-000).
The Western Electricity Coordinating Council is accepting comments on its report through a website link until April 7.
The Federal Energy Regulatory Commission’s Notice of Proposed Rulemaking proposes to reform both the pro forma Open Access Transmission Tariff and the pro forma Large Generator Interconnection Agreement to remedy deficiencies in the Federal Energy Regulatory Commission’s existing regional transmission planning and cost allocation requirements.
Among other things, the Notice of Proposed Rulemaking proposes to require public utility transmission providers to conduct long-term transmission planning with a horizon of 20 years or more, rather than the more commonly used 10-year planning horizon.
Long-term transmission planning is not occurring regularly or consistently in most regions, depriving customers the benefits of enhanced reliability and access to lower cost and diverse resources, the Federal Energy Regulatory Commission said in its Notice of Proposed Rulemaking.
In addition, transmission needs are being met outside the regional process and, for the most part, being met piecemeal in response to generator interconnection requests, leading to siloed transmission planning and resulting in increased interconnection costs that are becoming a higher percentage of the overall generation project costs, the Federal Energy Regulatory Commission said in its Notice of Proposed Rulemaking.
No projects have been selected in non-Regional Transmission Organization or Independent System Operator regions under the regional transmission planning regime since Oder 1000 was issued by the Federal Energy Regulatory Commission in July 2011, the agency said it its Notice of Proposed Rulemaking. Therefore, the Federal Energy Regulatory Commission said it believe reforms are needed.
Among the discussion topics in the Western Electricity Coordinating Council’s draft report is the uncertainty of load demand forecasts and how loads are going to be changing with the push toward decarbonization across all sectors of the economy at federal, state, and local levels. Those changes are likely to have an effect both on peak demand and on demand profiles, the Western Electricity Coordinating Council said, adding that for a highly decarbonized future, performing studies at an interconnection level might be more meaningful compared with the local level, due to uncertainty with the load forecasts at the local level.
In addition, the effects of policies at the distribution and sub-transmission level for a particular area may have a wide-ranging effect across the grid, so the policy impacts must be studied at a broader level where regions are evaluating impacts from one part of the grid to another, the Western Electricity Coordinating Council report said.
The Western Electricity Coordinating Council report cited approaches adopted by the Midcontinent Independent System Operator that developed scenarios that represent bookends of uncertainties and perform robustness tests on the planned system to determine how it would respond under various system conditions.
In its draft report, the Western Electricity Coordinating Council also noted another approach to long-term transmission planning is the use of probabilistic transmission planning to determine anticipated loads and resource profiles.
To study system planning under a 20-year time horizon, appropriate load forecasts will need to be developed, including not only the magnitude of demand but the appropriate hourly profiles, as well as the impacts of behind-the-meter generation, the Western Electricity Coordinating Council said in its draft report.
The Western Electricity Coordinating Council draft report also noted that at the interconnection level, “planning entities are mostly interested in getting data from their neighbors or other entities that might have a significant influence on their systems” so it would be beneficial to develop datasets in a coordinated manner across the interconnection.
To illustrate, the Western Electricity Coordinating Council’s different states have different policies concerning Distributed Energy Resources, which would need to be considered in the model for each state. Similarly, the Western Electricity Coordinating Council noted that electrification rates of residential and commercial heating and cooling systems and transportation may be different in different states.
The Western Electricity Coordinating Council draft report also noted the importance of weather and climate data with respect to load forecasts and transmission reliability particularly since some extreme weather events may affect multiple regions simultaneously.
The Western Electricity Coordinating Council said its Reliability Assessments Committee must decide how to proceed on issues such as modeling, datasets, tools, and scenario development. “Development of key datasets will be crucial to moving forward and providing value,” the Western Electricity Coordinating Council said in its draft report. “Challenges with long-term planning are complex, but the complexity of the problem should not keep entities from creating the required datasets.”
The question for the Reliability Assessments Committee to consider, the Western Electricity Coordinating Council said in its draft report is “What are the reasonable set of activities that the [Reliability Assessments Committee] should undertake so that, regardless of which direction the [Federal Energy Regulatory Commission] ruling eventually goes, the outcome of this effort will still be beneficial for a broader set of stakeholders?”