NERC is launching a new product called Reliability Vignettes, which are intended to capture current operating incidents of interest and project the circumstances of the incidents into the future as think pieces for system planning and operating considerations. NERC will publish Reliability Vignettes on an occasional basis as interesting system occurrences are identified.
The first Reliability Vignette — Future Wind Planning Informed by Current Operating Experience — uses the real-world operating experiences of two Balancing Authorities in a high-wind event as the basis for consideration of a future system that is wind- and solar-generation dominant. This document’s objective is to provide future resource planning considerations for registered entities to ponder, consider and/or implement as they design future operations of their system assets. Operating scenarios for the vignettes are summarized in an unattributable manner and shared with the industry, policymakers and interested parties.
Here is an excerpt from the first Reliability Vignette:
"Power systems with large amounts of wind resources are being faced with operational challenges when high winds force wind generation off-line. This operating incident revealed successful transmission operations and identified resource balancing needs that should be considered in the future planning of high-wind generation systems.
Future Resource Planning Considerations
As the BPS progresses to a carbon free/reduced carbon generation model, wind generation will likely produce a greater percentage of the total energy output at any given time. High-wind scenarios like what is described in this document could result in higher generation losses. Consequently, more extensive/comprehensive planning and operating prowess to manage the increased amount of generation loss is required. Additionally, there will be less dispatchable/flexible generation available in this type of scenario. These conditions elicit the following thoughts/considerations:
- Adequate transmission and dispatchable/flexible generation resources are needed to support operator flexibility as the amount of variable resources increase.
- Natural-gas-fired generation is the current and near-future primary balancing resource, and ensuring a reliable and flexible natural gas delivery and transportation system is imperative.
- Batteries are expected to become the new dispatchable resource of the future. Adequate amounts of battery energy storage systems will assist operators in managing the system during these types of incidents.
- An alternative option to batteries for managing these scenarios could be geographically dispersed generation reserves with appropriate transmission facilities. This would enable generation not impacted by a high wind event to be dispatched to the area experiencing losses.
- Probabilistic composite planning methods for generation and transmission loss will need to be incorporated to properly plan for generation reserve amounts and locations to accommodate these types of losses on the future grid. However, it must be recognized that “capacity-equivalent” forecast values of variable generation are only a forecast, and the impact of forecast error is magnified as variable generation increases.
- Generation forecasting will also be critical in future operating scenarios because accurately predicting the amount and the area of generation loss will be a necessity for operators to manage the system during these events.
- As this incident demonstrates, maintaining continuous forecasting updates provides more precise information improving operator preparation time prior to a potential storm/high wind incident."
Reliability Vignettes will be available on the Event Analysis, Reliability Assessment, and Performance Analysis page of NERC’s website.
