Skip to content
Menu Close

Enhancing Extreme Cold Weather Preparedness and Operations

Insights from the EOP-012-1 Readiness Assessment Project

In May 2024, MRO completed the EOP-012-1 Readiness Assessment project in collaboration with its Compliance Monitoring and Enforcement Program Advisory Council (CMEPAC). The readiness assessment program offers registered entities the opportunity to participate voluntarily in assessments related to new or updated standards before their enforcement date. The focus of this project was Reliability Standard EOP-012-1 – Extreme Cold Weather Preparedness and Operations – Requirement R2. This requirement was selected due to significant risks associated with extreme cold weather, and its implementation plan provided sufficient time for inclusion in this project.

The project aimed to identify best practices and lessons learned, and to foster open communication between entities and MRO. MRO sought participation from Generator Owners (GOs) within the region, commencing the project with an informational webinar in September 2023. Participating GOs provided documentation on cold weather preparedness plans, Corrective Action Plans (CAPs), and other relevant information, which was securely maintained during the project and then deleted.

The information provided was thoroughly reviewed by MRO staff and Subject Matter Expert interviews were conducted to better understand certain aspects of the entities’ operations, such as freeze protection measures and documentation of Generator Cold Weather Critical Components. Key questions centered on operational capabilities at Extreme Cold Weather Temperatures (ECWT), data accuracy and completeness, Generator Cold Weather Critical Components identification, and environmental considerations.

Common Questions Asked by MRO Staff During This Project

1. General Operations and Freeze Protection:

  • How do you determine the operational capability of generating units at the ECWT?
  • How does the ECWT compare to both the designed low and historical low operating temperatures?
  • How frequently do units operate below their minimum design temperature rating, and what precautions are implemented in such cases?
  • What freeze protection measures are necessary to ensure at least one hour of operation at the ECWT, and do you have documented evidence for these measures?
  • Did your assessment identify any generating units requiring new or enhanced freeze protection measures?
  • How do you ensure the adequacy of freeze protection measures for Generator Cold Weather Critical Components, including safeguards against wind and freezing precipitation?

2. Data and Documentation:

  • How do you select and validate the accuracy of National Oceanic and Atmospheric Administration (NOAA) weather stations data for ECWT calculation?
  • What challenges did you encounter in calculating the ECWT?
  • If you are using design temperature, is there documented evidence supporting the minimum design temperature data for your generating units?
  • How do you address and rectify missing data for NOAA weather stations, and is this process documented?

3. Critical Components and Lists:

  • How do you ensure the completeness of your Generator Cold Weather Critical Components list, and how is it utilized?
  • Do you have documented identification of Generator Cold Weather Critical Components for each unit?

4. Environmental and Regulatory Considerations:

  • Are there specific environmental constraints during winter that impact operations?
  • Are triggers for environmental regulations or permit violations documented, and are any automated?

5. Contracts and Compliance:

  • Do you have established fuel contracts for all units, and are any constraints documented?
  • Is there detailed analysis confirming the absence of a need for a CAP for units you’ve declared?

Some Questions Answered by MRO Staff

Note: The focus of this project was on EOP-012-1 R2, but at the time of the one-on-one discussions, MRO staff considered the draft language of EOP-012-2 when answering these questions.

1. Wind Farm ECWT Documentation

  • Question: What should a wind farm do if its calculated ECWT is lower than the Wind Turbines Operating Limitation due to structural integrity issues, with no actionable items to correct this “design” limitation?
  • Answer: Under EOP-012-1 R2, each generating unit must add or modify freeze protection measures to operate for at least one hour at its ECWT. If this isn’t feasible, under EOP-012-1 R7.1, the GO needs a declaration explaining and documenting constraints in a dated document. Also, EOP-012-2 R8 mandates regular review of constraint declarations.

2. Handling Missing NOAA Data

  • Question: How should missing NOAA data be managed? What if the nearest NOAA site lacks data back to January 1, 2000?
  • Answer: GOs should document their methodology for determining ECWT. Document the rationale on a per-unit basis or overall. This could involve aggregating data from multiple weather stations or selecting a comprehensive dataset from a more distant, but representative weather station. Make reasonable efforts to fill gaps, combining data from other stations or alternative sources.

3. Selecting Weather Data Sources Relative to Plant Site and Justifying It

  • Question: How should weather data sources be selected for ECWT calculations relative to the plant site? Also, when using two equidistant NOAA sites for ECWT calculation, must you justify the chosen site?
  • Answer: The standard does not prescribe a specific distance requirement for weather stations used in ECWT calculations near the plant site. GOs should prioritize using reliable data sources close to the plant, such as NOAA weather stations, Federal Aviation Administration (FAA) weather stations, or Environment and Climate Change Canada locations for Canadian entities. GOs should typically choose the closest location, but they may opt for a station farther away if its climatic conditions better represent those at the generating unit. Alternatively, GOs may use on-site weather stations if their data aligns reasonably well with nearby off-site sources dating back to January 1, 2000. In addition, justify site selection for transparency and reliability in your documentation.

4. Using Vendor Data for ECWT Calculation

  • Question: Are specific weather sources recommended for ECWT calculation if using vendor data?
  • Answer: Choose reliable sources near the plant, validating accuracy for compliance and operational reliability. On-site weather stations may be used if their data reasonably matches that of nearby off-site sources dating back to January 1, 2000. It is important to thoroughly document your process for selecting data sources, as previously discussed. While utilizing vendor data may help address gaps in NOAA data, it is essential to validate its accuracy for each location. We understand this validation effort involves significant work but is necessary to ensure compliance and operational reliability.

5. Blade Icing Event and CAP Requirement

  • Question: Does a wind farm experiencing a blade icing event causing a derate require a CAP?
  • Answer: Yes, under EOP-012-1 R6 if the event qualifies as a Generator Cold Weather Reliability Event, as defined in the NERC Glossary of Terms, the GO is required to develop a CAP.

6. Understanding “Engineering Analysis”

  • Question: What does “engineering analysis” entail?
  • Answer: Provide a detailed listing of components and their temperature limitations, along with assessment evidence.

7. Determining Operational Capabilities

  • Question: How do we determine operational capabilities if our units haven’t operated below the design temperature or ECWT?
  • Answer: In such cases, assess the minimum temperature values using either the design temperature or conduct an engineering analysis.

8. Defining Cold Weather Critical Components

  • Question: We are defining cold weather critical components at the system level (e.g., water, fuel oil). Is this approach acceptable?
  • Answer: The term “Generator Cold Weather Critical Component” refers to any component or associated fixed fuel supply component under the GO’s control, that is prone to freezing as such could cause a Generator Cold Weather Reliability Event. Components within heated permanent buildings are exempt from this definition. It is crucial to prioritize identifying specific components susceptible to freezing and critical to the operation of generating units. Therefore, focusing on identifying individual critical components rather than grouping them under broader systems (e.g., fuel oil system including filters, pumps, motors, and tanks) is essential for compliance.

9. Definition of “Exposed” Components

  • Question: What qualifies as “exposed” for components?
  • Answer: Any component located outside of a heated, permanent building is considered exposed.

10. Actuator Insulation and Heat Tracing

  • Question: If an actuator that is located outside and has insulation and heat tracing, is it still considered exposed?
  • Answer: Yes.

11. Recalculation of ECWT

  • Question: Must units recalculate its ECWT, and how often?
  • Answer: Yes, per EOP-012-2 R1.1 as well as EOP-012-1 R4.1, every five years.

Recommendations from MRO Staff

  1. Evidence-Based Conclusions: Maintain documented evidence supporting conclusions.
  2. Temperature Value Selection: Establish a method for selecting minimum temperature values derived from historical, design, or engineering analyses.
  3. Winterization Start and End Dates: Define the beginning of the winter season as the NOAA’s first freeze date at each plant location. Resumption of summer operations should align with the NOAA’s last freeze date.
  4. ECWT Calculation Methodology: Document the process for calculating ECWT, specifying data sources, sanitization protocols, and methods for handling missing data.
  5. Weather Station Selection Rationale: Justify the selection of weather stations used for ECWT calculations.
  6. Internal Controls for Preparedness: Implement comprehensive internal controls tailored to cold weather preparedness, covering detective, corrective, and preventative measures.

General Observations by MRO Staff

  1. Data Integrity Issues: Identified data gaps, quality issues, and incomplete records during ECWT calculations. Some ECWT data contained multiple temperatures for a range of hours and a single temperature for other hours within the same data set.
  2. Weather Station Selection: Most GOs opted for the nearest NOAA weather station to each generating plant. Where these stations lacked complete temperature records from January 1, 2000, GOs selected secondary stations that best reflected local weather conditions. Many GOs combined data from multiple stations to cover the required timeframe.
  3. Critical Component Documentation: Some reviewed Generator Cold Weather Critical Component lists revealed instances where equipment lacked documented locations and minimum operating temperatures.
  4. CAP Declarations: Some reviewed declarations lacked sufficient detail and must include dated documentation supporting the identified constraints.

Positive Observations by MRO Staff

  1. Proactive Measures: Some GOs have documented proactive measures in response to temperature forecasts indicating ambient temperatures will fall below predetermined thresholds for each unit.
  2. Temperature Management: Some GOs have demonstrated careful consideration in utilizing historical data to determine the lowest temperatures at which their units started up versus using operational lows during cold conditions.
  3. Effective Tools: The use of heat trace checklists and winterization heater lists has proven effective, providing comprehensive details and critical information necessary for winterization.
  4. Collaborative Efforts: Involving plant managers, foremen, entity compliance staff, and other personnel in developing cold weather preparedness documentation ensures practicality and utility in compliance efforts and daily operations.
  5. Commitment to Improvement: There is a notable commitment among entities to continuously improve their processes aimed at mitigating the impacts of operating in extreme cold weather conditions.

Areas for Further Clarification GOs want from the ERO

  1. Environmental Constraints Definition: Seek clearer definition of it.
  2. Weather Data Challenges: Address issues with obtaining accurate weather data and data validation.
  3. Gap-Filling Methods: Explore methods for using alternative data sources and statistical validation to address missing data.

Conclusion and Future Outlook

The EOP-012-1 Readiness Assessment project underscores MRO’s proactive engagement with stakeholders in anticipation of regulatory changes. This initiative has allowed GOs to enhance their cold weather preparedness strategies and gain valuable insights for future compliance under EOP-012-2. For MRO, the project has facilitated early identification of implementation challenges and gaps, thereby bolstering our preparedness. Participating entities have benefitted by aligning their operational practices with forthcoming standards, thereby promoting enhanced reliability and operational resilience.

Looking ahead, the recent approval of Reliability Standard EOP-012-2 by FERC, along with forthcoming modifications, sets the stage for continued adaptation and improvement in industry practices. This evolution will be further explored at the 2024 CMEP Conference hosted by MRO’s CMEPAC on July 24, 2024, where insights from the project will be presented.

Stakeholders are encouraged to register for this hybrid event before July 23, 2024.

Additionally, anticipate the release of questions and answers from the one-on-one sessions hosted by the ERO Enterprise during the “Cold Weather Preparedness Small Group Advisory Sessions General Session” project. NERC will soon post frequently asked questions and compliance monitoring approaches related to EOP-012-2, EOP-011-4, and TOP-002-5 as a result of this project.

Continued engagement and knowledge sharing will be essential as entities prepare for the implementation of EOP-012-2 and beyond. MRO remains committed to facilitating this dialogue, fostering compliance readiness, and ensuring operational resilience in the face of evolving risks.

For any inquiries, please contact [email protected].

– Sam Zewdie, MRO Principal Compliance Engineer

Print Page