RF 2020-2021 Outreach Approach, Lessons Learned, Best Practices & Cold Weather SAR Update - ReliabilityFirst
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RF 2020-2021 Outreach Approach,
Lessons Learned, Best Practices & Cold
Weather SAR Update
RF 2020 Cold Weather Readiness Approach due to COVID-19 As in the past, targeted entities (new generating facilities) and existing facilities that experienced first-time cold weather-related issues, would be requested to complete the RF Plant Winterization Survey. The deadline for these submittals would be extended due to COVID-19. As in the past, targeted entities for existing generating facilities that experienced repeat cold weather-related issues, would be requested to update their previous responses to the RF Plant Winterization Survey. The deadline for these submittals would also be extended due to COVID-19. Onsite site visits would be conducted if permitted by the generating facility or RF per each organization’s COVID-19 guidelines. In lieu of site visits, off-site spot checks would be conducted utilizing RFI’s and WebEx discussions in coordination with the plant staff commitments and availability due to COVID-19 . In lieu of site walk downs to confirm readiness of potential problem areas or mitigation of previous cold weather-related issues, photos would be requested. Videos would also be considered. 2 Forward Together • ReliabilityFirst
RF Evaluation of GADS Data
After evaluation of GADS data based on cold weather-related issues, only four generating facilities
met the RF 500 MW threshold to be considered for a winter readiness activity.
Since the amount of MWHs lost were minimal in all cases including the duration of these derates, it
was determined that no form of follow-up was required at this time.
RF attributed a reduction in the number of facilities and MWHs impacted by cold weather due to a
mild winter which resulted in the following:
• Lower peaks/average loads
• No major winter emergency events
• Few emergency procedures were required
• No gas pipelines issues were encountered
• Minimal generation alerts were issued
• Improved generator performance due to established cold weather preparation practices
Also, there were no new generating facilities registered in RF during 2020.
3 Forward Together • ReliabilityFirst
2020-2021 Winter Forecast (NOAA/Farmer’s Almanac)
It is predicted that recent warming trends will dominate in the eastern and northern parts of the U.S. for the upcoming winter,
with below-normal average temperatures limited to the western portion of the nation. The winter will not be extremely cold;
instead, it will be closer to normal.
On the precipitation side of things, expect “wet” to be a wintertime constant, with rain or average to below-average snowfall to
be the standard throughout most of the country. Specifically, precipitation will be below normal from Delaware into North
Carolina and the southern Appalachians. Snowfall will be greater than normal in the Northeast, Wisconsin, Upper Michigan,
4 and the High Plains; with below normal snowfall in most other areas that receive snow.
Forward Together • ReliabilityFirst
RF Winter Readiness Recommendations (GO/GOP) Begin winter readiness preparations in October to allow ample time to correct any deficiencies. Be aware of your facility’s minimum ambient design or winter operating temperature. Consider MISO or PJM winter guidelines as required or deemed appropriate. Ensure any lessons learned have been included in winter readiness program especially those they may impact the generation fleet or those with similar configurations. Complete training of operations and maintenance staff so they understand their roles and responsibilities regarding winter readiness. Ensure that MISO or PJM are always made aware of any cold weather-related operating limitation and the standby status of the generating facility (prewarming mode, maintaining flow through critical piping systems/equipment, idle and full, or drained). Ensure that all cold weather-related data is provided to MISO or PJM prior to a cold weather event. 5 Forward Together • ReliabilityFirst
ERCOT/TRE Weatherization Workshop
2019-2020:
80 units spot checked (November to February)
Fuel types
• Three coal-fired units
• 71 gas-fired units (conventional and combined cycle)
• 6 gas-fired black start contracted units.
23 units agreed to improve preparations and/or records
management
57 units had no observed deficiencies
6 Forward Together • ReliabilityFirst
ERCOT/TRE Weatherization Workshop
Common freezing causes of transmitter manifolds
and/or sensing lines:
• Tripped heat trace circuit breaker
• Blown fuse in heat trace panel
• Contractor error when terminating heat trace after testing
• Insulating contractor damage to heat trace
• Section of heat trace not functioning
• Incorrect heat trace for application
• Heat trace open-ended and not grounded
• Transmitter cabinet heater not functioning
• Poor or lack of wind break measures
• Transmitter(s) exposed to elements
• Gaps in insulation
7 Forward Together • ReliabilityFirst
ERCOT/TRE Weatherization Workshop
Lesson Learned No. 1 - November 12, 2019
• During cold front, a CT experienced a trip due to transition steam flow showing a
high reading.
• Inspection of the transmitter box showed that the heater and heat trace were not
energized.
‒ I&C technician found that the RTD (resistance temperature detector) that measures
ambient temperature to energize the heat trace circuits had failed. Manufacturer
default for a RTD failure was to de-energize heat trace circuits.
‒ It was also discovered that the transmitter box thermometer was reading 15 degrees
higher than actual enclosure temperature which caused the operator conducting the
rounds to record a false reading.
• Corrective actions:
− RTDs were replaced on all heat trace panels of this type.
− These heat trace panels were re-programed to energize heat trace circuits upon
failure.
− All transmitter box enclosure thermometers were replaced.
− During 2020 spring outage, internal box temperatures were telemetered to GMS for all
critical transmitters for monitoring by control room operators.
− Lesson learned was shared with remainder of company fleet.
8 Forward Together • ReliabilityFirst
ERCOT/TRE Weatherization Workshop
Heat trace panel – resistance temperature detector (RTD) failure
9 Forward Together • ReliabilityFirst
ERCOT/TRE Weatherization Workshop
• Lesson Learned No.2:
‒ Winter readiness plan was in place, but vague in many areas.
• Success of the plan was highly dependent on prior knowledge of the
plant.
• Many critical areas of the facility were not explicitly part of the plan
such as instrument air systems and heat trace circuits.
‒ Winter readiness plan was revised to include:
• Critical heat trace testing and comparison to previous year
• Critical insulation inspection
• Instrument air system readiness testing to ensure adequate dryness
• Minimum staffing requirements for the different phases of the winter weather plan
• Specified the different tasks required for winter preparation for each craft
• Developed a list of the critical areas in the plant that needed to be addressed
based on experience
10 Forward Together • ReliabilityFirstERCOT/TRE Weatherization Workshop
• Best Practices No.1:
‒ Due to freezing issues on the air-operated controller for the Feedwater
Control Valve, a removable insulation blanket was first utilized before
fabricating a temporary metal enclosure around the control valve assembly.
‒ Also to eliminate the possibility of condensation in the instrument air system,
certain PMs associated with the air dryers such as filter replacement,
desiccant replacement and dew point monitor calibration were implemented.
11 Forward Together • ReliabilityFirstERCOT/TRE Weatherization Workshop
• Best Practices No.2 – Enhancement of Heat Trace Circuit
Tracking:
12 Forward Together • ReliabilityFirstERCOT/TRE Weatherization Workshop
• Best Practices No.2 – Enhancement of Heat Trace Circuit
Tracking:
13 Forward Together • ReliabilityFirstERCOT/TRE Weatherization Workshop
• Best Practices No.2 – Enhancement of Heat Trace Circuit
Tracking:
14 Forward Together • ReliabilityFirstERCOT/TRE Weatherization Workshop
• Best Practices No.2 – Enhancement of Heat Trace Circuit
Tracking:
15 Forward Together • ReliabilityFirstERCOT/TRE Weatherization Workshop
• Best Practices No.3 – Inclusion of iMonnit system as a remote
method of monitoring the transmitter boxes.
‒ Benefits of Remote Temperature Monitoring:
• Global vs Individual Alarming
DCS will alarm a Heat Trace Panel; however, this includes several circuits
with several transmitter boxes.
iMonnit allows individual box alarms.
Allows O&M staff to troubleshoot quickly
Temperature sensor alarms allow for prompt maintenance before it becomes a
bigger issue
• Ability to trend temperature data
• Quick dashboard view of the heat trace health
• Additional personnel are not needed for physical box rounds during
cold weather
Physical rounds of transmitter boxes every 2-4 hours (ambient temperature
dependent) no longer needed
Operators print sensor status page every 2 hours when ambient
temperature is below 40 degrees F.
16 Forward Together • ReliabilityFirstERCOT/TRE Weatherization Workshop
Status page includes current box temperature, connectivity, and
battery capacity
Safety
‒ iMonnit System Overview (Equipment)
• Top/Down Equipment description:
Network Requirements
Cellular
Wifi (Mesh system
Ethernet Gateways
Temperature Sensors
AA 3.6v lithium battery
Frequency Hopping Spread
Spectrum (FHSS) 900 MHz
Estimated equipment cost for 320 sensors and 11 gateways was
approximately $62K
17 Forward Together • ReliabilityFirstERCOT/TRE Weatherization Workshop
• Best Practices No.3 – Inclusion of iMonnit system as a remote
method of monitoring the transmitter boxes.
‒ Temperature Sensors
‒ Temperature Trends
18 Forward Together • ReliabilityFirstERCOT/TRE Weatherization Workshop
• Best Practices No.3 – Inclusion of iMonnit system as a remote
method of monitoring the transmitter boxes.
‒ Ethernet Gateways
19 Forward Together • ReliabilityFirstERCOT/TRE Weatherization Workshop
‒ iMonnit System Platform
• Internet
Mesh System
Independent of business network
Setup behind its own firewall
• iMonnit Portal
Web-based Interface
Annual subscription is approximately $600 for up to 500 sensors
Subscription allows facility to poll each sensor every 10 minutes
One-minute polling option is available at extra cost
Interface allows:
User to import maps
Make global or individual changes to sensor settings
Trend sensor data
View battery life and connectivity
Creation of event email notifications
20 Forward Together • ReliabilityFirstCold Weather Preparedness SAR Update
Common themes:
• A continent-wide NERC Cold Weather Standard is not needed.
‒ SAR DT: The new standard will allow different levels of cold weather preparation to be
implemented across the ERO due to varying climates and cold weather conditions. It is
expected that generation located in northern areas of the country will require more extensive
and comprehensive cold weather preparation plans as compared to west coast or
southeastern-based generating units. These geographic differences including various plant
configurations will be taken into consideration. Exempting certain generator types or
geographical locations will also be considered by the SDT.
• Data requirements are already addressed in existing standards such as EOP,
IRO and TOP.
‒ SAR DT: Although these standards are associated with data requests, it is clear that the
reliability impacts of cold weather conditions were:
• Not thoroughly and effectively considered, or
• Insufficient data existed, or
• The data was not effectively utilized
21 Forward Together • ReliabilityFirstCold Weather Preparedness SAR Update (cont’d)
‒ SAR DT: While IRO-010 and TOP-003 broadly cover the data needed to perform "its
operational functions", this SAR is specific to cold weather data needed for TOP, BA, and RC
to perform regional planning and operational analysis. The format of receiving this data is yet
to be determined but would provide a reliability impact assessment specific to cold weather
events. The existing mandated NERC standards would be reviewed by the SDT for any
inclusion of regional specifications of cold weather assessment requirements and revised if
possible to reflect the information needed for regional reliability assessments. Also, the SDT
will consider the work of the Standards Efficiency Review (SER) Phase 2 team to avoid
duplication of efforts.
• Market rules will correct for generator unavailability or under performance.
‒ SAR DT: The market can be a driving force by utilizing incentives and penalties as a means
to ensure market participants are held accountable to their day-ahead commitments, but the
market does not specifically address the roles and responsibilities of those entities involved
with cold weather-related data and plant readiness requirements. Also, market rules,
ISO/RTO policies, interconnection agreements, and PUC rules fall under Item 3 of the three-
pronged approach per Recommendation 1 of the South Central Cold Weather Event report.
22 Forward Together • ReliabilityFirstCold Weather Preparedness SAR Update (cont’d)
‒ One of the Regional Winter Readiness Outreach programs has observed that
market incentives have created both positive and negative effects:
• Positive: To ensure availability and improve performance, entities are incorporating new
technologies to their generating facilities. As an example, due to power block trips and
derates caused by snow and ice accumulation on the combustion turbine inlet filters, a
generator owner replaced the single inlet air filter box configuration with a new tri-inlet
box design which also allowed for the installation of a hot air bleed system utilizing high
temperature air from the combustion turbine to melt snow and ice from the filter medium.
• Negative: Freezing of feedwater and attemperator lines have occurred due to entities
waiting for days during cold weather conditions for the market to schedule their
generation. They took no action to pre-warm, promote flow through or drain the piping,
contact the BA, or self-schedule their facility.
23 Forward Together • ReliabilityFirstCold Weather Preparedness SAR Update (cont’d)
• The need for accurate cold weather temperature design specifications or
historical demonstrated performance and operating limitations during cold
weather
‒ During the 2011 Southwest Cold Weather Event, BAs, RCs and generators often
lacked adequate knowledge of plant temperature design limits, and thus did not
realize the extent to which generation would be lost when temperatures dropped. It
was recommended that the RC/BA have available:
• The design temperatures of all generation resources.
• Take into consideration as an extreme weather event approaches which plants will not be
available based on their design temperature limits.
• Commit, for purposes of serving load and being counted as reserves, only those plants
whose temperature design limits fall within the forecasted temperature range.
24 Forward Together • ReliabilityFirstCold Weather Preparedness SAR Update (cont’d)
‒ As a result of the 2014 Polar Vortex, it was recommended that entities review the winter cold
weather temperature design basis for their generating units to determine if improvements are
needed, while ensuring that the generating unit’s ability to withstand higher temperatures in
the summer is not compromised.
‒ The 2017 South Central Cold Weather Event indicated that the ambient temperature design
rating of a generating unit was an important aspect of preparing for winter weather and
severe cold weather events, because it specified the temperature(s) at which the unit’s full
output can be achieved. It was noted that some entities did not know their units’ ambient
temperature design ratings, or did not incorporate those ratings into their freeze protection
measures.
‒ Since the SAR DT was made aware that certain RTO/ISO winter readiness outreach
programs have determined that plant minimum ambient design temperature may not relevant,
the SAR DT may consider removing the requirement for GOs/GOPs to provide temperature-
related design information or historical cold-weather performance information. It appears that
adequate maintenance of freeze protection could be more important in improving the
reliability of generating units during cold weather.
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