COURT OF APPEALS

EIGHTH DISTRICT OF TEXAS

EL PASO, TEXAS

CITY OF SAN ANTONIO acting by and 

through City Public Service Board a/k/a 

CPS ENERGY,

 Appellant,

v.

PUBLIC UTILITY COMMISSION OF

TEXAS,

 Appellee.

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§

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§

No. 08-14-00199-CV

Appeal from the

261st District Court

 of Travis County, Texas

 (TC# D-1-GV-13-000988)

O P I N I O N

The City of San Antonio, acting by and through City Public Service Board a/k/a CPS 

Energy (CPS Energy), appeals a district court judgment affirming a final order of the Public Utility 

Commission of Texas (PUC), in which the PUC imposed a $25,000 administrative penalty on CPS 

Energy for violating the PUC’s Wholesale Market Oversight Rule (the WMO Rule). CPS Energy 

raises several challenges to the validity of the PUC’s final order, contending, among other things, 

that the PUC misinterpreted the WMO Rule, that its application of the WMO Rule deprived CPS 

Energy of due process, and that the PUC’s final order was not supported by substantial evidence. 

We affirm.

1

 

1 This case was transferred from the Third Court of Appeals in Austin, and we decide it in accordance with the 
2

BACKGROUND

In order to address the dispute over the proper interpretation and application of the WMO 

Rule, it is necessary to understand the nature of the electricity market in Texas. Prior to the 

adoption of Chapter 39 of the Texas Utilities Code, also known as the Public Utility Regulatory 

Act or PURA, the electricity market in Texas essentially operated as a monopoly. TXU 

Generation Co., L.P. v. Pub. Util. Comm'n of Texas, 165 S.W.3d 821, 827 (Tex.App. – Austin 

2005, pet. denied). When it enacted PURA, the Texas Legislature made the determination to 

deregulate the production and sale of electricity for a large portion of the state, but chose not to 

deregulate the “transmission of energy.” TEX. UTIL. CODE ANN. § 39.001 (West 2016). In 

carving out an exception for the transmission of energy, the Legislature recognized that this aspect 

of the electricity industry is unique, and by its nature must be subject to some form of regulation. 

TXU Generation Co., L.P., 165 S.W.3d at 827. In particular, the Legislature recognized that 

because electricity cannot be easily stored once it is generated, the industry must rely on a complex 

transmission grid to provide needed energy to consumers throughout the state. In turn, it 

recognized that the grid must be constantly balanced by either adding or removing power to ensure 

a smooth and uninterrupted flow of energy to consumers, and that it was therefore necessary to 

assign an entity to be responsible for ensuring that balance. Id. at 828.

The Legislature assigned the task of overseeing and regulating this aspect of the industry to 

the PUC. TEX. UTIL. CODE ANN. § 35.004 (West 2016). As part of its authority, the PUC is 

authorized to certify independent organizations to perform various functions on its behalf to ensure

the “reliability and adequacy of the regional electrical network” within a particular power region. 

Id. at § 39.151(a), (c) (West 2016). For most of the state, that independent organization is the 

 

precedent of that Court to the extent required by TEX. R. APP. P. 41.3.
3

Electric Reliability Council of Texas (ERCOT), which manages the flow of electric power to 

approximately 23 million Texas customers within its region. TXU Generation Co. L.P., 165 

S.W.3d at 831.

The Utilities Code also authorizes independent organizations, such as ERCOT, to adopt 

rules, subject to the PUC’s oversight and review, to ensure the reliability of the electrical grid 

within its region. TEX. UTIL. CODE ANN. § 39.151(d) (West 2016). Those rules are commonly 

referred to as ERCOT “protocols.” 16 TEX. ADMIN. CODE § 25.503(c)(3). The various entities, 

such as CPS Energy, that choose to participate in the transmission of energy within the ERCOT 

region are referred to as “market participants” and are subject to those protocols. Id. at § 

25.503(c)(5, 6). In particular, the Code provides that market participants must observe all 

ERCOT rules and procedures, and that a failure to comply may, among other things, result in an 

enforcement action and ultimately the imposition of an administrative penalty. TEX. UTIL. CODE 

ANN. § 39.151(j) (West 2016).

In turn, ERCOT is required to contract with an entity selected by the PUC to act as the 

PUC’s “wholesale electric market monitor” to prevent and detect violations of the ERCOT 

protocols. Id. at § 39.1515 (West 2016). ERCOT contracted with Texas Reliability Entity, Inc. 

(“Texas RE”) to investigate potential ERCOT protocol violations and report those violations to 

PUC staff.

Also as part of its duty to oversee and monitor the various participants in this aspect of the 

electricity industry, the PUC adopted a global administrative rule, entitled the “Oversight of 

Wholesale Market Participants,” more commonly known as the “WMO Rule,” which has the 

stated purpose of establishing “the standards that the [PUC] will apply in monitoring the activities”
4

of these participants. 16 TEX. ADMIN. CODE § 25.503. The WMO Rule sets forth various duties 

of market participants, and in particular, requires that each “market participant shall be 

knowledgeable about ERCOT procedures,” and expressly requires all market participants to 

“comply with ERCOT procedures and any official interpretation of the Protocols issued by 

ERCOT or the [PUC].” Id. at § 25.503 (f)(1) and (2). 

The WMO Rule nevertheless provides in subsection (f) that a market participant may be 

“excused” from compliance with ERCOT instructions or Protocol requirements under the 

following relevant circumstances: 

 When such non-compliance is due to communication or equipment failure beyond 

the reasonable control of the market participant;

 When compliance would jeopardize public health and safety or the reliability of the 

ERCOT transmission grid, or create risk of bodily harm or damage to the 

equipment;

 When compliance would be inconsistent with facility licensing, environmental, or 

legal requirements[.]

Id. at § 25.503(f)(2)(C). The Rule, however, states that the market participant is excused under 

this subparagraph only for so long as the condition continues. Id.

In addition, the WMO Rule contains a separate section providing two affirmative defenses 

to any prohibited act set forth in subsection (f) of the Rule. Id. at § 25.503(h). In particular, 

subsection (h) of the WMO Rule provides that a market participant may avoid liability for 

engaging in an act prohibited by the Rule, if the participant establishes that: (1) its “conduct 

served a legitimate business purpose . . . and that it did not know, and could not reasonably 

anticipate, that its actions would . . . adversely affect the reliability of the regional electric 

network”; or (2) it “exercised due diligence to prevent the excluded act or practice.” Id.
5

The WMO Rule also provides an enforcement structure, which allows the Reliability 

Monitor (in this case Texas RE) to investigate possible ERCOT protocol violations, and provide its 

findings to PUC staff. Id. at § 25.503(k). The PUC staff is given the discretion to initiate an 

informal fact-finding review to investigate whether a market participant has violated the WMO

Rule, including the provision requiring compliance with ERCOT protocols. Id. at § 25.503(o).

If PUC staff finds that a possible violation exists, it may request that the PUC take appropriate 

enforcement action against the market participant, and may, among other things, recommend an 

administrative penalty against the participant. Id. at § 25.503(o)(4). The PUC may then initiate 

a formal enforcement proceeding against the market participant. Id. at § 25.503(o). Following a 

hearing, if a final order is entered against it, the market participant is entitled to judicial review of 

that order. TEX. UTIL. CODE ANN. §§ 15.001 (West 2016), 15.026 (West 2016). 

The ERCOT Protocol

In the present case, following initial investigations conducted by Texas RE and the PUC 

staff, the PUC initiated an enforcement action against CPS Energy based on its alleged violation of 

an ERCOT Protocol relating to ancillary or reserve energy services, which in turn violated 

subsection (f) of the WMO Rule requiring compliance with all ERCOT protocols. Reserve

services are used by ERCOT in various situations, including weather emergencies, in which 

reserve energy may be needed to balance the grid to ensure that customers in the ERCOT region 

are provided with sufficient energy on a continuing basis. Market participants, such as CPS 

Energy, who have become certified to offer reserve energy to ERCOT are known as Qualified 

Scheduling Entities (QSEs). When the need for reserve energy is predicted, a QSE may offer the 

use of reserve or standby energy services to ERCOT, including non-spinning reserve services
6

(commonly referred to as NSRS services), which are defined as ancillary services that can be 

“ramped to a specified output level within 30 minutes,” and can operate at a specified output level 

for at least an hour. In exchange for a fee, a QSE agrees to stand ready to provide NSRS to 

ERCOT during a specific timeframe, and agrees that it will initiate deployment of NSRS upon

receiving a deployment instruction by ERCOT. Once the instruction is given to deploy NSRS, 

ERCOT Protocol § 6.5.7.6.2.3(4) provides a precise timeline for deployment of the NSRS by a 

QSE:

 Within 20 minutes of deployment, the generator must update the NSRS

schedule to indicate the unit’s deployment;

 Within 25 minutes of deployment, the generator must reach its Low

Sustained Limit [“LSL”]; and

 Within 30 minutes of deployment, the generator must change the

resource status for the generating unit from offline to “on,” thus

allowing ERCOT to dispatch it.

The ERCOT protocol itself contains one relevant exception, providing that: “Except as 

otherwise stated in this Section . . . each QSE shall comply fully and promptly with a Dispatch 

Instruction issued to it, unless in the sole and reasonable judgment of the . . . QSE, such 

compliance would create an undue threat to safety, undue risk of bodily harm or undue damage to 

equipment[.]” ERCOT Protocol § 6.5.7.2(1). 

The February 2011 Cold Weather Event 

On January 27, 2011, in anticipation of predicted record cold temperatures in the ERCOT 

region beginning February 1 and lasting through February 3, ERCOT took steps to address the 

situation by, among other things, notifying its market participants and QSEs of the impending cold 

weather event to allow them to take necessary steps to prepare for it. In addition, ERCOT made 
7

arrangements with various QSEs, including CPS Energy, to provide reserve NSRS services at a 

specific time during the cold weather event. In particular, CPS Energy agreed to provide 96 

megawatts of NSRS services by utilizing two of its Braunig Combustion Turbines, the Braunig 

CT5 and the Braunig CT8, to be available from 4 to 5 a.m. on the morning of February 2, upon 

receiving a deployment instruction from ERCOT.

At 4:26 a.m., due to unprecedented demands on the grid due to the cold weather event, 

ERCOT provided instructions to the various QSEs, including CPS Energy, to deploy their NSRS 

services to ensure the ability to continue providing electricity to its customers in the region. CPS 

Energy immediately initiated the start-up sequence of both units two minutes later. The Braunig 

CT8 deployed successfully within the 30-minute timeframe required by the ERCOT Protocols. 

However, the Braunig CT5 failed to deploy within the required 30-minute timeframe, and instead, 

was not deployed until 6:09 a.m., approximately one and a half hours after CPS Energy received 

ERCOT’s initial deployment instruction.

CPS Energy’s generator was not the only NSRS generator that did not timely deploy that 

morning, and in fact, over half of the NSRS generators that ERCOT attempted to deploy that 

morning either failed to deploy or delayed in deploying. Further, throughout the entire cold

weather event, 225 generating units experienced a failure to start during freezing conditions, and at 

its lowest point, approximately one-third of the total ERCOT generation fleet was unavailable for 

deployment. This caused ERCOT to take action to reduce demand on the grid, and led to rolling 

blackouts that affected 3.2 million customers in the ERCOT area.

PUC Proceedings

Following the February cold weather event, Texas RE initiated an investigation into 
8

whether CPS Energy had violated ERCOT protocols on the morning of February 2 when the CT5 

unit failed to timely deploy. Texas RE initially notified CPS Energy of the possible violation, but 

when it could not reach an agreement with CPS Energy, it referred the matter to PUC staff.2 PUC 

staff thereafter conducted its own informal investigation of the matter, and ultimately initiated a 

formal enforcement proceeding against CPS Energy for allegedly violating the WMO Rule 

requiring compliance with the ERCOT protocols, and recommended the imposition of an 

administrative penalty of $25,000. The matter was then referred to the State Office of 

Administrative Hearings (SOAH), and a SOAH Administrative Law Judge (ALJ) held a hearing in 

January 2013.

At the hearing, there was no debate over whether the Braunig CT5 had failed to timely 

deploy within the time frame set forth in the ERCOT Protocol. However, CPS Energy sought to 

be excused from compliance based on the various exceptions and excuses set forth in the ERCOT 

protocols and the WMO Rule. CPS contended that the CT5’s failure to deploy was caused by an 

equipment failure—a non-functioning damper fan—that was unforeseen and beyond its 

“reasonable control,” and that compliance would have posed health, safety, and environmental 

concerns because deployment of the unit without a functioning damper fan could have caused the 

unit to explode or emit hazardous particles into the air.

At the hearing, CPS Energy relied primarily on the testimony of two of its employees who 

explained the events leading up to the CT5’s failure to timely deploy on the morning of February 2.

Samuel Hernandez, the operations manager for the Braunig Plant site, acknowledged that he had 

 

2

In its report to the PUC, the Texas RE investigator concluded that an ERCOT violation had occurred, but stated that:

“Even though the unit did not perform as expected within the required time frame, it is noted that CPS personnel acted 

quickly and effectively to get the unit started during the difficult and hectic morning while dealing with many other 

equipment issues. The Braunig CT5 unit is a 48-megawatt unit; therefore, the impact of being late to start-up was 

minimal to the overall reliability of ERCOT.”
9

received “alerts” from ERCOT before February 1 regarding the cold weather event that was 

projected to occur, and that CPS Energy’s management took steps in advance to prepare the plant 

for that event. According to Hernandez, CPS Energy had previously prepared the plant for 

winter, but upon receiving the alerts from ERCOT, it took additional actions to “further reinforce 

winter preparedness procedures” at the plant in general, and in particular, took steps to recheck the 

Braunig CT units to ensure their readiness.

3

Hernandez also testified that in anticipation of the cold weather event, he directed 

additional staff to be present at the Braunig plant site on the night of February 1 through the early 

morning hours of February 2. According to Hernandez, a “normal” operating night consists of six 

operators and one supervisor, but he directed the presence of two additional operators, two 

additional technicians, and an unspecified number of additional electricians. Hernandez further 

explained that many of his staff members had already worked “significant hours” to prepare the 

plant for the cold weather event before February 1, and in order to balance their shifts, he sent 

home an unspecified number of staff members that day, so they would be available for work the 

next day, as the cold weather event was anticipated to last at least three days.

Hernandez recalled that due to the extreme cold weather, CPS Energy began having issues 

with several of its generating units on the night of February 1, at both the Braunig plant site and 

other sites as well. Hernandez left the Braunig plant site at approximately 10:45 p.m. that night to 

assist with the “cold start” of other units at a different facility. He was therefore not at the 

 

3 CPS Energy provided evidence establishing that its maintenance of the Braunig units and the steps it took in 

preparing the units for winter were within industry standards, and neither the ALJ nor the PUC found that CPS Energy 

was negligent in that regard. The ALJ expressly found that CPS Energy was not at fault in how it maintained the units 

or in preparing the units for winter weather. Instead, the ALJ found that the sole issue was whether CPS Energy had 

adequately staffed its plant in preparation for the cold weather event and whether adequate staffing would have 

enabled CPS Energy to comply with the ERCOT deployment instruction.
10

Braunig plant site when ERCOT issued its instruction to deploy the two Braunig CT units early the 

next morning.

The undisputed evidence established that ERCOT provided its instruction to deploy the 

two Braunig CT generators at 4:26 a.m. on February 2, thereby requiring the units to be online at 

the LSL level by 4:51 a.m. Although the Braunig CT8 timely deployed, the Braunig CT5 did not.

The facts are undisputed that an operator in CPS Energy’s control room made three failed attempts 

to start the CT5 unit as follows: 

 4:28: CPS control room staff initiated start sequence of the CT5.

 4:39: Start sequence of the CT5 was interrupted.

 4:41: Start sequence was initiated a second time. 

 4:47: Start sequence was again interrupted. 

 4:49: Start sequence was initiated a third time. 

 5:04: Start sequence was interrupted again.

 

At approximately 5:01 a.m., the CPS Energy operator spoke with an ERCOT staff member in a 

recorded conversation, and advised him that the unit was not starting, that it was “tripping 

offline,” and that the unit was indicating a problem with “[l]ow temperature pressures.” The 

ERCOT staff member informed the operator of the urgent need to get the unit online, and advised 

the operator to “keep firing on it.”

At the hearing, various CPS employees explained that the CT5 unit contained an 

automated computer-based control system built into the unit that was designed and installed by 

CPS Energy and outside experts to monitor conditions during startup to detect unsafe conditions. 

They explained that this automated safety system had automatically shut down the start sequence 
11

because it had detected an unsafe condition. CPS Energy contended that absent the assistance of 

a technician who could troubleshoot or investigate the cause of the failure, its operator in the 

control room had no choice but to keep trying to start the unit. According to Hernandez, there 

were no technicians available to troubleshoot the problem with the CT5 at the time because the 

other two technicians who were onsite at the time had been assigned to address problems with the 

other larger generating units at the plant site. Hernandez further explained that CPS Energy 

decided to have the two technicians focus on the larger units at the plant site since the larger units

were capable of providing more needed electricity to the grid than the Braunig CT5.

Hernandez recalled that he was contacted by a senior plant manager at the Braunig plant 

site at approximately 4:30 a.m. on February 2, requesting that he return to the plant site to address 

the various problems occurring at the plant, shortly after ERCOT gave its instructions to deploy 

the Braunig CT units but before the startup failure occurred. The record reflects that it took 

Hernandez approximately one hour to reach the Braunig plant site after receiving the call, and he 

reported to the control room at approximately 5:30 a.m. Upon arrival, he was told that there 

were problems with the CT5 unit and at least three other units at the plant site. Hernandez 

immediately directed the control room operator to locate an Instrument and Controls (“I&C”)

technician to assist in troubleshooting the failed start-up of the CT5 unit.

The I&C technician who ultimately assisted in troubleshooting the problem with the CT5 

was William L. Warnke, who had been called to come to the plant site at approximately 4 a.m. 

Warnke arrived at the plant site at approximately 5:25 a.m. and reported to the control room where 

he was informed about the problem with the CT5. After discussing the problem with the other 

two onsite technicians, Warnke physically went to the unit itself to investigate the problem at 
12

approximately 5:46 a.m., and found that a tempering air fan discharge damper and its “associated 

linkage” were frozen and would not move. Warnke was able to break away some of the ice from 

the unit with a large wrench, allowing the damper to open. Shortly thereafter, the start sequence 

was initiated for a fourth time, and by 6:09 a.m. the CT5 was online generating electricity.

Warnke explained that it would have been impossible for the unit to operate with a frozen

discharge damper because the damper is necessary for the unit’s tempering air fans to operate; in 

turn, the fans are essential to the unit’s operation because they regulate the temperature control for 

the catalyst in the turbine exhaust duct. Warnke further explained that the built-in safety system 

in the unit is designed to automatically terminate the start-up process if an air fan discharge damper 

fails to open, and acknowledged that the control room operator had received an “alarm” signaling 

that a tempering air fan discharge damper had failed to open, thereby alerting him of the particular 

problem. Warnke testified that several negative outcomes could have occurred if the unit had 

been operated without the tempering air fans, including explosions, equipment damage, and air 

pollution emissions.

At the hearing, both Warnke and Hernandez expressed their opinions that the unit’s failure 

to start on the morning of February 2 was unforeseeable, asserting that CPS Energy had no reason 

to anticipate that there were be a damper failure of this nature. According to Hernandez, during 

his 33 years of plant operation experience, he had never seen a similar damper failure occur due to 

freezing weather. Warnke testified that “not once in CPS history has a damper of that type 

linkage froze over and caused issues with the damper opening.”

Both Hernandez and Warnke testified that although the Braunig CT units were only 

designed to operate at 20 degrees and above, the damper fans themselves were rated at zero
13

degrees and were therefore designed to open regardless of the temperature. 4 Warnke did 

acknowledge, however, that “[t]he weather forecast is an important consideration for all units,” 

and that the “ambient temperature surrounding the unit” is a factor to consider in ensuring the 

reliability of plant operations.

In response to CPS Energy’s arguments regarding the foreseeability of the equipment 

failure, the PUC did not focus simply on whether it was foreseeable for the damper to freeze over

and fail to open. Instead, the PUC focused on the more general question whether it was 

foreseeable that the Braunig plant site would experience start-up failures due to the anticipated 

cold weather event, and in turn, whether CPS Energy should have taken steps to ensure that it had 

adequate staff at the plant to address those potential issues. In particular, the PUC presented the 

testimony of Greg D. Graham, a Senior Protocol Compliance Analyst with Texas RE, who was 

responsible for investigating CPS’s violation of the ERCOT protocol. In his testimony, Graham 

focused on the fact that CPS Energy had several days’ advance notice of the severe cold weather 

event, and was therefore on notice that it could experience potential problems with all of its 

generators, including the Braunig CT units. Graham also pointed out that the Braunig CT units 

had just been declared commercial in December 2010, and had not been operated in cold weather, 

therefore rendering the units essentially untested. Graham further pointed out that the weather 

forecast was projecting temperatures below the “design criteria” for the Braunig units for the 

morning of February 2. In light of this forecast, Graham expressed his disagreement with CPS 

Energy’s conclusion that it could not have anticipated that its equipment might freeze, or that it 

 

4 After the February 2011 event, CPS Energy fabricated covers to place on the dampers. The ALJ found that CPS 

Energy had adequately prepared the plant for cold weather operations in accordance with industry standards, and 

therefore did not consider the lack of covers in determining whether CPS Energy should be excused for the ERCOT 

violation.
14

could not have anticipated that it might experience other start-up failures at the plant.

Given the known potential for such problems, Graham posited that CPS Energy should 

have had more staff on hand for the cold weather event, and in particular, more technicians to 

troubleshoot and investigate the start-up problems CPS Energy encountered on both February 1 

and 2. Graham found it significant that CPS Energy’s problems with the cold weather at the plant 

site surfaced as early as 10:55 p.m. on the night of February 1, when multiple generators failed to 

startup due to the cold weather. Graham opined that because CPS Energy had already assigned its 

only two technicians at the plant site to work on those failed generators, CPS Energy was on notice 

that it needed additional staff to address potential problems that might occur with the Braunig CT 

units when they would be needed the next morning. Graham pointed out that the entire plant site 

began failing hours before ERCOT gave its instruction to deploy the Braunig CT units, and he 

therefore believed that there was still time for CPS Energy to call in additional staff to remedy the 

situation at that time, but that CPS Energy failed to call for any additional help until hours later, 

when it was essentially too late.

Graham particularly faulted Hernandez, noting that when he left the Braunig plant site at 

10:45 p.m. on February 1 to address the start-up problems at another plant site, he was already 

aware that the Braunig plant site was having significant issues and that both technicians at the site 

were busy addressing problems with other generators. Graham therefore believed that

Hernandez, knowing he had no other available technicians at the plant site to address potential 

problems with the Braunig CT units, could have avoided the ERCOT protocol violation by 

reevaluating his staffing plan at that point and calling in additional personnel to ensure that the CT 

units successfully deployed.
15

Graham further emphasized that during the first three failed attempts to start the Braunig 

CT5, which began at 4:28 a.m., CPS Energy admittedly had no technicians available to investigate 

the problem, and took no action to address the issue until almost an hour and a half later when 

Hernandez and Warnke arrived on the scene. Graham believed the ERCOT violation could have 

been avoided if CPS Energy had taken steps to ensure that it had sufficient staff on hand to either 

inspect the CT units before the ERCOT instruction t deploy was given, or at least to enable CPS 

Energy staff to take reasonable steps to investigate the startup failure immediately after it occurred. 

Graham further opined that the need for additional staff was illustrated by the fact that CPS Energy 

“significantly increased” its staff the next day after the failure to deploy occurred.

Graham concluded that it was CPS Energy’s choice to offer the reserve energy to PUC on 

the morning in question, knowing the weather conditions at hand, and that it was therefore CPS 

Energy’s responsibility to adequately prepare to ensure that it met its obligation, knowing it would 

be subject to administrative penalties if it did not. In his opinion, that responsibility extended not 

only to ensuring that the units were mechanically sound, but also to ensuring that adequate staff 

was on hand to make certain the units deployed in a timely manner.

At the hearing, the PUC also presented the testimony of Ernest Garcia, the PUC staff 

member who investigated CPS Energy’s alleged protocol violation. Garcia testified that when he 

recommended that the PUC initiate enforcement proceedings against CPS Energy, his focus was 

also on CPS Energy’s failure to adequately staff the Braunig plant site in anticipation of the cold 

weather event, which he viewed as the ultimate cause of the ERCOT violation. Garcia noted that 

it was within CPS Energy’s control to have a technician available to address potential start up 

issues with its units, and he concluded that if the plant had been adequately staffed in anticipation 
16

of the cold weather event, “we would not be here today.” Garcia further explained that he 

considered CPS Energy’s violation serious, and he therefore recommended the maximum penalty, 

in part to deter future violations of the ERCOT protocol.

In rebuttal, both Hernandez and Warnke denied that the staffing levels had any effect on 

the equipment failure. Hernandez testified that they did have additional staff on site the morning 

of the incident, which he believed was sufficient under the circumstances known to CPS Energy at 

the time. Warnke also opined that having even more staff on site would not have helped CPS 

Energy avoid the ERCOT protocol violation. In particular, Warnke explained that the Braunig 

CT units typically take 20 minutes to reach LSL levels, and in his opinion, even if a technician had 

been standing at the unit at the time of start-up, it would have been virtually impossible for the 

technician to have investigated, diagnosed, and repaired the unit after it first tripped and to have 

the unit restarted within the required 25-minute period of time.

Warnke also explained that, as part of its increased staffing, CPS Energy had three 

operators at the plant site during the cold weather event who were specifically assigned to make 

hourly rounds of the plant, checking heat-tracing insulation, enclosures, portable heaters, heat 

lamps, and “anything that’s out there to prevent freezing.” However, he also acknowledged that 

when making their rounds, these operators would not have inspected the damper fans, because 

they were considered mechanical items not likely to freeze, and because they were located 

between two motors in an area that operators would not normally inspect. He therefore concluded 

that having additional operators at the plant would not have changed the outcome.

CPS Energy also presented the testimony of an industry expert witness, John Allen Moore. 

Moore acknowledged that plant operations may be affected by severe cold weather, and that 
17

staffing is a factor that a market participant should take into consideration in ensuring reliable plant 

operations when faced with a severe weather event, such as the event in February 2011. He 

therefore acknowledged that in light of the warnings it had received regarding the anticipated cold 

weather event, CPS Energy was obligated to provide “additional preparation and staffing to ensure 

or to help ensure as reliable operations as possible . . . [a]s reasonably possible.” Moore 

expressed his opinion, however, that CPS Energy did in fact take adequate “supplemental steps,” 

by having additional operators and technicians available at the plant to monitor operations and 

address conditions as they arose during the cold weather event. In Moore’s opinion, CPS Energy 

reacted to the CT5’s failure to deploy in an “efficient and responsible manner” in light of the 

conditions that were occurring at the plant site at the time.

The Ruling

Following the SOAH hearing, the ALJ issued its Proposal for Decision. The ALJ found 

that CPS Energy had violated the ERCOT Protocol when the CT5 unit admittedly failed to deploy 

within the timeframe required by the Protocol. The ALJ further concluded that CPS Energy had 

failed to establish an excuse under the WMO Rule. In particular, the ALJ concluded that CPS 

Energy had failed to establish that its non-compliance resulted from any health, safety, or 

environmental concerns. The ALJ also concluded that CPS Energy was not excused based on the 

exception in the WMO Rule for “equipment failure beyond the reasonable control of the market 

participant.” In making that determination, the ALJ agreed with CPS Energy that it was not 

negligent in its efforts to protect its equipment during the cold weather event, and that its actions in 

maintaining and winterizing its equipment were “in alignment with industry standards.” Instead, 

the ALJ believed that the sole issue in determining whether the equipment failure was beyond its 
18

reasonable control was “whether CPS provided adequate staffing in light of the severe weather and 

the effect it might have on the relatively new plant.” The ALJ noted that CPS Energy had 

presented evidence that it had provided additional staffing the morning of the equipment failure, 

but had failed to “establish a benchmark against which to judge its actions.” The ALJ believed 

that without an independent benchmark, it was “impossible to say that the staffing levels employed 

by CPS were reasonable or prudent.” Noting that CPS Energy had the burden to establish a valid 

excuse, and therefore to present evidence on that issue, the ALJ concluded that CPS Energy had 

failed to meet its burden of proving “that the failure to comply with ERCOT Protocols was beyond 

its reasonable control.”

The ALJ then addressed the serious nature of CPS Energy’s violation in failing to provide 

the NSRS service in a timely manner as promised to ERCOT, noting that “NSRS is an important 

tool that ERCOT uses to ensure the reliability of the ERCOT grid.” The ALJ also noted that CPS 

Energy had obligated itself to provide NSRS electricity during what was essentially an emergency 

situation, and that failing to take reasonable steps to meet its obligations was a “grave violation 

warranting the maximum penalty available to the Commission.” The ALJ further concluded that, 

“CPS’s failure to provide the NSRS it obligated itself to provide on February 2, 2011, contributed 

to the deterioration of the Grid on that morning, which ultimately led to ERCOT shedding load

(i.e., ordering rolling blackouts) to avoid a total system collapse.” In recommending the 

maximum penalty, the ALJ factored in the “deterrent effect” the penalty would have to encourage 

other market participants to avoid engaging in similar conduct in the future.

The PUC subsequently adopted the findings and conclusions of the ALJ. In its final order, 

the PUC found that CPS Energy had violated two ERCOT protocols: 
19

1) ERCOT Protocol 6.5.7.6.2.3(4), for CPS Energy’s failure to have the CT5 generator 

dispatching electricity within 30 minutes of ERCOT’s dispatch (or deployment) 

instructions. 

2) ERCOT Protocol 8.1.1.4.3(3)(b) for CPS Energy’s failure to provide a specific resource 

status to ERCOT within 25 minutes of ERCOT’s deployment instructions.

In its final order, the PUC concluded that CPS Energy bore the “burden of proving by a 

preponderance of the evidence that it should be excused from compliance with ERCOT dispatch 

instructions and protocol requirements,” and that CPS Energy had not met its burden to establish 

an excuse under the ERCOT protocols or the WMO rule. The PUC then concluded that CPS 

Energy had not met its burden of establishing any excuse under the ERCOT protocols or the WMO 

Rule. In doing so, the PUC’s order also focused on staffing issues. In particular, the PUC 

concluded that CPS Energy failed to prove that it had provided adequate staffing at the Braunig 

site in “light of its choice to offer NSRS from unproven units” during the cold weather emergency. 

It further concluded that CPS Energy had several opportunities on the morning in question to call 

in additional staffing “to ensure any start-up failures could be promptly addressed,” but failed to 

take any such necessary action.

Agreeing with the ALJ that the ERCOT protocol violations were serious, particularly 

because they occurred in the midst of an emergency situation, the PUC ordered CPS Energy to pay 

the maximum $25,000 administrative penalty for the violations. As permitted by statute, CPS 

Energy sought judicial review in the Travis County district court in September 2013. See TEX.

UTIL. CODE ANN. § 15.001 (West 2016). The trial court affirmed the PUC’s final order, and this 

appeal followed.

DISCUSSION

On appeal, CPS Energy raises several challenges to the PUC’s final order. In particular, 
20

CPS Energy claims the PUC misinterpreted or misapplied the WMO Rule in a manner that 

conflicted with a prior decision of the Austin Court of Appeals; that it formulated a new or novel 

interpretation of the WMO Rule and applied that new interpretation during the enforcement 

proceeding without giving CPS Energy “fair notice” of the interpretation; that the PUC applied the 

WMO Rule in a manner that was unreasonable, arbitrary, and capricious; and that the PUC’s order 

was not supported by substantial evidence. 

Standard of Review

In their challenges to the PUC’s final order, CPS Energy has raised a variety of issues, 

which we review under different standards of review. As a general matter, an appellate court 

must review the PUC’s final order under the “substantial evidence rule,” which requires us to give 

“significant deference to the agency in its field of expertise.” TEX. UTIL. CODE ANN. § 15.001

(“Any party to a proceeding before the commission is entitled to judicial review under the 

substantial evidence rule.”); see also CenterPoint Energy Houston Elec., LLC v. Pub. Util. 

Comm’n of Texas, 408 S.W.3d 910, 916 (Tex.App. – Austin 2013, pet denied) (we review a 

Commission order under the Administrative Procedure Act’s (APA) “substantial-evidence” 

standard); City of El Paso v. Pub. Util. Comm’n of Texas, 344 S.W.3d 609, 618 (Tex.App. – Austin 

2011, no pet.); State v. Pub. Util. Comm’n of Texas, 246 S.W.3d 324, 331 (Tex.App. – Austin 

2008, pet. denied).

In conducting our review, we may not substitute our judgment for that of the agency on 

matters committed to agency discretion. TEX. GOV’T CODE ANN. § 2001.174 (West 2016); H.G. 

Sledge, Inc. v. Prospective Inv. & Trading Co., Ltd., 36 S.W.3d 597, 602 (Tex.App. – Austin 2000, 

pet. denied). Further, we must “presume that the agency’s order is valid and that its findings, 
21

inferences, conclusions, and decisions are supported by substantial evidence,” and therefore, the 

party challenging the agency’s order has the burden to overcome this presumption. State, 246 

S.W.3d at 331-32 (citing City of El Paso v. Public Util. Comm’n, 883 S.W.2d 179, 185 

(Tex.1994)).

Our review under the substantial evidence rule is limited to determining whether the “record 

demonstrates some reasonable basis for the agency’s action.” Id. at 332. If “reasonable minds” 

could have reached the same decision, we will affirm the agency’s decision. We will reverse the 

agency’s decision only if it is “not reasonably supported by substantial evidence, in violation of a 

constitutional or statutory provision, in excess of the agency’s statutory authority, made through 

unlawful procedure, affected by other error of law, arbitrary or capricious, or characterized by an 

abuse of discretion.” Id. (citing TEX. GOV’T CODE ANN. § 2001.174(2)(A)-(F)).

Although we are required to defer to the agency’s findings of fact when reviewing an 

agency order, if an issue on appeal involves a question of law, we review that issue de novo. Tex. 

Dep’t of Pub. Safety v. Allocca, 301 S.W.3d 364, 367 (Tex.App. – Austin 2009, pet. denied). In 

particular, when an issue turns on the construction of a statute or administrative rule, that issue is 

considered a question of law requiring de novo review. State, 246 S.W.3d at 332; see also First 

Am. Title Ins. Co. v. Combs, 258 S.W.3d 627, 631 (Tex. 2008); CenterPoint Energy Houston Elec., 

LLC, 408 S.W.3d at 916 (when a dispute centers on the agency’s interpretation of its rules, 

questions of rule construction are reviewed de novo).

In general, a reviewing court must construe administrative rules, which have the same 

force as statutes, in the same manner as statutes. CenterPoint Energy Houston Elec., LLC, 408 

S.W.3d at 916 (“We interpret administrative rules, like statutes, under traditional principles of 
22

statutory construction.”). When an administrative rule or statute is unambiguous, it must be 

interpreted based on its plain language, unless that interpretation would produce an absurd result.

Rodriguez v. Service Lloyds Ins. Co., 997 S.W.2d 248, 254 (Tex. 1999); see also CenterPoint 

Energy Houston Elec., LLC, 408 S.W.3d at 916-17; Fleming Foods of Tex., Inc. v. Rylander, 6 

S.W.3d 278, 284 (Tex. 1999); State, 246 S.W.3d at 332. If an agency has failed to follow the 

clear, unambiguous language of its own regulation, we must reverse its action as arbitrary and 

capricious. Rodriguez, 997 S.W.2d at 255; see also CenterPoint Energy Houston Elec., LLC., 

408 S.W.3d at 916-17; Pub. Util. Comm’n v. Constellation Energy Commodities Grp., Inc., 351 

S.W.3d 588, 595 (Tex.App. – Austin 2011, pet. denied). 

However, if the rule is ambiguous or leaves room for policy determinations, we defer to the 

agency’s interpretation if the interpretation is reasonable, but not if the agency’s interpretation is 

plainly erroneous or inconsistent with the regulation or its underlying statutes. CenterPoint 

Energy Houston Elec., LLC, 408 S.W.3d at 916-17 (citing Rodriguez, 997 S.W.2d at 254–55); see 

also City of El Paso v. Pub. Util. Comm’n of Texas, 344 S.W.3d at 618-19; Railroad Comm’n of 

Tex. v. Texas Citizens for a Safe Future & Clean Water, 336 S.W.3d 619, 624–25 (Tex. 2011)

(although we must give “serious consideration” to a governmental agency’s construction of a 

statute it is charged with administering, this principle presupposes that the statute is ambiguous 

and the agency’s construction is reasonable and does not conflict with the statute’s language).

Further, courts “do not defer to administrative interpretation in regard to questions which do not lie 

within administrative expertise, or deal with a nontechnical question of law.” State, 246 S.W.3d 

at 332-33 (citing Rylander v. Fisher Controls Int’l, Inc., 45 S.W.3d 291, 302 (Tex.App. – Austin 

2001, no pet.)).
23

ANALYSIS

Issue One: Whether the PUC’s Interpretation and Application of the WMO Rule

Violated CPS Energy’s Due Process Right to Fair Notice 

CPS Energy contends that prior to the current enforcement proceeding, the WMO Rule had 

been interpreted by the Austin Court of Appeals in TXU Generation to mean that a market 

participant could not be held liable for actions resulting from “unforeseen” accidents or 

mechanical failures. CPS Energy believes that the Austin Court gave “assurances” to market 

participants that they would not be subject to liability for any such unforeseen events. CPS 

Energy contends that in the current proceeding, the PUC interpreted and applied the WMO Rule in 

a new and novel manner, which conflicted with TXU Generation. In particular, it argues that, 

without any notice of this interpretation, the PUC initiated enforcement proceedings against it for 

what CPS Energy believes was an unforeseeable mechanical failure on the morning of February 2, 

2011. CPS Energy argues that a regulatory agency is forbidden from giving a new interpretation 

of a rule for the “first time in an enforcement proceeding,” and that by doing so in this proceeding, 

the PUC deprived CPS Energy of any “meaningful, prehearing notice,” which undermined the 

fundamental fairness of the proceeding.

We agree with CPS Energy that a regulated party must be given “fair notice” of what type 

of conduct will subject it to an enforcement proceeding, and the regulated party must not be forced 

to guess what type of conduct will subject it to an enforcement proceeding or be clairvoyant in 

attempting to divine the agency’s interpretation of the rule in advance. Vista Healthcare, Inc. v. 

Tex. Mut. Ins. Co., 324 S.W.3d 264, 273 (Tex.App. – Austin 2010, pet. denied); see also

Christopher v. SmithKline Beecham Corp., __U.S. __, 132 S.Ct. 2156, 2168, 183 L.Ed.2d 153 

(2012) (it is improper for a regulatory agency to interpret and apply a rule in a novel manner for the 
24

first time in an enforcement proceeding). However, as explained below, we disagree with CPS 

Energy that it was not on notice that its conduct on the morning of February 2 could subject it to 

liability. We further conclude the PUC interpreted the WMO Rule in a manner that was 

consistent with TXU Generation and with the plain language of the Rule itself.

TXU Generation

In TXU Generation, the parties brought a facial challenge to the constitutionality of

subsection (g) of the WMO Rule, which provides that market participants are subject to 

enforcement actions if they engage in “[a]ny act or practice of a market participant that materially 

and adversely affects the reliability of the regional electric network or the proper accounting for 

the production and delivery of electricity among market participants[.]” 16 TEX. ADMIN. CODE

§ 25.503(g). Subsection (g) of the WMO Rule contains a list of seven “prohibited activities,” all 

of which are aimed at preventing unfair trade practices within a power region. The market 

participants in TXU Generation claimed the WMO Rule was unconstitutionally vague on its face, 

and failed to give market participants fair notice of what type of conduct could subject them to an 

enforcement proceeding. Among other things, the market participants were concerned about the 

seventh prohibited activity in subsection (g), which provides that a “[a] market participant shall not 

engage in market power abuse.” See id. at § 25.503(g)(7). The market participants noted that the 

Rule did not contain a precise definition of what actions would constitute a “market power 

abuse.”

5

 

 

5 The market participants also contended that the WMO Rule was invalid because it lacked an “intent” element, and 

would allow a market participant to be found liable for a “market power abuse” even if their actions were unintentional 

acts. The market participants argued that the Commission lacked the statutory authority to prohibit unintentional 

conduct, and argued that at the least, the Court should imply an “element of intent” into the Rule. TXU Generation, 

165 S.W.3d at 832-34. The Austin Court disagreed, noting that the PUC enacted the WMO Rule to protect

consumers and to ensure a reliable electricity network – a task that the Legislature expressly gave to the PUC. Id. at 

834. The Court concluded that the “WMO Rule reflects the Commission’s decision, based on its expertise, that both
25

The market participants claimed the WMO Rule was unconstitutionally vague because 

subsection (g) did not clearly define the type of activities that would be considered a “market 

power abuse,” claiming that the language in the Rule was too “open-ended,” was “confusing,” 

created “unknown risks,” and generally did not provide enough specificity to allow market 

participants to take measures to avoid violations. TXU Generation Co., L.P., 165 S.W.3d at 838-

40. As one example of their confusion, the market participants questioned whether they could be 

found liable for a “market abuse” under subsection (g)(7) of the Rule for “withholding” electricity 

in situations in which their failure to delivery electricity was due to “accidents or ordinary 

mechanical breakdowns,” such as “mechanical failures and computer glitches,” pointing out that 

such events could have an adverse effect on the electricity market through no fault of the market 

participants. Id. at 839-40. 

In addressing that concern, the Austin Court was unable to point to any provision in 

subsection (g) of the WMO Rule that would excuse the market participants from liability under 

those circumstances. However, the Court concluded that subsection (g) should not be read “in 

isolation,” and that it should instead be interpreted in conjunction with subsection (h) of the WMO

Rule, which sets forth various affirmative defenses to a violation of subsection (g). Id. at 840. In 

particular, subsection (h) expressly provides a market participant with two affirmative defenses to 

a claim of market power abuse if the market participant establishes that its conduct: (1) “served a 

legitimate business purpose consistent with prices set by competitive market forces; and that it did 

not know, and could not reasonably anticipate, that its actions would inflate prices, adversely 

 

intentional and unintentional actions in the wholesale market that adversely affect reliability must be prohibited in 

order to prevent market power abuse, ensure retail customers ‘safe, reliable, and reasonably priced electricity,’ and 

ensure reasonably priced electric power for ancillary services.” Id. The Court therefore expressly concluded that 

the Commission was entitled to bring enforcement actions for both intentional and unintentional conduct. Id.
26

affect the reliability of the regional electric network”; and (2) “if applicable, that it exercised due 

diligence to prevent the excluded act or practice.”

6

 16 TEX. ADMIN. CODE § 25.503(h). 

Paraphrasing subsection (h) as providing a defense when the “adverse effect on reliability, 

price, or accounting was not known or foreseeable with the exercise of due diligence,” the Austin

Court opined that this “provision gives clear notice that the unforeseen accidents described by 

TXU will not give rise to liability under the [WMO] rule.”7 TXU Generation Co. L.P., 165 

S.W.3d at 840. In concluding that the WMO Rule thereby gives participants notice of what type 

of conduct will give rise to liability, the Court concluded that the “rule does not require 

clairvoyance as to whether an action will impact price, reliability, or accounting – only diligence.” 

Id. at 840. 

Although we agree with CPS Energy that important lessons can be derived from TXU 

Generation, we also note that clear distinctions may be drawn between the issues posed in TXU 

Generation and the questions before this Court. First, TXU Generation was focused on the facial 

constitutionality of subsection (g) involving market power abuses, and whether the language used 

in that section was unconstitutionally vague and failed to give market participants clear notice of 

what type of conduct would cause a violation of subsection (g). 

In the present case, however, CPS Energy was not charged with a violation of subsection 

(g), and was instead found to have violated subsection (f). Subsection (f) clearly and in plain 

 

6 As discussed in more detail below, subsection (h) expressly provides that these affirmative defenses can also be 

applicable to subsection (f) violations for failures to comply with ERCOT protocols. 16 TEX. ADMIN. CODE § 

25.503(h). 

7 The Court also noted that the ERCOT protocols address “issues such as scheduled maintenance and the shutdown of 

plants,” which clearly give market participants guidance on what type of activities are considered prohibited. Id. at 

840 n.10. The Court noted that if an “action is authorized by ERCOT under its protocols, it is not a prohibited 

activity.” Id.
27

language informs a market participant that it must “comply with ERCOT procedures and any 

official interpretation of the Protocols issued by ERCOT or the commission.” 16 TEX. ADMIN.

CODE § 25.503(f). There is no ambiguity in subsection (f), and significantly, we note that CPS 

Energy does not contend that it was unaware of the ERCOT protocols it was found to have 

violated, or that it did not have notice of what type of conduct would cause it to be in violation of 

those protocols. In fact, CPS Energy acknowledges that it was aware that the ERCOT protocols 

set forth a specific timeline for having NSRS services deployed, and that it failed to comply with 

that timeline.

What is at issue in this case is whether CPS Energy was on notice of what type of situations 

would cause it to be excused from that duty. There are two separate provisions in the WMO Rule 

on which CPS Energy could have relied in seeking to excuse its performance. First, the WMO 

Rule contains the two affirmative defenses set forth in subsection (h), which were specifically 

addressed in the TXU Generation opinion, and which may excuse a market participant’s violation 

if it can demonstrate that it used “due diligence” to avoid the violation. 16 TEX. ADMIN. CODE § 

25.503(h). Second, the WMO Rule contains the specific excuse provisions within subsection (f) 

itself, which provide excuses for “equipment failure beyond the reasonable control of the market 

participant[,]” and the various excuses based on health, safety, and environmental concerns. Id. at

§ 25.503(f). 

In its brief, however, CPS Energy makes no mention of the affirmative defense provision 

found in subsection (h) of the WMO Rule, and instead focuses exclusively on whether it was 

entitled to rely on the excuse provisions found in subsection (f) of the Rule. Although TXU 

Generation focused exclusively on the affirmative defenses set forth in subsection (h), CPS 
28

Energy nevertheless repeatedly attempts to apply the standards set forth in the Austin Court’s 

discussion of subsection (h) to its analysis of the excuse provisions found in subsection (f). As 

discussed in more detail below, however, the particular excuses set forth in subsection (f) are based 

on different considerations, and warrant a separate and distinct discussion—one that the Austin 

Court was not called upon to make in TXU Generation. We believe that much of the confusion in 

this case stems from CPS Energy’s apparent failure to recognize the distinction between these two 

subsections. 

Nevertheless, to the extent that TXU Generation requires us to consider whether the 

equipment failure in this case was “foreseeable,” which appears to be the primary focus of CPS 

Energy’s argument in its brief, we turn our attention to that issue. 

Whether CPS Energy could have Reasonably Anticipated its Actions 

Would Adversely Affect the Electric Network 

CPS Energy argues throughout its brief that it should not be held liable for the equipment 

failure that occurred on February 2, as it was an “unforeseen” occurrence. In particular, CPS 

Energy contends that it presented undisputed evidence during the SOAH hearing that its failure to 

timely deploy the CT5 unit in accordance with the ERCOT protocol was due solely to 

“unforeseeable equipment failure[.]” CPS Energy points out that the evidence established that 

the CT5 unit failed to start due to a frozen damper fan, and claims it had no way of anticipating this 

failure. CPS Energy points out that two of its employees testified that they had never before 

encountered a frozen damper fan in their years of employment at CPS Energy, and that they had no 

reason to anticipate that the damper fan would freeze on the morning in question. CPS Energy 

also finds it significant that the ALJ expressly found that the equipment failure did not occur due to 

any maintenance issues or due to any failure by CPS Energy to prepare its equipment for the cold 
29

weather event. CPS Energy essentially believes that because it was not on notice of any 

preexisting mechanical issues with the damper fan, the PUC was required to find that the damper 

fan’s failure to open was an unforeseeable occurrence, absolving it of all blame. 

We believe, however, that CPS Energy’s focus is too narrow, and is in fact contrary to the 

actual language used in the WMO Rule. The first affirmative defense in subsection (h) of the 

WMO Rule (which the Austin Court specifically discussed in TXU Generation) expressly places 

the focus not on whether a particular piece of equipment might fail, but on whether the market 

participant could have “reasonably anticipate[d] that its actions would ... adversely affect the 

reliability of the regional electric network[.]” 16 TEX. ADMIN. CODE § 25.503(h). 

The real question then is whether CPS Energy could have “reasonably anticipated” that its 

“actions” leading up to and during the cold weather event would “adversely affect” the grid on the 

morning of February 2. In turn, CPS Energy’s “actions” leading up to the cold weather event 

consisted both of preparing the plant’s equipment for the event and in making staffing decisions. 

As set forth above, the PUC had no issue with the actions CPS Energy took in preparing its 

mechanical equipment for the event, and instead focused exclusively on its actions in staffing its 

plant. We believe that this was a fair and reasonable focus in light of the language used in 

subsection (h). 

As acknowledged by CPS Energy’s own expert witness, staffing decisions are a factor in 

preparing a plant for cold weather events. CPS Energy’s operations manager also recognized this 

when he made the decision to have additional staff on hand in anticipation of the February cold 

weather event. Further, the PUC also provided testimony that staffing can affect the reliability of 

the grid, particularly during severe weather events, as market participants are on notice that they 
30

may encounter equipment failures due to cold weather and must therefore consider whether they 

have sufficient staff on hand to address those failures. Moreover, there was no dispute among the 

witnesses at the SOAH hearing that CPS Energy could have reasonably anticipated that it would 

encounter equipment failures, at least of a general nature, as the plant was not rated for the 

temperatures projected to occur during the event. And finally, and perhaps most importantly, 

CPS Energy knew that it had promised ERCOT to provide NSRS services during the cold weather 

event from its two untested Braunig CT units, and it knew that if it did not provide those services as 

promised, the grid could be adversely affected during what could have been, and in fact ended up 

being, an emergency situation. Therefore, we conclude that the PUC presented substantial 

evidence that CPS Energy could have “reasonably anticipated” that its actions in staffing its plant 

prior to the cold weather event could have adversely affected the grid. 

Also, the evidence established that CPS Energy did in fact begin experiencing significant 

freezing and consequent equipment failures at its plant site the night before it was required to 

provide the NSRS services to ERCOT, which diverted the attention of its only two technicians at 

the plant, and as CPS Energy admits, rendered them unavailable to address any issues that might 

have arisen, and did in fact arise, with the deployment of the CT5 unit. As the PUC noted, this 

occurred hours before the time CPS Energy had promised to have the CT5 unit ready to deploy, 

and CPS Energy therefore had sufficient time to take additional actions to ensure that it had a 

technician available to address potential problems with the CT5, yet it waited several hours before 

it called in additional staff, and effectively did so at a time when it was too late to avoid the adverse 

effect of the CT5’s failure to deploy. 

Whether CPS Energy Exercised Due Diligence
31

These same factors are relevant in determining whether the second affirmative defense set 

forth in subsection (h) of the WMO Rule would apply, i.e., whether CPS Energy “exercised due 

diligence to prevent the excluded act or practice.” 16 TEX. ADMIN. CODE § 25.503(h). Thus, in 

determining whether CPS Energy exercised due diligence to prevent the ERCOT protocol 

violation, the PUC was entitled to consider not only whether CPS Energy took reasonable steps to 

prepare its equipment for the cold weather event, but also whether it took reasonable steps to 

ensure that its plant was adequately staffed for that event. Once again, it is significant to 

remember that CPS Energy had voluntarily promised to provide NSRS services to ERCOT at a 

specific time on the morning of February 2, during an extreme cold weather event, and it was 

therefore incumbent upon CPS Energy to use due diligence to ensure that it would have an 

adequate staff to meet its obligations, and thereby avoid an ERCOT protocol violation.

In fact, even under normal operating conditions, common sense dictates that market 

participants, and utility providers in particular, must exercise due diligence in ensuring not only 

that their equipment is in sound mechanical condition, but that they have adequately staffed their 

plants to ensure that they are able to comply with the ERCOT protocols so as to avoid WMO Rule 

violations. Utility providers, such as CPS Energy, are subject on a daily basis to numerous 

ERCOT protocols that require them to produce electricity at a certain volume, and market 

participants are aware that they may suffer penalties for overproduction or underproduction at any 

given time. Under CPS Energy’s approach, if a utility provider chose to understaff its plant, 

knowing that this could possibly lead to a complete or partial shutdown of its facilities, the 

provider would be able to escape liability for any consequent ERCOT violation by simply arguing 

that it maintained its equipment in sound condition, without being held accountable for its lack of 
32

staffing.

Similarly, there can be no doubt that a QSE in particular must exercise due diligence in not 

only maintaining its equipment, but also in staffing its plant to ensure that it will be able to produce 

NSRS services to ERCOT at a time when promised, if it wishes to avoid an ERCOT protocol 

violation. In this regard, CPS Energy’s obligation to ERCOT was not simply to have an operator

initiate a startup process when requested by ERCOT. Instead, as discussed in more detail below, 

its duties were many and continuing in nature. Under the express terms of the ERCOT protocol, 

CPS Energy was required to initiate startup within a certain timeframe; ensure that its generator 

reached the LSL level within a certain timeframe; to ensure that its generator started producing 

electricity within a certain time; and to continue to produce electricity for a certain time. 

Therefore, CPS Energy was obligated to have sufficient staff on hand throughout this entire 

process to ensure that it would be able to meet its obligations to ERCOT. 

Further, what constitutes an adequate staff on any given occasion will vary depending on 

the circumstances, and will require the PUC to make a factual determination on a case-by-case 

basis whether due diligence was exercised. At one extreme, there may be some cases where the 

lack of due diligence is obvious, and other cases where the adequate exercise of due diligence is 

unquestioned. In most enforcement cases, however, the facts will not be so clear. In those cases,

if the market participant desires to excuse its performance, it will be required to present evidence 

that it exercised due diligence in an attempt to meet its obligations. 

In a case involving normal operating conditions, this standard might be fairly low. 

However, the present case involved anything but “normal” operating conditions, and CPS Energy 

was aware days in advance that it would be facing an unprecedented severe weather event that
33

called for unique and unusual preparations. As such, we conclude there was substantial evidence 

from which the PUC could have concluded that, in light of the unique facts of this case, CPS 

Energy did not adequately staff its plant to ensure that it would be able to meet its obligations to 

ERCOT. 

CPS Energy, however, argues that allowing the PUC to determine whether it had adequate 

staffing levels at any given time will allow the PUC to “second-guess” a market participant’s 

decision regarding how to staff its plant; will allow the PUC to use “hindsight” in accusing a 

market participant of not having an adequate staff; and will otherwise require market participants 

to engage in “clairvoyance” in trying to anticipate what the PUC might deem to be adequate 

staffing levels on any given occasion. We disagree, and instead conclude that allowing the PUC 

to make this type of determination was within its authority.

The Legislature expressly gave the PUC the authority in the WMO Rule to determine 

whether a market participant’s conduct was excused based on a due diligence defense, and 

therefore gave the PUC the right to consider all relevant factors in making this determination. 

Further, in order to protect a market participant’s rights, the Legislature gave market participants 

the right to a hearing on this issue, at which the participant is entitled to present evidence whether 

it exercised due diligence, whether its actions were reasonable, and whether its actions met 

industry standards.

We note that CPS Energy does not contest the PUC’s right in conducting a due diligence 

analysis to consider whether a market participant was negligent in maintaining its equipment, yet it 

appears to believe that allowing the PUC to determine whether it had adequate staffing will 

somehow pose a greater danger that the PUC will act without reference to guiding principles or 
34

that it will require market participants to have to guess at what the PUC expects of it. However, 

we see no distinction between allowing the PUC to make these two types of determinations, nor do 

we believe that it requires clairvoyance by market participants to know they are required to use 

diligence not only in maintaining their equipment but also in staffing their plants as well. As the 

Austin Court recognized, the WMO Rule makes clear what is expected of a market participant, and 

the “rule does not require clairvoyance as to whether an action will impact price, reliability, or 

accounting – only diligence.” TXU Generation Co., L.P., 165 S.W.3d at 840.

For this same reason, we reject CPS Energy’s contention that the PUC’s interpretation of 

the WMO Rule imposed a “strict liability” standard on market participants that allows the PUC to 

find a violation virtually any time it has a mechanical failure, whether foreseeable or not. Instead, 

as set forth above, in any given case, the PUC will be guided in its decision-making process by the 

principles set forth in the WMO Rule, including the affirmative due-diligence defense provisions 

found in subsection (h) of the Rule, as well as the excuse provisions found in subsection (f) of the 

Rule, to which we now turn our attention. Issue One is overruled.

Issue Two: Whether the Equipment Failure was Beyond 

CPS Energy’s Reasonable Control

The primary focus of the parties’ argument in the proceedings below, as well as on appeal, 

is whether CPS Energy was excused from complying with the ERCOT protocol to have its CT5 

generator online in a timely manner under subsection (f)(2)(c) of the WMO Rule, which provides, 

in part, that a market participant may be excused for non-compliance “due to . . . equipment failure 

beyond the reasonable control of the market participant[.]” 16 TEX. ADMIN. CODE § 

25.503(f)(2)(C). In contending that the PUC erred in concluding that it was not excused under 

this provision, CPS Energy raises two fundamental challenges to the PUC’s decision, contending 
35

that the PUC erroneously applied the Rule when it adopted an “unreasonable interpretation” of this 

provision, and that the PUC’s decision was not supported by substantial evidence.

Burden of Proof to Establish an Excuse under the WMO Rule

Initially, we note that the PUC shoulders the initial burden to establish that a market 

participant has violated a WMO Rule; however, once the PUC has met that initial burden, the 

WMO Rule, by its plain language, provides that the burden then shifts to the market participant to 

establish an excuse under subsection (f) of the Rule: “A market participant who does not comply 

with a Protocol requirement or official interpretation of a requirement, or honor a formal 

commitment to ERCOT, has the burden to demonstrate, in any commission proceeding in which 

the failure to comply is raised, why it cannot comply with the Protocol requirement or official 

interpretation of the requirement, or honor the commitment.” 16 TEX. ADMIN. CODE § 

25.503(f)(4). Further, we note that the WMO Rule also places the burden of proof on the market 

participant to establish the affirmative defenses set forth in subsection (h) of the Rule, stating that: 

“A market entity claiming an exclusion or defense under this subsection, or any other type of 

affirmative defense, has the burden of proof to establish all of the elements of such exclusion or 

defense.” Id. at § 25.503(h).

The PUC’s Application of the WMO Rule

CPS Energy correctly points out that the undisputed evidence established that the ERCOT 

protocol violation in this case initially resulted from equipment failure, in the form of a frozen 

damper fan that failed to open during the Braunig CT5’s start-up process. CPS Energy contends 

that it further presented undisputed evidence to establish that the equipment failure was beyond its 

reasonable control, in accordance with the excuse language set forth in subsection (f)(2)(C) of the 
36

WMO Rule, and that the PUC erred in concluding otherwise.

CPS Energy’s initial argument centers on its belief that the PUC did not apply the correct 

legal standard for determining whether the equipment failure was within CPS Energy’s reasonable 

control, contending that this is an “unambiguous, well-defined, objective” legal standard that 

requires a court to find both that: (1) the failure itself was caused by the party’s own negligence; 

and (2) that the failure was foreseeable. It contends that the equipment failure in this case was 

neither caused by its own negligence nor was it foreseeable, and concludes therefore that the PUC 

applied the WMO Rule in an unreasonable or arbitrary and capricious manner. We disagree with 

CPS Energy’s interpretation of the Rule.

Initially, CPS Energy cites a line of cases for the proposition that one of the primary factors

in determining whether an event is beyond a person’s reasonable control is whether the party “by 

its own negligence, affirmatively caused the condition that prevented performance.”8 Most of the 

cases cited by CPS Energy, however, involve situations in which a court was called upon to 

interpret a contract containing a “force majeure” clause, which excused the party when its 

performance was prevented by a force majeure event, i.e., an act that was outside the party’s 

“reasonable control.” In most of those cases, the party’s own negligence was the cause of its 

 

8

See, e.g., Sun Operating Ltd. P’ship v. Holt, 984 S.W.2d 277, 288, n.4 (Tex.App. – Amarillo 1998, pet. denied) (in 

interpreting “force majeure” clause in party’s contract, court held that if a party’s delay was due to its negligence, it 

could not be viewed as resulting from a “circumstance within its reasonable control” and therefore could not be 

considered a “force majeure event”); Hydrocarbon Mgmt., Inc. v. Tracker Exploration, Inc., 861 S.W.2d 427, 435 

(Tex.App. – Amarillo 1993, no writ) (party could not invoke the “force majeure clause” in a contract, where it was 

unable to operate a well in compliance with the terms of a lease because the Texas Railroad Commission shut down its 

operations after its multiple failures to comply with the Commission’s orders, rendering the non-compliance to be 

within its “reasonable control”); Moore v. Jet Stream Investments, Ltd., 261 S.W.3d 412, 420 (Tex.App. – Texarkana 

2008, pet. denied) (lessee who was required to operate an oil and gas lease could not rely on the force majeure clause 

in the parties’ contract, where the Railroad Commission shut down its operations for failure to comply with the 

Commission’s financial assurance regulations). see also Seamless Floors by Ford, Inc. v. Value Line Homes, Inc., 438 

S.W.2d 598, 602-03 (Tex.Civ.App. – Fort Worth 1969, writ ref’d n.r.e.) (in interpreting a contract that placed liability 

on contractor for acts of its own negligence, the court noted that the contractor would only be liable for “negligent acts 

or omissions which would be within its reasonable control”).
37

inability to perform the contract, and therefore, it was held that the party’s nonperformance was 

not caused by a “force majeure event” that was outside the party’s reasonable control. See e.g.,

Hydrocarbon Mgmt., Inc. v. Tracker Exploration, Inc., 861 S.W.2d 427, 435 (Tex.App. – Amarillo 

1993, no writ) (party could not invoke the “force majeure clause” in a contract, where it was 

unable to operate a well in compliance with the terms of a lease because the Texas Railroad 

Commission had shut down its operations after its multiple failures to comply with the 

Commission’s orders, rendering the non-compliance to be within the party’s “reasonable 

control”). CPS Energy is correct that neither the ALJ not the PUC believed that CPS Energy was 

negligent in causing the initial equipment failure due to any failure on its part in maintaining or 

preparing the equipment for the cold weather event. As CPS Energy points out, the ALJ 

expressly found, and the PUC agreed, that CPS Energy had adequately maintained its equipment,

that it took all necessary precautions in accordance with industry standards to winterize its 

equipment, and that it generally took steps to “prevent and troubleshoot equipment failures known 

to occur in winter weather conditions.”

CPS Energy appears to believe that its duties stopped there, and that the PUC was not 

entitled to take into consideration what steps it took once its Braunig plant began experiencing 

significant freeze issues and consequent startup failures starting the night of February 1. Yet, it 

appears that CPS Energy could have taken additional steps at that time to ensure the timely 

deployment of is Braunig units the next morning. For example, as Graham pointed out in his 

testimony, CPS Energy could have called in additional staff once these freeze issues began in order 

to ensure that it had sufficient staff to prevent and address potential startup problems with the 

Braunig CT units the next morning. Further, CPS Energy overlooks that once the entire Braunig 
38

plant began experiencing freeze problems, it could have assigned one of its operators or 

technicians to inspect the CT units before the anticipated ERCOT instruction to deploy was given,

which could have prevented the startup failure in the first place. If an operator or technician had 

inspected the unit before the anticipated ERCOT instruction was given, it is likely that the frozen 

damper would have been discovered, and the problem could have been easily addressed by 

knocking the ice off of it as Warnke did hours later, thereby preventing any ERCOT violation. 

Similarly, CPS Energy could have required its staff to start up the CT units earlier in the morning 

of February 2, prior to the anticipated ERCOT deployment instruction, to determine if the units 

were operational, which in turn, would have given staff time to troubleshoot any problems prior to 

the critical moment when ERCOT gave its deployment instruction. In light of the fact that the 

entire Braunig plant site, along with CPS Energy’s other plant sites in the area, were experiencing 

significant freeze issues and multiple startup failures hours before the anticipated ERCOT 

deployment instruction was given, it would not have been unreasonable for the PUC to conclude 

that CPS Energy was required to have adequate staff on hand to ensure a timely deployment and to 

avoid startup failures at the critical time when NSRS energy was needed to balance the grid. 

Moreover, CPS Energy also asks us to overlook the duties that it owed to ERCOT after the 

startup failure occurred, and it appears to believe that the issue of whether it had adequate staff on 

hand to repair the equipment after it failed was irrelevant to the question of whether an ERCOT 

protocol violation occurred. In particular, CPS Energy contends that there is “no statute, rule, 

protocol, or standard regarding the efforts that a market participant must make and resources that 

must be available to repair an equipment failure once it has occurred.” We disagree. 

It is important to recognize the continuing nature of CPS Energy’s duties on the morning of 
39

February 2, 2011. CPS Energy pledged to stand ready to provide NSRS services to ERCOT upon 

its instruction from 4 to 5 a.m. that morning. It further pledged to have the NSRS services 

available to ERCOT within 30 minutes of its deployment instructions. And, most importantly, it 

pledged to provide the NSRS services to ERCOT for an hour after deployment.

Although CPS Energy may have been entitled to an excuse for compliance with the 

ERCOT protocol timelines when the equipment failure initially occurred, the language in

subsection (f) clearly states that the excuse does not last forever. Instead, it states that a “market 

participant is excused under this subparagraph only for so long as the condition continues.” 16

TEX. ADMIN. CODE § 25.503(f)(2)(C). This raises two possibilities: (1) that the excuse 

continues for as long as the “equipment failure” lasts; or (2) the excuse continues for as long as the 

“equipment failure beyond the reasonable control of the market participant[.]” We believe that 

the latter possibility is the only reasonable interpretation of this provision. By its very terms, the 

“condition” that provides the excuse in the WMO Rule is not “equipment failure” standing alone, 

but is instead “equipment failure beyond the reasonable control of the market participant[.]” Id. 

Any contrary interpretation would lead to the untenable position of allowing a market participant 

to simply throw up its hands and absolve itself of any blame once an initial equipment failure 

occurs, with no requirement that it make reasonable efforts to address the failure. Given the 

Legislature’s recognition of the crucial importance of keeping the grid in balance and electricity 

flowing to customers in a reliable manner, we cannot conclude this would be the Rule’s intent. 

We therefore conclude that CPS Energy was allowed to rely on the equipment failure as an excuse 

for its performance under subsection (f) only for as long is the equipment failure was “beyond its 

reasonable control.” 
40

In turn, we conclude that the PUC was allowed to make the factual determination of 

precisely when the equipment failure was no longer beyond CPS Energy’s “reasonable control,” 

and what steps CPS Energy was required to take to address that failure at that point in time. The 

question of whether CPS Energy adequately staffed its plant to be able to address the equipment 

failure after it initially occurred was a pivotal issue in the PUC’s analysis. And, whether CPS 

Energy had adequate staff on hand to address the failure once it occurred was clearly a factor 

within CPS Energy’s “reasonable control.”

The “Foreseeability” Factor

CPS Energy, however, argues that we should include a “foreseeability” analysis in 

determining whether the equipment failure was “beyond its reasonable control.” In particular, 

CPS Energy contends that it was unreasonable for the PUC to determine that it did not properly 

staff its plant in anticipation of an “unforeseeable” event, such as the frozen damper fan, which 

occurred on the morning of February 2. According to CPS Energy, it was unreasonable and

illogical for the PUC to conclude that it had any reasonable control over an unforeseeable event of 

this nature, and that it should have staffed its plant in advance based on an event that had not even 

occurred. Once again, CPS Energy contends that the PUC’s decision, if allowed to stand, will 

give the PUC the authority to second guess staffing decisions after the fact, and force market 

participants to engage in “clairvoyance” in trying to anticipate staffing needs in advance of 

virtually all unforeseeable and unanticipated events. According to CPS Energy, this will require 

market participants to adhere to an unobtainable standard of perfection and will essentially render 

all of the excuses set forth in subsection (f) meaningless. CPS Energy therefore contends that the 

PUC’s interpretation of the WMO Rule was not only unreasonable, but arbitrary and capricious, 
41

and made without reference to any guiding principles.

We disagree with CPS Energy’s “foreseeability” analysis for the same reasons we 

disagreed with its argument that it could not have reasonably anticipated that its actions in failing 

to adequately staff its plant would adversely affect the ERCOT electric network. As set forth 

above, the evidence presented at the SOAH hearing indicated that the February cold weather event 

was highly anticipated for days in advance. Further, all witnesses agreed that it was foreseeable 

that the cold weather event could lead to equipment failures at the Braunig plant site, and that 

adequate staffing was therefore needed to prevent and address those possible failures. And, more 

importantly, CPS Energy knew that it had a continuing duty to take all reasonable steps to ensure 

that the Braunig CT5 was ready to deploy on the morning of February 2, which included the duty 

not only to ensure that the unit was mechanically sound, but also to ensure that it had adequate staff 

to make certain that it would start up properly and continue running for the required period of time.

As CPS Energy does not deny that staffing its plant at an adequate level was a factor within 

its reasonable control, we believe that the PUC properly considered this factor in determining 

whether the equipment failure—the CT5’s failure to deploy the morning of February 2—was 

beyond CPS Energy’s reasonable control under the excuse provisions of subsection (f). 

The PUC’s Decision was based on Substantial Evidence

As set forth above, the PUC’s decision that CPS Energy was not excused from compliance 

with the ERCOT protocol under subsection (f) was based on two factors: (1) CPS Energy failed 

to carry its burden to prove that it provided “adequate staffing” at the Braunig plant site on the 

morning of February 2, in “light of its choice to offer NSRS from unproven units;” and (2) CPS 

Energy had several opportunities on the morning in question to “call in additional staffing . . . to 
42

ensure any start-up failures could be promptly addressed” but failed to do so.

In contending that this conclusion was not supported by substantial evidence, CPS Energy 

points out that it did in fact provide additional staffing at the plant, adding six additional operators 

and two technicians, which, at the time, it believed was sufficient to address any foreseeable 

problems the plant might encounter. CPS Energy further contends that the record is barren of any 

evidence demonstrating that this was not an “adequate” staffing level, and that the PUC failed to 

present any evidence to demonstrate that having more staff members on hand would have avoided 

the ERCOT violation.

The PUC did not have the burden of proof on this point, however. Instead, it was CPS 

Energy’s burden to establish an excuse and demonstrate that it took all reasonable steps within its 

control to avoid the ERCOT violation, and in particular to adequately staff its plant to ensure that 

the CT5 would operate as required. As the ALJ found, CPS Energy failed to meet this burden of 

proof because it failed to present any evidence to establish that it staffed its plant in accordance 

with industry standards during the cold weather event. Further, the PUC was entitled to rely on 

the testimony of the PUC’s witness, Greg Graham, who expressed his opinion that, in light of the 

potential for problems that could have occurred during the cold weather event and did in fact occur 

on the morning when CPS Energy had promised to provide NSRS services to ERCOT, CPS 

Energy should have had more staff available to troubleshoot and investigate start-up problems 

CPS Energy encountered on both February 1 and 2. Further, as Graham also pointed out, when 

the entire plant site started to encounter significant problems hours before it was required to deploy 

the Braunig CT5, CPS Energy knew that its two available technicians were assigned to other tasks, 

and that if problems occurred with the CT5, there would be no technicians to assist with the CT5’s 
43

deployment.

Further, regardless of the adequacy of its staffing levels, the record raises a significant 

question whether CPS Energy took all of the steps that were within its “reasonable control” to 

prevent the startup failure in the first instance, and to address that failure in a timely manner after it 

occurred. As set forth above, it is not unreasonable to conclude that CPS Energy should have 

required one of its employees to inspect or test the CT units before the anticipated ERCOT 

instruction was given, particularly in light of the significant freeze issues that had been occurring

several hours beforehand and in light of its knowledge that it would be required to provide NSRS 

power to ERCOT at a specific time the morning of February 2. Taking such actions could have 

detected the frozen damper fan in advance of the ERCOT deployment instruction, and thereby 

avoided the protocol violation in the first instance. 

Moreover, we find it significant that CPS Energy’s own witnesses testified that when the 

CT5 first failed to deploy, the control room operator received an alarm indicating that a tempering 

air fan discharge damper had failed to open, thereby alerting the operator to the particular problem. 

As CPS Energy was on notice there problem with the damper fan, it is unclear why CPS Energy 

did not direct one of the eight operators already at the plant to physically walk to the unit to inspect

the fan. This is particularly curious, as the record indicated that at least three of these operators 

were expressly tasked with the job of walking around the plant site throughout the cold weather 

event to inspect equipment for freeze damage. Having been alerted to the problem with the fan 

for over an hour before Warnke arrived at the plant and knocked the ice off the damper, it is 

unclear why CPS admittedly did not send one of these operators to the unit earlier to view the fan 

to determine if it was perhaps suffering from freeze damage, which was a distinct possibility in 
44

light of the weather conditions.

We also find it significant that although CPS Energy claims that the two technicians at the 

plant site were too busy with other tasks to investigate the problems with the CT5, Warnke 

testified that when he first arrived at the plant, the two technicians took the time to speak with him 

about the problems with the CT5 before Warnke walked out to the unit. In sum, at best, the record 

is in conflict regarding whether those technicians were unavailable to inspect the CT5 unit to 

determine if the damper fan was frozen.

We therefore conclude that the record adequately demonstrates that at several points in 

time during the morning of February 2, CPS Energy had various options at its disposal, which were 

within its reasonable control, to prevent and address the equipment failure, yet it failed to exercise 

any of those options. Because an equipment failure is excused only for as long as it is beyond a 

market participant’s control, we conclude that any excuse CPS Energy could have initially relied 

upon when the equipment first failed expired long before Warnke arrived at the scene to address 

the problem over an hour after CPS was alerted to the problem.

Accordingly, we conclude there was substantial evidence to support the PUC’s decision 

that CPS Energy failed to carry its burden of proving that the equipment failure on the morning of 

February 2, 2011 was “beyond its reasonable control,” and that the PUC therefore properly 

determined that CPS Energy was not excused from the ERCOT protocol under subsection (f) of 

the WMO Rule on that basis. Issue Two is overruled.

Issue Three: Whether CPS Energy was Excused from Complying with the ERCOT 

Protocols Based on the Health, Safety, and Environment Excuses in the WMO Rule

CPS Energy also relied on two other excuses found in subsection (f)(2)(C) of the WMO 

Rule. First, it relied on the provision in the Rule that allows a market participant to be excused 
45

from compliance with an ERCOT protocol “if compliance would jeopardize public health and 

safety or the reliability of the ERCOT transmission grid, or create risk of bodily harm or damage to 

the equipment[.]” 16 TEX. ADMIN. CODE § 25.503(f)(2)(C). Second, it relied on the related 

provision that a market participant is excused from compliance with an ERCOT protocol if 

“compliance would be inconsistent with facility licensing, environmental, or legal 

requirements[.]” Id.

CPS Energy contends that it presented undisputed evidence at the hearing that the events 

that occurred on the morning of February 2 fit within both of these excuses. In particular, it 

contends that it presented undisputed evidence that the Braunig CT5 unit failed to deploy on the 

morning of February 2 because the damper fan would not open, and that if it had attempted to 

operate the unit without the damper fan, this would have created a serious risk of an explosion, 

posing serious health and safety issues, destruction of the unit, and possible air pollution issues, 

which would have, in turn, caused CPS Energy to be in violation of air quality standards or its 

TCEQ-issued air permits.

The PUC, however, expressly concluded that CPS Energy could not rely on these 

exceptions, primarily because it found that there was no danger of any of these risks occurring, 

since the unit contained a built-in safety system ensuring that the unit would automatically shut 

down when it detected a safety risk, just as it did on the morning of February 2. CPS Energy, on 

the other hand, finds it irrelevant that the unit had a built-in safety system, pointing out that the 

evidence established that a CPS operator could have overridden the control system, and forced the 

unit to operate without the damper fan. CPS Energy points out that the record established that if 

the operator had done so, and the unit had started without an operating damper fan, this would have 
46

created the very risk to public safety and the environment that subsection (f) sought to avoid.

According to CPS Energy, the PUC’s “treatment of this undisputed evidence turns the WMO Rule 

on its head,” and in effect, would require a market participant to comply with an ERCOT protocol

regardless of the risk it might pose, thereby essentially eviscerating the entire excuse provisions

contained in subsection (f).

There is nothing in the record, however, to indicate that the control room operator made 

any attempt to override the safety system, or that the ERCOT operator ever suggested that he do 

so. In reality, no safety concerns existed at the time ERCOT gave its instruction to deploy the 

unit, or at any time thereafter when the operator was attempted to start the system. Further, 

overriding the safety system was not CPS Energy’s only option to avoid the protocol violation. It

had other means at its disposal to comply with the ERCOT protocol. CPS Energy staff could have 

tested or inspected the CT5 unit prior to the anticipated deployment time, which would have given 

it sufficient time to address the problem with the frozen damper prior to the anticipated ERCOT 

deployment instruction. Moreover, once the control room operator received the alarm indicating 

that the damper fan had failed to open, CPS Energy was on notice it needed to take all reasonable

steps to determine the cause of the failure. We find it significant, as the PUC did, that due to 

inadequate staffing, CPS Energy was unable or unwilling to take any steps to determine the cause 

of that failure until over an hour later when Warnke finally arrived at the plant site to inspect the 

fan.

CPS Energy also objects that in reaching its conclusion, the ALJ interpreted the WMO 

Rule to imply an “element” requiring a market participant “to have taken all reasonable steps” to 

avoid a WMO Rule violation before the market participant is entitled to rely on the excuse 
47

provisions set forth in that Rule. In particular, CPS Energy points out that the ALJ found that 

CPS Energy had not taken all reasonable steps to avoid the ERCOT protocol violation due to its

failure to adequately staff its plant in anticipation of the cold weather event, and therefore 

concluded that CPS Energy was not allowed to rely on the subsection (f) excuses.

CPS Energy contends this was an erroneous interpretation and “unsound” application of 

the WMO Rule, contrary to the Rule’s plain language. According to CPS Energy, the plain 

language of the Rule makes it clear that the “only relevant factual determination” to be made in 

applying this excuse provision is whether a market participant’s compliance with the ERCOT 

instruction would have posed one of the enumerated dangers to safety, bodily harm, and 

equipment. In CPS Energy’s opinion, the PUC’s decision, in allegedly adding a new element to 

the excuse provision in the Rule, was improper and exceeded its authority. CPS Energy also 

contends that this was a new or novel interpretation of the Rule, and that CPS Energy was therefore 

not on notice of this interpretation prior to the enforcement proceeding, contending that it was once 

again thereby deprived of “fair notice” of the type of conduct that was expected of it in this 

situation. We disagree.

First, when a rule is ambiguous or otherwise leaves room for policy determinations, we 

defer to the agency’s interpretation if the interpretation is reasonable. CenterPoint Energy 

Houston Elec., LLC, 408 S.W.3d at 916-17 (citing Rodriguez, 997 S.W.2d at 254–55); see also

City of El Paso v. Pub. Util. Comm’n of Texas, 344 S.W.3d at 618-19. Second, when an 

administrative rule or statute is unambiguous, it must be interpreted based on its plain language, 

but not if such an interpretation would produce an absurd result. Fleming Foods of Tex., Inc., 6 

S.W.3d at 284; State, 246 S.W.3d at 332.
48

In the present case, regardless of whether the WMO Rule is ambiguous, we believe there is 

room for the PUC to make the policy determination that a market participant is obligated to 

exercise due diligence in meeting its duty to comply with an ERCOT protocol before it should be 

allowed to raise an excuse from compliance based on health, safety, or environmental concerns. 

As the PUC points out, to interpret the WMO Rule otherwise would lead to the absurd result that a 

market participant could seek to excuse a failure to comply with an ERCOT protocol or an ERCOT 

instruction to deliver power, based on a health or safety risk, even if that very risk was caused by 

the market provider’s own negligence in not maintaining its equipment or in failing to adequately 

staff its plant. As the PUC points out, the excuses set forth in the WMO Rule do not give market 

providers a “free pass” to act with negligence in violating ERCOT protocols or instructions, and to 

later claim an excuse of this nature; instead the market participant must act with due diligence to 

avoid the potential violation in the first place.

Contrary to CPS Energy’s claim, this interpretation is not unreasonable, and instead 

promotes the very goals the Legislature sought to achieve in adopting the regulatory and 

enforcement scheme set forth in PURA, i.e., to ensure the “reliability and adequacy of the regional 

electrical network,” and to ensure that market participants comply with ERCOT protocols in 

furtherance of that goal. TEX. UTIL. CODE ANN. §§ 39.151(a, c), 39.1515(a, c). Any 

interpretation to the contrary would essentially allow a market participant to avoid an enforcement 

proceeding regardless of whether its negligent conduct adversely affected the reliability of the 

grid, and would be contrary to the legislative intent of ensuring the grid’s reliability. Therefore, 

we conclude the PUC’s interpretation of its own rule was reasonable. 

Moreover, we disagree with CPS Energy’s contention that the PUC adopted a new or novel 
49

interpretation of the WMO Rule when it read an element of “diligence” into the Rule’s excuse 

provisions. Instead, as pointed out above, the Austin Court spoke on this issue over ten years ago 

in TXU Generation, when it advised market participants that in the final analysis, the WMO Rule 

requires market participants to be guided at all times by the concept of “diligence.” TXU 

Generation, 165 S.W.3d at 840. 

CPS Energy seeks to rely on the health, safety, and environmental excuses set forth in the 

WMO Rule on the ground its Braunig CT5 Unit failed to deploy due to a safety issue related to the 

damper fan’s failure to open, which could have caused the unit to explode or otherwise be 

damaged if the unit was operated under those conditions. However, this safety issue could have 

been avoided if CPS Energy had exercised due diligence prior to the initial startup by having its 

staff test or inspect the unit before the anticipated time the ERCOT deployment instruction was 

given. Further, even if the safety excuse was valid when the initial startup sequence was first 

interrupted by the safety feature in the unit, CPS Energy’s duty to ERCOT did not end at that point. 

Instead, its duty to ensure that the CT5 unit timely deployed was continuing in nature. Thus, once 

the control room operator received the signal that the unit had shut down because the damper fan 

had failed to open, alerting it that a safety issue existed, it was incumbent upon CPS Energy to 

exercise due diligence to address that problem as quickly as possible, so that it could, in turn, 

comply with the ERCOT instruction to deploy the unit in a timely manner. 

Requiring CPS Energy to take reasonable steps not only to prevent but also to address 

safety issues once they arise, and to do so as quickly and as diligently as possible, is both 

reasonable and consistent with the plain language of the WMO Rule, which allows the market 

participant to rely on an excuse only for as long as the “condition continues.” 16 TEX. ADMIN.
50

CODE § 25.503 (f)(2)(C). This language is a clear warning to market participants that they must 

exercise due diligence to detect and correct any underlying problems that may be causing an 

excuse—in this case, the damper fan’s failure to open—as quickly as possible to ensure that they 

are able to meet their ERCOT obligations within a reasonable timeframe. It would lead to an 

absurd result if the WMO Rule were interpreted otherwise, as market participants would then be 

able to rely on an excuse for as long as they might chose, without taking any steps to come into 

compliance with the Rule within a reasonable timeframe. 

Yet, CPS Energy essentially did just that the morning of February 2, waiting for over an 

hour to take any reasonable steps to investigate the cause of the damper fan’s failure to open, either 

because it did not have adequate staff to do so, or because it chose not to assign its available staff to 

perform that task. Either way, at that point, the PUC was entitled to make the determination that 

CPS Energy was no longer entitled to rely on any of the excuse provisions contained in the WMO 

Rule due to its own lack of due diligence. 

Accordingly, we conclude that the PUC did not erroneously interpret the WMO Rule, and 

that it properly rejected CPS Energy’s claim that it was excused from compliance with the ERCOT 

protocol for any health, safety, or environmental concerns. Issue Three is overruled.

Issue Four: Whether CPS Energy was Excused from Complying with the ERCOT 

Protocols Based on the Exemptions found in the Protocols themselves 

In its last issue, CPS Energy claims that it should be excused from complying with the 

ERCOT protocols based on the exemptions found in the protocols themselves, which CPS Energy 

refers to as “trump” provisions. CPS Energy contends that these exemptions are “safe harbor” 

provisions, and that in effect, if a market participant comes within one of these provisions, it 

cannot be said to have violated another separate ERCOT protocol. While we agree that these 
51

protocols could, if applicable, exempt a market participant from compliance with another ERCOT 

protocol or instruction, we do not agree that these protocols provide CPS Energy with any relief in 

this case. 

The Operating Limits Protocol

First, CPS Energy cites to what it refers to as the “operating limits” protocol:

ERCOT shall consider all equipment operating limits when issuing Dispatch 

Instructions. Except as stated in Section 6.5.9 Emergency Operations, if a Dispatch 

Instruction conflicts with a restriction that may be placed on equipment from time to 

time by a TSP, a DSP, or a Generation Resource’s QSE to protect the integrity of 

equipment, ERCOT shall honor the restriction. 

ERCOT Protocol 6.5.3.(1). CPS Energy believes that its actions on February 2 came within this 

“exemption,” because the CT5 unit failed to deploy due to a “restriction” that was placed on the 

unit—apparently referring to the automated safety system that caused the unit to automatically 

shut down on the morning of February 2, when it detected a safety issue. The PUC, on the other 

hand, contends that this protocol is inapplicable to the facts of this case. We agree with the PUC. 

We note that this particular subsection comes under the Protocol Section, entitled, 

“Equipment Operating Ratings and Limits.” ERCOT Protocol 6.5.3. Two subsections are 

contained within this protocol. The first, which CPS Energy cites, deals with “equipment 

operating limits” and relates to “restrictions” that the market participant itself has placed on its 

own equipment to ensure the safety of its equipment. In turn, the second subsection in the 

protocol provides a list of these various limits, which relate to a generating unit’s operating 

capabilities.

9

 ERCOT Protocol 6.5.3.(2). The second subsection specifically provides that a

 

9

In particular, this second protocol provides that: “Each TSP shall notify ERCOT of any limitations on the TSP’s 

system that may affect ERCOT Dispatch Instructions. ERCOT shall continuously maintain a posting on the MIS 

Secure Area of any TSP limitations that may affect Dispatch Instructions. Examples of such limitations may include: 

temporary changes to transmission or transformer ratings, temporary changes to range of automatic tap position 
52

market participant must “notify ERCOT of any limitations on the [participant’s] system that may 

affect ERCOT Dispatch Instructions,” and then requires ERCOT to “continuously maintain a 

posting on the MIS Secure Area of any . . . limitations that may affect Dispatch Instructions.” Id.

As the PUC points out, these operating protocols are not applicable to the present situation. 

When the CT5 unit failed to deploy, it was not because CPS Energy was addressing any issues 

involving the type of “equipment operating limits” contemplated by these protocols. In other 

words, CPS Energy had not placed any “restrictions” on its equipment of the type contemplated. 

Further, as required by the protocol itself, CPS Energy did not notify the PUC of any “equipment 

operating limits” described by those protocols. As such, we reject CPS Energy’s claim that it was 

entitled to rely on this protocol to excuse its compliance with the ERCOT instruction on the 

morning of February 2.

10

The Compliance Protocol

Second, CPS Energy cites to what it refers to as the “compliance” protocol: 

Except as otherwise specified in this Section, each TSP and each QSE shall comply 

fully and promptly with a Dispatch Instruction issued to it, unless in the sole and 

reasonable judgment of the TSP or QSE, such compliance would create an undue 

threat to safety, undue risk of bodily harm or undue damage to equipment, or the 

Dispatch Instruction is otherwise not in compliance with these Protocols.

ERCOT Protocol 6.5.7.9(1). CPS Energy contends that its actions on February 2 came within the 

clear language of this protocol, because it could not comply with the ERCOT instruction to deploy 

the Braunig CT5 unit due to safety concerns, and because the risk that deploying the unit, without 

 

capabilities on auto-transformers, fixing or blocking tap changer, changes to no-load tap positions or other limitations 

affecting the delivery of energy across the ERCOT Transmission Grid. Any conflicts that cannot be satisfactorily 

resolved may be brought to ERCOT by any of the affected Entities for investigation and resolution.” 

10 CPS Energy argues that because Protocol 6.5.3 does not itself contain a notice provision, we should not conclude 

that any such notice was required. However, as noted above, these two protocols are found within the same section 

and must be read together. 
53

a functioning damper fan, would have caused bodily harm or undue damage to equipment. The 

PUC points out, however, that this protocol by its plain language applies only when the market 

participant makes a decision based on its “sole and reasonable judgment” that compliance with an 

ERCOT instruction would cause a risk of that nature. In the present case, CPS Energy made no 

such judgment to refuse to comply with the ERCOT instructions. Instead, after the CT5 unit had 

automatically shut down when it detected a damper fan malfunction, CPS Energy continued to try 

to deploy the unit, and made two additional failed attempts to start it, with no apparent concern that 

it might need to investigate any safety issues before doing so. As such, it cannot be said that CPS 

Energy used its “sole and reasonable judgment” not to comply with the ERCOT protocol that 

morning due to any safety concerns. 

More importantly, however, we note that CPS Energy failed to notify ERCOT that it was 

relying on this provision on the morning in question, as required by ERCOT Protocol 6.5.7.9(2), 

which provides: 

If the recipient of a Dispatch Instruction does not comply because in the sole and 

reasonable judgment of the TSP or QSE, such compliance would create an undue 

threat to safety, undue risk of bodily harm, or undue damage to equipment, then the 

TSP or QSE must immediately notify ERCOT and provide the reason for 

non-compliance.

CPS Energy contends that this notice provision is inapplicable to the compliance protocol, 

apparently believing that it is in an entirely separate and unrelated protocol, and that it would be 

improper to read the two provisions in conjunction. We disagree. Both of these provisions are 

found under the heading “Compliance with Dispatch Instructions,” and are simply subsections of 

ERCOT Protocol 6.5.7.9. The first subsection provides the exemption itself, and the second 

subsection, mirroring the exemption language used in the first subsection, expressly requires 
54

market participants relying on the first subsection to provide notice to ERCOT of its intent to do 

so. It is therefore obvious that these two provisions must be read together. 

CPS Energy next contends that even if it were required to provide notice under this 

protocol, it did in fact give sufficient notice to ERCOT during the conversation its control room 

operator had with the ERCOT operator on the morning of February 2, when it first reported the 

unit’s failure to deploy. In particular, CPS Energy points out that its control room operator

advised the ERCOT operator that the unit was “tripping offline,” and that the reason for the failed 

start was “low tempering pressures.” CPS Energy contends that this should be considered 

sufficient notice that a safety issue existed, and that its operator should not have been required to 

provide the ERCOT operator with a detailed “legalese” account of the failure. CPS Energy 

further contends that requiring a market participant to provide a detailed description of a safety 

issue in order to invoke this protocol is an unreasonable interpretation of the protocol, pointing out 

that fully developed information about a generation unit failure is rarely available in real time, and 

that in an emergency situation, a market participant operator will rarely have the ability to provide 

detailed information about a safety issue to an ERCOT operator on a contemporaneous basis.

We agree that the ERCOT protocol does not require the market participant to provide a 

highly detailed account of a safety issue during an emergency situation, any more than it requires 

an ERCOT operator to be clairvoyant in attempting to discern whether a market participant is 

attempting to rely on the exemption in the protocol. Instead, what the rule does require, by its 

plain language, is a clear communication from the market participant to ERCOT that it is failing or 

refusing to comply with an ERCOT instruction because it has made a reasonable judgment that 

doing so would create an undue safety threat or risk of harm. As set forth above, CPS Energy did 
55

not notify ERCOT that it had made any such a judgment because, in point of fact, it had not made 

such a judgment. Instead, the undisputed evidence demonstrated that the CPS Energy control 

room operator agreed with the ERCOT operator to continue trying to start the unit, and expressed 

no concern to the ERCOT operator that doing so might cause any type of safety or health risk. 

These continued attempts to start the unit, before addressing the root cause of the startup failure 

over an hour later, undercuts any contention that CPS Energy believed, in its reasonable judgment,

that continuing to try to start the unit in compliance with ERCOT instructions would have in fact 

created any undue safety risks. 

Accordingly, we conclude that CPS Energy was not entitled to rely on the provisions of the 

compliance protocol to exempt it from liability for violating the WMO Rule. Issue Four is 

overruled.

CONCLUSION

The trial court’s judgment is affirmed.

STEVEN L. HUGHES, Justice

November 30, 2016

Before Rodriguez, J., Hughes, J., and Larsen, J. (Senior Judge)

Larsen, J. (Senior Judge), sitting by assignment