© CONSTELLATION ENERGY GROUP, INC. THE OFFERING DESCRIBED IN THIS PRESENTATION IS SOLD AND CONTRACTED BY CONSTELLATION NEWENERGY, INC., A SUBSIDIARY OF CONSTELLATION ENERGY GROUP, INC. BRAND NAMES AND PRODUCT NAMES ARE TRADEMARKS OR SERVICE MARKS OF THEIR RESPECTIVE HOLDERS. ALL RIGHTS RESERVED. ERRORS AND OMISSIONS EXCEPTED. 1 Comparability There is a misconception that the only entity that can be held responsible for a Load Resource failure is the QSE based upon: 1.The QSE provides the ancillary service 2.The QSE has a financial relationship with ERCOT This is not comparable to that of generation. There are a number of instances within the Protocols where Generation Resources are held accountable for their own failure.

© CONSTELLATION ENERGY GROUP, INC. THE OFFERING DESCRIBED IN THIS PRESENTATION IS SOLD AND CONTRACTED BY CONSTELLATION NEWENERGY, INC., A SUBSIDIARY OF CONSTELLATION ENERGY GROUP, INC. BRAND NAMES AND PRODUCT NAMES ARE TRADEMARKS OR SERVICE MARKS OF THEIR RESPECTIVE HOLDERS. ALL RIGHTS RESERVED. ERRORS AND OMISSIONS EXCEPTED. 2 According to the TRE for the current market… Power Generation Company (PGC) requirements are as follows: 1.Automatic Voltage Regulator (AVR) Performance 2.Black Start Procedures 3.Black Start Service and Performance 4.Generator Modeling Requirements 5.Generator Under-Frequency Relay Coordination 6.Net Dependable Capability Performance 7.Outage Scheduling Procedures, 12-Month 8.Reactive Testing 9.Reliability Must-Run (RMR) Generation Performance 10.System Operator Training These are the requirements to which Resources are held accountable. The summary can be found at:

© CONSTELLATION ENERGY GROUP, INC. THE OFFERING DESCRIBED IN THIS PRESENTATION IS SOLD AND CONTRACTED BY CONSTELLATION NEWENERGY, INC., A SUBSIDIARY OF CONSTELLATION ENERGY GROUP, INC. BRAND NAMES AND PRODUCT NAMES ARE TRADEMARKS OR SERVICE MARKS OF THEIR RESPECTIVE HOLDERS. ALL RIGHTS RESERVED. ERRORS AND OMISSIONS EXCEPTED. 3 Black start comparison Section 2 of the Nodal Protocols: Black Start Service (BSS) - An Ancillary Service provided by a Resource able to start without support of the ERCOT Transmission Grid. Black Start Resource - A Generation Resource under contract with ERCOT to provide BSS. Load Resource - A Load capable of providing Ancillary Service to the ERCOT System and registered with ERCOT as a Load Resource. Section of the Nodal Protocols: (1) Black-Start Service is obtained by ERCOT through Black Start Agreements with QSEs for Generation Resources capable of self-starting… Therefore, a Black Start Resource is an ancillary service represented by a QSE. Further, while a Black Start Resource does have a contract directly with ERCOT, there is a relationship (through registration) between ERCOT and Load Resources.

© CONSTELLATION ENERGY GROUP, INC. THE OFFERING DESCRIBED IN THIS PRESENTATION IS SOLD AND CONTRACTED BY CONSTELLATION NEWENERGY, INC., A SUBSIDIARY OF CONSTELLATION ENERGY GROUP, INC. BRAND NAMES AND PRODUCT NAMES ARE TRADEMARKS OR SERVICE MARKS OF THEIR RESPECTIVE HOLDERS. ALL RIGHTS RESERVED. ERRORS AND OMISSIONS EXCEPTED. 4 Black start comparison Section of the Nodal Protocols: (2) ERCOT shall revoke the qualification of a Black Start Resource and reduce the Black Start Resources’ Hourly Standby Fee (if under an existing Black Start Agreement) to zero during the time of disqualification if the Black Start Resource fails to perform successfully during a test described herein, until the Black Start Resource is successfully retested. ERCOT may limit the number of retests allowed. Retesting is required only for the aspect of system Black Start Service capability for which the Black Start Resource failed. If a Black Start Resource under an existing Black Start Agreement does not successfully re-qualify within two months of failing a test described herein, ERCOT shall decertify the Black Start Resource for the remainder of the calendar year as described in Section 7, Black Start Decertification, of Section 22, Attachment D, Standard Form Black Start Agreement. Testing failures are not the liability of the QSE for Black Start. This appears consistent with Load Resource testing in NPRR243 Section (9).

© CONSTELLATION ENERGY GROUP, INC. THE OFFERING DESCRIBED IN THIS PRESENTATION IS SOLD AND CONTRACTED BY CONSTELLATION NEWENERGY, INC., A SUBSIDIARY OF CONSTELLATION ENERGY GROUP, INC. BRAND NAMES AND PRODUCT NAMES ARE TRADEMARKS OR SERVICE MARKS OF THEIR RESPECTIVE HOLDERS. ALL RIGHTS RESERVED. ERRORS AND OMISSIONS EXCEPTED. 5 Black start comparison Section of the Nodal Protocols: (3) ERCOT shall decertify a Black Start Resource for the remainder of the contract term if the Black Start Resource fails to perform successfully during an actual ERCOT System blackout event and the Black Start Resource has been declared available, as defined in Section 22, Attachment D. Performance failures are not the liability of the QSE for Black Start. Further, the penalty is decertification – similar to suspension of Load Resources for a failure. Since there is no direct financial penalty from ERCOT, the ERCOT to QSE financial relationship is not a requirement.

© CONSTELLATION ENERGY GROUP, INC. THE OFFERING DESCRIBED IN THIS PRESENTATION IS SOLD AND CONTRACTED BY CONSTELLATION NEWENERGY, INC., A SUBSIDIARY OF CONSTELLATION ENERGY GROUP, INC. BRAND NAMES AND PRODUCT NAMES ARE TRADEMARKS OR SERVICE MARKS OF THEIR RESPECTIVE HOLDERS. ALL RIGHTS RESERVED. ERRORS AND OMISSIONS EXCEPTED. 6 Relay comparison Section of the Nodal Operating Guides: (2) Although relaying of tie points between facility owners is of primary concern to the ERCOT System, internal protective relay system often directly, or indirectly, affects the adjacent area also. Facility owners are those Entities owning facilities in the ERCOT System. Facility owners have an obligation to implement relay application, operation, and preventive maintenance criteria that assure the highest practicable reliability and availability of service to the ultimate power consumers of the concerned area and neighboring areas. Protective relay system of individual facility owners shall not adversely affect the stability of ERCOT System interconnections. Additional minimum protective relay system requirements are outlined in the North American Electric Reliability Corporation (NERC) Reliability Standards.

© CONSTELLATION ENERGY GROUP, INC. THE OFFERING DESCRIBED IN THIS PRESENTATION IS SOLD AND CONTRACTED BY CONSTELLATION NEWENERGY, INC., A SUBSIDIARY OF CONSTELLATION ENERGY GROUP, INC. BRAND NAMES AND PRODUCT NAMES ARE TRADEMARKS OR SERVICE MARKS OF THEIR RESPECTIVE HOLDERS. ALL RIGHTS RESERVED. ERRORS AND OMISSIONS EXCEPTED. 7 Relay comparison Section of the Nodal Operating Guides: (3) These objectives and design practices shall apply to all new protective relay system applied at 60 kV and above unless otherwise specified. It is recognized that there may be portions of the existing ERCOT System that do not meet these objectives. It is the responsibility of individual facility owners to assess the protective relay system at these locations and to make any modifications that they deem necessary. Similar assessment and judgment should be used with respect to protective relay system existing at the time of revisions to this guide. Special local conditions or considerations may necessitate the use of more stringent design criteria and practices.

© CONSTELLATION ENERGY GROUP, INC. THE OFFERING DESCRIBED IN THIS PRESENTATION IS SOLD AND CONTRACTED BY CONSTELLATION NEWENERGY, INC., A SUBSIDIARY OF CONSTELLATION ENERGY GROUP, INC. BRAND NAMES AND PRODUCT NAMES ARE TRADEMARKS OR SERVICE MARKS OF THEIR RESPECTIVE HOLDERS. ALL RIGHTS RESERVED. ERRORS AND OMISSIONS EXCEPTED. 8 Relay comparison Section of the Nodal Operating Guides: (7) All facility owners shall give sufficient advance notice to ERCOT of any changes to their facilities that could require changes in the protective relay system of neighboring facility owners. (8) Facility owners’ operations personnel shall be familiar with the purposes and limitations of the protective relay system. (9) The design, coordination, and maintainability of all existing protective relay systems shall be reviewed periodically by the facility owner to ensure that the protective relay systems continue to meet ERCOT System requirements. This review shall include the need for redundancy. Where redundant protective relay systems are required, separate AC current inputs and separately fused DC control voltages shall be provided with the upgraded protective relay system. Documentation of the review shall be maintained and supplied by the facility owner to ERCOT or NERC on their request within 30 days. This documentation shall be reviewed by ERCOT for verification of implementation.

© CONSTELLATION ENERGY GROUP, INC. THE OFFERING DESCRIBED IN THIS PRESENTATION IS SOLD AND CONTRACTED BY CONSTELLATION NEWENERGY, INC., A SUBSIDIARY OF CONSTELLATION ENERGY GROUP, INC. BRAND NAMES AND PRODUCT NAMES ARE TRADEMARKS OR SERVICE MARKS OF THEIR RESPECTIVE HOLDERS. ALL RIGHTS RESERVED. ERRORS AND OMISSIONS EXCEPTED. 9 Relay comparison Section of the Nodal Operating Guides: (10) Upon ERCOT’s request, within 30 days, Resource Entities shall provide ERCOT with the operating characteristics of any generator’s equipment protective relay system or controls that may respond to temporary excursions in voltage, frequency, or loading with actions that could lead to tripping of the generator. (11) Upon ERCOT’s request, within 30 days, Resource Entities shall provide ERCOT with the operating characteristics of any generator’s equipment protective relay system or controls that may respond to temporary excursions in voltage, frequency, or loading with actions that could lead to tripping of the generator. It is clear that within the Nodal Operating Guides, the design, maintenance, any needed testing, and operation of relays are the sole responsibility of the facility owner, not the QSE. This same standard should be made clear for Load Resources.

© CONSTELLATION ENERGY GROUP, INC. THE OFFERING DESCRIBED IN THIS PRESENTATION IS SOLD AND CONTRACTED BY CONSTELLATION NEWENERGY, INC., A SUBSIDIARY OF CONSTELLATION ENERGY GROUP, INC. BRAND NAMES AND PRODUCT NAMES ARE TRADEMARKS OR SERVICE MARKS OF THEIR RESPECTIVE HOLDERS. ALL RIGHTS RESERVED. ERRORS AND OMISSIONS EXCEPTED. 10 Conclusion The responsibility for QSE or Load Resource failure should be: 1.Clear – so that responsibilities are well-known in advance and compliance ramifications assigned to the appropriate party. 2.Reasonable – It would be impossible to attempt to codify in Protocol the myriad of deployment methods, contractual arrangements, etc. of a Load Resource. This must be recognized and realistic Protocol language implemented. 3.Consistent – Load Resources should not be held to higher standards than other entities, nor should there be different standards between ERCOT, TRE and PUCT. The above can be met with: 1.A NOGRR (text included with NPRR243 doc for simplicity) to address clarification that UFR requirements are on par with other relays (see Section (c); Section included for ease of reference only – no changes). 2.Inclusion of language modeled after the TRE Standard (TOP R4) to ensure consistency of compliance standards for deployments (see NPRR (f), (g) and (h)).