Texas Staff File Revised Reserve Margin Questions for Consideration

Staff of the Public Utility Commission of Texas have filed a revised set of questions regarding the Commission's review of the ERCOT reserve margin which Staff recommends be issued for public comment.

Staff also sought confirmation that the Commission wishes to hold a Commission-led workshop in March or April as previously contemplated.

Staff's suggested questions are below:

ERCOT's 1-Event-in-10-Years (0.1 LOLE) Reliability Standard

1. Please comment on the origins of the 0.1 LOLE standard currently in use in ERCOT. Does the historical rationale for the use of this standard still hold today?

2. Does the 0.1 LOLE target correspond with a rational or cost-effective level of reliability?

Expected Unserved Energy (EUE)

3. Please comment on the Brattle Group's recommendation that ERCOT adopt an EUE-based standard.

4. If an EUE-based standard is implemented, how should the target amount of EUE be determined? How would economics be considered in this determination, if at all?

Economically Optimal Reserve Margin (EORM)

5. If ERCOT bases its reliability standard on the EORM (as certain other regions do), how often should it be calculated and by what process should its assumptions be evaluated?

6. Different end-use customers have different risk preferences. If ERCOT adopts a risk-averse EORM, how should a system-wide estimate of risk aversion reflect this diversity?

Related Issues

7. Are there any combinations of standards that are complementary to each other? If so, please explain how the combination of any such standards would be useful in measuring reliability.

8. Should any additional factors be considered when choosing a reliability standard?

Project 42302