Please provide any potential topics your organization would like considered as scope for the Gas Resource Management working groups and stakeholder initiative:
Vistra appreciates the CAISO seeking feedback on challenges that gas Electric Generators (EG) are having with participating in CAISO’s day-ahead market or real-time Western Energy Imbalance market. We believe it is critical that this effort tackles the difficult challenges that EG have been raising with the CAISO about managing gas system operator directed outages through existing outage management practices.
As a gas EG we receive instructions from the gas company to take outages so that the necessary work can be performed. While we understand these outages may need to be taken to maintain the reliability of the gas infrastructure, the gas companies are usually inflexible on when the outages can be scheduled, and these outages generally do not overlap with EG planned outages that generally take place in the Spring. Further, in addition to gas operator directed outages, EG also receive Long Term Service Agreement (LTSA) vendors instructed outages to avoid plant failures. An EG would only advance plan to have substitution during an outage for EG planned outages it is aware of and can control when they occur during that month. In both gas company directed outages and LTSA directed outages an EG would not have advance notice to secure substitute capacity for any RA capacity. If identified prior to T-45, Vistra accepts that the existing policies require substitute capacity when shown on the RA plan at T-45. However, imposing the same standards on outages identified after the RA showing during a period where substitute capacity is illiquid, and in most cases unavailable, is unreasonable. This scope should include outages outside an EG control identified after T-45 that occur to gas-fired EG that we cannot control.
Example 1 - Gas company directed outage for pipeline maintenance work after T-8
For example, the gas pipeline needs a maintenance outage that results in curtailment of EG on that portion of the pipeline. In this instance, we as the SC of the affected EG must submit outage card to the CAISO, however there are challenges with this because some pipeline maintenance advance notice may not yet define the days or hours, or MMBtu amounts that will be reduced. As such, it is likely that we will not know the hours and amounts until the forced outage horizon, when we submit this gas operator instructed outage to CAISO today it is under a “Ambient not due to Temp” card, which is exposed to Resource Adequacy Availability Incentive Mechanism (RAAIM) penalties. However, the CAISO Tariff adopted exclusions to RAAIM for certain outage types in Section 188.8.131.52(d) that include an outage in a nature of work category specified in BPM that relates to administrative action by resource owner, a cause outside of the control of the resource owner, short-term use limitation, or non-Run-of-River hydro resources management of water related operational or regulatory limitations. This example of an outage type meets the criteria outlined because it is not within the control of the EG, however outage management manual does not allow for a card to support this outage reason where the card is flagged as meeting these criteria. This is an existing issue that should be addressed to provide an outage card eligible for this outage type that is excluded from RAAIM per Tariff Section 184.108.40.206(d).
Example 2 - Gas company directed outage for non-routine pipeline (pigging) prior to T-8
There are also outages required by the gas company communicated more than eight days prior to the operating day that the CAISO calls Planned Outages in its Business Practice Manual. For example, gas companies can identify the set of days and hours within the day that the EG must operate to provide must flow amount to support pigging work. When submitting the outage prior to eight days before the operating day, the CAISO treats this as a planned outage when in practice it is a forced outage that is noticed sooner than eight days. The Tariff refers to Maintenance Outages that are known at least eight days prior to the operating day. The Tariff does not detail how forced outages outside the resource owner control that are issued prior to eight days of the operating day should be handled, because the Tariff only refers to maintenance outages. Maintenance outages are defined in Appendix A as, “A period of time during which an Operator (i) takes its transmission facilities out of service for the purposes of carrying out routine planned maintenance, or for the purposes of new construction work or for work on de-energized and live transmission facilities (e.g., relay maintenance or insulator washing) and associated equipment; or (ii) limits the capability of or takes its Generating Unit or System Unit out of service for the purposes of carrying out routine planned maintenance, or for the purposes of new construction work.” This leads to confusion when there is a lack of clarity in the Tariff on how Maintenance Outage rules should apply to Planned Outages that are not maintenance outages. For example, Vistra interprets the Appendix A definition of maintenance outage to refer to planned maintenance work on the Electric Generator or its interconnection facilities not work being performed by Transmission Operator or by Gas Operator that triggers curtailments on EG without our ability to affect those outages. Today, there is a path for submitting an EG outage triggered by transmission maintenance work performed on transmission elements under the “Transmission Induced” outage card that is exempt from RAAIM. However, there is no associated card for “Gas system induced” that is also exempt from RAAIM for an EG outage triggered by gas operator’s maintenance work. This issue has caused repeated challenges with gas management of EG as should be discussed in this effort. We believe discussions on improving how planned outage substitution obligations are defined, enforced, and addressed should be discussed in this effort as this is a significant challenge.
Example 3 - Reliability directed outages from e.g., Long Term Service Agreement vendor
In addition to gas operator directed outages, EG also receive Long Term Service Agreement (LTSA) vendors instructed outages to avoid plant failures. For example, an EG may have planned and scheduled their Maintenance Outage far in advance and secured substitute capacity for that month. However, when the LTSA vendor instructs based on its tests that the maintenance work must be moved up, this effectively moves a planned maintenance outage forward due to plant failure risks if not taken when told to do so. This results in needing to submit a new outage card that may not have substitution, where today CAISO declines the outage request if there is no substitution. It is not reasonable to expect a SC to be able to secure substitution in e.g., the T-20 days prior to the start date of the accelerated outage. As a result, the CAISO would in most cases decline the outage, where the process for seeking approval to resubmit the outage as forced outage is not adequately defined. Consequently, Vistra generally believes this process requires CAISO leadership level approval, which adds burdens on CAISO staff. It is critical to understand that these outages are not optional. The outages impact critical plant equipment of gas generation that if it is continued to operate and leads to plant failure, which take more time to return to service. It is not in the best interest of the EG or grid to operate a plant such that it has an imminent risk of plant failure that could lead to it being out of service when needed for reliability. We believe discussions on improving how planned outage substitution obligations are defined, enforced, and addressed should be discussed in this effort as this is a significant challenge for EG.
Vistra recommends the following solutions be considered in scope:
- Advanced notice forced outages should be explicitly discussed and any necessary rules identified. Advanced notice forced outages are outages outside the resource owner control that are identified up to eight days prior to operating day. For purposes of compromising on the solutions, Vistra is comfortable starting with defining these as between T-45 and T-0 of the compliance month.
- Advanced notice forced outages that EG cannot delay or reschedule, since they are out of the owner’s control, whether gas or plant operations related should not be denied as planned outages and then forced to resubmit as forced. These should be accepted as planned outages that do not require substitution since the outage was identified after T-45 day showing. The logic is that at the time of showing the resource on the supply plan this outage was not known by the seller, and after which the RA resource cannot reasonably be expected to find substitute capacity for any advance notice forced outages due to lack of liquidity and structure of substitute capacity markets.
- Outage management practices could be revised to accommodate the gas company or LTSA vendor directed outages by:
- For the gas operator directed outages: These types of outages are entered into by the direction of the gas company and only after determined that they cannot move. The appropriate outage card for this type of work would be to treat it consistent with transmission outages. CAISO should ensure that EGs have an outage card that is not exposed to RAAIM for submitting these types of outages occurring after T-45.
- For the reliability triggered EG outages instructed by LTSA vendor: These types of outages are entered into when plant equipment fails or is in danger of imminent failure resulting in a curtailment of dispatchable capacity. This is the appropriate description for these types of outages. However, CAISO should not expose them to RAAIM since these are outside the EG owner’s control. Additionally, CAISO should add Advanced Notice Forced time period to its processes for T-45 to T-8 and allow card to not require substitution for both Advance Noticed Forced and Forced but require substitution for any planned outages (up to T-45 from start of month).