In the January 26, 2022 meeting of the Resource Adequacy Subcommittee (RASC), stakeholders were invited to submit feedback on proposed accreditation reforms problem statement (see slide 8 of posted presentation).
Comments are due by February 9.
This Feedback is being submitted on behalf of Minnesota Power. The comment is a revision marked description from the Jan 26, 2022 RASC presentation from Slide 8 - Draft Problem Statement.
Draft Problem Statement and Scope for the Framing Stage
Draft Problem Statement: Significant growth of renewable and storage resources in the MISO footprint and the accreditation and energy dispatch availability of these resources have implications to Resource Adequacy, system resiliency, and planning. MISO’s existing accreditation methods for renewable and energy storage resources require further evaluation. This is needed to ensure the capability and reliability contribution of these resources during periods of highest reliability risk is properly accounted for.
Scope: Evaluate a range of accreditation methods for wind, solar and storage resources for stakeholders to consider and vet. Include accreditation considerations for all use-limited and emerging resources, including DER, hybrids and storage resources.
Key considerations:
• Reliability contribution during peak hours compared to periods of highest reliability risk
• Reliability contribution impacted by higher volumes and correlation between resource classes
• Reliability contribution needed from non use-limited resources to support increased levels of renewable and storage resources.
The (EOCs) Entergy Operating Companies appreciate the opportunity to comment on MISO's draft problem statement for Accreditation Reforms. The EOCs support MISO revisiting and establishing accreditation processes for wind and solar resources. The EOCs believe that a key consideration in this analysis should be an investigation of the impact that the North-South RDT constraint has on the solar and wind reliability contribution/ELCC results.
DTE appreciates the opportunity to provide feedback on the proposed accreditation reforms problem statement. DTE is generally supportive of MISO’s proposed problem statement, but requests that the last sentence be modified as such:
This is needed to ensure the capability and reliability contribution of these resources during all periods of the year is properly accounted for.
The second bullet on Slide 8 states "Reliability contribution impacted by higher volumes and correlation between resource classes". This is particularly true for renewable resources like wind and solar. Renewable resource outputs are highly correlated with each other.
For example, on January 28-30, 2020 MISO experienced a "wind drought" of 99% over its entire footprint that lasted for 39 hours. This resulted in the loss of approximately 22 GW of wind capacity at the time.
In the future with higher levels of renewables, it will take less and less severe wind drought to cause a similar or greater loss of capacity. For example,
With 30 GW of wind, a 90% wind drought results in the loss of 27 GW
With 40 GW of wind, an 80% wind drought results in the loss of 32 GW
With 50 GW of wind, a 70% wind drought results in the loss of 35 GW
With 60 GW of wind, a 60% wind drought results in the loss of 36 GW
With 70 GW of wind, a 50% wind drought results in the loss of 35 GW
As one can see, the risk increases as the amount of wind increases, so that even much less severe wind droughts can lead to greater loss of capacity. Wind droughts of 50% are quite common. With Future III calling for more than 110 GW of wind (and over 140 GW of solar), the capacity risk will be great.
Since most battery storage installations have only four hours of storage (4 MWH/MW), it would also take a wind drought of much less than 39 hour duration to cause problems.
MGE and MPPA generally support WPPI's comments.
Thanks,
David Sapper
dbsapper@ces-ltd.com
The OMS Resources Work Group (OMS RWG) supports the draft problem statement and scope that MISO has proposed for this issue. This feedback does not represent a position of the OMS Board of Directors.
While the OMS RWG acknowledges that the accreditation process for wind and solar resources should be the primary objective of these discussion, we encourage MISO to give sufficient time for discussion on the accreditation of use-limited and emerging resources, including hybrids and storage resources, as the quantities of these resources are ever-growing in the Generator Interconnection Queue.
We would like MISO to explore the full suite of options for resource accreditation and not limit the discussion to refining the existing wind ELCC accreditation methodology to fit other intermittent and use-limited resource types. This investigation should include comparative analysis of capacity accreditation calculations for each of these resource types under current and potential methodologies.
Savion, LLC (“Savion”) would like to thank MISO for bringing this item to stakeholders for discussion. In the January 26, 2022 meeting of the Resource Adequacy Subcommittee (RASC), stakeholders were invited to submit feedback on proposed accreditation reforms problem statement.
Savion is generally in agreement with MISO’s goal to apply a rigorous performance-based test on renewable generation. However, Savion is concerned for the potential of discriminatory treatment of renewables which are evaluated on highly correlated availability measures while conventional generation is evaluated using forced outage measures ignoring correlated availability risks. One glaring example of this type of risk is fuel supply interruptions deemed outside management control.
Savion looks forward to being an active participant in these discussions.
Consumers Energy appreciates the opportunity to provide feedback regarding the proposed renewable resources accreditation reform problem statement.
CE supports MISO’s effort to reform accreditation based on availability to better reflect the reliability value the resources provide to the grid. CE supports feedback from other stakeholders requesting that MISO broaden its problem statement and scope to include a comprehensive performance-based resource accreditation for all resource types and include hybrid, storage and other non-thermal resources (including but not limited to LMRs and Demand Response) that are not currently accredited based on availability in addition to the wind and solar accreditation reviews prioritized in this problem framing. This will help align and allow for forward-looking planning and operations for all resource types on a more equitable basis.
CE also questions how MISO will account for widespread loss of a particular intermittent resource, such as extensive cloud cover and/or a wind drought for an extended period of time over a large portion of MISO’s footprint as renewable penetration increases.
Public Service Commission of Wisconsin Office of Regional Markets staff appreciate the opportunity to provide feedback to the RASC: Resource Adequacy Accreditation Reforms Draft Problem Statement (20220126) issue. First, we want to reiterate the feedback provided by the Organization of MISO States Resources Work Group in support of a thorough review of accreditation methodologies for intermittent and use-limited resources, including wind, solar, hybrid, and storage resources. In further support of this and to emphasize a comprehensive process from the outset, we would like to suggest the following revisions to the scope to reflect this:
Revised Scope: Revisit and review the established accreditation process for wind resources and solar resources. Discuss and explore accreditation methods for other use-limited and emerging resources, including hybrids and storage resources.
We believe this revision would clarify an open process to determine the best methodologies to accredit each of these resource types going forward, informed by, but independent from, existing methodologies, and based on stakeholder discussion and comparative review of potential options. This is important to fully consider potential options and take into account the characteristics of each resource as well as the value they provide to resource adequacy and reliability. We again appreciate this opportunity to provide feedback and are available to address any questions regarding this feedback. Thank you.
Comments on Draft Problem Statement and Scope for
Accreditation Review for Wind and Solar
Clean Grid Alliance (CGA) values the opportunity to provide these comments and appreciates that MISO is continuing its work to evaluate and improve its resource adequacy construct. Our main concern with this effort it is important that consideration of accreditation of renewable resources also considers the accreditation methodologies for thermal resources, to ensure that MISO’s resource adequacy construct is internally consistent and results in capacity to meet demand in all hours of the year.
All resources should be evaluated for their contribution to system resource adequacy in a consistent manner to ensure reliability. Failure to do so is unduly discriminatory and provides preferential treatment for thermal plants without justification. MISO should ensure that the accreditation methodologies are based on the same high-risk hours, and the same correlated weather and load data. MISO rightfully considers the correlated risk of outages for wind and solar but does not consider correlated risks for thermal or hydro generation. This effort should include the consideration of the effective load carrying capability of thermal plants and the correlated risks of thermal plant fuel supply disruptions. The accreditation methodology proposed under the Seasonal Capacity Construct recently filed at FERC allowed for several exemptions to availability metrics which might inappropriately increase the capacity credit for traditional resources. For these reasons accreditation of thermal resources may need to be reconsidered alongside evaluation of renewable resources.
Relative to the comments above, we offer the suggested redline changes to the Draft Problem Statement, the Scope, and the Key considerations presented by MISO that will be submitted separately so that the redlines will be visible.
MidAmerican appreciates the opportunity to provide feedback on the proposed accreditation reforms for renewables.
MidAmerican agrees that a changing resource portfolio with rapid growth of intermittent resources may require an enhancement to accreditation to ensure an appropriate level of reliability is maintained. The enhancement must come with two key principles. The first principle is it must be based in data analytics and the second is that it must provide for a reasonable transition plan.
The capacity auction parameters for the balancing auction must only consider the current renewable penetration levels rather than forecasted penetration levels. Engineering-based studies that determine a minimum of one day in ten-year loss of load expectation is met should not rely on judgement with respect to determinations of capacity accreditation.
MISO should increase its efforts through the Regional Resource Assessment to develop studies under various levels of renewable penetration and transmission infrastructure buildout to forecast future capacity accreditation for renewables. These studies should also evaluate the complementary nature of wind, solar and storage as described by Brattle in the RASC presentation from January 26, 2022. If new and materially different capacity accreditation processes are implemented, they should occur over a minimum of five years allowing for sufficient time for MISO and resource planners to understand and adapt to the new resource adequacy criteria. This transition period will also enable information from the new MISO Regional Resource Assessment initiative to begin informing the transition process.
Alliant Energy appreciates MISO’s concern for reliability and the need for RA evolution. LSEs need more input on the range of potential accreditation concepts MISO is exploring. This input is needed well in advance of (i.e., years in advance of) implementation to ensure long-term resource plans cover the contingencies of MISO RA changes. This should also include data points that LSEs could utilize in long term planning such as impacts to reserve margins, accreditation rates, etc. So, MISO should include the following key considerations:
WEC Energy Group recommends that the draft problem statement on accreditation include all non-Schedule 53 resources (as Schedule 53 is currently drafted), not just intermittent resources. Additionally, all resources should receive comparable capacity accreditation under the new availability-based accreditation approach.
In addition to replacing "intermittent" with "non-Schedule 53", we recommend the following changes to the last sentence of the draft problem statement:
"This is needed to ensure the capacity contribution of all resources during periods of highest reliability risk is properly accounted for on a comparable basis."
WPPI appreciates the opportunity to provide feedback in this matter. We are open to revisiting current accreditation process for wind and to exploring comparable processes for solar resources as well as other use-limited and emerging resources including hybrids and storage. During MISO’ s presentation at the January 26th RASC meeting, MISO suggested that the existing wind ELCC methodology is not focused on hours of highest risk, However, it appears to us that the existing ELCC methodology, which considers every operating hour in calculation of the MISO-wide wind ELCC, is inherently focused on the periods of highest risk. We recognize that the subsequent step of allocating this MISO-wide number to individual resources uses a subset of high-demand hours that may not precisely match the hours of highest risk, but this would merely adjust the ELCC allocation among generators and not the aggregate accounting of wind’s reliability contribution. We ask MISO to clarify its concerns about a lack of focus of the current ELCC methodology on periods of highest risk. Finally, WPPI suggests MISO expand the scope to determine whether existing wind accreditation, or accreditation as proposed to be revised, should be subject to the same UCAP/SAC scaling up that MISO proposed in ER22-495 for Schedule 53 resources. |
Wolverine supports MISO's effort to reform accreditation based on availability to better reflect the reliability value the resources provide the grid. MISO's recently filed seasonal construct is a step in the right direction for thermal resources and the proposed problem statement attempts to take the next step on non-thermal resources. However, Wolverine requests MISO broaden its problem statement beyond renewables, hybrid, and storage to include all non-thermal resources (e.g., LMRs/demand response) that are not currently being accredited based on their availability.
Any renewable accreditation must take into account the widespread loss of these intermittent resources. For example, a MISO-wind wind drought that occurred on January 28-30, 2020 where wind output dropped to 1% for 39 consecutive hours. Or consider extensive cloud cover over a large portion of MISO significantly reducing solar output. Also, snow-covered solar panels in northern MISO could render thousands of MW unavailable for days or weeks during the winter.
Extreme weather is not the only risk to MISO. A series of calm cloudy days, which is much more likely will pose great risk to MISO as renewable penetration increases.