IPWG: DER Interconnection Process Steps, Timeframes, and Deposits (20220606)

Entergy Operating Company Feedback on the Distributed Energy Resource (DER) Interconnection Study Process

July 8, 2022

The following feedback on the proposed Distributed Energy Resource (DER) Interconnection study process presented by MISO at the at the June 6, 2022 meeting of the Planning Subcommittee (PSC) is offered by the Entergy Operating Companies (Entergy)[1], as requested by MISO.

MISO specifically requested feedback on proposed:

• Process steps and associated timeframes and
• Coordination between MISO, Transmission Owners, and Electric Distribution Companies for issuing deposit invoices and collecting funding.

Regarding the Screening Process, Entergy appreciates MISO changing the screening criteria to 5 MW OR 1%, but we continue to stress the importance of MISO using minimum loadings (rather than peak loadings) to determine the potential impact of DERs on the transmission system.  Entergy remains concerned that MISO’s proposed study approach may result in masking potential impacts to the Transmission System and continue to support the use of the worst-case scenario, daytime minimum loading, for screening, which is intended to evaluate whether a more in-depth study is warranted to evaluation the potential for issues.

Regarding the proposed timeframes and coordination:

• The proposed 10-day turnaround for the TO to coordinate the payment of the study fees for the Affected systems studies may be presented with many challenges, depending on the arrangements in place between the TO and the EDC relating to this process.  Therefore, Entergy recommends that these timeframes be characterized as “targets” or “best effort”
• Regarding the DER information requested by MISO, there is potential for a DER to be registered with MISO without having gone through the EDC’s registration process, and because of this Entergy requests that MISO cross check the information submitted by the TO with information registered to participate in MISO’s market(s) to ensure completeness of information in relevant study models.   

Entergy also requests that MISO address the following details regarding its planned analysis:

• Once the aggregate DER at a substation exceeds the 5 MW reverse power flow threshold, would MISO require all future DER interconnections at this substation be evaluated (even very small installations like a single rooftop solar)?
• How does MISO plan to consider the combined transmission impacts from the two ongoing queues: DPP queue and the DER interconnection queue?

DTE appreciates the opportunity to provide feedback to MISO on the DER interconnection process and coordination for affected systems studies.  In general, DTE supports the screening thresholds that MISO has established for DER affected systems studies, however DTE would propose that MISO evaluate injections during both peak and off-peak conditions.

PGR appreciates the opportunity to provide feedback on the proposed the Distributed Energy Resource (DER) Interconnection Process and provides the following comments for MISO’s consideration:

• As indicated in the presentations, a multi-entity, multi-study process is proposed for the interconnection of DERs. PGR understands the complexity associated with DER operations in MISO and appreciates MISO’s attempts to utilize screens to reduce the adverse effects of such a pancaked process. However, as proposed, the scope and likely timing of the proposed study process for such small generation assets seems disproportionate to their likely injection to and impact on the bulk electric system (BES).  PGR would suggest that MISO work directly with its TOs, to the extent possible, to reduce or eliminate the pancaked study process between them and to better ensure that interconnection requestors have adequate transparency regarding the status of requests. Some potential process steps that should be evaluated to reduce complexity and process time include:
• The introduction of concurrent and coordinated screenings and studies between MISO and the TO;
• The implementation of screening criteria; and
• Thresholds that more accurately reflect the actual, likely impact of DERs on the BES.
• Since the process is dependent upon the TO’s conveyance of monies, etc. to MISO, PGR would suggest that MISO provide clarity on the process to cure deficiencies or tardiness such that the interconnection requestor is not adversely impacted where an error occurs on the part of the TO, e.g., a TO fails to respond to MISO’s invoice for the deposit amount on time.
• The threshold criteria that trigger a MISO Affected System study process for DERs should align with the likely impact of DER injections into the BES. While PGR appreciates that there are a very small percentage of DERs that could adversely affect BES-level operations and that there is some consistency between the thresholds indicated here and those used in other study processes, the current thresholds, as proposed, do not align well with the actual, likely risks of DER injections. For this reason, PGR opposes the modification of the “and” to an ”or” and, further, would recommend that MISO consider using a straight 3% distribution factor impact as its screening threshold along with the 5 MW injection.
• MISO should also provide more clarity on the timeline for MISO to return the study results to DER customers once MISO starts the study process. There is language on the cadence of the DER Affected System studies being periodic and, potentially, on a quarterly basis, but more definitive language on the timing of the results of the study and the end of study cycle is important.

PGR generally supports MISO bringing more transparency and equity into the DER study approach.

Alliant Energy continues to believe that a low load or off peak-peak screen is an important factor when assessing the impact of DER.  Fundamentally, when there is less load on the system, the potential impact of DER is higher.  Focusing just on the system peak will potentially miss DER that has the potential to have impacts on the transmission system.  MISO’s proposal to use peak and shoulder models for the detailed Affected System studies will not be helpful if resources are not appropriately identified from the initial screening process.

Also, regarding Fast Track processes, MISO should be aware that state and distribution level interconnection processes can also have their own Fast Track process.  For example, in Iowa some DER resources qualify for a Fast Track process where the distribution company is required to respond to the interconnection request in 20 days.  MISO should explain how the proposed DER process will factor state level interconnection process. In particular, MISO’s proposal to perform studies on a quarterly basis could create delays in distribution level interconnection processes.  It’s possible these delays could cause DER interconnection customers to file complaints with the distribution company and/or state regulatory body.  As one way to address this issue, MISO may need to perform some sort of hosting capacity analysis.

It would also be helpful for MISO to further explain how various types of DER will be handled as part of this process.  For example, does DER such as energy storage that is installed purely as a backup resource need to be factored in information and screening criteria?  Also, how would DER that can be controlled be treated as part of the screening and potential further study process?

Regarding the coordination among MISO, transmission owners and Electric Distribution Companies (EDCs), Alliant Energy agrees that it is appropriate for transmission owners to manage information and payment exchanges with EDCs and/or DER customers.  Transmission owners need to be engaged and aware of DER activity and ultimately the purpose of this process is to understand potential impacts on the transmission system.  EDCs can help supply information as needed but transmission owners should have the responsibly to manage the interactions with parties potentially impacting their system.

Alliant Energy does see a need for the treatment of study deposits to be thought through more.  For example, if multiple DERs together trigger a screening criteria does each DER interconnection customer need to pay a $60,000 deposit?  Or would this study deposit be shared among the DER interconnection customers, and if so, how would this sharing take place?

We appreciate the opportunity to provide feedback on the proposed process and look forward to further discussion with MISO.

ITC thanks MISO for the opportunity to comment on its DER Interconnection Presentation at the June IPWG meeting.  ITC offers the following feedback on MISO’s proposed processes:

• We appreciate MISO making the screening criteria 5 MW OR 1% change, but MISO should be using minimum loadings (rather than peak loadings) to determine the potential impact of DERs on the transmission system.  We remain concerned that MISO’s study approach is going to mask issues and continue to feel the worst-case scenario should be evaluated, daytime minimum loading, for purposes of screening.  This is only a screening test and thus does not mean that any identified issues will need to be resolved.  Rather, it simply indicates that a more in-depth study is required if issues are found.

• MISO’s proposal in not practical for TOs that are not vertically integrated.  In particular, ITC has a strong concern with MISO’s idea of holding the TO responsible for coordinating the payment of the study fees for the Affected systems studies (outlined on slides 9 through 12) even though a TO may have no current business relationship or direct knowledge of entities connecting to an adjacent distribution system.  MISO’s desire to minimize MISO’s efforts is understandable but requiring a TO who has no relationship with the DER owners to manage information and payment required by MISO is unreasonable.

• This is inappropriate and unworkable for a number of reasons.  A TO may have no current business relationship with the connecting DER entities.  The TO may not be the entity whose distribution system to which they are connecting.  MISO  appears to be attempting to inappropriately transfer responsibility to the TO which rightfully should belong to MISO itself.  A number of stakeholders made comments to this effect during the presentation and ITC reiterates the concerns that the TOs cannot be held responsible for the information management and payment for a third party.  We appreciate establishing protocols of many kinds with respect to DERs is new territory for MISO, but it should not attempt to transfer responsibilities most appropriately borne by the RTO onto the TOs. 

• ITC has a concern with the proposal for the TO be responsible for aggregating all of the DER information by substation and in having the TO be the entity required submit it to MISO.  This information typically would be submitted to the entity the DER units would be connecting to (i.e. the load serving entities when they need to be studied for connection).  It would make more sense for the LSE’s to input this information into a system for MISO to track than for MISO to require the TO to try to obtain and track the details of this data for those units that propose to connect.  The LSE is the entity with the relationship to the DER, not the TO.  Transferring this responsibility to the TOs would in effect make the TO responsible for the data which is not under their control or knowledge. 

• Fundamentally, MISO should work directly with the DER because the studies being performed are on the direct behalf of the DER not the LSE or the TO.  While ITC understands this might mean a significant amount of coordination for MISO as DERs become more prevalent, this is the most appropriate method because the TOs will most likely not have a contractual relationship with the DERs. 

• Further, the timeframes proposed by MISO are unrealistic for a situation where the TO does not have an existing relationship with the DER.  This could become very complex for TOs with only a 10 day turnaround time proposed by MISO for the TO to obtain the funds from the DER and make a study deposit to MISO. 

• Finally, the proposed reliance on the TOs for data collection and provision and study deposits is imposing administrative burden and costs on the TOS without any recompense. 

ITC appreciates that DERs are a new frontier for MISO and that many details must still be worked out.  Reliance on the TOs to be responsible for the data and study deposits is not appropriate for the reasons outlined above.  We hope that MISO will rethink these suggestions and discuss alternatives with the stakeholders to find more appropriate solutions.