IPWG: Use of Energy Storage to Mitigate Constraints in GI Studies (PAC2021-3) (20210525)

Utilizing storage as a constraint mitigation would not only benefit the transmission system, but also developers. Currently it can be difficult for developers to justify adding storage to projects, needed as it is. Adding some sort of mechanism (fast track study, transmission credits, etc) would potentially help alleviate the large network upgrades, in turn allowing more projects to interconnect and achieve in adding more storage onto the system.

Transmission Owner Sector Feedback on Use of Energy Storage to Mitigate Constraints in GI Studies

June 15, 2021

In the May 25, 2021 meeting of the Interconnection Process Working Group (IPWG), stakeholders were invited to send feedback regarding the Integrated Roadmap Issue, “Use of Energy Storage to Mitigate Constraints in GI Studies.”  The Transmission Owners Sector (Owners or TOs) appreciates the opportunity to comment and provides the feedback below for MISO’s consideration.

At the May meeting of the IPWG, MISO recommended closing an Integrated Roadmap item regarding the Use of Energy Storage to Mitigate Constraints in GI Studies that was assigned to the PAC, as it can be addressed in three items under discussion in the PSC (BPM language for Storage as a Transmission Only Asset (SATOA), Non-Transmission Alternative and Transmission Alternative Selection. 

The Owners ask that rather than closing this item, it should be moved to the PSC for discussion in coordination with the other IR items noted in MISO’s PSC presentation as relevant.  Among other topics requiring discussion, the Owners believe that if a IC is permitted to use storage to mitigate a constraint in a GI study, an operating guide would be needed, that these types of discussions would be best to be held at the PSC, and that it would be best to track the IR Issue through the PSC, rather than closing it out to the other topics. 

6/15/21

Invenergy LLC ("Invenergy") appreciates the opportunity to provide feedback on the use of energy storage to mitigate constraints in the interconnection process, which was addressed by MISO at the May 25, 2021 Interconnection Process Working Group ("IPWG").  

Put simply - we do not agree that MISO's current tariff and BPM or changes to the tariff and BPM being discussed in the context of MTEP (via BPM 20) explicitly allow for storage to be utilized to mitigate constraints in the interconnection process.  Without an explicit reference in BPM 15 it can be argued that MISO actually intended to disallow the use of storage to mitigate constraints.  Invenergy does not believe that was MISO's intent and adding clarifying language to the BPM should not be a heavy lift.

In addition, MISO should consider adding language that allows an interconnection customer to mitigate their own constraints with battery storage.  This is an issue of great importance to stakeholders and at a minimum we would like to see a real and fulsome discussion on this at IPWG.

Thank you,

Nicole Luckey

Vice President, Regulatory Affairs

Invenergy LLC

WPPI agrees that this is an important issue—specifically that the ability of local storage to mitigate interconnection issues needs to be better recognized in the Generator Interconnection process, and that addressing this issue will tend to provide more appropriate incentives for installation of storage near new generation.  That said, we are amenable to the suggestion that this issue is sufficiently closely related to the MTEP Selection of Non-Transmission Alternatives (IR092) that these issues should be addressed in tandem and may be reasonably consolidated into a single issue.

Rather than closing out the issue of Energy Storage to Mitigate Constraints in GI Studies (PAC2021-3), Alliant Energy supports treating this issue as a parking lot item while other issues at the PSC (PAC004, IR092) are discussed.  Once those issues are resolved, a check can then be made if this issue (PAC2021-3) has truly been addressed or if further discussion is warranted.