The Minnesota Public Utilities Commission recently issued an order revising the state's interconnection policies, which govern how distributed energy resource (DER) projects such as solar and energy storage systems connect to the electric distribution grid. The ruling, published on Friday, October 23, 2026, was substantially shaped by recommendations from a technical subgroup of the Distributed Generation Working Group (DGWG), which was facilitated by the Interstate Renewable Energy Council (IREC), and builds upon work that IREC has been engaged in in Minnesota for a decade. The order adopts changes to the state's Distributed Energy Resource Technical Interconnection and Interoperability Requirements (TIIR) and Distributed Energy Resources Interconnection Process (DIP)1. The revisions will streamline the interconnection process for clean energy and energy storage projects by improving how utilities evaluate their potential grid impacts.
Under the revised rules, review processes will more accurately reflect a project's potential grid impacts because they will be based on how projects will actually be operated, rather than worst-case scenario assumptions often used in grid modeling. Specifically, the rules now differentiate between nameplate rating (how much power a project is capable of producing) and export capacity (the maximum amount of power it will actually send to the electric grid), and generally use export capacity in many of the screening processes utilities use. As battery energy storage has become more prevalent, it has become more common for projects to store some or all of the power they produce. When interconnection rules fail to recognize how these export-limiting or non-export projects actually operate, clean energy projects are more likely to be required to pay for unnecessary and costly grid infrastructure upgrades or denied approval to connect to the grid entirely.
"This ruling, which brings to fruition years of engagement by IREC in Minnesota, is a significant milestone in modernizing Minnesota's interconnection rules to align with how clean energy and energy storage projects actually operate. The changes adopted by the Commission will enable clean energy projects in Minnesota to connect to the grid more efficiently and affordably," said Yochi Zakai, Partner at Shute, Mihaly & Weinberger, counsel for IREC, and facilitator of the DGWG subgroup whose recommendations were adopted by the Commission.
Many of the changes adopted in the ruling are based on provisions pioneered by IREC and partners under a U.S. Department of Energy-funded program called Building a Technically Reliable Interconnection Evolution for Storage (BATRIES). Among the major changes adopted in the Commission's order are:
- Modification of Fast Track Process eligibility to clarify that size limits apply to project export capacity, and that there is no maximum limit on nameplate rating;
- Modification of Simplified Process eligibility to include projects with an export capacity of up to 20 kW and a Nameplate Rating of up to 50 kW (previously 20kW was the max, with no differentiation between nameplate rating and export capacity);
- Modification of Initial and Supplemental Review screens to use export capacity instead of nameplate rating;
- The addition of an "inadvertent export" screen (first developed under the BATRIES project) which is to be used when there is a 250 kW+ difference between nameplate rating and export capacity;
- Modification of the requirements for the System Impact Study, to specify that it "will take into account the proposed DER's design and operating characteristics, and study the project according to how the project is proposed to be operated." (e.g., if there is export limiting).
Inadvertent export is power that is unintentionally exported from a DER when on-site load drops off suddenly, before the export control system responds to the signal to limit or stop export. Original research published in the BATRIES report sheds light on the grid impacts of inadvertent export and required response times by power control systems and led to the development of the screens adopted in this ruling.
This ruling, which is the culmination of over nine months of work by the Distributed Generation Workshop Group (DGWG) and a decade of engagement by IREC in Minnesota interconnection proceedings, will make the process of connecting clean energy projects to the grid faster and more affordable for customers and developers. It brings Minnesota's interconnection rules in line with national best practices that reflect the realities of how clean energy projects operate on the electric grid and the inherent flexibility in how DER projects can be designed. IREC applauds the Commission for its ruling and appreciates the contributions of other members of the DGWG.
Footnotes
- While the order makes clear the changes to the TIIR and the MN DIP, the revised versions of these documents have not yet been released.
