After five years and numerous fits and starts, the Vermont PUC’s final rules on storage projects have been approved and issued in final form. The new rules – PUC Rule 9.000 – are effective May 1, 2026.
Here is a quick rundown:
- Projects less than 5MW(ac) are generally exempt from PUC Rule 5.400 for large generation.
- New storage facilities must comply with existing interconnection rules set out in PUC Rule 5.500, as well as other safety codes such as NFPA 855, NFPA 70, relevant IEEE/ANSI standards, and where applicable, the VT Division of Fire Safety’s Vermont Electrical Safety Rules for installations in “Public Buildings.”
- The rule provides several application and review tracks for project depending on their characteristics:
- There is a new fast-track for battery energy storage facilities between 100kW(ac) – 5MW(ac) that are proposed for “an existing or proposed structure, an existing substation yard, or an existing radio tower site without any earth disturbance or vegetation clearing required for installation or interconnection.” This section reduces typical application requirements and provides a 46-day “deemed approval” for projects that do not receive any substantive comments.
- Projects between 100kW(ac) and 5 MW(ac) where “earth disturbance or vegetation clearing is required for installation or interconnection” must proceed through a more typical PUC Section 248 review process similar to the process for solar net metering projects between 150kw(ac) and 500kW(ac).
- Finally, there is a track for (1) battery storage facilities with a nameplate rating greater than 5 MW(ac) and (2) non-battery storage facilities with a nameplate rating of 100kW(ac) or greater. This track requires compliance with Rule 5.400 and full 248 (or 248(j)) review typical of large-scale generation.
- The new Rule provides additional separate criteria for (1) petitions for new construction of co-located generation and energy storage facilities; (2) petitions for new construction of energy storage facilities co-located with existing generation facilities, different ownership; and (3) petitions for new construction of energy storage facilities co-located with existing generation facilities, same ownership.
- The Rule adds requirements and thresholds for aggregators and operators participating in wholesale markets.
- Finally, the Rule adds decommissioning requirements for battery projects larger than 100kW(ac).
Please reach out to David Carpenter or Josh Leckey of the in DRM’s Renewable Energy group for more information.
