Single-Plant Determinations, Vested Rights, and Administrative Preclusion in Vermont's Renewable Energy Siting: Commentary on In re Petition of Otter Creek Solar LLC (2025 VT 65)

Single-Plant Determinations, Vested Rights, and Administrative Preclusion in Vermont's Renewable Energy Siting:
Commentary on In re Petition of Otter Creek Solar LLC, 2025 VT 65

I. Introduction

The Vermont Supreme Court’s decision in In re Petition of Otter Creek Solar LLC, 2025 VT 65, is another major entry in a growing line of “single-plant” cases involving Vermont’s renewable energy programs. It sits squarely alongside In re Portland Street Solar LLC, 2021 VT 67, and In re Chelsea Solar LLC, 2021 VT 27, and confirms—indeed consolidates—the broad, functional approach the Court and the Public Utility Commission (PUC) take to determining when multiple renewable facilities constitute a single “plant” under 30 V.S.A. § 8002(18).

The case arises from Allco Renewable Energy’s coordinated development of three solar projects in Bennington—initially called Battle Creek 1, 2, and 3, later styled Battle Creek Solar, Warner Solar, and Stark Solar. Otter Creek Solar LLC (an Allco affiliate) sought a Certificate of Public Good (CPG) under 30 V.S.A. § 248 for Warner Solar after already securing a standard-offer contract and CPG for Battle Creek Solar and a standard-offer contract and CPG for Stark Solar.

The PUC denied a CPG for Warner Solar, concluding that Warner Solar and Battle Creek Solar constitute a single “plant” under § 8002(18). Because that combined plant would exceed the 2.2 MW statutory cap for standard-offer eligibility in 30 V.S.A. § 8005a(b), Warner Solar could not lawfully participate in the Standard Offer Program and therefore could not obtain a CPG on the record presented.

On appeal, Otter Creek advanced a wide array of arguments:

  • The PUC misapplied, or applied the wrong version of, the “single-plant” test.
  • The PUC should have used a modified “GlobalFoundries” test crafted for Tier II projects, not the Chelsea Solar / Portland Street test developed in the standard-offer and net-metering context.
  • The developer had a vested right to have its petition adjudicated under the “old” single-plant standard in place when it filed the CPG application.
  • Claim and issue preclusion barred the PUC from re-litigating the single-plant issue after it awarded Warner a standard-offer contract in the RFP process.
  • The PUC lacked authority under 30 V.S.A. § 248 to revisit “single-plant” status at the CPG stage.
  • Due process was violated when the PUC departed from the hearing officer’s proposed decision and relied on a different item of shared infrastructure, and when it did not allow further amendment or hearing.

The Supreme Court rejected every one of these contentions and affirmed. In doing so, it solidified several important principles in Vermont energy and administrative law:

  • The two-prong single-plant test from Portland Street and Chelsea Solar governs standard-offer and § 248 CPG proceedings, and the PUC’s broad interpretation of “common ownership,” “contiguity in time of construction,” “proximity,” and “common equipment and infrastructure” is sustained.
  • Developers have no vested right in an earlier judicial interpretation of an unchanged statute; the vested-rights doctrine applies only to subsequent changes in statutes or regulations.
  • PUC decisions in the standard-offer Request for Proposals (RFP) process are not adjudicatory and carry no claim- or issue-preclusive effect.
  • The PUC may—and sometimes must—apply the single-plant definition in § 8002(18) when deciding § 248 CPG petitions, because plant capacity affects the applicable review framework and available waivers.
  • As long as parties receive a proposed decision, a chance to comment, and an opportunity for briefs and oral argument under 3 V.S.A. § 811, the PUC may issue a final decision relying on different reasoning grounded in the same evidentiary record without violating due process.

II. Summary of the Opinion

The Court, per Justice Eaton, held:

  1. Correct Test Applied; Single-Plant Status Upheld. The PUC properly applied the established two-prong single-plant test under § 8002(18) as articulated in Portland Street and Chelsea Solar. It did not abuse its discretion in finding that:
    • Warner Solar and Battle Creek Solar are part of the same “project” (common ownership, contiguity in time of construction, and proximity); and
    • They share common equipment and infrastructure, chiefly a distribution line upgrade paid for by the developer and necessary to interconnect both projects.
  2. No Obligation to Apply GlobalFoundries Test. The PUC appropriately followed this Court’s single-plant precedents rather than its own modified proximity standard for Tier II cases articulated in its GlobalFoundries declaratory ruling. Supreme Court precedent, not PUC declaratory rulings, controls.
  3. No Vested Right in Pre–Chelsea Solar Interpretation. The vested-rights doctrine protects applicants from later changes in statutes or regulations, not from later judicial clarifications of existing law. Because § 8002(18) did not change during the pendency of the Warner CPG petition, Otter Creek had no vested right to an earlier, narrower interpretation of “plant.”
  4. No Claim or Issue Preclusion from RFP Process. The standard-offer RFP process is not an adjudicatory proceeding. The PUC did not hold hearings, take testimony, make findings of fact, or otherwise operate in a judicial capacity with respect to the Warner bid. Accordingly, its RFP determinations had no preclusive effect on later CPG adjudication, and the single-plant question was open at the CPG stage.
  5. PUC May Apply Single-Plant Test in CPG Proceedings. Consistent with Chelsea Solar, the Court reaffirmed that the PUC may consider plant capacity and the § 8002(18) “plant” definition in § 248 CPG proceedings. Capacity determines whether statutory exemptions and rule-based waivers keyed to plant size are available; a mischaracterized plant size renders the applicant’s CPG evidence defective.
  6. No Due Process Violation; Proper Use of Proposed Decision Procedure. The PUC complied with 3 V.S.A. § 811 by circulating a proposed decision, inviting comments, and holding oral argument. It did not need to recirculate a second “proposed” decision when it ultimately relied on a different piece of shared infrastructure than the hearing officer emphasized. Otter Creek had notice of the issues and a meaningful opportunity to be heard.
  7. No Entitlement to New Hearing. The Court rejected Otter Creek’s requests for remand or a new evidentiary hearing, including its contentions regarding financial incentives, technical components (like the gang-operated airbreak switch), and an alleged right to amend its interconnection proposal. Some issues were immaterial; others were moot given the Court’s holdings; and the amendment issue was unpreserved.

III. Legal and Factual Background

A. Vermont’s Renewable Energy Policy and the Standard Offer Program

Vermont’s energy policy, codified in 30 V.S.A. § 202a and § 8001, emphasizes reliable, sustainable, and regionally distributed renewable generation, with a specific goal of:

“[P]roviding support and incentives to locate renewable energy plants of small and moderate size across the State….”
— 30 V.S.A. § 8001(a)(7)

The Standard Offer Program, established in 30 V.S.A. § 8005a, furthers that aim by requiring Vermont distribution utilities to purchase power from eligible small renewable plants at set prices for fixed terms. To remain targeted at “small and moderate” facilities, the statute limits eligibility to renewable energy plants with a “plant capacity of 2.2 MW or less.” § 8005a(b).

The statutory starting point is the definition of “plant” in § 8002(18). It sets both the meaning of a “plant” and the criteria for deciding whether multiple facilities are, in fact, one plant:

A group of facilities… shall be considered one plant if the group is part of the same project and uses common equipment and infrastructure such as roads, control facilities, and connections to the electric grid. Common ownership, contiguity in time of construction, and proximity of facilities to each other shall be relevant… .

Crucially, the Standard Offer Program is only one regulatory layer. Even after a project wins a standard-offer contract, the developer must still obtain a Certificate of Public Good (CPG) under § 248 before constructing or even beginning site preparation for the facility. § 248(a)(2)(A)–(B).

B. The “Single-Plant” Test Under 30 V.S.A. § 8002(18)

Over several cases, the Vermont Supreme Court has distilled § 8002(18) into a two-prong test:

  1. Same Project Prong. Are the facilities part of the same “project”? This is assessed by examining:
    • Common ownership (broadly construed to include control and beneficial interest, not just formal title);
    • Contiguity in time of construction (covering the full development lifecycle, from planning and studies through physical construction and interconnection); and
    • Proximity (geographic closeness, layout, and physical buffers or lack thereof).
  2. Common Equipment and Infrastructure Prong. Do the facilities share “equipment and infrastructure such as roads, control facilities, and connections to the electric grid”? This includes not just who ultimately owns a piece of equipment, but whether it is:
    • Non-preexisting (not there before the projects);
    • Necessary for both facilities to interconnect; and
    • Paid for (or otherwise provided) by the developer(s).

If both prongs are met, the group of facilities is one “plant” for purposes of § 8005a’s 2.2 MW cap and related programs. If either prong fails, the facilities are treated as separate plants.

C. The Bennington Projects: Battle Creek, Warner Solar, and Stark Solar

The factual setup in Otter Creek Solar is intricate but central to understanding the Court’s application of the test:

  • In response to the PUC’s 2016 Standard Offer RFP, Otter Creek (an Allco affiliate) proposed three adjacent projects on neighboring parcels off Rice Lane in Bennington:
    • Battle Creek 1 (later Battle Creek Solar);
    • Battle Creek 2 (later Warner Solar);
    • Battle Creek 3 (later Stark Solar).
  • The projects were close together: Warner Solar (Battle Creek 2) would sit roughly 150 feet east of Battle Creek Solar; Stark Solar would lie to the north and east, closer to Rice Lane.
  • All three were to interconnect along Rice Lane and rely on Green Mountain Power’s (GMP) distribution system.

In the 2016 RFP:

  • The PUC awarded a standard-offer contract to Battle Creek 1 (Battle Creek Solar); it did not award contracts to Battle Creek 2 and 3 at that time.
  • Otter Creek obtained a CPG and then constructed Battle Creek Solar. Critical to later analysis, Battle Creek Solar paid for and triggered the construction of a 2,400-foot three‑phase line extension from its interconnection point on Rice Lane west to Silk Road and into a GMP substation.
  • Battle Creek Solar commenced operation in September 2019.

In the 2018 RFP cycle:

  • Otter Creek resubmitted proposals for the other two parcels, now renamed Warner Solar (former Battle Creek 2) and Stark Solar (former Battle Creek 3).
  • The PUC awarded both Warner Solar and Stark Solar standard-offer contracts in the 2018 solicitation.
  • At the same time, the PUC explicitly rejected a different dam proposal on “single-plant” grounds—an important indicator that the single-plant issue is routinely analyzed in standard-offer RFP processes.

Otter Creek then sought separate CPGs for Stark Solar and Warner Solar. The hearing officer stayed both proceedings pending this Court’s decision in Chelsea Solar. After this Court decided Chelsea Solar and later Portland Street, the PUC:

  • Issued a CPG for Stark Solar after finding that Stark and Battle Creek were not a single plant.
  • Expressly flagged, however, that Warner Solar—physically located between Stark and Battle Creek—might be a single plant with one or both of them.
  • Ultimately concluded that Warner Solar and Battle Creek Solar were a single plant and denied Warner a CPG.

IV. Detailed Analysis of the Court’s Reasoning

A. Application of the Two-Prong Single-Plant Test

1. First Prong: Same Project (Common Ownership, Contiguity, and Proximity)

a. Common Ownership

The Court reaffirmed the broad, substance-over-form approach to “common ownership” adopted in Portland Street. Rather than looking only to the nominal LLC holding title to each facility, the PUC examined:

  • The corporate structure behind each project;
  • Who ultimately controls development decisions;
  • Who owns or controls the underlying land; and
  • Who holds or will hold the membership interests in the project LLCs as part of financing arrangements.

The record showed that:

  • A single individual (Thomas Melone) owned Vineyard Sky Allco Limited LLC, which in turn owned Allco Renewable Energy.
  • Allco, through various subsidiaries (including Otter Creek Solar LLC, Battle Creek Solar LLC, and Warner Solar LLC), controlled development of both Battle Creek Solar and Warner Solar.
  • Another Allco affiliate, PLH Vineyard Sky LLC, held the underlying parcels being leased to the project LLCs.
  • Membership interests of Battle Creek Solar LLC had been sold to another Allco-related entity (Vineyard Solar Fund Three, LLC) through sale-leaseback financing; the Warner Solar interests were expected to follow a similar pattern.

Otter Creek claimed that because no single Allco entity held formal title to both project LLCs’ assets, the “common ownership” factor was not met. The Court explicitly rejected this formalistic view, as it had in Portland Street:

  • The term “common ownership” is intentionally broad and would be rendered meaningless if it were limited to strict identity of the titled owner.
  • The Legislature’s purpose—to prevent large projects from partitioning themselves into nominally separate entities and thereby capturing small-project incentives—requires examining “elements of control and interest beyond the formal corporate status of the immediate owner of each facility.”

The Court thus held the PUC acted within its discretion in finding common ownership based on overlapping control, financing structures, and landholding entities linked through the Allco corporate group.

b. Contiguity in Time of Construction

Otter Creek contended that because Battle Creek Solar and Warner Solar were developed five to six years apart on the calendar, they lacked “contiguity in time of construction.” The Court, citing Portland Street, again rejected a narrow “shovels-in-the-ground” view of construction timing.

Instead, “construction” encompasses the full development process: concept, planning, studies, interconnection requests, permitting, physical buildout, and commissioning. The key facts included:

  • The three Bennington projects originated together as “Battle Creek 1, 2, and 3,” indicating unified, simultaneous conception.
  • Multiple interconnection and engineering studies were commissioned for the benefit of both Battle Creek and Warner Solar, evidencing a coordinated development process.
  • Battle Creek Solar began physical construction in March 2019 and entered operation in September 2019.
  • Otter Creek filed its CPG petition for Warner Solar in February 2019—squarely overlapping the physical construction and commissioning of Battle Creek Solar.

The Court emphasized that the apparent multi-year time gap was largely a function of PUC stays (waiting for Chelsea Solar, then for Stark Solar’s single-plant resolution), not an absence of continuity in the developer’s own planning and execution. On those facts, a finding of contiguity in time of construction was well within the PUC’s discretion.

c. Proximity

Proximity concerns geography and the physical “feel” of separate facilities:

  • How far apart are they?
  • Do array rows align in parallel or appear as a continuous field?
  • Are there meaningful natural or built buffers (roads, rivers, vegetation, topographic breaks, buildings) between them?

Here, the PUC found, and the Court accepted, that:

  • Warner Solar and Battle Creek Solar would be roughly 150 feet apart;
  • Their array rows would run parallel to each other; and
  • A railroad track and trees between the parcels were insufficient buffers in light of the closeness and overall layout of the two utility-scale arrays.

Drawing from Portland Street, where two solar arrays 100–180 feet apart with parallel rows and no natural boundaries were deemed proximate, the Court held that 150 feet and similar layout, with only modest intervening features, plainly satisfied the proximity factor.

With all three same-project factors—common ownership, contiguity in construction, and proximity—met, the Court agreed that Warner and Battle Creek were part of the same “project” under the first prong.

2. Second Prong: Shared Equipment and Infrastructure (The “But‑For” Distribution Line Test)

The second prong asks whether the facilities “use[] common equipment and infrastructure such as roads, control facilities, and connections to the electric grid.” A key issue in recent cases has been shared distribution lines.

Prior precedents (Chelsea Solar and Portland Street) adopt a functional “but-for” test, asking:

  1. Did the shared line (or other infrastructure) preexist the projects, or was it built specifically to serve them?
  2. Could each facility interconnect to the grid without that shared infrastructure?
  3. Did the developer(s) pay for the infrastructure (even if the utility ultimately owns it)?

In Chelsea Solar, for example, the Court held a line extension satisfied the test even though GMP ultimately owned it:

“But for the line extension, the facilities could not exist. And but for the facilities, the line extension would not exist.” — Chelsea Solar, 2021 VT 27, ¶ 20

a. The Battle Creek–Warner Interconnection Arrangement

For Battle Creek Solar:

  • Battle Creek paid for and constructed a 2,400‑foot upgrade/extension from its Rice Lane interconnection point to GMP’s Silk Road line and substation.
  • The PUC found that this upgrade was necessary for Battle Creek to interconnect safely and reliably, and that the cost allocation was set via the PUC’s Rule 5.500 interconnection processes.

For Warner Solar:

  • Warner’s proposed design was to extend from the Battle Creek point of interconnection—i.e., to rely on the Battle Creek-funded Rice Lane extension as its path to Silk Road and the GMP substation.
  • The PUC found that, absent the Battle Creek upgrades, Warner Solar would itself have been responsible for the same or equivalent upgrades to achieve safe, reliable interconnection.

From this, the PUC concluded that the Battle Creek-funded line along Rice Lane was:

  • Not a preexisting facility;
  • Necessary for Warner Solar’s as-proposed interconnection; and
  • Paid for by the developer of one of the two related facilities (Battle Creek Solar).

b. Otter Creek’s Arguments and the Court’s Responses

Otter Creek raised several specific challenges:

  1. Refund Argument. Battle Creek claimed it was entitled to a refund from GMP for portions of the upgrade (citing a GMP tariff), implying it had not “truly” paid for the line. The Court upheld the PUC’s refusal to entertain this collateral payment dispute:
    • The upgrade payments were determined through established interconnection procedures.
    • Payment had already been made without objection.
    • Any refund fight was not properly before the PUC in this CPG case.
  2. GMP-Funded Future Upgrade. Otter Creek argued that an independent, planned GMP upgrade along Harwood Hill Road would, once built, allow Warner Solar to interconnect without depending on the Battle Creek-funded line segment. The Court’s key holding here is important as a general principle:
    • The PUC evaluates projects as proposed, not based on hypothetical alternative configurations that might be developed later.
    • To allow a large project to avoid single-plant treatment merely by pointing to future alternative interconnections would defeat the legislative goal of limiting incentives to genuinely independent small projects.
    The Court also noted that even considering the planned GMP upgrade, Warner would still rely in part on the Battle Creek-upgraded segment to get to the substation; the “but-for” test remained satisfied.
  3. Other Equipment (e.g., DTT Scheme, Airbreak Switch). The hearing officer initially relied heavily on a Direct Transfer Trip (DTT) scheme as shared infrastructure. Later engineering updates rendered the DTT unnecessary, so the PUC emphasized instead the shared distribution line and associated upgrades. Because the line by itself satisfied the “but-for” test, the Court found no need to address other components like the gang-operated airbreak switch in detail.

The Court concluded that the PUC did not abuse its discretion in finding common equipment and infrastructure. Both prongs of the single-plant test were therefore satisfied, and Warner Solar and Battle Creek Solar constituted one “plant” for § 8002(18) purposes, exceeding the 2.2 MW cap.

B. Rejection of the Alternative GlobalFoundries Single-Plant Test

Otter Creek argued that the PUC was bound to apply the modified “proximity” analysis it announced in its GlobalFoundries declaratory ruling (concerning Tier II of the Renewable Energy Standard), rather than the approach articulated in Portland Street and Chelsea Solar.

In GlobalFoundries, the PUC reasoned that while the same statutory definition of “plant” applies in the Tier II context, the policy purposes differ from those of the standard-offer program:

  • Standard-offer: primarily about protecting ratepayers from large projects artificially carved into smaller segments to capture above-market incentives.
  • Tier II: includes additional aesthetic and siting rationales tied to the 5 MW cap, which may shift how “proximity” is evaluated.

The Supreme Court effectively sidestepped weighing in on whether GlobalFoundries was rightly reasoned in the Tier II context. Instead, it emphasized two points:

  1. Supreme Court precedent controls. The binding interpretation of § 8002(18) for standard-offer and CPG purposes is found in Portland Street and Chelsea Solar, not in PUC rulings. The PUC properly followed those cases.
  2. The case at bar is a standard-offer/§ 248 case, not a Tier II case. Whatever refinements might be appropriate under Tier II’s distinct statutory purposes were not before the Court and did not constrain the PUC’s approach here.

Otter Creek also suggested a “Common Benefits Clause” (Vermont’s analog to equal protection) problem in using different proximity analyses in different statutory contexts. The Court did not engage that argument in depth, implicitly rejecting it by holding that:

  • Differentiating between programs (Standard Offer vs. Tier II) because of their different legislative purposes is rational; and
  • In any event, Warner Solar’s case falls squarely within the standard-offer precedent line, where the test is already clearly settled by the Court’s own decisions.

C. Vested Rights: No Freeze on Judicial Interpretation

Perhaps the most clearly “new” doctrinal statement in this opinion concerns the scope of the vested-rights doctrine in Vermont administrative law.

Vermont follows a relatively developer-friendly “minority” rule: once a proper permit application is filed, the applicant’s rights “vest” in the law and regulations then in effect. See In re Times & Seasons, LLC, 2011 VT 76, ¶¶ 13–14. This protects applicants against later-enacted ordinances or statutory amendments that would otherwise retroactively derail a pending project.

Otter Creek argued that when it filed the Warner Solar CPG petition in February 2019, the single-plant doctrine was governed by pre–Chelsea Solar precedent, and that the PUC therefore could not apply the clarifications and expansions articulated in Chelsea Solar (April 2021) and Portland Street (September 2021) to its case.

The Court’s answer is categorical:

  • The vested-rights doctrine protects against changes in statutes, regulations, or ordinances after an application is filed.
  • It does not freeze in place a particular judicial interpretation of those statutes or regulations.
  • Section 8002(18) itself did not change during the pendency of the Warner Solar CPG; only this Court’s understanding of how to apply it was clarified and refined.

Thus, the PUC was required to interpret the unchanged statute consistent with this Court’s most recent controlling decisions at the time it rendered its own final decision. There is no vested right in having the law misapplied or applied under an outdated precedent.

This holding is significant beyond energy law, as it reaffirms a general principle: time-of-application vesting is about legislatures and rulemakers changing the law, not about courts sharpening or correcting the law’s meaning.

D. Claim and Issue Preclusion: The RFP Process Is Not Adjudicatory

Otter Creek next argued that, because the PUC had already awarded Warner Solar a standard-offer contract, it must have necessarily determined—at least implicitly—that Warner was not a single plant with Battle Creek. Consequently, Otter Creek contended, claim preclusion (res judicata) and/or issue preclusion (collateral estoppel) barred the PUC from revisiting the single-plant issue during Warner’s CPG case.

The Court undertook a classic administrative-preclusion analysis:

  • Claim preclusion bars relitigation of any claim that was or could have been litigated in a prior proceeding with a final judgment, between the same parties, concerning the same cause of action.
  • Issue preclusion bars relitigation of a specific issue actually litigated and necessarily decided in a prior proceeding.
  • Both doctrines can apply to administrative decisions—but only if the agency was acting in a judicial or adjudicatory capacity and employed procedures “substantially similar” to those of courts (notice, the right to present evidence, an opportunity for argument, findings of fact, and a final decision on the record).

Here, the PUC’s standard-offer RFP process did not resemble such an adjudication:

  • There were no formal hearings, sworn testimony, or cross-examination.
  • No formal findings of fact or legal conclusions were issued regarding Warner’s single-plant status.
  • Participants could submit comments, but that did not transform the RFP process into a contested, adversarial case.

Accordingly:

  • The RFP awards were not “final judgments” in an adjudicatory sense.
  • No specific issue, including single-plant status, was actually litigated and decided with the procedural protections required for preclusion.

Thus, neither claim nor issue preclusion barred the PUC from freshly adjudicating the single-plant question during the CPG proceeding. The Court’s reasoning underscores that not every agency action is adjudicatory, and that preclusion applies only where the agency’s process genuinely resembles a court proceeding.

E. PUC Authority to Use the Single-Plant Test in CPG Proceedings

Otter Creek contended that plant capacity and the § 8002(18) “plant” definition were irrelevant at the CPG stage unless expressly cross-referenced in § 248. It argued that once the PUC had granted a standard-offer contract, plant-size eligibility was “settled” and the PUC was obligated to focus only on the § 248(b) public-good criteria, not on single-plant issues.

The Court again relied on Chelsea Solar. There, the PUC had denied a CPG after determining that two nominally separate 2.0‑MW projects were actually a single 4.0‑MW plant and thus ineligible for standard-offer benefits. The developer argued the PUC could not fold single-plant analysis into the CPG review. The Court rejected that proposition:

  • The developer bears the burden to show CPG eligibility under § 248.
  • Where the developer’s evidence assumes a 2.0 MW plant but the facts show a 4.0 MW plant, the evidence is “defective” for § 248 purposes.
  • Plant capacity is integrally connected to whether the developer may lawfully rely on statutory or rule-based waivers (e.g., of § 248(b)(4) and (6)) that are offered only to small, standard-offer-eligible facilities.

In Otter Creek Solar, the Court reaffirmed this reasoning and noted:

  • The PUC, under § 8007(b), has promulgated simplified procedures and conditional waivers of certain § 248 criteria for plants from 150 kW to 2.2 MW, expressly keyed to plant capacity.
  • Otter Creek’s own Warner Solar CPG submissions relied on these waivers, repeatedly describing Warner as a 2.2 MW plant over the 150 kW threshold (and thus eligible for streamlined treatment).

Thus, the PUC was not only permitted, but functionally obligated, to verify whether Warner Solar was in fact a standalone 2.2 MW project or part of a larger plant. Single-plant status was “material” to the appropriate scope and rigor of the § 248 review, and therefore squarely within the PUC’s authority under § 248.

F. Due Process, Proposed Decisions, and Final Orders

Otter Creek’s procedural due process argument centered on an alleged “unfair surprise” in the PUC’s final order. The hearing officer’s proposed decision:

  • Found that several items (a DTT scheme, the Battle Creek line upgrade, and six listed system upgrades) could satisfy the common-infrastructure prong.
  • But stated that because the DTT scheme alone satisfied the “but-for” test, the PUC “need not” decide whether the other infrastructure also did so, and did not fully address Otter Creek’s arguments about GMP’s future upgrades potentially “breaking” the connection.

After parties commented, the Commission:

  • Accepted GMP’s representation that updated standards meant the DTT scheme was no longer needed.
  • Consequently shifted its focus to the shared distribution line and associated upgrades as satisfying the “but-for” test.

Otter Creek claimed it was entitled to a renewed opportunity to file exceptions once the PUC altered the rationale from the hearing officer’s proposal.

The Court looked to 3 V.S.A. § 811, which governs contested cases:

  • The statute requires that the agency serve a proposal for decision on the parties and allow them to file exceptions and present briefs and oral argument before the officials who will decide the case.
  • It does not require circulation of a second proposal if the final decision adopts different reasoning on issues that were already squarely raised and argued.

Here, the statutory requirements were fully met:

  • A proposed decision was circulated.
  • Otter Creek submitted written comments, including arguments about the distribution line upgrades and the impact of future GMP upgrades.
  • The PUC held oral argument.

The Court concluded that Otter Creek had notice of the key issue—shared infrastructure—and an opportunity to be heard. The fact that the PUC ultimately relied more heavily on one item (the line) than another (the DTT scheme) did not create a due process violation or a new obligation to re-propose.

The Court also observed that 3 V.S.A. § 812, which governs final decisions, contains no requirement of a second notice or comment round. The Court declined to read such a requirement into the statute, reaffirming the general principle that courts “do not read into a statute something which is not there.”

G. Denial of Requests for a New Hearing / Remand

Otter Creek identified three supposed grounds for a new hearing:

  1. The “financial incentive” rationale. Otter Creek objected to a PUC statement referencing the role of single-plant analysis in ensuring that large projects do not impose “detrimental impact on Vermont ratepayers” by capturing inappropriate incentives. It sought to introduce evidence that Warner Solar would actually save ratepayers money. The Court held this was immaterial:
    • The statement related to the PUC’s justification for applying the standard-offer single-plant test (as opposed to the Tier II variant) and had no bearing on whether Warner and Battle Creek were in fact a single plant.
    • Arguments about whether Warner would save or cost ratepayers money do not alter the statutory definition of “plant” or the two-prong test.
  2. Gang-operated airbreak switch and other components. Since the Court agreed that the shared distribution line alone satisfied the “but-for” test, any alleged errors in treating the airbreak switch as shared infrastructure were harmless. No new hearing was warranted.
  3. Opportunity to amend interconnection route. Otter Creek pointed to a hearing officer remark suggesting that if the Commission ultimately found Warner to be a single plant with Battle Creek or Stark, Otter Creek “may decide” to propose an alternative interconnection route under Rule 5.407 (substantial change). Otter Creek argued that, because the PUC never formally invited or facilitated an amendment, remand was required.
    • The Court found this argument unpreserved: Otter Creek never actually moved to amend its proposal or sought permission to change the interconnection route either before or after the Commission’s final order.
    • Without a specific request and ruling below, there was nothing for the Court to review on this point.

Consistent with Vermont’s strong preservation rule, unraised issues generally cannot be entertained on appeal.

V. Precedents Cited and Their Influence

A. Core Single-Plant Cases

  • In re Portland Street Solar LLC, 2021 VT 67. This case is the central doctrinal anchor:
    • It formalized the two-prong single-plant test under § 8002(18).
    • It adopted an expansive reading of “common ownership” (control and beneficial interest, not just formal title).
    • It interpreted “contiguity in time of construction” to include the full development lifecycle.
    • It elaborated the “but-for” test for shared distribution lines and clarified that “equipment and infrastructure” constitutes a single category covering items like roads, control facilities, and grid connections, not two separate requirements.

    Otter Creek Solar repeatedly cites and relies on Portland Street for all of these points.

  • In re Chelsea Solar LLC, 2021 VT 27. Chelsea is pivotal for two reasons:
    • It applied the same two-prong test, treating two 2.0‑MW projects as a single 4.0‑MW plant due to a shared line extension.
    • It confirmed that the PUC may consider single-plant status at the § 248 CPG stage and may deny a CPG where the developer’s application rests on a mischaracterization of plant size and corresponding program eligibility.

    In Otter Creek Solar, this precedent directly supports the Court’s holdings that:

    • The PUC properly applied the single-plant analysis in the CPG proceeding; and
    • Warner Solar’s CPG application was defective because it treated a larger combined plant as a standalone 2.2 MW facility eligible for standard-offer benefits and streamlined § 248 review.

B. Standard of Review and PUC Authority

  • In re Apple Hill Solar LLC, 2019 VT 64. Provides the general appellate standard:
    • The Court affords “deferential” review to the PUC’s factual findings (clearly erroneous standard).
    • Legal conclusions are upheld if rationally derived from a correct interpretation of law and supported by the findings.

    This deferential posture informs the Court’s repeated statements that the PUC “did not abuse its discretion” in interpreting and applying § 8002(18) to the facts of the Warner/Battle Creek configuration.

  • In re Derby GLC Solar, LLC, 2019 VT 77. Cited for the breadth of PUC authority to interpret and implement § 248. It undergirds the Court’s conclusion that the PUC may factor plant capacity and single-plant status into its CPG determinations where those issues affect the scope of review and available waivers.

C. Statutory Interpretation and Anti-Superfluity

  • In re Mountain Top Inn & Resort, 2020 VT 57. Reinforces the principle that statutes should be read to give effect to all words, avoiding interpretations that render language superfluous. This supports the Court’s insistence that “common ownership” in § 8002(18) must be construed broadly enough to have real bite; otherwise that factor would rarely ever be satisfied.

D. Vested Rights and Administrative Finality

  • In re Times & Seasons, LLC, 2011 VT 76. Articulates Vermont’s time-of-application rule for vested development rights. Otter Creek Solar narrows its reach by clarifying that the doctrine applies to new laws (statutes, regulations, ordinances), not to subsequent judicial interpretations of existing statutes.
  • In re Tariff Filing of Central Vermont Public Service Corp., 172 Vt. 14 (2001); Sheehan v. Dep’t of Employment & Training, 169 Vt. 304 (1999); Delozier v. State, 160 Vt. 426 (1993). These cases collectively explain when administrative decisions are adjudicatory for preclusion purposes:
    • The agency must act in a judicial capacity, using procedures analogous to those of courts.
    • Informal or policy-driven determinations, or decisions reached after mere comment rather than adversarial hearing, do not carry preclusive effect.

    Otter Creek Solar relies on this body of law to conclude that the PUC’s standard-offer RFP decisions are not adjudications and therefore cannot bar later litigation of single-plant status in a CPG proceeding.

E. Due Process and Preservation

  • In re M.R., 2025 VT 6. (cited for the basic elements of procedural due process: notice and opportunity to be heard). The Court uses this to frame its conclusion that the PUC’s use of the proposed-decision process under 3 V.S.A. § 811 satisfied constitutional requirements.
  • Pratt v. Pallito, 2017 VT 22; In re White, 172 Vt. 335 (2001). These reinforce Vermont’s strict preservation doctrine: issues not clearly presented below with sufficient specificity will not be addressed on appeal. This supports the Court’s refusal to entertain Otter Creek’s belated complaint that it was denied an opportunity to amend its interconnection proposal.
  • State v. O’Neill, 165 Vt. 270 (1996). Stands for the principle that courts should not read into statutes obligations that are not there unless necessary to make the statute workable. This underpins the Court’s refusal to graft a second “proposed decision” requirement into 3 V.S.A. § 811 or § 812.

VI. Simplifying Key Legal Concepts

A. Standard Offer Program vs. CPG

  • Standard Offer Program (30 V.S.A. § 8005a). A procurement and pricing mechanism: winning projects get long-term contracts at fixed prices. It is not a construction or siting permit.
  • Certificate of Public Good (CPG) (30 V.S.A. § 248). A siting and public-interest determination. No construction or site preparation may commence until the PUC finds the project “promotes the general good of the State.”

Winning a standard-offer contract is only the first step. A project can still be denied a CPG if:

  • It fails to meet § 248’s public-good criteria; or
  • It is not actually eligible for the statutory waivers or program benefits the applicant assumed (e.g., because multiple facilities are a single plant exceeding capacity limits).

B. What Is a “Single Plant”?

Under § 8002(18), multiple facilities count as one “plant” if:

  • They are part of the same project—as evidenced by who controls them, how and when they were developed, and where they are relative to each other; and
  • They share common equipment and infrastructure like roads, control facilities, or grid interconnections that were built specifically for them and are necessary for each to operate.

The test is fact-intensive and functional; developers cannot avoid single-plant treatment simply by:

  • Using different LLCs;
  • Staggering physical construction slightly; or
  • Changing paper ownership of shared infrastructure while its function remains the same.

C. The “But-For” Test for Shared Infrastructure

To determine if a given piece of infrastructure makes facilities part of a single plant, Vermont cases ask:

  • But for this infrastructure, could each project interconnect and operate?
  • But for the projects, would this infrastructure have been built?

If the answer to both is “no”—and the developer (rather than the utility) triggered and funded the upgrade—then the infrastructure is considered “shared” for single-plant purposes.

D. Vested Rights in Vermont

“Vested rights” in development law means: Once you file a complete application, you are evaluated under the laws and regulations then in force, and later changes in those laws generally do not apply to your application.

In Vermont:

  • This applies to subsequent legislative or regulatory changes (e.g., a new zoning ordinance or statutory amendment).
  • It does not protect applicants against:
    • Courts clarifying or correcting what the existing statute has always meant; or
    • Agencies or courts applying newly decided precedent interpreting the same statute.

E. Claim Preclusion vs. Issue Preclusion

  • Claim preclusion (res judicata) stops parties from re-litigating the same cause of action after a final judgment, including claims that could have been raised earlier.
  • Issue preclusion (collateral estoppel) stops parties from re-litigating a specific issue of fact or law that was actually litigated and necessarily decided in a previous case.

For administrative decisions to have preclusive effect, the agency’s process must function much like a court—formal notice, evidence, hearings, arguments, and a final written decision based on a record. Informal, policy-driven processes (like competitive bid solicitations with comment opportunities) generally do not qualify.

F. Proposed Decisions and Final Orders

In Vermont’s contested administrative cases:

  • A hearing officer often issues a proposed decision.
  • Parties may file exceptions, briefs, and request oral argument before the ultimate decisionmakers (here, the PUC commissioners).
  • The Commission then issues a final order, which may adopt, reject, or modify the hearing officer’s reasoning, as long as it is based on the same evidentiary record.

So long as this process is followed, the agency meets its obligations under 3 V.S.A. § 811. There is no requirement that every analytical shift from the proposal to the final decision trigger a new round of proposals and exceptions.

VII. Likely Impact of the Decision

A. For Renewable Energy Developers and Project Structuring

Otter Creek Solar sends a strong, clear signal to developers:

  • Attempts to “slice” what is functionally a single large project into nominally separate 2.2 MW (or smaller) standard-offer projects will be closely scrutinized.
  • The PUC and courts will examine:
    • Who ultimately controls the entities;
    • Whether projects were planned and studied together;
    • Physical layout and spacing; and
    • How and by whom grid-connection infrastructure was built and paid for.
  • Future or hypothetical alternative interconnections will not defeat single-plant status if the project as proposed relies on shared infrastructure to function.

Developers who wish to maintain separate-plant treatment for multiple nearby facilities will need:

  • Genuinely independent ownership and control;
  • Clear temporal separation in planning, permitting, and construction; and
  • Distinct interconnection paths that do not rely on shared, developer-built upgrades.

B. For PUC Practice and Program Administration

The decision confirms and strengthens several PUC practices:

  • The PUC may revisit single-plant questions at multiple stages (RFP, CPG) if new facts emerge or if earlier stages were not adjudicatory.
  • The Commission is not bound by its hearing officers’ proposed rationales and may refine or shift its reasoning in the final order, provided parties had a full procedural opportunity to be heard on the underlying issues.
  • The PUC’s single-plant analysis, as developed in the standard-offer and net-metering context, remains robust and is backed by Supreme Court precedent.

C. For Future Litigation on Tier II and GlobalFoundries

Although the Court did not pass directly on the validity of the PUC’s modified proximity analysis in GlobalFoundries, it drew a clear boundary:

  • For standard-offer and § 248 CPG cases, Portland Street and Chelsea Solar govern.
  • For Tier II cases, the PUC may attempt to justify tailored applications of § 8002(18) grounded in distinct statutory purposes, but such interpretations will ultimately be reviewable by this Court when a case squarely presents the issue.

Thus, Otter Creek Solar reinforces that any divergence in single-plant analysis between programs must be justified by clear differences in statutory purpose, and is subject to eventual judicial scrutiny.

D. For Vermont Administrative Law Generally

Beyond energy siting, the decision clarifies:

  • No vested right exists in an agency’s or court’s old interpretation of an unchanged statute. Applicants should expect that evolving case law will be applied to pending matters unless the Legislature explicitly provides otherwise.
  • Not all agency decisions are adjudicatory. Developers cannot rely on informal program decisions (such as RFP awards) to preclude later, more formal adjudication under different statutory frameworks.
  • Due process in agency adjudications is satisfied by the combination of proposed decisions, opportunities for exceptions, briefing, and argument, even where the final decisional rationale differs somewhat from the hearing officer’s proposal.

VIII. Conclusion

In re Petition of Otter Creek Solar LLC is best understood as a consolidation and extension of the Supreme Court’s recent single-plant jurisprudence rather than a radical departure. It:

  • Affirms the broad, functional two-prong single-plant test under § 8002(18) as articulated in Portland Street and Chelsea Solar, and applies it to a sophisticated multi-facility solar development.
  • Clarifies that the vested-rights doctrine protects applicants from later statutory or regulatory changes—not from subsequent judicial clarifications of existing law.
  • Confirms that the PUC’s informal RFP decisions do not have claim- or issue-preclusive effect in later, formal CPG adjudications.
  • Reiterates that plant capacity and single-plant status are integral to § 248 review, particularly where program-specific waivers keyed to capacity are in play.
  • Upholds the PUC’s use of the proposed-decision process and finds no due process violation in the Commission’s choice to rely on different shared-infrastructure components than the hearing officer emphasized, so long as the issues were aired and the evidentiary record was complete.

For Vermont’s renewable energy landscape, the message is clear: the Court and the PUC will enforce the small-plant focus of the Standard Offer Program by looking past formal labels and corporate structures to the economic and technical reality of multi-facility projects. Developers seeking to participate in incentive-driven programs must design, structure, and interconnect their projects with this robust single-plant doctrine firmly in mind.

Case Details

Year: 2025
Court: Supreme Court of Vermont

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