OPINION

FLOREY, Judge.

In this certiorari appeal, relators Large Power Intervenors (the LPIs)1 challenge a final order in rate proceedings initiated by respondent Minnesota Power. The LPIs argue that the Minnesota Public Utilities Commission (the commission) violated the plain language of Minn. Stat. § 216B.1696 by excluding approximately $15.5 million of additional sales revenue from Minnesota Power's 2016 general-rate case. The commission had determined, in a different docket which is not the subject of this appeal, that the amount would be refunded to Minnesota Power's non-EITE customers in order to comply with section 216B.1696. Because the commission's decision to account for the additional sales revenue in the EITE docket, rather than in the general-rate case, was reasonable and in conformity with the plain language of section 216B.1696, we affirm.

FACTS

I. Factual and Procedural Background

In 2015, the legislature passed Minn. Stat. § 216B.1696 (the EITE statute), which sets forth a public policy favoring competitive rates for EITE customers:2

Minn. Stat. § 216B.1696, subd. 2(a).

The statute directs the commission to approve a qualifying utility's proposed EITE rate schedule "upon a finding of net benefit to the utility or the state." Id., subd. 2(b). An EITE rate schedule allows the utility to offer EITE customers credits that reduce the rate that they pay for electricity. This is important because it has allowed those customers to operate facilities that were otherwise cost-prohibitive.

The utility must then track in a separate account "the difference in revenue between what would have been collected under the electric utility's standard tariff and the EITE rate schedule." Minn. Stat. § 216B.1696, subd. 2(d). "In its next general rate case or through an EITE cost recovery rate rider between general rate cases, the commission shall allow the utility to recover any costs, including reduced revenues, or refund any savings, including increased revenues, associated with providing service to a customer under an EITE rate schedule." Id. But, a utility may not "recover any costs" from, or "refund any savings" to, any EITE customer or low-income residential ratepayers. Id.

A. EITE Docket

On June 30, 2016, Minnesota Power filed a petition, under Minn. Stat. § 216B.1696, to establish a competitive rate for EITE customers. Minnesota Power proposed an EITE rate schedule that would provide a usage-based "Energy Charge Credit" to EITE customers who met certain conditions, and it proposed to recoup the cost of the credit through a surcharge on non-EITE, non-exempt customers. Minnesota Power predicted that the credit would spur increased electricity purchases by EITE customers, satisfying the statute's requirement that any EITE rate schedule approved by the commission produce a "net benefit" to the utility or the state. Minn. Stat. § 216B.1696, subd. 2(b).

On December 21, 2016, the commission approved Minnesota Power's proposed EITE rate schedule, but ordered Minnesota Power to file a rate-design proposal detailing how to recover the cost, or refund additional revenues, associated with implementing the EITE rate. The commission also ordered Minnesota Power to establish a tracker account to measure "the difference in revenue between what would have been collected under the electric utility's applicable standard tariff and the EITE rate schedule." The commission's December order provided that it "shall become effective immediately." Neither the LPIs nor Minnesota Power applied for rehearing within the time period allowed (20 days) under Minn. Stat. § 216B.27, subd. 1 (2018).3

On December 30, 2016, Minnesota Power made a compliance filing that included its cost-recovery proposal, several rate-design alternatives, and a revised communications plan. The matter came before the commission on March 9, 2017, and on April 20, 2017, the commission issued its order.

In the April 20, 2017 order, the commission:

The commission ordered Minnesota Power to submit a compliance filing within 30 days "setting forth the surcharge and refund mechanisms in detail, including the baseline gross revenue for 2016 and the methodology for determining net revenue increases." The order provided that it shall become effective immediately. Neither the LPIs nor Minnesota Power applied for rehearing within 20 days of the order.

On May 22, 2017, Minnesota Power submitted a compliance filing in which it proposed three modifications to the baseline calculation. On October 13, 2017, the commission issued an order (1) approving Minnesota Power's proposal to exclude rider revenue from the 2016 baseline calculation; (2) requiring Minnesota Power to use the actual 2016 calendar-year revenue from EITE customers as the baseline for calculating the extent of any refundable increases (thereby rejecting Minnesota Power's proposal to recognize that it had already accounted for the increased EITE-customer sales revenue by lowering its requested final rates in the pending rate case); and (3) rejecting Minnesota Power's proposal to use 2016 billing units, rather than revenue, as the baseline for calculating refunds. The commission reasoned that it had already determined, in the April 20, 2017 order, that Minnesota Power should use 2016 revenues as the baseline:

On November 2, 2017, Minnesota Power and the LPIs sought reconsideration. The commission issued an order on January 2, 2018, denying reconsideration, and indicating that a more detailed order would follow within 30 days. On February 7, 2018, the commission issued a more detailed, final order denying reconsideration. In the February 2018 order, the commission found that (1) Minnesota Power's and LPIs' petitions were untimely and (2) the petitions did not present a basis for reconsideration.

With regard to the first finding, the commission noted that both Minnesota Power's and the LPIs' petitions focused on the surcharge-refund mechanism and the revenue-comparison baseline that were authorized in the April 2017 order. The commission determined that, to the extent Minnesota Power and the LPIs sought reconsideration of the April 2017 order, their petitions were untimely given that neither party had applied for a rehearing of that order within the statutorily mandated 20 days. See Minn. Stat. § 216B.27, subd. 1. With regard to the second finding, the commission determined that the petitions did not present a basis for reconsideration because they did not raise new issues, point to new and relevant evidence, or expose errors or ambiguities in either the April 2017 or the October 2017 order. On March 8, 2018, the LPIs filed a notice of appeal (A18-0382 or the EITE-docket appeal).

B. Rate-Case Docket

During the pendency of the EITE docket, on November 2, 2016, Minnesota Power filed a general-rate case, under Minn. Stat. § 216B.16, seeking an annual rate increase of approximately 9.1 percent. The filing included a proposed interim-rate schedule. The next month, one of Minnesota Power's customers, U.S. Steel, issued a press release publicly announcing its plans to restart, in 2017, its Keewatin mining facility (Keetac). The anticipated increased revenue from Keetac prompted Minnesota Power to request a lower interim-rate increase than it had proposed in its initial rate filing. On April 13, 2017, the commission approved Minnesota Power's interim-rate request.

On March 12, 2018, the commission issued an order addressing multiple issues, including how Minnesota Power was to account for increased sales revenue from Keetac. The commission explained that, after Minnesota Power learned of U.S. Steel's intention to restart Keetac, Minnesota Power "revised its sales forecast ... by including in its test year nine months of anticipated electricity rates to Keetac in 2017."

The commission concluded that, "[b]ecause evidence in the record support[ed] a conclusion that sales to Keetac [would] continue for the foreseeable future, [Minnesota Power] [would] be required to reflect 12 months of sales, and a corresponding $1.8 million revenue increases, in its test year calculations." The commission provided:

On March 30, 2018, the LPIs filed a petition for reconsideration, stating the petition was "in response to errors in the Commission's rate design methodology" and to "reiterate its concerns regarding the Commission's failure to properly implement the EITE statute." On May 29, 2018, the commission denied the LPIs' petition for reconsideration on issues related to the EITE rate and EITE cost recovery. On June 28, 2018, the LPIs petitioned our court for a writ of certiorari to review the commission's March 12, 2018, and May 29, 2018, orders (the rate-case appeal).

C. Judicial Review of Commission's Orders

On June 19, 2018, our court issued an order limiting the scope of the EITE-docket appeal to the October 2017 order. We stated, "The scope of the appeal does not extend to issues finally decided in the commission's April 20, 2017 order, including the issue of whether the commission's requirement of a refund mechanism violates Minn. Stat. § 216B.1696." On July 25, 2018, we dismissed the EITE-docket appeal, concluding that the LPIs and Minnesota Power failed to properly preserve the issues for judicial review. Reiterating our decision in the June 19 order, we stated that "the requirement for a refund mechanism with a 2016 baseline was decided in the commission's April 2017 order," and, therefore, issues finally decided in the April 2017 order were beyond the scope of the appeal. The supreme court denied the LPIs' request for further review. In re Minn. Power's Revised Petition for Competitive Rate for EITE Customers, No. A18-0382 (Minn. App. July 25, 2018) (order), review denied (Minn. Sept. 26, 2018).

On September 18, 2018, we issued an order denying the commission's motion to dismiss the rate-case appeal—the matter now before us. We concluded that the LPIs were precluded from using the appeal as a vehicle to challenge the April 20, 2017 order in the EITE docket, but determined that, whether the commission erred by excluding certain revenues from Minnesota Power's rate case involved issues related to, but distinct from, the issues decided in the EITE docket.

ISSUE

Did the commission err by accounting for the additional EITE-customer sales revenue in the EITE docket rather than the rate-case docket?

ANALYSIS

The interpretation of Minn. Stat. § 216B.1696, as well as its interplay with a general-rate determination, are both matters of first impression. Furthermore, how the commission is to integrate implementation of the EITE statute with a general-rate case is, no doubt, complex.

Our review of the commission's orders is governed by the Minnesota Administrative Procedure Act (MAPA). Minn. Stat. §§ 14.63-.69, 216B.52 (2018). Under the MAPA, we may reverse or modify the commission's decision if the decision prejudiced the petitioners' substantial rights because it was:

Minn. Stat. § 14.69. The party challenging an agency decision bears the burden of proving that the decision violated provisions of the MAPA. In re Review of 2005 Annual Automatic Adjustment of Charges for All Elec. & Gas Utils., 768 N.W.2d 112, 118 (Minn. 2009).

Because the commission's decision to account for the additional EITE-customers' sales revenue in the EITE docket constitutes a legal conclusion, "we review this decision under an arbitrary and capricious standard." In re Max Schwartzman & Sons, Inc., 670 N.W.2d 746, 752-53 (Minn. App. 2003). The commission's decision is arbitrary and capricious if it represents its own will, rather than its judgment. Id. at 753.

Id. (quotation omitted). "If there is room for two opinions on a matter, the [c]ommission's decision is not arbitrary and capricious, even though the court may believe that an erroneous decision was reached." 2005 Annual Automatic Adjustment of Charges, 768 N.W.2d at 120.

An administrative agency's decision enjoys a presumption of correctness. In re Annandale & Maple Lake NPDES/SDS Permit Issuance for Discharge of Treated Wastewater, 731 N.W.2d 502, 514 (Minn. 2007). "Deference should be shown by courts to the agencies' expertise and their special knowledge in the field of their technical training, education, and experience." Id. (quotation omitted). Appellate courts "have deferred to an agency's expertise and special knowledge when (1) the agency is interpreting a regulation that is unclear and susceptible to more than one interpretation; and (2) the agency's interpretation is reasonable." Id. at 515; see also Risdall v. Brown-Wilbert, Inc., 753 N.W.2d 723, 733 (Minn. 2008). We consider several factors when determining the level of judicial deference afforded to the agency's interpretation: (1) "the nature of the regulation at issue"; (2) "whether the subject matter of the regulation is within the agency's technical training, education, and experience"; and (3) whether "the agency's interpretation of an unclear regulation is reasonable." In re Alexandria Lake Area Sanitary Dist. NPDES/SDS Permit No. MN0040738, 763 N.W.2d 303, 312-13 (Minn. 2009).

While appellate courts "retain the authority to review de novo errors of law which arise when an agency decision is based upon the meaning of words in a statute," see In re Denial of Eller Media Co.'s Applications for Outdoor Adver. Device Permits in Mounds View, 664 N.W.2d 1, 7 (Minn. 2003), "[w]e extend judicial deference ... to agency decision-makers in the interpretation of statutes that the agency is charged with administering." Max Schwartzman & Sons, 670 N.W.2d at 754; see also In re Excess Surplus Status of Blue Cross & Blue Shield of Minn., 624 N.W.2d 264, 278 (Minn. 2001).

In determining whether an agency has properly applied a statute, courts focus on the words of the law "to ascertain and effectuate the intention of the legislature." Minn. Stat. § 645.16 (2018); First Nat'l Bank of N. v. Auto. Fin. Corp., 661 N.W.2d 668, 670 (Minn. App. 2003), review denied (Minn. Aug. 5, 2003). "If the meaning is plain and unambiguous we apply that meaning as a manifestation of legislative intent." Id. "Plain meaning embodies ordinary use of the language in the context of the whole-act structure, applying the usual conventions of grammar and syntax." Id. Where an agency's interpretation contravenes the plain language of the statute, it is not entitled to judicial deference. In re Claim for Benefits by Meuleners, 725 N.W.2d 121, 124 (Minn. App. 2006). The dispute in this appeal centers on the commission's interpretation and application of Minn. Stat. § 216B.1696, subd. 2(d), which provides:

The LPIs argue that,6 by accounting for the approximately $15.5 million of additional sales revenue in the EITE docket, rather than in the rate-case docket, the commission violated the plain language of subdivision 2(d). The LPIs allege that the improper accounting resulted in EITE and low-income residential customers being "forced to pay more than 25% of the cost" of the EITE rate, which contradicts the plain language of the statute directing EITE-surcharge-eligible customers to bear the cost.

The LPIs argue that the commission's actions violated the express mandates of Minn. Stat. § 216B.1696, subd. 2(d). According to the LPIs, subdivision 2(d) provides for "either a surcharge or a refund, but not both, with EITE customers and low-income customers being excluded from both." The LPIs also argue that the statutory language directing Minnesota Power to recover costs or refund savings in either the "next general rate case or through an EITE cost recovery rate rider between general rate cases," see Minn. Stat. § 216B.1696, subd. 2(d), required the commission to account for the additional revenue in the rate-case docket.

We conclude that the commission did not err by accounting for the additional EITE-customer sales revenue in the EITE docket. The LPIs' claim that the commission violated the plain language of the EITE statute by excluding the approximately $15.5 million of additional sales revenue from the rate-case docket is problematic for at least three reasons: (1) the plain language of subdivision 2(d) makes clear that the commission must allow Minnesota Power to "recover any costs" from, or "refund any savings" to, non-EITE, non-exempt customers associated with providing a discounted EITE rate to EITE customers;7 (2) subdivision 2(d) expressly prohibits Minnesota Power from "refund[ing] any savings" to EITE and low-income customers; and (3) the commission's accounting of the additional sales revenues from the rate case to the EITE case was a consequence of the surcharge-refund mechanism established in the April 20, 2017 order—an order that is beyond the scope of this appeal.

Pursuant to subdivision 2(d), the commission approved, in its April 20, 2017 order, a cost-recovery rider authorizing Minnesota Power to surcharge non-EITE, non-exempt customers for the cost of the EITE rate, and directing Minnesota Power to refund to those customers "any revenue increases resulting from increased sales to customers taking service under the EITE rate schedule." The LPIs failed to seek reconsideration of the commission's order.

In accordance with the April 20, 2017 EITE-docket order, the commission directed, in its March 12, 2018 rate-case order, that $15.5 million of Keetac revenue "must be used as an offset or refund in the section 216B.1696 tracker." Because $15.5 million of additional EITE-customer revenue would be accounted for as a refund in the EITE docket, the commission required a "reduction of net test year revenue" in the rate-case by an equal amount. The commission explained:

In its March 12, 2018 rate-case order, the commission expressly rejected, as contrary to the plain language of the EITE statute, the LPIs' argument that "revenue increases from EITE customers cannot be accounted for in the section 216B.1696 tracker." Subdivision 2 directs Minnesota Power to "create a separate account to track" certain revenue increases for refund. Minn. Stat. § 216B.1696, subd. 2(d). The statute provides that, in the "next general rate case or through an EITE cost recovery rate rider between general rate cases," Minnesota Power is permitted to recover costs or refund savings associated with providing a discounted EITE rate. Id. The LPIs argue that, because the commission never approved a cost-recovery rider in the EITE docket, the "next general rate case" is the rate-case docket. We reject this assertion for three reasons.

First, the LPIs waived this argument by not presenting it to the commission in their petitions for reconsideration. See Minn. Stat. § 216B.27, subd. 2. Second, the commission authorized an EITE cost-recovery rate rider in its April 20, 2017 EITE-docket order. In the order, the commission expressly directed Minnesota Power to collect a surcharge from non-EITE, non-exempt customers as well as refund to those customers any revenue increases resulting from increased sales associated with the EITE rate. Again, this refund-surcharge mechanism, approved by the commission in the EITE docket, is beyond the scope of this appeal.

Finally, even if we deemed the language of Minn. Stat. § 216B.1696 to be susceptible to more than one interpretation, we would reach the same result. See Annandale, 731 N.W.2d at 514. In highly technical and complex matters, such as the case before us, we defer to an agency's expertise and special knowledge in interpreting a statute it is charged with administering. See Max Schwartzman & Sons, 670 N.W.2d at 754; Annandale, 731 N.W.2d at 514. There is no indication that the commission's decisions were unreasonable, arbitrary, or capricious, and we are not persuaded that its interpretation of section 216B.1696 violates the statute's plain meaning. We, therefore, defer to the commission's implementation of the EITE statute.

DECISION

The commission's decision to account for $15.5 million of additional sales revenue in the EITE docket was not arbitrary and capricious. Pursuant to Minn. Stat. § 216B.1696, subd. 2(d), the commission determined that the increased revenue would be refunded to non-EITE customers to offset the surcharges associated with providing a discounted EITE rate to EITE customers. The commission's decision was reasonable and in conformity with the plain language of section 216B.1696. Accordingly, we affirm the commission's March 12, 2018 and May 29, 2018 orders.

Affirmed.