MGE ENERGY INC

Rate Matters

In December 2023, the PSCW approved the 2024/2025 rate application for an increase of 1.54% for electric rates and a 2.44% increase for gas rates in 2024. The PSCW also approved a 4.17% increase for electric rates and a 1.32% increase to gas rates for 2025.

Details related to MGE's 2024/2025 rate proceeding are shown in the table below:

(a)

Average rate base amounts reflect MGE's allocated share of rate base and do not include construction work in progress (CWIP) or a cash working capital allowance and were calculated using a forecasted 13-month average for the test periods. The PSCW provides a return on selected CWIP and a cash working capital allowance by adjusting the percentage return on rate base.

(b)

50% of the forecasted 13-month average CWIP for the test periods earns an AFUDC return. Projects eligible to earn 100% AFUDC are excluded from this balance and discussed further in the Management Discussion and Analysis of Financial Condition and Results of Operations - Significant Events section.

(c)

Authorized returns on common equity may not be indicative of actual returns earned or projections of future returns, as actual returns will be affected by the volume of electricity or gas sold.

See Footnote 9 of Notes to Consolidated Financial Statements in this Report for further discussion of rate proceedings and an earnings sharing mechanism if MGE earns above the authorized return on common equity.

ATC

MISO transmission owners, including ATC, are involved in two complaints filed at FERC by several parties challenging that the base ROE in effect for MISO transmission owners, including ATC, was no longer just and reasonable. Each complaint provided for a 15-month statutory refund period: November 12, 2013 through February 11, 2015 (the "First Complaint Period") and February 12, 2015 through May 11, 2016 (the "Second Complaint Period").

In May 2020, FERC issued an order further refining the methodology for setting authorized ROE. This refined methodology increased the authorized ROE from 9.88% to 10.02%. This base ROE is effective for the First

Complaint Period and for all periods following September 2016. This order also dismissed the second complaint. Accordingly, no refunds were ordered for the Second Complaint Period.

As a result of the May 2020 FERC order, our share of ATC's earnings reflected a $0.6 million reduction of our reserve. Additionally, our share of ATC's earnings reflected the derecognition of a possible refund related to the Second Complaint Period as ATC considered such a refund to be no longer probable. However, due to pending requests for rehearing, a loss related to the 2015 complaint remains possible. Our share of the estimated refund for the Second Complaint Period is approximately $2.3 million. MGE has not recorded a possible loss for the Second Complaint Period.

Several petitions for review of FERC’s prior orders were filed with the U.S. Court of Appeals for the D.C. Circuit (the "Court") and an oral argument was held in November 2021. In August 2022, the Court ruled that four of the five arguments made by the complaining parties were unpersuasive. However, the Court agreed that FERC’s decision to reintroduce a risk-premium model into its ROE methodology was arbitrary and capricious. The Court vacated the underlying orders for the First Complaint Period and remanded to FERC for further proceedings. In 2022, our share of ATC's earnings reflected an estimated possible loss of approximately $0.9 million, inclusive of interest and net of tax, for a possible additional refund for the First Complaint Period and for the period following the Second Complaint Period. Although the Court agreed that FERC was correct to use the base ROE established in the first complaint to adjudicate the second, and that FERC was right to dismiss the second complaint, the second complaint was also remanded for FERC to reopen proceedings. Any reduction in ATC's ROE could result in lower equity earnings and distributions from ATC in the future.

We derived approximately 5.7% and 5.9% of our net income during the three months ended March 31, 2024 and 2023, respectively, from our investment in ATC.

Uyghur Forced Labor Protection Act

In June 2021, the U.S. Customs and Border Protection (CBP) issued a Withhold Release Order (WRO) against silica-based products made by Hoshine Silicon Industry Co. Ltd., a company located in China's Xinjiang Uyghur Autonomous Region. As a result of this WRO, CBP is holding many solar panels imported into the United States until importers can prove that the panels do not contain materials originating from this region. The Uyghur Forced Labor Protection Act (UFLPA), a federal law that became effective on June 21, 2022, further established that all goods mined, produced, or manufactured wholly or in part in Xinjiang or by certain defined entities are prohibited from U.S. importation. Suppliers for MGE's current solar projects were able to provide the CBP sufficient documentation to meet WRO compliance requirements, and MGE expects the same will be true for UFLPA purposes, however we cannot currently predict what, if any, impact the UFLPA will have on the overall supply of solar panels into the United States and the related impact to timing and cost of solar projects included in our capital plan. In the event that such disruptions cause costs to exceed the levels approved for specific projects, we have filed and expect to continue to file a notification with the PSCW and expect to request recovery of any cost increases in MGE's future rate proceedings.

U.S. Department of Commerce Investigation

In March 2022, the U.S. Department of Commerce announced a solar tariff investigation on solar panels from four Southeast Asian countries. This investigation could result in additional tariffs on solar panels. In June 2022, the U.S. Department of Commerce issued a 24-month exemption from tariffs for solar panel and module imports from these four countries. MGE is currently assessing the potential impact of these disruptions on current and future solar projects which may result in an increase in costs or delays in construction timelines. In the event that such disruptions cause costs to exceed the levels approved for specific projects, we have filed and expect to continue to file a notification with the PSCW and expect to request recovery of any cost increases in MGE's future rate proceedings.

Adoption of Accounting Principles and Recently Issued Accounting Pronouncements

See Footnote 2 of Notes to Consolidated Financial Statements in this Report for discussion of new accounting pronouncements.