MGE ENERGY INC

Rate Matters

In December 2021, the PSCW approved a settlement agreement for MGE's 2022 rate case. As part of the settlement agreement, the PSCW approved a 0.96% increase in 2023 gas rates and a potential 2023 electric rate change to be addressed through a limited rate case reopener.

In December 2022, the PSCW approved the electric rate case reopener. The reopener provides for a 9.01% increase to electric rates for 2023.

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 application also approves a 4.17% increase for electric rates and a 1.32% increase to gas rates for 2025.

Details related to MGE's 2022/2023 approved settlement agreement, 2023 electric limited reopener, and 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 which 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.a. of the Notes to Consolidated Financial Statements in this Report for further discussion of rate proceedings.

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 6.4% and 5.9%, respectively, of our net income for 2023 and 2022 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.

Critical Accounting Estimates - MGE Energy and MGE

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and judgments that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities. On an on-going basis, we evaluate our estimates, including those related to regulatory assets and liabilities, unbilled revenues, pension obligations, and income taxes. We base our estimates on historical experience and on various assumptions that are believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities that are not readily apparent from other sources. Those values may differ from these estimates under different assumptions or conditions. We believe the following critical accounting estimates affect our more significant judgments used in the preparation of our consolidated financial statements.

Regulatory Assets/Liabilities

Regulatory assets represent costs that have been deferred to future periods when it is probable that the regulator will allow future recovery of those costs through rates. MGE bases its assessment of recovery on precedents established by the regulatory body. Regulatory liabilities represent previous collections from customers that are expected to be refunded to customers in future periods. Regulatory assets and regulatory liabilities typically include deferral of energy costs, the normalization of income taxes, pension and other postretirement costs, the deferral of certain operating expenses, and non-ARO removal costs. The accounting for these regulatory assets and liabilities is in accordance with regulatory accounting standards.

MGE continually assesses whether the regulatory assets and liabilities meet the criteria for probability of future recovery or deferral. This assessment considers factors such as changes in the regulatory environment, recent rate orders to other regulated entities under the same jurisdiction, and the status of any pending or potential deregulation legislation. If future recovery of costs becomes no longer probable, the assets and liabilities would be recognized as current-period revenues or expenses.

Amortization of regulatory assets and liabilities is provided over the recovery or deferral period as allowed in the related regulatory agreement.

Unbilled Revenues

Revenues from the sale of electricity and gas are recorded when they are delivered to customers. Sales quantity is measured by customers' meters. Due to the large volume of those meters, it is impractical to read all of them at month end. Meters are read on a systematic basis throughout the month based on established meter-reading schedules. Consequently, at the end of any month, there exists a quantity of electricity and gas that has been delivered to customers but has not been captured by the meter readings. As a result, management must estimate revenue related to electricity and gas delivered to customers between meter-read dates and the end of the reporting period. These estimates include:

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The amount of electricity expected to be lost in the process of its transmission and distribution to customers (referred to as line loss) and the amount of electricity actually delivered to customers.

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The amount of gas expected to be lost in the process of distribution to customers and the amount of gas actually delivered to customers.

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The mix of sales between customer rate classes having different rates, which is based upon historical utilization assumptions.

MGE monitors the reasonableness of the unbilled revenue estimate through the review of ratios such as unbilled electric consumption compared to billed electric sales. To confirm the reasonableness of unbilled gas, the estimated unbilled consumption is compared to various other statistics, including percent of gas available for sale, change in unbilled month-to-month and change in unbilled compared to the prior year.

Pension and Other Postretirement Benefit Plans

MGE provides employees with certain retirement (pension) and postretirement (health care and life insurance) benefits. In order to measure the expense and obligations associated with these benefits, management must make a variety of estimates, including discount rates used to value certain liabilities, the expected return on plan assets set aside to fund these costs, the rate of compensation increase, employee turnover rates, retirement rates, health care trends, mortality rates, and other factors. These accounting estimates may change due to the uncertainty attached to the estimate as well as the fact that these estimates are difficult to measure. Different estimates used could result in recognizing different amounts of expense over different periods of time. Recovery in rates is expected.

MGE uses third-party specialists to assist with evaluating its assumptions and measurement of the costs and obligations associated with these retirement benefits. The discount rate and expected return on plan assets are based primarily on available investment yields and the historical performance of plan assets. They are critical accounting estimates because they are subject to management's judgment and can materially affect financial performance.

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Assumed return on assets. This assumption represents the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested (or to be invested) to provide for the benefits included in the projected benefit obligation. For 2023, MGE used an assumed return on assets of 7.00% for pension and 6.59% for other postretirement benefits. In 2024, the pension asset assumption will increase to 7.24% and the postretirement benefit assumption will increase to 6.81%. The annual expected rate of return is based on projected long-term equity and bond returns, maturities and asset allocations. Holding other assumptions constant, for every 1% reduction in the expected rate of return on plan assets, annual pension and other postretirement cost would increase by approximately $4.0 million, before taxes.

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Discount rate. The discount rate represents the rate at which pension obligations could effectively be settled on a present-value basis. MGE uses high-grade bond yields as a benchmark for determining the appropriate discount rate. MGE uses individual spot rates rather than a weighted average of the yield curve spot rates to measure the service cost and interest cost components for net periodic benefit cost. Holding other assumptions constant, a 0.5% decrease in the discount rate on the obligation balance as of December 31, 2023, would increase annual pension and other postretirement cost by approximately $1.2 million, before taxes.

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Medical trend assumptions. The health care cost trend rate is the assumed rate of increase in per-capita health care charges.

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Mortality rate assumption. Expected mortality rates are used in the valuation to determine the expected duration of future benefit payments to the plan participants. MGE utilizes mortality tables and projection scales developed by the society of actuaries. These tables and scales were last updated in 2021.

See Footnote 11 of the Notes to Consolidated Financial Statements in this Report for additional discussion of these plans.

Income Tax Provision

MGE Energy's and MGE's income tax provisions, including both current and deferred components, are based on estimates, assumptions, calculations, and interpretation of tax statutes for the current and future years. Determination of current-year federal and state income tax will not be settled for years.

Management regularly makes assessments of tax return outcomes relative to financial statement tax provisions and adjusts the tax provisions in the period when facts become final.

Additionally, in determining our current income tax provision, we assess temporary differences resulting from differing treatments of items for tax and accounting purposes. These differences result in deferred tax assets and liabilities, which are recorded in our balance sheets. When we maintain deferred tax assets, we assess the likelihood that these assets will be recovered through adjustments to future taxable income. Future tax benefits are recognized to the extent that realization of such benefits is more likely than not. A valuation allowance is recorded for those benefits that do not meet this criterion. We record an allowance reducing the asset to a value we believe will be recoverable based on our expectation of future taxable income. We believe the accounting estimate related to the valuation allowance is a critical accounting estimate because it is highly susceptible to change from period to period as it requires management to make assumptions about our future income over the lives of the deferred tax assets, and the impact of increasing or decreasing the valuation allowance is potentially material to our results of operations.