Rate Matters

3 Months Ended

Mar. 31, 2025

Rate Matters - MGE Energy and MGE.

Rate Proceedings.


	Rate increase	Return on Common Equity	Common Equity Component of Regulatory Capital Structure	Effective Date
Approved 2024/2025 rate proceeding(a)(b)
Electric	1.54%	9.7%	56.1%	1/1/2024
Gas	2.44%	9.7%	56.1%	1/1/2024
Electric(c)	2.63%	9.7%	56.1%	1/1/2025
Gas	1.32%	9.7%	56.1%	1/1/2025
Proposed 2026/2027 rate proceeding(d)
Electric(e)	4.89%	10.0%	56.1%	1/1/2026
Gas(e)	2.33%	10.0%	56.1%	1/1/2026
Electric(f)	4.33%	10.0%	56.0%	1/1/2027
Gas(f)	2.16%	10.0%	56.0%	1/1/2027

(a)

The electric rate increase was driven by an increase in rate base including our investments made in West Riverside, local solar, continued investment in grid modernization, as well as higher costs for transmission, pension and OPEB, and uncollectible costs (including costs previously deferred from prior years). This increase in electric costs is offset by a decrease in fuel costs and benefit from lower tax expense (including impacts from the Inflation Reduction Act). MGE filed an updated 2025 fuel forecast with the PSCW in 2024, which will impact rates in 2025, based on any variance between the forecast submitted as part of the rates and updated forecast. In addition, the PSCW authorized MGE to defer a recovery of and a return on costs associated for any change in the in service date for Paris and force majeure costs for Badger Hollow II and Paris that were not reflected in

this rate filing. The PSCW also approved deferral of any differential in PTC tax credits reflected in rates and actual credits produced. These deferrals will be reflected in MGE's next rate case filing. The gas rate increases were also driven by our investment made in grid modernization and higher pension and OPEB and uncollectible costs (including costs previously deferred from prior years). This increase in gas costs is offset by a tax benefit related to excess deferred taxes. Included in the gas residential rate is a reduction in the customer fixed charge.

(b)

The 2024/2025 rate order includes an earnings sharing mechanism, under which, if MGE earns above the authorized Return on Equity (ROE) in the rate order: (i) the utility will retain 100.0% of earnings for the first 15 basis points above the authorized ROE; (ii) 50.0% of the next 60 basis points will be required to be deferred and returned to customers; and (iii) 100.0% of any remaining excess earnings will be required to be refunded to customers. The earnings calculation excludes fuel rules adjustments. See "Fuel Rules" below.

(c)

The PSCW approved a 2025 Fuel Cost Plan in December 2024. The plan lowered the 2025 increase in electric rates to 2.63% to reflect lower expected fuel costs.

(d)

In April 2025, MGE filed a proposed 2-year rate case and PSCW approval is pending. A final order is expected before the end of the year.

(e)

The proposed electric rate increase is driven by an increase in rate base including our investments made in Paris (battery), Darien (battery), Sunnyside (solar), West Riverside, and continued investment in grid modernization, as well as higher costs for transmission. The increase in electric costs is offset by a decrease in fuel costs, changes in pension and OPEB, and benefit from lower tax expense (including impacts from the Inflation Reduction Act). The proposed gas increase is driven by an increase in rate base including continued distribution infrastructure improvements designed to enhance reliability and safety and system modernization. The increase in gas costs is offset by changes in pension and OPEB.

(f)

The proposed electric rate increase is driven by an increase in rate base including investments made in Koshkonong (solar), Sunnyside (battery), and High Noon (solar/battery) projects, and continued investment in grid modernization projects. The increase in electric costs is offset by a benefit from lower tax expense (including impacts from the Inflation Reduction Act). The proposed gas rate increase is driven by an increase in rate base.

Fuel Rules.

Fuel rules require Wisconsin utilities to defer electric fuel-related costs that fall outside a symmetrical cost tolerance band around the amount approved for a utility in its annual fuel proceedings. Any over- or under-recovery of the actual costs is determined in the following year and is then reflected in future billings to electric retail customers. The fuel rules bandwidth is set at plus or minus 2% in 2025 and 2024. The electric fuel-related costs are subject to an excess revenues test. Excess revenues are defined as revenues in the year in question that provide MGE with a greater return on common equity than authorized by the PSCW in MGE's latest rate order. The recovery of under-collected electric fuel-related costs would be reduced by the amount that exceeds the excess revenue test. These costs are subject to the PSCW's annual review of fuel costs completed in the year following the deferral. The following table summarizes deferred electric fuel-related costs:


	Fuel Costs (Savings) (in millions)	Refund or Recovery Period
2022	$8.8(a)	October 2023 through September 2024
2023	($7.2)(a)	October 2024 through December 2024
2024	($3.0)	(b)
2025	($0.8)	(c)

(a)

There was no change to the refund or recovery in the fuel rules proceedings from the amount MGE deferred.

(b)

In March 2025, MGE filed its application for reconciliation of actual fuel costs for 2024 with the PSCW proposing to return these savings in October 2025. These costs will be subject to the PSCW's annual review of 2024 fuel costs, expected to be completed in 2025.

(c)

These costs will be subject to the PSCW's annual review of 2025 fuel costs, expected to be completed in 2026.