Revenue

9 Months Ended

Sep. 30, 2019

Revenue from Contract with Customer [Abstract]

Revenue from Contract with Customer

Revenue - MGE Energy and MGE.

Revenues disaggregated by revenue source were as follows:

		Three Months Ended				Nine Months Ended
(In thousands)		September 30,				September 30,
Electric revenues		2019		2018		2019		2018
Residential	$	42,442	$	42,371	$	107,772	$	107,847
Commercial		63,466		61,638		165,481		159,264
Industrial		3,760		3,668		10,013		11,193
Other-retail/municipal		9,543		9,431		26,728		26,245
Total retail		119,211		117,108		309,994		304,549
Sales to the market		1,163		1,505		3,914		6,334
Other revenues		233		562		978		1,750
Total electric revenues		120,607		119,175		314,886		312,633
Gas revenues
Residential		11,342		11,916		67,659		64,087
Commercial/Industrial		4,825		5,570		40,833		38,728
Total retail		16,167		17,486		108,492		102,815
Gas transportation		1,126		829		3,756		3,018
Other revenues		84		92		299		319
Total gas revenues		17,377		18,407		112,547		106,152
Non-regulated energy revenues		214		213		481		904
Total Operating Revenue	$	138,198	$	137,795		427,914	$	419,689

Performance Obligations

A performance obligation is a promise in a contract to transfer a distinct good or service to the customer and is the unit of account. A contract's transaction price is allocated to each distinct performance obligation and recognized as revenue when, or as, the performance obligation is satisfied. The majority of MGE Energy's and MGE's contracts have a single performance obligation.

Retail Revenue (Residential, Commercial, Industrial, and Other Retail/Municipal)

Retail revenue of electric and gas utility service represent MGE's core business activities. Tariffs are approved by the PSCW through a rate order and provide MGE's customers with the standard terms and conditions, including pricing terms. The performance obligation to deliver electricity or gas is satisfied over time as the customer simultaneously receives and consumes the commodities provided by MGE. MGE recognizes revenues as the commodity is delivered to customers. Meters are read on a systematic basis throughout the month based on established meter-reading schedules and the customer is subsequently billed for their services. At the end of the month, MGE accrues an estimate for the unbilled amount of commodities delivered to customers. The unbilled revenue estimate is based on daily system demand volumes, weather factors, estimated line losses, estimated customer usage by class, and applicable customer rates.

Utility Cost Recovery Mechanisms

MGE's tariff rates include a provision for fuel cost recovery. The PSCW allows Wisconsin utilities to defer electric fuel-related costs, less excess revenues, that fall outside a symmetrical cost tolerance band. Any over/under recovery of the actual costs in a given year is determined in the following year and is then

reflected in future billings to electric retail customers. Over-collection of fuel-related costs that are outside the approved range will be recognized as a reduction of revenue. Under-collection of these costs will be recognized in "Purchased power" expense in the consolidated statements of income. The cumulative effects of these deferred amounts will be recorded in "Regulatory assets" or "Regulatory liabilities" on the consolidated balance sheets until they are reflected in future billings to customers. See Footnote 10.b. for further information.

MGE received a PSCW order in January 2018 to defer the over-collection of income tax expense collected in customer rates during 2018 as a result of the Tax Cuts and Jobs Act (the Tax Act) reduction in the income tax rate to 21 percent. See Footnote 10.c. for further information.

MGE has other cost recovery mechanisms. For example, any over-collection of the difference between actual costs incurred and the amount of costs collected from customers is recorded as a reduction of revenue in the period incurred.

Sales to the Market

Sales to the market include energy charges, capacity or demand charges, and ancillary charges represented by wholesale sales of electricity made to third parties who are not ultimate users of the electricity. Most of these sales are spot market transactions on the markets operated by MISO. Each transaction is considered a performance obligation and revenue is recognized in the period in which energy charges, capacity or demand charges, and ancillary services are sold into MISO. MGE reports, on a net basis, transactions on the MISO markets in which it buys and sells power within the same hour to meet electric energy delivery requirements.

Transportation of Gas

MGE has contracts under which MGE provides gas transportation services to customers who have elected to purchase gas from a third party and have the gas delivered via pipelines within MGE's service territory. Revenue is recognized as service is rendered or gas is delivered to customers. Tariffs are approved by the PSCW through a rate order and provide gas transportation customers with the standard terms and conditions, including pricing terms.