Duke Energy recognizes revenue consistent with amounts billed under tariff offerings or at contractually agreed upon rates based on actual physical delivery of electric or natural gas service, including estimated volumes delivered when billings have not yet occurred. As such, the majority of Duke Energy’s revenues have fixed pricing based on the contractual terms of the published tariffs, with variability in expected cash flows attributable to the customer’s volumetric demand and ultimate quantities of energy or natural gas supplied and used during the billing period. The stand-alone selling price of related sales are designed to support recovery of prudently incurred costs and an appropriate return on invested assets and are primarily governed by published tariff rates or contractual agreements approved by relevant regulatory bodies. As described in Note 1, certain excise taxes and franchise fees levied by state or local governments are required to be paid even if not collected from the customer. These taxes are recognized on a gross basis as part of revenues. Duke Energy elects to account for all other taxes net of revenues.

Performance obligations are satisfied over time as energy or natural gas is delivered and consumed with billings generally occurring monthly and related payments due within 30 days, depending on regulatory requirements. In no event does the timing between payment and delivery of the goods and services exceed one year. Using this output method for revenue recognition provides a faithful depiction of the transfer of electric and natural gas service as customers obtain control of the commodity and benefit from its use at delivery. Additionally, Duke Energy has an enforceable right to consideration for energy or natural gas delivered at any discrete point in time and will recognize revenue at an amount that reflects the consideration to which Duke Energy is entitled for the energy or natural gas delivered.

As described above, the majority of Duke Energy’s tariff revenues are at-will and, as such, related contracts with customers have an expected duration of one year or less and will not have future performance obligations for disclosure. Additionally, other long-term revenue streams, including wholesale contracts, generally provide services that are part of a single performance obligation, the delivery of electricity or natural gas. As such, other than material fixed consideration under long-term contracts, related disclosures for future performance obligations are also not applicable.

Electric Utilities and Infrastructure earns the majority of its revenues through retail and wholesale electric service through the generation, transmission, distribution and sale of electricity. Duke Energy generally provides retail and wholesale electric service customers with their full electric load requirements or with supplemental load requirements when the customer has other sources of electricity.

Retail electric service is generally marketed throughout Duke Energy's electric service territory through standard service offers. The standard service offers are through tariffs determined by regulators in Duke Energy's regulated service territory. Each tariff, which is assigned to customers based on customer class, has multiple components such as an energy charge, a demand charge, a basic facilities charge and applicable riders. Duke Energy considers each of these components to be aggregated into a single performance obligation for providing electric service, or in the case of distribution only customers in Duke Energy Ohio, for delivering electricity. Electricity is considered a single performance obligation satisfied over time consistent with the series guidance and is provided and consumed over the billing period, generally one month. Retail electric service is typically provided to at-will customers who can cancel service at any time, without a substantive penalty. Additionally, Duke Energy adheres to applicable regulatory requirements in each jurisdiction to ensure the collectability of amounts billed and appropriate mitigating procedures are followed when necessary. As such, revenue from contracts with customers for such contracts is equivalent to the electricity supplied and billed in that period (including unbilled estimates).

Wholesale electric service is generally provided under long-term contracts using cost-based pricing. FERC regulates costs that may be recovered from customers and the amount of return companies are permitted to earn. Wholesale contracts include both energy and demand charges. For full requirements contracts, Duke Energy considers both charges as a single performance obligation for providing integrated electric service. For contracts where energy and demand charges are considered separate performance obligations, energy and demand are each a distinct performance obligation under the series guidance and are satisfied as energy is delivered and stand-ready service is provided on a monthly basis. This service represents consumption over the billing period and revenue is recognized consistent with billings and unbilled estimates, which generally occur monthly. Contractual amounts owed are typically trued up annually based upon incurred costs in accordance with FERC published filings and the specific customer’s actual peak demand. Estimates of variable consideration related to potential additional billings or refunds owed are updated quarterly.

The majority of wholesale revenues are full requirements contracts where the customers purchase the substantial majority of their energy needs and do not have a fixed quantity of contractually required energy or capacity. As such, related forecasted revenues are considered optional purchases. Supplemental requirements contracts that include contracted blocks of energy and capacity at contractually fixed prices have the following estimated remaining performance obligations:

Gas Utilities and Infrastructure earns its revenue through retail and wholesale natural gas service through the transportation, distribution and sale of natural gas. Duke Energy generally provides retail and wholesale natural gas service customers with all natural gas load requirements. Additionally, while natural gas can be stored, substantially all natural gas provided by Duke Energy is consumed by customers simultaneously with receipt of delivery.

Retail natural gas service is marketed throughout Duke Energy's natural gas service territory using published tariff rates. The tariff rates are established by regulators in Duke Energy's service territories. Each tariff, which is assigned to customers based on customer class, have multiple components, such as a commodity charge, demand charge, customer or monthly charge and transportation costs. Duke Energy considers each of these components to be aggregated into a single performance obligation for providing natural gas service. For contracts where Duke Energy provides all of the customer’s natural gas needs, the delivery of natural gas is considered a single performance obligation satisfied over time, and revenue is recognized monthly based on billings and unbilled estimates as service is provided and the commodity is consumed over the billing period. Additionally, natural gas service is typically at-will and customers can cancel service at any time, without a substantive penalty. Duke Energy also adheres to applicable regulatory requirements to ensure the collectability of amounts billed and receivable and appropriate mitigating procedures are followed when necessary.

Certain long-term individually negotiated contracts exist to provide natural gas service. These contracts are regulated and approved by state commissions. The negotiated contracts have multiple components, including a natural gas and a demand charge, similar to retail natural gas contracts. Duke Energy considers each of these components to be a single performance obligation for providing natural gas service. This service represents consumption over the billing period, generally one month.

Fixed capacity payments under long-term contracts for the Gas Utilities and Infrastructure segment include minimum margin contracts and supply arrangements with municipalities and power generation facilities. Revenues for related sales are recognized monthly as natural gas is delivered and stand-ready service is provided, consistent with invoiced amounts and unbilled estimates. Estimated remaining performance obligations are as follows:

Commercial Renewables earns the majority of its revenues through long-term PPAs and generally sells all of its wind and solar facility output, electricity and RECs to customers. The majority of these PPAs have historically been accounted for as leases. For PPAs that are not accounted for as leases, the delivery of electricity and the delivery of RECs are considered separate performance obligations.

The delivery of electricity is a performance obligation satisfied over time and represents generation and consumption of the electricity over the billing period, generally one month. The delivery of RECs is a performance obligation satisfied at a point in time and represents delivery of each REC generated by the wind or solar facility. The majority of self-generated RECs are bundled with energy in Duke Energy’s contracts and, as such, related revenues are recognized as energy is generated and delivered as that pattern is consistent with Duke Energy’s performance. Commercial Renewables recognizes revenue based on the energy generated and billed for the period, generally one month, at contractual rates (including unbilled estimates) according to the invoice practical expedient. Amounts are typically due within 30 days of invoice.

Commercial Renewables also earns revenues from installation of distributed solar generation resources, which is primarily composed of EPC projects to deliver functioning solar power systems, generally completed within two to 12 months from commencement of construction. The installation of distributed solar generation resources is a performance obligation that is satisfied over time. Revenue from fixed-price EPC contracts is recognized using the input method as work is performed based on the estimated ratio of incurred costs to estimated total costs.

For the Electric and Gas Utility and Infrastructure segments, revenue by customer class is most meaningful to Duke Energy as each respective customer class collectively represents unique customer expectations of service, generally has different energy and demand requirements, and operates under tailored, regulatory approved pricing structures. Additionally, each customer class is impacted differently by weather and a variety of economic factors including the level of population growth, economic investment, employment levels, and regulatory activities in each of Duke Energy’s jurisdictions. As such, analyzing revenues disaggregated by customer class allows Duke Energy to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. For the Commercial Renewables segment, the majority of revenues from contracts with customers are from selling all of the unit-contingent output at contractually defined pricing under long-term PPAs with consistent expectations regarding the timing and certainty of cash flows. Disaggregated revenues are presented as follows:


	Year Ended December 31, 2021
			Duke				Duke		Duke		Duke		Duke
(in millions)	Duke		Energy		Progress		Energy		Energy		Energy		Energy
By market or type of customer	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Electric Utilities and Infrastructure
Residential	$	10,097	$	3,054	$	5,084	$	2,156	$	2,928	$	767	$	1,188	$	—
General	6,375		2,210		2,883		1,378		1,505		440		825		—
Industrial	2,924		1,145		894		634		260		135		750		—
Wholesale	2,199		472		1,385		1,164		221		56		285		—
Other revenues	879		264		716		387		329		83		86		—
Total Electric Utilities and Infrastructure revenue from contracts with customers	$	22,474	$	7,145	$	10,962	$	5,719	$	5,243	$	1,481	$	3,134	$	—

Gas Utilities and Infrastructure
Residential	$	1,131	$	—	$	—	$	—	$	—	$	354	$	—	$	777
Commercial	561		—		—		—		—		143		—		418
Industrial	158		—		—		—		—		20		—		137
Power Generation	—		—		—		—		—		—		—		92
Other revenues	133		—		—		—		—		28		—		45
Total Gas Utilities and Infrastructure revenue from contracts with customers	$	1,983	$	—	$	—	$	—	$	—	$	545	$	—	$	1,469

Commercial Renewables
Revenue from contracts with customers	$	217	$	—	$	—	$	—	$	—	$	—	$	—	$	—

Other
Revenue from contracts with customers	$	29	$	—	$	—	$	—	$	—	$	—	$	—	$	—

Total revenue from contracts with customers	$	24,703	$	7,145	$	10,962	$	5,719	$	5,243	$	2,026	$	3,134	$	1,469

Other revenue sources(a)	$	394	$	(43)	$	95	$	61	$	16	$	11	$	40	$	100
Total revenues	$	25,097	$	7,102	$	11,057	$	5,780	$	5,259	$	2,037	$	3,174	$	1,569

(a) Other revenue sources include revenues from leases, derivatives and alternative revenue programs that are not considered revenues from contracts with customers. Alternative revenue programs in certain jurisdictions include regulatory mechanisms that periodically adjust for over or under collection of related revenues.


	Year Ended December 31, 2020
			Duke				Duke		Duke		Duke		Duke
(in millions)	Duke		Energy		Progress		Energy		Energy		Energy		Energy
By market or type of customer	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Electric Utilities and Infrastructure
Residential	$	9,806	$	2,997	$	5,017	$	2,059	$	2,958	$	726	$	1,064	$	—
General	6,194		2,233		2,779		1,312		1,467		442		740		—
Industrial	2,859		1,137		901		649		252		137		683		—
Wholesale	1,864		380		1,228		1,034		194		32		224		—
Other revenues	914		281		596		294		302		82		72		—
Total Electric Utilities and Infrastructure revenue from contracts with customers	$	21,637	$	7,028	$	10,521	$	5,348	$	5,173	$	1,419	$	2,783	$	—

Gas Utilities and Infrastructure
Residential	$	930	$	—	$	—	$	—	$	—	$	300	$	—	$	630
Commercial	446		—		—		—		—		117		—		329
Industrial	127		—		—		—		—		17		—		110
Power Generation	—		—		—		—		—		—		—		34
Other revenues	87		—		—		—		—		17		—		70
Total Gas Utilities and Infrastructure revenue from contracts with customers	$	1,590	$	—	$	—	$	—	$	—	$	451	$	—	$	1,173

Commercial Renewables
Revenue from contracts with customers	$	227	$	—	$	—	$	—	$	—	$	—	$	—	$	—

Other
Revenue from contracts with customers	$	26	$	—	$	—	$	—	$	—	$	—	$	—	$	—

Total revenue from contracts with customers	$	23,480	$	7,028	$	10,521	$	5,348	$	5,173	$	1,870	$	2,783	$	1,173

Other revenue sources(a)	$	388	$	(13)	$	106	$	74	$	15	$	(12)	$	12	$	124
Total revenues	$	23,868	$	7,015	$	10,627	$	5,422	$	5,188	$	1,858	$	2,795	$	1,297


	Year Ended December 31, 2019
			Duke				Duke		Duke		Duke		Duke
(in millions)	Duke		Energy		Progress		Energy		Energy		Energy		Energy
By market or type of customer	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Electric Utilities and Infrastructure
Residential	$	9,863	$	3,044	$	4,998	$	2,144	$	2,854	$	733	$	1,087	$	—
General	6,431		2,244		2,935		1,368		1,567		451		802		—
Industrial	3,071		1,215		934		675		259		147		774		—
Wholesale	2,212		462		1,468		1,281		187		46		235		—
Other revenues	770		276		548		317		231		80		89		—
Total Electric Utilities and Infrastructure revenue from contracts with customers	$	22,347	$	7,241	$	10,883	$	5,785	$	5,098	$	1,457	$	2,987	$	—

Gas Utilities and Infrastructure
Residential	$	976	$	—	$	—	$	—	$	—	$	315	$	—	$	661
Commercial	508		—		—		—		—		130		—		378
Industrial	141		—		—		—		—		19		—		122
Power Generation	—		—		—		—		—		—		—		51
Other revenues	129		—		—		—		—		19		—		110
Total Gas Utilities and Infrastructure revenue from contracts with customers	$	1,754	$	—	$	—	$	—	$	—	$	483	$	—	$	1,322

Commercial Renewables
Revenue from contracts with customers	$	223	$	—	$	—	$	—	$	—	$	—	$	—	$	—

Other
Revenue from contracts with customers	$	24	$	—	$	—	$	—	$	—	$	—	$	—	$	—

Total revenue from contracts with customers	$	24,348	$	7,241	$	10,883	$	5,785	$	5,098	$	1,940	$	2,987	$	1,322

Other revenue sources(a)	$	731	$	154	$	319	$	172	$	133	$	—	$	17	$	59
Total revenues	$	25,079	$	7,395	$	11,202	$	5,957	$	5,231	$	1,940	$	3,004	$	1,381

As described in Note 1, Duke Energy adopted the new guidance for credit losses effective January 1, 2020, using the modified retrospective method of adoption, which does not require restatement of prior year reported results. The following table presents the reserve for credit losses for trade and other receivables based on adoption of the new standard.


	Years Ended December 31, 2020 and 2021
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Balance at December 31, 2019	$	76	$	10	$	16	$	8	$	7	$	4	$	3	$	6
Cumulative Change in Accounting Principle	5		1		2		1		1		—		—		1
Write-Offs	(58)		(13)		(23)		(8)		(14)		—		—		(6)
Credit Loss Expense	75		13		29		9		20		—		—		11
Other Adjustments	48		12		13		13		—		—		—		—
Balance at December 31, 2020	$	146	$	23	$	37	$	23	$	14	$	4	$	3	$	12
Write-Offs	(58)		(21)		(25)		(12)		(13)		—		—		(9)
Credit Loss Expense	54		27		25		11		14		—		—		7
Other Adjustments	(20)		13		(1)		(1)		1		—		—		5
Balance at December 31, 2021	$	122	$	42	$	36	$	21	$	16	$	4	$	3	$	15

Trade and other receivables are evaluated based on an estimate of the risk of loss over the life of the receivable and current and historical conditions using supportable assumptions. Management evaluates the risk of loss for trade and other receivables by comparing the historical write-off amounts to total revenue over a specified period. Historical loss rates are adjusted due to the impact of current conditions, as well as forecasted conditions over a reasonable time period. The calculated write-off rate can be applied to the receivable balance for which an established reserve does not already exist. Management reviews the assumptions and risk of loss periodically for trade and other receivables.


	December 31, 2021
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Unbilled Receivables(a)(b)	$	964	$	316	$	266	$	193	$	73	$	4	$	27	$	106
0-30 days	2,104		595		800		405		393		42		51		202
30-60 days	212		77		72		44		28		4		13		12
60-90 days	88		37		41		21		20		1		1		2
90+ days	249		106		65		37		28		47		11		7
Deferred Payment Arrangements(c)	115		55		45		22		23		2		—		4
Trade and Other Receivables	$	3,732	$	1,186	$	1,289	$	722	$	565	$	100	$	103	$	333


	December 31, 2020
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Unbilled Receivables(a)(b)	$	969	$	328	$	283	$	167	$	116	$	2	$	16	$	86
0-30 days	1,789		445		707		398		307		60		26		149
30-60 days	185		80		54		25		29		8		3		8
60-90 days	22		1		10		4		6		2		1		3
90+ days	119		16		32		9		23		30		12		9
Deferred Payment Arrangements(c)	215		96		80		52		28		—		—		7
Trade and Other Receivables	$	3,299	$	966	$	1,166	$	655	$	509	$	102	$	58	$	262

(b) Duke Energy Ohio and Duke Energy Indiana sell, on a revolving basis, nearly all of their retail accounts receivable, including receivables for unbilled revenues, to an affiliate, CRC, and account for the transfers of receivables as sales. Accordingly, the receivables sold are not reflected on the Consolidated Balance Sheets of Duke Energy Ohio and Duke Energy Indiana. See Note 17 for further information. These receivables for unbilled revenues are $82 million and $121 million for Duke Energy Ohio and Duke Energy Indiana, respectively, as of December 31, 2021, and $87 million and $134 million for Duke Energy Ohio and Duke Energy Indiana, respectively, as of December 31, 2020.