v3.24.0.1
Regulation (Tables)
 12 Months Ended
Dec. 31, 2023
Regulated Operations [Abstract]  
Schedule of Nature of Regulation
Nature of Regulation
Allowed
Common
Equity
(%)
Allowed ROE (1)
(%)

Regulated Utility		Regulatory Authority20232022Significant Features
ITC
Federal Energy Regulatory Commission ("FERC")60.0 

10.77
(2)
10.77
Cost-based formula rates, with annual true-up mechanism (3)
Incentive adders
TEP
Arizona Corporation Commission ("ACC") 54.3 9.55 
(4)
9.15 COS regulation
Historical test year
FERC
(5)
9.79 9.79 Formula transmission rates
UNS ElectricACC52.8 9.50 
(6)
9.50 
UNS GasACC50.8 
9.75
9.75 
Central Hudson New York State Public Service Commission ("PSC")
48.0
(7)
9.00
9.00 COS regulation
Future test year
FortisBC Energy British Columbia Utilities Commission ("BCUC")45.0 
9.65
(8)
8.75 
COS regulation with formula components and incentives (8)
FortisBC ElectricBCUC41.0 
9.65
(8)
9.15 Future test year
FortisAlbertaAlberta Utilities Commission ("AUC")37.0 
8.50
8.50 
PBR (9)
Newfoundland PowerNewfoundland and Labrador Board of Commissioners of Public Utilities45.0 
8.50
8.50 COS regulation
Future test year
Maritime ElectricIsland Regulatory and Appeals Commission40.0 
9.35
9.35
COS regulation
Future test year
FortisOntario (10)
Ontario Energy Board40.0 
8.52-9.30
8.52-9.30
COS regulation with incentive mechanisms
Caribbean Utilities (11)
Utility Regulation and Competition OfficeN/A
7.50-9.50
6.25-8.25
COS regulation
Rate-cap adjustment mechanism
based on published consumer price indices
FortisTCI (12)
Government of the Turks and Caicos IslandsN/A
15.00-17.50
15.00-17.50
COS regulation
Historical test year

(1)    ROA for Caribbean Utilities and FortisTCI
(2)    Includes the allowed common equity and base ROE plus incentive adders for ITCTransmission, METC, and ITC Midwest. See "Significant Regulatory Matters" below
(3)    Annual true-up collected or refunded in rates within a two-year period
(4)    Allowed common equity of 54.3% and ROE of 9.55% effective September 1, 2023. See "Significant Regulatory Matters" below
(5)    The allowed common equity component for FERC transmission rates is formulaic, and is updated annually based on TEP's actual equity ratio
(6)    Allowed common equity of 53.7% and ROE of 9.75% effective February 1, 2024. See "Significant Regulatory Matters" below
(7)    Effective July 1, 2021 Central Hudson's approved common equity component of capital structure was 50%, declining by 1% annually to 48% in the third rate year. A general rate application requesting new customer rates effective July 1, 2024 is ongoing. See "Significant Regulatory Matters" below
(8)    See "Significant Regulatory Matters" below. Formula and incentives have been set through 2024
(9)    FortisAlberta was subject to a COS revenue requirement in 2023. In 2022, FortisAlberta was subject to PBR, including mechanisms for flow-through costs and capital expenditures not otherwise recovered in customer rates. See "Significant Regulatory Matters" below
(10)    Two of FortisOntario's utilities follow COS regulation with incentive mechanisms, while the remaining utility is subject to a 35-year franchise agreement expiring in 2033
(11)    Operates under licences from the Government of the Cayman Islands. Its exclusive transmission and distribution licence is for an initial 20-year period, expiring in April 2028, with a provision for automatic renewal. Its non-exclusive generation licence is for a 25-year term, expiring in November 2039
(12)    Operates under 50-year licences from the Government of the Turks and Caicos Islands, which expire in 2036 and 2037