INTANGIBLE ASSETS (Details) - CAD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
INTANGIBLE ASSETS
Cost	$ 5,726	$ 5,535
Accumulated Amortization	(1,708)	(1,527)
Net	4,018	4,008
Amortization expenses
Amortization expense for intangible assets	$ 483	$ 348	$ 294
Software
INTANGIBLE ASSETS
Weighted Average Amortization Rate (as a percent)	10.90%	12.00%
Cost	$ 2,019	$ 2,067
Accumulated Amortization	(1,042)	(1,148)
Net	$ 977	$ 919
Power purchase agreements
INTANGIBLE ASSETS
Weighted Average Amortization Rate (as a percent)	4.20%	4.50%
Cost	$ 64	$ 63
Accumulated Amortization	(23)	(21)
Net	$ 41	$ 42
Project agreement
INTANGIBLE ASSETS
Weighted Average Amortization Rate (as a percent)	4.00%	4.00%
Cost	$ 163	$ 152
Accumulated Amortization	(36)	(27)
Net	$ 127	$ 125
Customer relationships
INTANGIBLE ASSETS
Weighted Average Amortization Rate (as a percent)	8.60%	8.50%
Cost	$ 2,701	$ 2,532
Accumulated Amortization	(459)	(215)
Net	$ 2,242	$ 2,317
Other intangible assets
INTANGIBLE ASSETS
Weighted Average Amortization Rate (as a percent)	5.90%	3.90%
Cost	$ 621	$ 475
Accumulated Amortization	(148)	(116)
Net	$ 473	$ 359
Under development
INTANGIBLE ASSETS
Weighted Average Amortization Rate (as a percent)	0.00%	0.00%
Cost	$ 158	$ 246
Accumulated Amortization	0	0
Net	$ 158	$ 246