X0306 4 2019-01-22 0 0001419242 ATLANTIC POWER CORP AT 0001136877 MOORE JAMES J JR C/O ATLANTIC POWER CORPORATION 3 ALLIED DRIVE, SUITE 220 DEDHAM MA 02026 1 1 0 0 Chief Executive Officer Common shares 2019-01-22 4 M 0 179968 A 647108 D Common shares 2019-01-22 4 F 0 89983 2.37 D 647108 D Transition notional shares 2019-01-22 4 M 0 269951 2.37 D Common shares 269951 269952 D Mr. Moore acquired shares pursuant to the vesting (disclosed on Table II) of transition notional shares awarded in 2015. Two thirds of the vested transition notional shares were settled in common shares and one third were settled in cash, which was deposited into the reporting persons applicable payroll tax withholding account. Mr. Moore vested 50%, plus accumulated dividend equivalent units, of the transition notional shares granted in 2015. The vesting date for these transition notional shares was the four year anniversary of their grant date. /s/ John S. Miele, attorney-in-fact 2019-01-24