0000921895-20-001308 SC 13D/A 1 20200507 20200507 ATLANTIC POWER CORP 0001419242 4900 550886410 A1 1231 SC 13D/A 34 005-87139 20857736 3 ALLIED DRIVE SUITE 155 DEDHAM MA 02026 617-977-2400 3 ALLIED DRIVE SUITE 155 DEDHAM MA 02026 MANGROVE PARTNERS 0001535392 980652572 E9 1231 SC 13D/A 645 MADISON AVENUE, 14TH FLOOR NEW YORK NY 10022 212-897-9535 645 MADISON AVENUE, 14TH FLOOR NEW YORK NY 10022 SC 13D/A 1 sc13da1308511011_05072020.htm AMENDMENT NO. 13 TO SCHEDULE 13D