0000080255-13-000101 SC 13G/A 1 20130207 20130207 CALPINE CORP 0000916457 4911 770212977 DE 1231 SC 13G/A 34 005-48317 13580283 717 TEXAS AVENUE SUITE 1000 HOUSTON TX 77002 7138302000 717 TEXAS AVENUE SUITE 1000 HOUSTON TX 77002 PRICE T ROWE ASSOCIATES INC /MD/ 0000080255 6200 520556948 MD 1231 SC 13G/A 100 EAST PRATT ST BALTIMORE MD 21202 (410)345-6603 P.O. BOX 89000 BALTIMORE MD 21289 SC 13G/A 1 cpn13gadec12.htm CPN AS OF 12/31/2012