EXHIBIT 23.4 [GILBERT LAUSTSEN JUNG ASSOCIATES LTD LETTERHEAD] GILBERT LAUSTSEN JUNG ASSOCIATES LTD. Petroleum Consultants 4100, 400-3rd Avenue S.W., Calgary, Alberta, Canada T2P 4H2 (403) 266-9500 Fax (403) 262-1855 LETTER OF CONSENT We hereby consent to the incorporation by reference on Form 10-K of Calpine Corporation (the "Company") and to the references to this firm for the Company's estimated Canadian proved reserves contained on Form 10-K for the year ended December 31, 2003. Yours truly, GILBERT LAUSTSEN JUNG ASSOCIATES LTD. ORIGINALLY SIGNED BY Myron J. Hladyshevsky, P. Eng. Vice-President Calgary, Alberta March 8, 2004