Exhibit 12 CENTERPOINT ENERGY HOUSTON ELECTRIC, LLC AND SUBSIDIARIES (AN INDIRECT WHOLLY OWNED SUBSIDIARY OF CENTERPOINT ENERGY, INC.) COMPUTATION OF RATIOS OF EARNINGS TO FIXED CHARGES (MILLIONS OF DOLLARS) <Table> <Caption> NINE MONTHS ENDED SEPTEMBER 30, -------------------------- 2005 2006 ------------ ------------ Net Income ............................................................. $ 208 $ 233 Income taxes .......................................................... 90 114 Capitalized interest ................................................... (2) (3) ----------- ----------- 296 344 ----------- ----------- Fixed charges, as defined: Interest ............................................................ 257 181 Capitalized interest ................................................ 2 3 Interest component of rentals charged to operating income ........... 1 1 ----------- ----------- Total fixed charges ................................................. 260 185 ----------- ----------- Earnings, as defined ................................................... $ 556 $ 529 =========== =========== Ratio of earnings to fixed charges ..................................... 2.14 2.85 =========== =========== </Table>