The source of energy for the satellites are its solar panels which generate power by themselves.
But, to reach the orbit , it uses the fuel to push the rocket . It needs fuel to power the rocket into the designated orbit.
Several liquid propellants are used in the rockets to launch the rockets into space. There after the satellites power themselves by the solar panels.
A large reflective mirrors focus the sun's rays and direct it towards solar panels , hence solar power is produced which is ud=sed to power the internal use of satellite.