From Earth, we were shown that the aligning of symbols took tremendous amounts of energy, how did they manage to do it from the alien world (Abydos), it seems like a pretty big logical problem.
In the movie, the subject of powering the Stargate is not mentioned but, as you say, the power seems to be used for turning the gate itself.
From a Wikia
No Dial Home Device is ever shown in the film, making it unclear how Dr. Daniel Jackson managed to redial the gate. This issue is apparently solved in the novelization of the movie, written by Dean Devlin & Roland Emmerich. In this book, the inner circle of the Stargate device is described as freely slid by hand. In fact, the novelization implies that all the dialing computer at SGC does is to mechanically slide the inner circle by means of two rubber wheels clamped to the lower side Stargate device.
So the Stargate in the movie was self-powered and just required dialing which could, if necessary be done by hand.
For the TV series though, this was changed and the gate did require power and TV series got around this by having a DHD which stored the energy required to power the Stargate even if it was dialied (i.e. ring turned) manually.
As Earth didn't have a DHD, they powered the TV gate from the Colorado power system and Carter built a computer version of a DHD.