Screen Control Using Wakelocks

I was toying around with different ways of turning the screen on and off and of course Wakelocks show up quite alot in this discussion. From what I gather, I can acquire a wakelock (partial or full) to turn the screen on and keep it on for the whole duration my app (or service) is running, and then release it to turn the screen off. My question is on the huge issue of battery consumption surrounding wakelocks. As long as I make sure to to acquire it just to keep the screen on and release it to turn the screen off (or when the screen turns off), battery consumption should be minimal right? The wakelock's only there when the screen is on so it will definitely let the phone go into deep sleep when the screen's off but does the wakelock actually consume battery itself while it's acquired? Or is all the fuss just bad programming (leaving the wakelock on when the screen turns off, etc.)?