how much power does it consume by that I mean will it change the electric bill at all and if so how much?
I do not turn off my PC at all and I Play games like battlefield 4 and skyrim(modded) for a few hours every night.
Not sure about the R9 290's power draw in game play. I would hazard a guess at between a hd 7970 and 7990 to be honest. On the other hand I believe they have zero core technology which basically turns the card off when not in use so the the power it draws when your system is idle would be next to nothing. So it may actually lower your electricity bill. I haven't got one though so this is purely speculation.