Electrical cost for indoor grow..I'm scared

I live in Mich. and would like to do an indoor grow,but am worried about being discovered through my electric usage.I've heard that when your electric usage increases by so much the police get tipped off. Is there any truth to this?I'd like to start with a couple of 400w hps lights. Any thoughts?

My computer has a 400w power supply, my tv uses a bit more, I think. Thats about equal to 2 400w bulbs.