The problem with switching like that is that if you forget, you end up in a considerably more expensive plan after your contract expires.
Almost a year ago, I signed up for a company called
Energy Ogre that monitors the rates, keeps track of your contract expiration, and moves you to the cheapest provider every time your contract expires. Many times, they have access to promotional rates that aren't publicly available (or at least not that I've found). If you're set up on automatic billing, they get it set up for the new provider. You don't have to do anything. And they do all this for $10/month.
They've switched me a couple times. The first time, I got 6.5 cents/kWh. This time, it's even less. Last month, I used 2536 kWh and my total bill was $139.14.
