I have been trying to figure this out ever since Texas started deregulating power distribution. Of course it used to be quite simple when you got your power from a local monopoly. They decided what you paid and that was all that there was too. Now there are probably around a hundred power companies in Texas. If you look around you can find a number of web pages likes choosetexaspower.org which list the ones which are available where you live, usually there will be around three or four on the site, but it depends a lot on how many people there are in the are. Obviously a lot of power companies want to sell power in places where there a whole lot of consumers all living one by the other. It is not the same if you live out in the vast expanses of Texas where you have to get in your pick up truck and drive for ten minutes to see your nearest neighbor.
I have been working on a doctrine for how to pick a power company. Of course you want the lowest rate so you go to a site like choosetexaspower.org and you find out who gives you that. In a lot of cases there is not going to be a whole lot of difference in the choices that are available to you. They all know pretty much what their competitors are charging and they are going to offer something which is going to be comparable to the market price. You do not judge the provider simply on price however. You want someone who is going to come through for you reliably when you need them. There are going to be outages no matter who you pick, but you want the one who is going to respond to problems best.