The thing with these elecricity companies is the lack of expansion, which pretty much means that they have a monopoly in the area they're in and they're not going to expand more to get more customers -- unless more building occurs where they are. Due to these, these stocks don't have much volatility. These stocks are income stocks, meaning that they pretty much just pay out a good amount of their earnings in dividends to people who own their stocks.
I'd rather buy an index fund then bet on different companies.