Power stock Exelon ( EXC) weighs in as the biggest power retailer in the U.S., with capacity to serves loads of 190 terawatt hours. The firm owns regulated power utilities as well as unregulated merchant generation assets with a combined 34 gigawatts of capacity spread across seven states. The acquisition of Constellation Energy this year adds a big regulated utility in the form of Baltimore Gas & Electric (your author's electric utility), bringing the total company-wide customer list to 6.6 million households. The majority of Exelon's power generation is nuclear, a factor that gives the firm access to extremely low cost capacity (around $15 per megawatt-hour), even if political hurdles prove challenging. In a big way, those challenges are a good thing for Exelon -- it means that barriers to entry are huge for other firms that want to build nuclear plants across the U.S. >>5 Rocket Stocks to Buy a Spain Gets Bailed Out Not surprisingly, Exelon's major regulated utility operations make it a dividend powerhouse as well. Because regulated utilities have relatively consistent, predictable revenue streams, they make ideal income investments -- even if wholesale power generation adds some volatility to earnings. The firm's yield currently weighs in at 5.6%, a hefty payout for any dividend firm, especially right now. Pickens and company added 290,000 shares of Exelon to the BP Capital portfolio last quarter, taking on a $5 million stake in the firm.