For more than a century, Americans have been conditioned to think of coal as a cheap and abundant energy source—and for much of that period it was true. However, the passage of time can change such things, and it has. Big time. Today’s reality is, as the nation’s aged coal-fired power plants continue to get older, using coal for electricity generation has gotten more and more expensive. Like cars, homes, or most anything else, coal plants require more investment in repairs and maintenance as they age. These investments become an ever-greater portion of the power generation cost. In Arizona, a recent filing by Tucson Electric Power (TEP) shows just how dramatic this reality is affecting the price of coal-generated electricity. TEP projects that the 2020 to 2030 cost of electricity from two of the primary coal plants it relies on, Four Corners and San Juan, will be $80 per megawatt hour (MWh) or more. In its cost chart (see below), TEP also projects power from new combined cycle gas plants to cost more than $50 per MWh, while solar power comes in at only $29 per MWh. Regardless of where you live, if coal is a big part of your utility’s power mix, odds are it is causing your electricity rates to be higher than they should be. The investment firm Lazard Asset Management, which keeps track of global energy prices, reports that the cost for electricity from coal-fired power plants can run as much as $143 per MWh. By contrast, many solar contracts, especially in the Western U.S., are selling electricity for less than $25 per MWh....