A recent report from the Energy Information Administration (EIA) shows that nearly all of the utility-scale power plants in the United States that have been decommissioned since 2008 were powered by fossil fuels. Of that total number of retired plants, coal power facilities and natural gas steam turbines accounted for 47 percent and 26 percent of the totals. Most of the planned retirements through 2020 will also fall into these categories.
A number of factors were considered before shuttering these facilities, but age and inefficiency are often the final nails in the coffin. For example, the coal power plants retired since 2008 were an average of 52-years-old and churning out 105 megawatts of power. In comparison, modern plants burning coal are nearly 15 years younger and producing three times as much power.
Other factors can include changes in regional electricity use, federal or state policies that affect plant operation, and state regulations that require or encourage the use of renewable energy sources. Improving technologies also play a part with newer, more efficient operational capabilities.
For example, older natural gas steam turbine technologies may be replaced as more efficient and operationally flexible replacements become available. For natural gas plants, this often means replacing steam turbines with combined-cycle and combustion-turbines that burn cleaner while producing more power. Also picking up the slack for many of these retired fossil fuel plants are expanding wind and solar energy production sites that are slowly contributing more to the electrical grid.