A number of impending environmental regulations have created uncertainties about the ability of certain coallâ€fired power plants (utility owned and merchant owned) to remain profitable into the extended future. While impending greenhouse gas (GHG) regulation is one of the largest threats to coal-fired power plants’ economic viability, a number of other increasingly stringent environmental programs, including new rules regulating emissions of sulfur dioxide (SO2), nitrogen oxides (NOx) and Hazardous Air Pollutants (HAPs), will adversely affect these plants’ economics. Most significantly, upcoming HAPs regulations will likely compel an increasing number of coal-fired power plants to install SO2 capture technology called “scrubbers” if they wish to operate into the extended future. Additional controls, including fabric filters, activated carbon injection, and potentially selective catalytic reduction (SCRs), will also likely be required. Scrubbers, as well as the other control technologies, represent a significant capital investment. Thus the operators of many coal-fired power plants will face the choice between installing this control equipment and continuing to operate under these increasingly stringent regulations or avoid the large capital expenditures associated with installing control equipment by retiring the marginally economic power plants before these regulations take effect. These pressures will only be exacerbated by increasingly stringent water and ash disposal regulations that effect coal-fired generation. Further, in addition to federal regulation, some states are requiring even more stringent water, air, and waste emission reductions adding pressure to utilities to retire older, higher emitting power plants.
Not all coal-fired power plants in service face the dilemma of installing the necessary emission control equipment. Of the approximately 310 GW of coal fired generating capacity in the U.S., about 150 GW already have installed the scrubbers (see Figure 1). Another approximately 50 GW have scrubbers permitted or under construction. Thus only about one third of the U.S. coal-fired generating capacity, or about 110 GW, will have to decide whether to install the necessary control equipment or potentially shut down.
INGAA commissioned ICF International to provide a simple estimate of the amount of coal-fired generation capacity that is currently not scrubbed, or planned to be scrubbed, and that is potentially at risk due to these impending air regulations. Of this universe of unscrubbed units, ICF estimated which units are potentially at risk based on two criteria: 1) age; and 2) efficiency, as measured by the plant’s heat rate.