The United States Environmental Protection Agency (EPA) has proposed to ease CO2 emissions rules set up in the New Source Performance Standards (NSPS). Under the Clean Air Act (CAA), the EPA has proposed to revise the existing rules requiring new coal-fired power plants to use the best system of emission reduction (BSER), which was considered to be the carbon capture and storage (CCS) technology. The EPA now considers that this technology that has not been proven at commercial scale and that it blocked the development of new coal-fired power plant since there are currently no plans to build new coal-fired power plants in the United States.
The new proposal would allow newly built coal-fueled plants to pump more CO2 into the atmosphere, above the 1,400 lb CO2/MWh cap set in the 2015 Clean Power Plant (CPP). It would revise the standards for newly constructed steam units as separate standards for large and small units: large units would be allowed to emit 1,900 lb CO2/MWh while small units would emit 2,000 lb CO2/MWh. For newly constructed coal refuse-fired units, the proposed emission rate would be 2,200 lb CO2/MWh, regardless of size.
The EPA is slowly rolling back Obama-era climate regulations and unveiled the the Affordable Clean Energy (ACE) in August 2018, a new regulation proposal to replace the previous administration's CPP.