The EPA published the latest version of its new source performance standards (NSPS) for carbon pollution from new power plants in the Federal Register on Jan. 8, setting in motion a 60-day public comment period.

The action stems from the 2007 Supreme Court decision in Massachusetts v. EPA that defined greenhouse gases as an air pollutant under the Clean Air Act (CAA), which the EPA has argued requires it to issue regulations controlling them. The EPA first proposed similar standards in early 2012, then revised them in response to more than 2.5 million public comments, releasing another draft in September 2013. The latest version is little changed from the September draft.

The rule sets a limit of 1,100 lb CO2/MWh for utility boilers, integrated gasification combined-cycle (IGCC) units, and small gas-fired combustion turbines. The limit for larger gas-fired combined cycle plants is 1,000 lb CO2/MWh. The standard is widely viewed as an effective ban on construction of new coal-fired power, as it will be impossible for a coal plant to meet the standards without carbon capture and storage (CCS) technology.

The EPA assumes CCS will be available, though it has so far not met expectations, with a variety of groups from the International Energy Agency and the Global CCS Institute seeing little chance of meaningful progress without significant policy support. Currently there are no operating power plants with CCS installed. A number of significant projects have been cancelled on economic concerns, and the only CCS-equipped power plant in the U.S. with any likelihood of coming online in the near future—Mississippi Power’s Kemper County IGCC project—has experienced massive cost overruns and repeated delays. Startup is not expected before the end of this year.

The EPA’s action drew sharply varying responses from industry and environmental groups. Mike Duncan, president and CEO of the American Coalition for Clean Coal Electricity, said in a statement, “Contrary to claims made by EPA and other Administration officials, NSPS is just another step in President Obama’s dangerous climate change campaign that’s putting America’s energy future in jeopardy.”

The American Public Power Association released a statement saying it was “extremely disappointed” with the rule, predicting that it would “limit our future resource options and could likely lead to higher electricity rates in the coming years.” It also predicted that CCS was “unlikely” to be economically viable within the near future.

In contrast, the Environmental Defense Fund hailed the move, with attorney Megan Ceronsky saying, “This is a big step forward toward getting some common-sense limits on the carbon pollution that causes climate change. These standards will move us toward cleaner power generation, which will protect public health and encourage the development of new technologies that will boost the U.S. economy. Opponents of this rule need to explain why they think it’s okay to have unlimited carbon pollution.”

The proposed rule does not apply to existing plants, but a provision in the CAA would require the EPA begin formulating such standards once the NSPS are final. This is thought to part of the reason for the EPA’s slow progress with the NSPS, since they are certain to be challenged in court and a loss at this stage would prevent the EPA from enacting rules on existing plants.

The Supreme Court has agreed to hear a narrow challenge to the EPA’s authority to regulate greenhouse gases this term, but it is not expected to revisit the Massachusetts decision. Comments on the proposed rule are due by Mar. 10.

—Thomas W. Overton, gas technology editor (@thomas_overton, @POWERmagazine)