EPA released a draft of its Clean Power Plan Rule yesterday, a topic that dominated my Twitter feed all day and already is sharpening the debate on the use of policy and the Clean Air Act to reduce carbon emissions. Our first reaction to the rule was that it likely will have little impact on carbon policy in Washington State. We already enjoy one of the least carbon-intensive energy infrastructures due to the abundance of hydroelectric energy in Washington, and Washington has already negotiated the phase-out of its only coal fired power plant, operated by TransAlta in Centralia, through the passage of Engrossed Second Substitute Senate Bill 5769 back in 2011.

Then, yesterday afternoon, the AP released this story with the headline, “EPA says Washington must cut emissions by 72 percent,” and a picture of a coal train in downtown Seattle. The article contains a few quotes from various parties regarding the implications of the proposed Clean Power Plan Rule in Washington. I was curious where the 72 percent number came from, and decided to dig into the draft rule yesterday evening.

Here is what I found:

The proposed rule is lengthy–the pre-publication version is 645 pages long. The rule sets goals for states to achieve with respect to carbon emissions from power plants, with a nationwide goal of a 30% reduction from 2005 levels by 2030. The goals are expressed as a rate, defined as CO2 emissions from fossil fuel-fired power plants in pounds per fossil-fuel fired generation capacity of a state, with the rate expressed as pounds per megawatt hour (MWh). The legal basis EPA relies on in setting these goals is Section 111(d) of the Clean Air Act, which, under EPA’s interpretation of that provision of the Clean Air Act, gives EPA the authority to determine the “best system of emission reduction” (BSER) for fossil fuel-fired generation units.

EPA is proposing to use a “building block” approach to BSER, combined with the goals discussed above to achieve the 30% reduction in carbon emissions that is the goal of the Clean Power Plan Rule. The “building block” approach involves four different strategies that can be implemented by states to varying degrees to fit the individual states circumstances. Those strategies are:

1) Making fossil fuel power plants more efficient through improving equipment and processes to yield as much energy from a unit of fuel burned.
2) Switching to low-emitting sources such as natural gas combined cycle units.
3) Using more zero-emitting and low-emitting power sources, including renewable energy sources and new nuclear power.
4) Increasing electricity efficiency.

EPA engaged in a detailed state-by-state analysis of the carbon intensity of fossil fuel energy sources to establish a “baseline” of that intensity as the first part in setting the goals under the proposed Clean Power Plan Rule. EPA then engaged in an analysis (also on a state-by-state basis) of what it considered reasonable to achieve if states implement the four building blocks. It is this analysis that resulted in the 72% reduction number in the AP story linked above.

The details of how the goals were computed are outlined in this technical document, with the actual numbers for each state reported in Appendix 5, starting on Page 25, along with how EPA believes the application of individual building blocks will reduce the current emission rates. If you review those numbers, you’ll see that Washington currently has a emission rate of 756 pounds per MWh, with a goal of 215 pounds per MWh. This is the 72% reduction that is the basis for the AP article.

However, what the AP article misses (but others have picked up on, with Craig Welch’s coverage in the Seattle Times being the best example) is that the vast majority of carbon emissions in Washington associated with energy production come from Centralia. The numbers EPA used on this point are available in the spreadsheets here, and TransAlta’s emissions account for approximately 80% of the total fossil fuel emissions of carbon dioxide in Washington. So, the phase-out of TransAlta’s facility alone (which would count under EPA’s proposed rule) will indeed mean that the goal set by EPA will be easy for Washington to meet.

This highlights Washington’s relatively unique position nationally with respect to the carbon intensity of its energy sources. If you review the numbers in Appendix 5, you’ll see that Washington already has some of the lowest emissions rate of carbon from fossil-fuel energy sources, and its goal will be the lowest of any of the goals proposed by EPA. However, I suspect that goal will be not a challenge for Washington to meet. The challenge for Washington may be a broader one. Governor Inslee has made a point about being a leader on climate change issues, having set a broad, ambitious agenda recently by executive order. I hope that that leadership also includes critical analysis of changes in energy policy on a national scale that will result in further emissions reductions–for instance, at times there have been rumblings in Washington about revisiting nuclear power as an alternative to fossil fuels, something that may not be the most politically attractive dialogue to have, but one that is probably needed as we wrestle on a national scale with reducing carbon emissions.