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The EPA's just came out with the final version of the Clean Power Plan (CPP), and North Carolina is already saying it will fight it[1]. This is very ironic, because the state has already made great progress in the development of renewable energy, with the state ranking second (2014), in the nation, in new solar capacity, and a new wind farm is on the way[3]. These investments, in renewable energy, are a result of the states Renewable Energy Portfolio Standard (REPS)[4], which requires 12.5 % of the states electricity sales to be from Renewable Energy, by 2021, so meeting the states CPP requirements of 36 % reduction in CO2 emissions[5] by 2030 should not be difficult. However, the REPS was passed in 2007 by a Democrat government, and the current government, which is all Republican, does not seem motivated to keep up the good work. One reason is that Governor Pat McCrory, who got elected in 2012, and many of the Republican legislator ran their campaigns strongly on drill baby drill platforms, and have continued pursuing the idea that North Carolina can become a natural gas producing state through fracking[6]. However, if you take a closer look at North Carolina's shale gas potential, you will find that this idea is a joke. I covered this topic in a previous blog post, but want to go into more detail in this post, and relate it to renewable energy sources of methane, in the state, which could be used to meet CPP emission reductions.

The region in North Carolina that is being studied for its shale gas potential is a Triassic basin which runs from Durham southwest to the border with South Carolina. The portion with the most potential, is the Deep River Basin in Lee county[7]. The USGS, in 2007, did an assessment of oil and gas resources on the East Coast[8], where they estimated that the Deep River Basin has 1.66 trillion cubic feet (TCF) of natural gas. This sounds like a big number, but when you compare it with other known shale gas reserves it is not very impressive. For instance the Marcellus Formation in western Pennsylvania, eastern Ohio, and West Virginia, has had reserve estimates as high as 410 TCF[9]! That is a big difference, but what makes it even bigger is that the production rates of shale wells, drop by 50% in the first year [fig. 1].

Shale Gas Well Production Cycle

Because of this steep decline, multiple wells have to be drilled from the same surface location (Multi-well pad), to pay for the investment in the infrastructure[10]. The cost in infrastructure also requires many Multi-well pads within the drilling region. Figure 2, gives you an idea of the scale in which drilling is occurring in the Marcellus Formation.

Marcellus Shale Gas Play

One way to compare that with the potential of the Deep River Basin, is to use coal maps as a proxy for the potential of shale gas. Figure 3, is a map of coal regions in the US, and you can approximate the location of the Marcellus Formation using coal regions in western Pennsylvania, eastern Ohio, and West Virginia. If you look at North Carolina there is a little squiggle in the center of the state. That is the Deep River Basin!

US Coal Regions, including Deap River Basin

While McCory and the Republicans pursue this joke, they have been neglecting the development of another source of methane, bio-methane from Animal Manure. It has gotten so bad that Duke Energy is looking to other states to provide bio-methane, and the NC pork lobby is having to fight them[11]. You may think that North Carolina does not have adequate supply of manure, but it turns out the the state is up to its armpits in the stuff [fig. 4].

Methan Potential, from Agricultural Manure

In 2005 Milbrandt[12] estimated that North Carolina had 370 thousand tonnes (TT) of bio-methane from agricultural manure, placing it first among all states! If you convert that to TCF it comes out to 19,754,237 TCF. If you add other sources of bio-methane, such as from landfills and waster water systems, it increases to 45,648,305 TCF. In 2012 North Carolina used 127,498,052 TCF of natural gas in electricity generation, so bio-methane potentially could supply 35% of the states gas for electricity generation. That is a significant contribution, but what is far more important is it would create a stable market for bio-methane, and that in turn would encourage farmers to invest their own money into methane production from manure. This would be a very good thing for farmers, who already have to manage this manure. By encouraging them to sell the bi-product of methane, farmers could create a more efficient system, increasing revenue while at the same time reducing their farms impact on the environment. Shovel baby shovel!