1. There is a single document (Howarth et al.) that was published that used poor methods to est. the global warming potential (GWP) of shale gas. This doc has been frequently cited by the greenies, but now should be dismissed as an outlier that used the wrong input figures and forgot to account for efficiency gains in electricity gen. from nat gas V coal.
"Among the available estimates, the most controversial (and often cited) is that of Howarth et al. [17] which asserts that the GWP of shale gas is greater than that of coal. Although the authors calculated the GWP of the extracted gas at 84–224 g CO2-eq./MJ, they focused on the top end of the estimated range to arrive at their conclusion. Primarily, this high estimate is due to the use of a high GWP for methane over a 20-year time horizon (GWP20) of 105 kg CO2-eq./kg CH4, based on work by Shindell et al. [28] rather than the more-widely accepted value of 75 kg CO2-eq./kg as estimated by the IPCC [29]. By comparison, the GWP over 100 years (GWP100), also estimated by the IPCC and used more commonly, is 25 kg CO2-eq./kg CH4. Furthermore, the authors express the results per MJ of energy contained within the fuel as opposed to kWh of electricity generated, thereby ignoring the higher average efficiency of gas compared to coal-fired power plants. Several other issues also contributed to the high estimates, such as overestimation of fugitive methane emissions and the assumption of no flaring to reduce the GWP by converting methane into carbon dioxide, despite flaring being common and/or legally required in the US. Readers are directed to several works by other authors for more detailed criticism of the study by Howarth et al. in regard to the above points [16], [18], [19], [20], [22] and [30]."
2. Fracking beats solar and wind power on some measures, beats coal on most, it's weakest attribute shown by this study can be solely attributed to 'land farming' of drilling waste/cuttings. One compound being the cheif culpret.
If land filling is used instead then shale comes out very well indeed against all other options.
I can't recall what methods of fill disposal DTE normally use in their CBM wells, land filling is more common in US I believe.
DTE Price at posting:
11.7¢ Sentiment: Buy Disclosure: Held
