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Is Shale Gas Too Good to Be True?

Yesterday I participated in a webinar on The Energy Collective examining the sustainability aspects of the shale gas revolution. The online audience asked good, probing questions, and if there was a theme to them, it seemed to be that somehow the sudden abundance of natural gas resulting from a novel combination of shale-exploitation technologies–as well as the technologies themselves–must at a minimum be considered a mixed blessing, if not actually too bitter a pill to swallow, because of its perceived shortcoming and the potential threat it poses to other, favored energy technologies. I find that simultaneously understandable and unfortunate.

I came of age just as US attitudes concerning energy shifted from the assumption of perpetual abundance to perennial insecurity and periodic scarcity. Energy security has been a consistent theme of public discourse for my entire adult life, varying only in intensity as we lurched from crisis to crisis with long respites in between. If the shale gas revolution had arrived thirty years earlier, I’m confident it would have been embraced as a national windfall–a jackpot lottery win. After all, we’re talking about a newly accessible resource that is equivalent to finding an Iraq’s worth of hydrocarbons under our feet, not deep offshore or in some distant country. Yet despite boosting US gas production to levels unseen since the early 1970s and resetting gas prices to pre-2000 levels, after adjusting for inflation, the reception of shale gas has been decidedly mixed, as witnessed by yesterday’s vote by the New York legislature to impose a six-month moratorium on gas drilling in a state overlying a portion of one of the largest gas reservoirs in the world.

Shale gas isn’t the silver bullet for our energy and emissions problems, but it can contribute significantly towards alleviating both. Combined-cycle power plants burning gas emit only about 45% as much greenhouse gases as best-in-class coal-fired power plants, and comparisons to the oldest, least-efficient US coal plants are even more favorable. At current gas prices, which are mainly the result of the shale gas boom, the resulting power is cheaper than from any renewable source without substantial subsidies, and than most even after subsidies. In the last several years gas-fired power plants have taken market share from coal equivalent to the entire output of all US wind farms, and there’s no wait for scaling-up.

At the same time, the concerns about shale gas reflected in some of yesterday’s questions are entirely understandable, particularly in an era dominated by low trust in all institutions. For example, is it possible that unreported natural gas leaks are releasing enough methane, which is a strong greenhouse gas, to offset all the emissions benefits from gas-fired generation? Perhaps, even though the gas leaks identified in a new GAO report amount to just 0.2% of US marketed production, and thus equate to only about 6% of the CO2-equivalent emissions associated with US gas consumption. But as I noted in the webinar, even if the leaks are in fact much larger they are controllable; they are not an inherent feature of shale gas production in the way coal’s CO2 emissions are inherent in coal combustion.

Concerns about water consumption and safety hit even closer to home. Having reviewed the list of fracking chemicals on Halliburton’s website, I wouldn’t want them in my drinking water, either, any more than I’d want my family consuming any of the various household chemicals under our kitchen sink or elsewhere in our home. However, there’s nothing about the process of hydraulically fracturing shale strata thousands of feet deeper underground than the deepest aquifers that puts our drinking water at any greater risk than many routine industrial or agricultural operations. As a technology fracking is neither newer nor riskier than many other things to which we don’t give the slightest thought. Much of the attention it has gained is the result of its application in unaccustomed places–a reaction shared by wind turbines, utility-scale solar plants, and long-distance transmission lines.

The biggest uncertainties associated with shale gas don’t concern the size of the resource or our ability to extract it safely, but whether we will decide to allow this to be done on a scale that would make a meaningful difference in our energy and emissions balances, or under such tight restrictions that we will forgo its game-changing potential. Like anything, shale gas drilling and fracking must be done responsibly, in accordance with state and local regulations and to industry standards that are constantly improving. Post-Deepwater Horizon, that’s a much tougher sell, but it doesn’t make it any less important. Shale gas isn’t perfect energy, not because of any unique imperfections, but because there is no perfect energy source. It requires mature, reasonable assessments of its risks that don’t assume that there is.

Geoffrey Styles's picture

Thank Geoffrey for the Post!

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Rick Engebretson's picture
Rick Engebretson on Dec 2, 2010

Consume now, and leave the mess for future generations. The economic philosophy of “the greediest generation.”

And while we’re at it, a new arms race with Russia and a little war in Korea might employ our kids after (if) they get out of Afghanistan.

Charles Barton's picture
Charles Barton on Dec 2, 2010

Goeffry, I am planning a post on some of the major problems with the current natural gas uphoria.  I would, however like to point out a flaw in william Post’s reasoning.  While it is true that CCGT do operate with impressive thermal efficiency, it is also unfortunately true, that CCGT do not perform well when paired with wind or solar.  OCGTs work better in that role.  OCGTs respond quickly to the fluxuating energy output of renewables, while CCGT operate more efficiently when producing electricity at a stable rate.  Grid modelers who have tried to model a high renewable energy penetrated grid, found that wind most quickly displaces CCGT generated electricity, while requiring the addition of OCGT capacity. 

Unfortunately operating OCGT as a renewable backup, decreases its combustion efficience.  When the OCGT operates with peak combustion efficiency it produces CO2 and H2O vapor.  As an OCGT becomes more inefficient, the OCGT produces more carbon monoxide (CO), and methane.  If even 1% of the methane in natural gas escapes combustion it is the equivalent of doubling an OCGT’s CO2 output.  Although a loss of 1% of the methane is not a big economic deal when natural gas burned in an OCGT, it represents a very significant proble if AGW mitigation is considered.  Thus the pairing of natural gas and renewables carries with it significant liabilities, that natural gas advocates tend to sweep under the rug. 


Rick Engebretson's picture
Rick Engebretson on Dec 2, 2010

With the nuclear waste, mining waste, transmission lines and windmills, turbines in all these plans; where do people live? Where do people grow food, find water, raise a family?

We can grind up the planet if our criteria disregards waste and unlivability and look like we are making a profit!

Geoffrey Styles's picture
Geoffrey Styles on Dec 2, 2010


It’s a controversial point, and I’ve seen studies supporting both sides of this argument, but what you’ve described makes a lot of sense.  If wind backs out CCGT when it’s available but requires simple-cycle GT backup when it’s not, the difference should count against the emissions reductions attributable to wind.  Likewise for solar and other intermittent or cyclical renewables.  That’s not a reason not to pursue them, but a fair (full-system) accounting would make the tradeoffs less black and white, while raising the effective $/ton of CO2 abated by this strategy.  Methane leaks, whatever their magnitude, surely look like low-hanging fruit compared to alternatives yielding costs of up to $500/ton or more.   

Geoffrey Styles's picture
Geoffrey Styles on Dec 2, 2010


I don’t follow your figure for CCGT. A plant with an efficiency of 60% has an effective heat rate of 5688 BTU/kWh.  At around 119 lb/MMBTU for typical pipeline gas, that yields an emissions rate of 0.68 lb. CO2/kWh.  (Might  you be off by a lb/kg conversion factor?)

Geoffrey Styles's picture
Geoffrey Styles on Dec 2, 2010


Thanks for the clarification.  I knew gas was quoted in HHV but wasn’t aware that CCGT efficiencies were done on LHV, since most of the CCGTs I’ve seen were in cogen service (with condensers).  In any case, the lower efficiency on HHV would increase the lb./kWh above what I calculated.

Geoffrey Styles's picture
Geoffrey Styles on Dec 2, 2010


Guess I didn’t ask the right questions when I visited my former company’s cogen plants, years ago.  Thanks for the Power Engineering 101 refresher. 

Cheers,  Geoff

David Lewis's picture
David Lewis on Dec 5, 2010

If you read the GAO 2010 report you cite, which you could not possibly have done given that you say it reports .2% leaks on total US gas production, you’ll see a reference to a GAO report done on the same subject in 2004.  

The same ground was covered.  Industry told GAO it was squeaky clean (emissions less than 1%).  GAO noted that although prices had almost tripled from 1993 to 2003, gas was still being vented and flared.  

Anomalies such as the fact that a “major oil and gas producer recently paid a $49 million settlement for unauthorized flaring and venting that went undetected for several years…” were mentioned, but the situation was accepted to be what industry said:  “flaring and venting are not viewed as major problems in this country”, and GAO reported industry was saying “it may be difficult to justify devoting much attention to them”.

GAO had been tasked with examining how data was gathered, to determine what could be said after examining the data, and to recommend how to improve future data collection and to reduce leaks.  

They said in 2004 government should require industry to provide better data, and action should be taken on the basis of what was known already.    

In 2004 GAO was also tasked with estimating what was going on in the rest of the world.  If you cared how much methane was entering the atmosphere as a result of natural gas use, data reporting was a joke.  Countries report what they feel like.  Russia said it didn’t vent or flare at all.  GAO noted that NOAA satellites observed “significant” Russian flaring. GAO ended up “estimating” that 3% of global gas production then was vented or flared.  This is in the range that means the global use of gas, up to 2004 has been as bad or worse than using coal.  

Back to the US:  Its 2010 and its time for GAO to do another report.  Why?  Industry didn’t think it had a problem in 2004, it was fixing it anyway then, why the EPA STAR program had been running for a decade with 100 different ideas for how to stop leaks and 65% of the industry was signed up. Anyone would expect GAO to find that by investigating again they were wasting taxpayers money and should be reprimanded.

Tiny details that stick out:  

EPA’s STAR program reported 114 Bcf reductions in leaked gas in 2008 alone, this is 15 years after supposedly enthusiastic industry efforts that were reported as ongoing in 2004.  That was said to be .4% of production.  All production figures were qualified:  they were from federal lands onshore or offshore, never including nonfederal leases or state controlled operations.  EPA did say it felt whatever limited figures it had for one sector would extend roughly out to others.  How do you cut out leaks amounting to .4% of production in one year of a program the 2010 report states industry is having trouble getting involved with (a complete opposite description than in 2004) that has been going gung ho for 15 years?   What were the leaks in 1993 – 6%?

The Associated Press reported 50 Bcf leaks which is where I assume you get your .2%.  Look at page 25, footnote 50.  “In addition to the 50 Bcf, an additional 252 Bcf in reductions could have been had if “nonfederal” wells were included.  The estimate, now jacked up to 302 Bcf, is what can be stopped up ECONOMICALLY.  Its only 40% of what the EPA estimates is actually leaking.  This is the gas the industry would make money on if it stopped letting it leak.  Payback periods under discussion were months to 2 years.  The rest of it is what the industry has convinced authorities would actually cost it money. We’re up to 3.4% leaks now.  

I’ll write it up when I’ve studied the issue some more.  It looks like what is happening is the US industry is committed to believing methane leaks don’t matter because climate change can’t happen so its been dragging its feet all this time.  BP cleaned up its act in the basin it dominates, one other company was mentioned and that’s it.  The rest of would be suicidal for the industry if the public was interested in seeing them get the job done. 

Professor Howarth is unimpressive?   GAO looks to be describing the same situation, because its the truth. 

Geoffrey Styles's picture
Geoffrey Styles on Dec 6, 2010


You’re right that the 0.2% I was referring to was the 50 BCF of avoidable gas loss from federal leases that GAO found.  I apologize if the wording didn’t make it clear that I wasn’t saying this was all the gas that might be leaking, though I would note that the combined assessment of “vented and flared” includes sources with very different outcomes for climate impact, based on the difference in the GWPs for CH4 when leaked or vented and CO2 from flaring.  However, in zeroing in on the 0.2% figure, you skated right by the key sentence in the paragraph: “…even if the leaks are in fact much larger they are controllable; they are not an inherent feature of shale gas production in the way coal’s CO2 emissions are inherent in coal combustion.”  In other words, methane leaks for oil and gas systems are largely a fixable problem, and at much lower cost than the CCS technologies needed to make comparable reductions in the CO2 emissions from coal.  I’m not suggesting a free pass for methane leaks, but they do not eliminate the emissions-reduction potential of a shift from coal to gas power generation.  I do agree with you that this is an area on which the industry must focus more effort.

As for Dr. Howarth, I certainly never referred to him as “unimpressive”.  I just listened to the podcast of the webinar–where you got this remark–and it was very clear that I was referring to aspects of his earlier paper, which from Marc’s reading of your subsequent question during the webinar you conceded was “not impressive”. 

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