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Natural Gas’ hidden leakage issue?

November 17th, 2012 · 4 Comments

While there are many celebratory discussions and pronouncements about reduced U.S. emissions due to natural gas displacing coal, some voices caution that all may not be as it seems.  There is a hidden problem that may — or may not — be within the accounting.  Errant methane may blow away the claimed greenhouse gains from how much cleaner natural gas burns.
The following video provides some stark evidence of one part of the ‘errant emissions’ challenge:


Part of the problem: in all seriousness, we don’t seem to know the extent of leakage throughout the natural gas system (from drilling to transportation to storage to end use …) and thus don’t have good data to leverage to support robust and accurate analysis of the trade-offs between the use of natural gas and other energy sources (whether for heating, electricity, or otherwise).

There are a series of studies and discussions on the issue. A reasonable one to start with is an EDF study. While the title sets the hackles of fossil fools, among enivronmental organizations, EDF rates as is quite business and natural gas friendly).  The EDF website on a recent methane leakage study. To give an idea of the situation, they analyzed the carbon impacts of coal vs natural gas and the impact of natural gas leakage for this situation:

new natural gas combined cycle power plants reduce climate impacts compared to new coal plants; this case is true as long as leakage remains under 3.2%.

Alright, when comparing new (top of the line) vs new (top of the line), natural gas is better than coal as long as leakage is less than 3.2%.

Now, to be clear, the preceding sentence is

Assuming the Environmental Protection Agency’s (EPA) 2009 leakage rate of 2.4% (from well to city)

Okay, that looks great, with a new (high-end) natural gas facility, there is perhaps a 15-20% CO2 equivalent benefit for the natural gas compared to coal due to the methane leakage rate being 0.8% below the threshhold level since methane is about 20 times as significant as Co2 over 100 years (EPA perspective from dated material, but more recent IPCC is roughly 34x) and even worse in terms of near-term climate change impacts.
However, there is a quite serious and key issue: we don’t “know” the actual methane leakage rates.  From the “FAQs” for the EDF study is this:

Last year, EPA discovered some differences in its 1990s-era emission estimates for a small number of key source types and those reported by natural gas companies to EPA in the voluntary Natural Gas STAR program.  EPA used the best data it had available, mainly the self-reported estimates under the STAR program, which ended up roughly doubling its previous estimate of total industry emissions.

Consider this information
  • The EPA doubled its leakage estimate based on the self-reporting in a voluntary program?
  • That self-reporting comes from
    • big players who are
    • trying to show their best face and
    • are theoretically committed to do better.
  • This self-reporting doesn’t have the wildcatters, the small players, etc …
  • And, again, this is the “self-reported estimates” which we can have some confidence weren’t targeting erring on making themselves look worse than reality (as opposed to better). And,
  • That data is several-years time late and almost certainly doesn’t account well for fracking.
The EPA’s 2.4% is almost certain not an accurate accounting for across the entire natural gas production and distribution system. (Remembering, of course, that this was a doubling of their previous estimated well-to-wheel leakage rate.)

In other words, that 20% benefit almost certainly doesn’t exist.  In discussions with people with closer knowledge / expertise on this issue, they’re estimating a much higher leakage figure across the industry (highlighting, for example, the over 30% of natural gas being flared in North Dakota, that these figures are focusing on producing wells (and not (poorly) capped wells nor the exploratory drilling nor …), etc …).

By the way, the EDF study lays out strongly why the embrace of the Pickens’ Plan was such lunacy:

At current leakage rate estimates, converting a fleet of heavy duty diesel vehicles to natural gas would result in nearly 300 years of climate damage before any benefits were achieved.

And, well, how many millenia are required to have any benefits if the leakage rate is 3% or 4% or …  And, note, that system assumes that the leakage rate doesn’t increase with 1000s (or 10,000s or 100,000s) of additional retail distribution points for refueling those NGVs.
In private discussions, people well informed about this issue are rather upfront when asked about this: we don’t know what the leakage rate is in the U.S. production and use of natural gas. We didn’t know it with “traditional” natural gas, with any accuracy, and the complexities of fracking have made the error bar even higher.  And, sadly, the error bar is almost certainly solely toward the ‘higher than’ EPA estimates rather than lower.
Now, there is a ‘good’ side to the story: this is a ‘fixable’ problem that wouldn’t cost that much to address because the leaking methane has value, it is carbon energy that could be put to use (for chemical production, electricity, heating, etc …).  Somewhat like Wal-mart and Dupont discovering that a real focus on energy efficiency (and climate impact reduction) had a serious benefit for profitability, a serious focus on reducing leakage through the natural gas (and biogas and coal-seam gas and …) would not just reduce climate impacts but could also foster improved economics.  NDRC’s Leaking Profits report is a good place to start on this (for an excellent discussion, related to is release, see Dan Lashof’s Time to tighten up …).
Bottom line, however …
  • Methane leakage is a serious problem.
  • We do not really know how big a problem.
  • Until we know how big a problem, be wary of claims about how natural gas is a climate change solution.
Note: Work done in Australia lays out how this is far from solely a U.S. issue.

LEVELS of the potent greenhouse gas methane have been recorded at more than three times their normal background levels at coal seam gas fields in Australia, raising questions about the true climate change impact of the booming industry.

Tags: Energy

4 responses so far ↓

  • 1 Weekend Environmental Must-Reads – November 17-18, 2012 | Stuart H. Smith // Nov 18, 2012 at 8:27 am

    [...] Natural Gas’ hidden leakage issue? [...]

  • 2 Greenhouse Gas Levels Reach New Record High – Greg Laden's Blog // Nov 20, 2012 at 8:37 am

    [...] Third, and less understood, and perhaps not even part of the current calculation of greenhouse gas release, is the extra methane that is being released at large but as yet understudied quantities from drilling operations including those that involve fracking. [...]

  • 3 #ObamaEnv: Steps for Presidential Action in light of Inaugural Address // Jan 22, 2013 at 9:47 am

    [...] — and make public — fracking more seriously, including methane leakage within the natural gas system.  Target — at a minimum — reducing the amount of leaked [...]

  • 4 Daniel Kieve // May 11, 2014 at 2:49 am

    Interesting article about a serious flaw in current energy system and energy policy. Why however do you state that methane is around 20 times more potent than CO2 as a greenhouse gas in the near term? It IS now estimated by the IPCC to be 84-86 times more potent over a 20 year time frame. Surely 20 years should be considered ‘near term’. Over 12 years (methane atmospheric lifetime) methane is more than 100 times worse than CO2. Even over 100 years the Global Warming Potential is 34 according to the IPCC but official national databases still use a figure of 21 (an inaccurate estimate of methane’s 100 year GWP based on an old IPCC report). This fact does not contradict your argument but would make it stronger. Please therefore put in a more accurate figure .

    Thank you for catching this and providing substance/recommendation. Changed to:

    since methane is about 20 times as significant as Co2 over 100 years (EPA perspective from dated material, but more recent IPCC is roughly 34x) and even worse in terms of near-term climate change impacts.

    Since this was written awhile ago, can’t explain how I put in the short-term against the 20x because I knew/know that it is far worse than that in near-term (20 year) impact. Typo … or … ???

    Also, need to do additional work to look at full life-cycle — such as leakage rates in cities.

    All those advocated natural gas vehicles/such are totally ignoring, for example, the risk of massive additional leakage from 1,000,000s of additional refueling points.

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