17 Jun 2013

Fugitive methane emissions: the achilles’ heal of the natural gas push?

Written by Jim Pierobon

Buoyed by low prices, environmental benefits and thousands of newly created jobs, the push to produce more natural gas in the U.S. is reaching its stride thanks largely to horizontal drilling and hydraulic fracturing. But do we understand the implications, some of which might negate the environmental gains?

The answer to many objective analysts is: not yet.

image002This is a sizable ‘nut’ to crack. Let’s focus here only on “fugitive” methane emissions.  These are emissions of methane that escape into the atmosphere throughout the process of extracting, transmitting (including liquifying) and deploying natural gas.

Since April, there have been three important contributions to what is becoming a much-needed conversation about whether fugitive methane emissions, over time, could eliminate the advantage natural gas has other fossil fuels, most notably coal burned to generate electricity and gasoline as a transportation fuel:

1. An working paper by the World Resources Institute that outlines state and federal policies and industry best practices to cost-effectively reduce fugitive methane emissions;

2. The Environmental Protection Agency’s (EPA’s) annual Inventory of U.S. Greenhouse Gas Emissions and Sinks; and

3.  Finding the Facts: What the EPA Greenhouse Gas Inventory Says About Methane Emissions From Natural Gas Systems, by the American Gas Association(AGA). Here AGA presents new data and analysis demonstrating that methane emissions from natural gas systems are low and are on declining trend.

As the primary component of natural gas, methane is 72 times stronger than carbon dioxide (CO2) over a 20-year horizon; 25 times stronger over a 100-year horizon (see graph).  While methane represents only about 10-12% of all U.S. greenhouse gas emissions, its potency — if unchecked — could significantly dilute what is perhaps the most talked-about benefit of more natural gas in America’s, and the world’s, energy future.

When extracted from the well, natural gas is made up of about 83% methane. After it’s processed through the the point of delivery, natural gas is more than 90% methane. At current estimated leakage rates, fugitive emissions cast credible doubts about the benefits of switching cars and trucks off of gasoline or diesel fuel to natural gas.

There are numerous ways to ‘spin’ these and other analyses to advocate one position or another. But, as I like to do here at The Energy Fix, take a step back and focus on next steps that can address the threat and risks of fugitive methane emissions. Are they overblown? What can be done to mitigate them? How much could industry, realistically, do on its own?

In AGA’s analysis of EPA’s annual “Inventory,” as the report is widely known, Energy Policy Analyst Richard Meyer asserts the effective natural gas emissions rate-per-unit is 1.5%. That is significantly lower than the 2.2% and 2.4% derived using data from the EPA’s 2009 and 2010 inventories.

Meyer notes that EPA revised its estimates of natural gas systems’ methane emissions downward 33 percent for 2010, from 215.4 million metric tons (MMTe) of CO2 equivalent in the 2012 Inventory to 143. 6 MMTe in the 2013 Inventory.

Connect the dots and you’ll see what is long-term downward trend for methane emissions.  Annual methane emissions have dropped 10 percent since 1990 and are 17 percent below the recent peak in 2007, Meyer states.

While natural gas utilities have added almost 300,000 local connections to serve an additional 17 million customers — and increase of 30 percent each — methane emissions from distribution systems have dropped 16 percent since 1990, according to the AGA.

While it may be reasonable to conclude that methane emissions are less of a risk or threat than perhaps most informed people think, that does not mean the risk or threat can be ignored.

In the meantime, industry, think tanks, regulators and lawmakers can manage the risk with next steps outlined by the World Resources Institute’s working paper.  I spotlight a few of them here, each of which WRI contends is economically viable and in the industry’s long-term best interests.

A comprehensive review of WRI’s re commendations runs from page 38 – page 42. Note: the recommendations apply also the development of oil shale, as well as, natural gas shale production.

Natural Gas Star logo

CREDIT: U.S. EPA

  • Recognize and reward companies that voluntarily demonstrate a commitment to advancing best practices. The “Natural Gas Star” program (logo, right) could be expanded and more frequently updated to serve as a clearinghouse for technologies and practices. These would enable companies to comply with new rules and air regulations contained in the promulgation of New Source Performance Standards (NSPS) and National Emissions Standards for Hazardous Air Pollutants (NESHAPs).
  • Use Section 111 of the Clean Air Act to set greenhouse gas emissions performance standards for new and existing natural gas infrastructure and equipment. These standards generally are developed by industry leaders with state regulators and implemented by states.
  • Expand the scope of the Toxic Release Inventory to require emissions reporting from oil and gas pre-production and production-stage operations. This can help policymakers better understand risks of exposure to hazardous air pollutants, especially near urban areas. Section 112 of the Clean Air Act expressly authorized the EPA to do this.
  • Develop and publish a menu of policy options for states and provide regulatory assistance to adopt them, especially where shale oil and gas production operations are increasingly rapidly.
  • Establish a FracFocus-like database for voluntary reporting of air emissions funded through public sources that are independent of industry; make submissions subject to third-party verification; and make raw data readily accessible to enable the aggregation, analysis and cross-referencing by independent researchers.

Now these and other recommendations by WRI strike me almost as an unrealistic wish list. But they seem to be within the collective grasp of the largest industry players to seize a leadership role and help frame the process.  With the way the data are trending, the implementation of several of these actions could lead to emission reductions that result in virtually unchallengeable relative benefits for the climate.

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