Methane: A Uniquely Difficult Greenhouse Gas Mitigation Problem

Transcription

1 Harvard Kennedy School Energy Policy Seminar Series Methane: A Uniquely Difficult Greenhouse Gas Mitigation Problem Robert Kleinberg Schlumberger Cambridge, Massachusetts 19 March 2018

2 Schlumberger Schlumberger is the actual provider of exploration, drilling, and production services to the oil and gas industry. The views expressed herein are those of the author and do not necessarily represent those of Schlumberger. Dimmit County, Texas Greene County, Pennsylvania 2

3 Outline Natural gas as a source of energy and greenhouse gases Sources of atmospheric methane Is it worthwhile replacing coal with natural gas? Leak detection and repair in the petroleum industry Current and potential policy responses Natural Gas = 80% 100% methane (CH 4 )

4 States.png U.S. Natural Gas Consumption (2016) 27.5 trillion cubic feet = sphere 7 miles in diameter

5 Natural Gas Has Overtaken Coal in Electric Power Generation 14 Electric Power Fuel Costs ($/GJ) Coal Natural Gas Electric Power (TW-hour/month) Year Coal EIA Electric Power Monthly; All Sectors Natural Gas Year EIA Electric Power Monthly; All Sectors EIA Electric Power Monthly: All Sectors

6 Unsubsidized Levelized Cost of Energy Residential Solar Solar + Storage Utility Solar Offshore Wind Wind Coal Nuclear Gas Combined Cycle Lazard s Levelized Cost of Energy, November 2017

7 Natural Gas Emits About Half as Much Carbon Dioxide as Coal CO 2 Intensity (g/kwh) Coal CO 2 Intensity (g/kwh) Natural Gas international comparison fossil power efficiency.pdf

8 U.S. Carbon Dioxide Emissions from Energy Consumption 7000 US Total CO2 Emissions Million Metric Tons Carbon Dioxide Kyoto Protocol (CO 2 only) Coal Natural Gas Oil Kyoto Protocol Target for USA: Return to 1990 emission levels by US Energy Information Administration

9 Carbon dioxide emissions are decreasing, but carbon dioxide is not the only greenhouse gas Total Emissions in ,587 Million Metric Tons CO 2 Equivalent greenhouse gases 04/overview1.png

10 Methane is a More Potent Greenhouse Gas than Carbon Dioxide CO 2 Remaining in Atmosphere Carbon Dioxide Alvarez, PNAS, CH 4 Remaining in Atmosphere Alvarez, PNAS, 2012 Methane Years After 1 kg CO 2 Pulse Years After 1 kg CH 4 Pulse Global Warming Potential Relative to 1 kg CO Global Warming Potential of CH 4 + decay products (ozone, stratospheric water, CO 2 ) Alvarez, PNAS, Years After 1 kg CH 4 Pulse (IPCC AR4) after a century, methane is still 25x more potent than carbon dioxide

11 Relative to pre-industrial levels, atmospheric methane has increased much more than carbon dioxide Atmospheric Carbon Dioxide (ppm) Carbon Dioxide x since Atmospheric Methane (ppb) Methane x since Year (AD) Year (AD) change science/causes climate change.html 07/ghgconc2000 large.jpg ftp://aftp.cmdl.noaa.gov/products/trends/ch4/ch4_annmean_gl.txt

12 Outline Natural gas as a source of energy and greenhouse gases Sources of atmospheric methane Is it worthwhile replacing coal with natural gas? Leak detection and repair in the petroleum industry Current and potential policy responses

13 (Global) 75% Oil & Gas 25% Coal IEA World Energy Outlook 2017

14 Maasakkers, Environmental Science & Technology, methane emissions

15 Identification of Methane Emissions in an Urban Setting Crosson, Phillips, Hutyra, Turnbull, Sweeney, Ackley, Tan (2011)

16 Fugitive Methane from Oil + Natural Gas = billion cubic ft per year 1.4% 2.8% of US Natural Gas Consumption (25,500 bcf in 2012) Fugitive Methane (billion cubic feet per year) Large Uncertainties in Methane Emissions Maasakkers, Environmental Science & Technology, 2016 Coal Crude Oil Natural Gas Landfills + Wastewater Total Agriculture US Anthropogenic Emissions % confidence intervals Fugitive Methane (million metric tons per year) For a litany of measurement problems see IEA World Energy Outlook 2017, Section 10.2 This is very depressing for anyone advocating data-driven policy making.

17 Outline Natural gas as a source of energy and greenhouse gases Sources of atmospheric methane Is it worthwhile replacing coal with natural gas? Leak detection and repair in the petroleum industry Current and potential policy responses

18 Is it Worthwhile Replacing Coal with Natural Gas? Per unit of produced electrical power, natural gas combustion produces half the carbon dioxide of coal combustion. Methane leaks, if greater than about 2.5% of methane used, eliminate the GHG advantage of natural gas vs. coal. Coal combustion also produces pollutants such as particulate matter and sulfur dioxide, which have a cooling effect. Global air temperature

19 Effect of Partial Conversion of Coal to Gas in Global Power Generation Warming Due to Aerosol Reduction Cooling Due to CO 2 Reduction 50% coal to gas conversion Wigley, Climatic Change (2011) 108: Model assumes 1.25%/year reduction of coal use for forty years, with gas use increasing to keep produced electrical energy constant. Warming in early years due to reduction of coal-associated black carbon and sulfate aerosols.

20 Wigley Used Old Data U.S. and China have dramatically reduced emissions of sulfur dioxide and particulate matter from coal powered electric power generation. India has not. 15 Sulfur Dioxide Emission from Electric Power Generation Wigley India gram SO 2 per kg Coal 10 5 US Data from EIA surveys and estimates China Data from NASA Ozone Monitoring Instrument Year US: Energy Information Administration Electric Power Annual, 2007, 2016 China, India: Li, Nature Scientific Reports, doi: /s

21 Is it Worthwhile Replacing Coal with Natural Gas? Per unit of produced electrical power, natural gas combustion produces half the carbon dioxide of coal combustion. Methane leaks, if greater than about 2.5% of methane used, eliminate the GHG advantage of natural gas vs. coal. Coal combustion also produces pollutants such as particulate matter and sulfur dioxide, which have a cooling effect. Air pollution control measures largely eliminate particulate matter and sulfur dioxide, at the cost of increased global warming. After removal of pollutants, coal-to-gas switching has a real advantage in decreasing global warming. Where anti-pollution measures have not yet been instituted, coal-to-gas switching reduces air pollution, but has little net effect on global warming.

22 Outline Natural gas as a source of energy and greenhouse gases Sources of atmospheric methane Is it worthwhile replacing coal with natural gas? Leak detection and repair in the petroleum industry Current and potential policy responses

23 Challenges of Well Site Methane Leak Detection & Repair 40 CFR Part 60, Subpart OOOOa - Standards of Performance for Crude Oil and Natural Gas Facilities for which Construction, Modification or Reconstruction Commenced After September 18, a(a):... fugitive emissions are defined as: Any visible emission... observed using optical gas imaging or an instrument reading of 500 ppm or greater using Method 21. [Meter Resolution] 6.3 The scale of the instrument meter shall be readable to ±2.5 percent of the specified leak definition concentration. [Carrier Gas Flow Rate] 6.4 The instrument shall be equipped with an electrically driven pump to ensure that a sample is provided to the detector at a constant flow rate. The nominal sample flow rate, as measured at the sample probe tip, shall be 0.10 to 3.0 l/min (0.004 to 0.1 ft 3/min) when the probe is fitted with a glass wool plug or filter that may be used to prevent plugging of the instrument. [Probe Diameter] 6.5 The instrument shall be equipped with a probe or probe extension or sampling not to exceed 6.4 mm (1/4 in) in outside diameter, with a single end opening for admission of sample. Federal Register / Vol. 81, No. 107 / Friday, June 3, 2016 / Rules and Regulations 40 CFR 60: pages ; OOOOa: pages /subpart OOOOa

24 Challenges of Well Site Methane Leak Detection & Repair 40 CFR Part 60, Subpart OOOOa 4 Natural Gas Drying & Metering Washington County, Pennsylvania There is no notion that the repair threshold of 500 ppm equates to the target leak rate of 6 cu.ft./hr. Kleinberg, EPA Meeting Notes, 19 Aug Method 21 Optical Gas Imaging cu.ft./hr Infrared Image 1 3 Kleinberg, Southwest Research Institute, July UnL VGvx0

25 Typical Refinery or Chemical Plant Leak Detection and Repair: A Best Practices Guide, EPA 305 D , October 2007

26 Super-Emitters A. P. Ravikumar et al., Environmental Science & Technology (2017) Environmental Defense Fund / Stanford University / Schlumberger Airborne survey to find super-emitter sites

27 Outline Natural gas as a source of energy and greenhouse gases Sources of atmospheric methane Is it worthwhile replacing coal with natural gas? Leak detection and repair in the petroleum industry Current and potential policy responses

28 Economic Incentive for Reduction of Vented & Fugitive Methane One year payback time X 80 billion Mcf/year = $0.8 billion Economic Analysis of Methane Emission Reduction Opportunities in the On Shore Oil and Natural Gas Industries ICF International for National Governors Association, December See also IEA WEO 2017 Sec

29 If You Can t Sell the Gas, There is No Economic Incentive to Repair Leaks Negative values: cost of remediation can be recovered (gas price = $3/mcf) Positive values: cost of remediation cannot be recovered Economic Analysis of Methane Emission Reduction Potential from Natural Gas Systems ICF International for ONE Future, May 2016

30 Current and Potential Policy Responses: Discouragingly Ineffective Economic Incentives Not as compelling as industry and environmental groups pretend Only 20% of repairs pay back in the best-case scenario Leak Detection & Repair Command and control: Technologically inflexible due to regulatory inertia Diagnostics do not quantify the actual problem Hard to implement effectively Carbon-Equivalent Tax You can t tax what you can t measure Cap and Trade You can t trade what you can t measure Discourage Use of Natural Gas Gas is the most versatile energy source available Alternatives (coal, nuclear, etc) are worse Moral Suasion A challenging problem in energy technology innovation policy

31 Recent Bibliography International Energy Agency Chapter 10: The Environmental Case for Natural Gas World Energy Outlook 2017, November 2017 K. Konschnik and S.M. Jordaan Reducing fugitive methane emissions from the North American oil and gas sector Climate Policy, 2018, Improving Characterization of Anthropogenic Methane Emissions in the United States National Academies of Sciences, Engineering, and Medicine, 27 March 2018

32 Robert L. Kleinberg, Ph.D. Schlumberger One Hampshire Street Cambridge, MA Dimmit County, Texas Member of the National Academy of Engineering 32