Improvement of an Airborne Natural Gas Leak-Detection System
Developing cost effective leak detection methods for natural gas transmission lines
The Regents of the University of California, on behalf of the Davis Campus
Recipient
Davis, CA
Recipient Location
3rd
Senate District
4th
Assembly District
$288,260
Amount Spent
Completed
Project Status
Project Result
Measurements of controlled releases organized by PG&E agree very well with actual emissions. The method developed by the research team was further tested in Aliso Canyon and the results were published in Science magazine. The research team performed detection and quantification of leaks in major transmission lines bringing natural gas to California from other states. The results suggest that methane leaks from transmission lines are very minor and most of the emissions come from compressor stations associated with the transmission lines.
The Issue
Early detection of leaks from natural gas transmission pipelines is critical for many reasons, including: 1) methane is a potent global warming agent; 2) public safety may be compromised in the immediate areas around the leaks; and 3) when some fraction of the gas is lost due to leakage, revenue is lost along with it. Several technologies currently exist for leak identification. Those that have proven effective operate onboard helicopters at low altitude and great expense. Manual sampling is also possible, but it will take a long time to sample the entire length of transmission lines.
Project Innovation
The research team used an aircraft instrumented to measure atmospheric methane and ethane. The researchers conducted flights over known leaks to determine the probability of detection for a single pass and to estimate the number of passes required for any given confidence level. They also identified atmospheric conditions suitable for surveys using this technology. Finally, the researchers were able to quantify the magnitude of the detected leaks under different meteorological conditions for Aliso Canyon, natural gas pipelines, and other facilities. Ethane was measured to distinguish methane from natural gas from other sources of emissions such as landfills, which was very useful for the measurements at Aliso Canyon.
Project Benefits
Detecting leaks from transmission pipelines and other facilities is important because these leaks increase costs to ratepayers, reduce the climate benefits of natural gas, and may be associated with public safety issues. The ARB Scoping Plan developed under AB 32 mandates reductions of methane emissions from the natural gas sector and SB 1371 requires the CPUC to implement strategies to reduce emissions from transmission lines. This research is informing these efforts.
Environmental Sustainability
A cost effective method to detect leaks from natural gas transmission pipelines could allow a more timely elimination of these leaks and result in immediate climate benefits.
Safety
Detecting leaks from transmission pipelines and other facilities is important because these leaks increase costs to ratepayers, reduce the climate benefits of natural gas, and may be associated with public safety issues.
Key Project Members
