CU Boulder Team Tracks Methane Leaks with Lasers

With a $1.3 million grant from the Department of Energy’s Office of Fossil Energy, researchers from the University of Colorado Boulder, the University of California Davis, the National Institute of Standards and Technology (NIST) and aircraft operator Scientific Aviation will field a ground-based laser system to take a closer look at emissions from natural gas storage facilities across the U.S.

Principal investigator Greg Rieker, center, in blue, discusses the project with team members while atop their mobile laboratory in rural Colorado. Courtesy of CU Boulder.

Greg Rieker, assistant professor of mechanical engineering at CU Boulder and the principal investigator of the study, said their efforts will represent the first field-based campaign of its kind.

"This is an incredible opportunity to bring together cutting edge technologies and researchers to answer an important, practical question. We aim to produce results that will enable sound policy decisions and business practices that keep everyone safe, and keep natural gas in the ground until we're ready to use it,” said Rieker.

The laser system, which sends invisible, eye-safe laser beams through the atmosphere to distances well over one mile, was developed under a recent grant from the DOE's Advanced Research Project Agency - Energy (ARPA-E). It is able to measure changes in methane concentrations in the air down to one part-per-billion. The date received will be used to gain a better understanding of how emissions of methane come out of the ground, equipment, and abandoned well heads around storage facilities, and whether these emissions are steady through time or vary.

The UC-Davis and Scientific Aviation teams will mount light aircraft flights around the storage facility where the ground system is deployed. They will also monitor a large number of other facilities throughout the country. The aircraft is equipped with methane detection technology that will provide estimates of total emissions arising from storage facilities.

Natural gas for power generation and heating is typically extracted and processed in remote areas before being transported closer to cities for storage. The gas is stored at high pressures in underground reservoirs and caverns. The location of storage sites near cities offers rapid on-demand delivery, but poses significant environmental, health and safety risks in the event of a mishap.

A state-of-the-art gimbal with a custom-built telescope and laser pitch / catch system automatically scans the field for retroreflectors, which are too small to be seen in the distance. Courtesy of CU Boulder.

The team believes the monitoring technology may serve a longer-term purpose as a continuous monitoring system for storage facilities.

"Any time we find a home for our technologies in the private sector is a big win for us and for the agencies that fund our research. We genuinely hope that will be the case here," said Rieker.

The team will share results of the study with the EPA for inclusion in its greenhouse gas emissions inventory for the U.S.