Energy Commission Effort to Locate Methane Leaks Takes Flight

Technology used to explore celestial bodies is helping researchers find methane leaks in California’s natural gas sector. But instead of satellites, the search is being carried out by a propeller-driven aircraft.

In 2016, the California Energy Commission awarded a contract to NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, to conduct an aerial survey of natural gas infrastructure in high priority parts of the state to identify locations emitting large amounts of methane. The $600,000 contract was funded through the Energy Commission’s Natural Gas Research and Development program.

Methane is the primary component of natural gas and is a powerful greenhouse gas and ozone precursor. Recent legislation seeks to reduce methane emissions in the state by 40 percent from 2013 levels by 2030.

The gas is invisible to the human eye but not to the next generation imaging spectrometer on the NASA/JPL survey aircraft. Greenhouse gas molecules like methane absorb light at specific wavelengths, giving each a “signature” in the electromagnetic spectrum. The spectrometer provides near real-time detection and display of methane plume images. The airborne version was developed by JPL for Earth science research, but similar instruments are being used in space exploration across the solar system.
 

Up-close look at the imaging spectrometer on board the NASA/JPL survey aircraft.

Survey flights began in September and concluded last month. Each typically lasted about five hours as the aircraft, cruising at around 10,000 feet, flew back and forth in a lawnmower-like pattern over large areas with natural gas pipelines, processing facilities, refineries, power plants, or storage facilities. With each pass, the imaging spectrometer captured data to create a map showing the location of methane sources and estimates of their emission rates.

The survey comes ahead of state regulations taking effect in January requiring oil and gas operators to beef up their methane leak detection processes and institute better controls on methane emissions. The survey will help the state better characterize leakage and other emissions from the natural gas system and improve greenhouse gas estimates.

This is the second phase of the state’s comprehensive effort to identify methane emissions through remote sensing. The first phase was funded by the California Air Resources Board (CARB) and conducted by JPL in 2016. That survey focused on dairies, landfills, and waste-water plants. Both projects have benefited from additional flights over California and methane data analysis systems funded by NASA.

The preliminary findings from the first phase are available on the CARB website. A combined final report on both phases will be available later this year.