Technology

Google Earth to map methane leaks

 By RP Siegel

Methane, the principal component in natural gas, is roughly 30 times more potent as a greenhouse gas than carbon dioxide over the long term. When the gas is burned, it breaks down into carbon dioxide and water, reducing the impact. But when unburned methane is released, that poses a more serious problem. Leaky gas pipes have been identified as a concern for climate change, as well as a safety issue, not to mention a revenue loss for gas companies. That’s why efforts to contain methane leakage have taken on an increased urgency in recent years… 

Joe von Fischer is a Professor of Biology at Colorado State University (CSU). His specialty is Ecosystems Ecology. A primary area of interest for von Fischer is the relationship between bacteria in the soil and methane emissions in Arctic Tundra. He had spent years taking measurements of soil emissions, using traditional gas chromatography, a slow, painstaking process. Recent advances in infra-red lasers have made these types of measurements much faster and more convenient. Instead of collecting samples and bringing them back to the lab, von Fischer purchased a laser-based instrument capable of very precisely measuring very small concentrations of methane in air instantaneously. As von Fischer points out in his TED talk, although methane gas is invisible to the human eye, it is visible in the infra-red portion of the spectrum, which allows this type of instrument to essentially “see” it.

Upon his return from the Arctic, von Fischer asked his team what else they might do with this instrument. They decided to mount it into their pickup truck and drive it around the CSU campus in Fort Collins to see what they might find. “We found some of the usual suspects by the water treatment plant and by the town landfill, but there were a number of other methane spikes that were really surprising,” he says.

The researchers followed up on one area that was showing ten times the background level of methane at an industrial site. When they returned with the maintenance crew, they found the source of the leak, tightened a loose fitting, and the leaking stopped. This method proved very useful, because it provided am extremely reliable, accurate assessment of the leakage rate much more quickly than previous methods. The instrument determines precise methane concentration by measuring the amount of light absorbed in a very specific wavelength associated with the presence of methane.

Mapping the invisible

What happened next came about largely by chance. The Environmental Defense Fund (EDF) had contacted Google Earth Outreach, a non-profit arm of Google, focused on environmental issues, about using their street view mapping cars to collect data on methane leaks. The street view cars are the ones that drive over thousands of miles of roads, taking pictures along every street to provide the street view images that accompany Google maps. What they lacked was the technology for accurately measuring methane leak rates. It was totally by chance that the EDF’s chief scientist, Steven Hamburg happened to come to the Colorado State campus to give a talk, which is where he and von Fischer met.

From there, the two decided to work together to equip these Google Streetview cars with the methane analyzers and produce maps of methane leaks. Ultimately four cars were equipped with analyzers that produced maps in 11 US cities. Among these were Boston, Los Angeles, Chicago, Dallas and Pittsburgh. Results showed that cities with older corrosion-prone distribution lines, such as Boston, Staten Island and Syracuse, had leaks that released 25 times more methane per mile of road than cities with newer infrastructure, such as Burlington and Indianapolis. According to von Fischer some pipelines currently in service date back to the 1890s.

As a follow-on, PSEG, New Jersey’s largest utility, has been using this mapping capability to focus and prioritize its $905 million gas infrastructure replacement program. Google Earth cars spent six months canvassing across PSEG’s service area, identifying those sections of pipe most in need of replacement. By doing so PSEG was able to reduce methane emissions from targeted areas by 83 percent while replacing 35 percent fewer miles of pipe. The technology helped the company realize the greatest return on its investment, eliminating the largest leaks, and reducing the impact on the global climate. Because methane deteriorates more quickly in the atmosphere than CO2, reducing it now can have a significant effect on warming—in a relatively short time.

SEE MORE: Methane Emissions & Mobile Solutions by Andrew Burger

about the author
RP Siegel
Skilled writer. Technology, sustainability, engineering, energy, renewables, solar, wind, poverty, water, food. Studied both English Lit.and Engineering at university level. Inventor.