Thousands of natural gas wells dot the landscape in the Marcellus Shale of Pennsylvania, Ohio and West Virginia, and a growing number of pipelines transport gas throughout the Northeast. But all of this infrastructure comes with a downside: leaks of the potent greenhouse gas methane at all stages of production and delivery.
A few years ago, northeastern Pennsylvania was one of the hottest drilling spots in the country. Most of the drilling rigs are gone now, forced out by the crash in prices, but the hills and dairy farms around the region are now criss-crossed with pipelines, compressor stations and other infrastructure siphoning gas away from those wells.
One of the benefits of natural gas is that when it burns it produces far less carbon dioxide than coal. But, here’s the problem: Methane is also a powerful greenhouse gas, and if natural gas is not burned, then pure methane gets released into the atmosphere. Methane has a much higher global warming potential than carbon dioxide, and lasts for 25 years.
Researchers have found that the EPA has been underestimating methane leak rates for years. A team of researchers from Carnegie Mellon University travels areas of Pennsylvania in vans equipped with high-tech methane sensors, trying to locate and measure leaks. The data is helpful, but researchers are still not sure exactly how much methane escapes Pennsylvania's, or the country’s, natural gas system; each step of these networks contains hundreds of places where gas could escape.
Southwestern Energy, one of Pennsylvania’s largest natural gas producers, has worked with the Environmental Defense Fund on several studies to better understand methane pollution. Mark Boling, a vice president for the company, says spending money on equipment that can prevent methane leaks is just good business. Methane they can sell by keeping it in their pipelines will help defray the cost of working to prevent leaks, Boling says.
Some natural gas producers are also contracting with high-tech satellite companies to help find and reduce leaks in their systems. NASA has used satellites to measure greenhouse gases for years, but as sensors improve, they may become an even better tool in the search for methane leaks.
GHGSat, a Montreal-based company, recently launched a satellite called ‘CLAIRE,’ which is equipped with high-resolution methane sensors. The company’s clients include ExxonMobil and Shell
“Industrial operators would be financially motivated to better understand their emissions, so that they can control and ultimately reduce them — because really what they’re doing at that point is reducing their own financial risk,” Germain says.
Daniel Jacob, a Harvard climate scientist, agrees that satellites could work as an early warning system to help on-the-ground teams find and fix leaks. “Satellites can provide you with detection,” Jacob explains. “They can tell you, ‘Aha! You’ve got a hot spot here.’ And then, once you’ve figured out from space that you have a hotspot, you can dispatch ground-based instruments or maybe low-flying aircraft to figure out where the methane is coming from.”
Jacob’s last research project used satellite data with a resolution of 10 square kilometers; his current project uses CLAIRE, which has a resolution of just 50 square meters. CLAIRE is scheduled to start sending methane readings back to Earth this fall.