Robert M. La Follette School of Public Affairs
Monday, May 24, 2021

Edwards finds that repairs to natural gas distribution system don’t always work

Morgan Edwards Morgan Edwards

For the network of pipelines that bring natural gas to homes throughout the U.S., leaks are an ongoing challenge. Repairing those leaks can lead to safety and climate benefits by reducing the amount of methane (a potent greenhouse gas) released into the atmosphere. But a new study led by La Follette School Assistant Professor Morgan Edwards found these repairs are not always successful, leaving some of the potential benefits of leak repair on the table.

Working with Amanda Giang (University of British Columbia), Gregg Macey (Brooklyn Law School), and the Massachusetts nonprofit HEET, Edwards set out to measure the effectiveness of repairing methane leaks. They published their results Environmental Science & Technology.

The research team used utility-reported data to map almost 10,000 locations in Massachusetts where a leak was reported or repaired after a repair took place. This represents a 20% failure rate. For a sample of directly measured leaks, over half of repairs did not successfully eliminate on-site emissions. Improved repairs and accelerated transitions off gas can help Massachusetts meet state climate targets, the researchers wrote.

Repair failures highlight benefits of energy transitions. “Repairing gas leaks was already a near-term climate solution,” notes Edwards. “Now that we have a fuller understanding of the costs of repair, including repair failures, the net benefits of transitioning off gas are greater.” In Massachusetts, gas utilities have already begun, with the support of state agencies and climate advocates, to invest in installations of networked geothermal, an innovative non-emitting replacement for gas infrastructure.

Repair is still more cost-effective than replacement. Despite the failure rates uncovered in this research, the authors found that repairing gas leaks is still more cost-effective than pipeline replacement. “New pipelines are still more expensive and lock our energy system into high-carbon infrastructure,” explains Edwards.

We can improve the effectiveness of repairs. By prioritizing the largest leaks and by improving repair outcomes, we can increase the effectiveness of pipeline repairs. Massachusetts has enacted a first-in-the-nation policy to prioritize the repair of large volume leaks. The results of this research by Edwards and colleagues have already informed newly filed legislation incentivizing more advanced systemic repair technologies to extend the life of the existing infrastructure.

Data transparency enables smarter climate policy. These findings highlight the importance of data transparency for managing energy systems and tracking progress on state and local climate action. “This analysis was only possible because utilities report leaks and repairs publicly in Massachusetts,” remarks Edwards. “This isn’t the case in many other states with similarly old and leak-prone pipelines.”

“I love when science and data drive policy,” says Zeyneb Magavi, co-executive director of HEET. “Research like this gives us the information needed to more efficiently triage older leaking infrastructure and encourages us to more rapidly modernize our energy system, building better infrastructure for a better future.”