January 2022, Vol. 249, No. 1
Features
Methane Leak Detection Moving to Higher Plateaus
By Danielle Wong Moores, Energy Writer
The U.S. government under President Joe Biden continues to look at rules or fees requiring companies to track and limit volumes of methane released into the atmosphere. Meanwhile, at November’s COP26 meeting in Scotland, the U.S. announced its participation in the Global Methane Pledge to cut methane emissions 30% by 2030 from 2020 levels.
Investment companies such as BlackRock are also keeping a close eye on sustainability practices such as methane reduction.
In 2020, BlackRock’s CEO Larry Fink warned in a letter to investors, “Given the groundwork we have already laid engaging on disclosure, and the growing investment risks surrounding sustainability, we will be increasingly disposed to vote against management and board directors when companies are not making sufficient progress on sustainability-related disclosures and the business practices and plans underlying them.”
That’s the stage that oil and gas companies find themselves performing upon as they continue their work to monitor, measure and report on ESG and sustainability.
Major companies such as ExxonMobil, BP, Exelon and Southern Company, along with many others, have announced net zero goals by 2050 or sooner. That’s less than 30 years away at most. Real-time monitoring – and repair – of leaks has become the new low-hanging fruit.
Space Age
In September 2019, Duke Energy announced its goal to achieve net-zero carbon emissions from electric generation by midcentury. A year later, it added a net-zero goal by 2030 for its natural gas business. It then joined ONE Future, a coalition of 50 natural gas companies working to reduce methane emissions across the natural gas value chain to 1% or less.
As it was conducting this work, the utility consulted with key environmental stakeholders, who challenged the utility to go after true measurement of methane, not merely calculations of net zero on a spreadsheet. “That’s when we came to realize that the real time or near-real-time measurement of methane is really something that [for] the industry is a struggle,” said Sasha Weintraub, senior vice president of Duke Energy’s natural gas business.
Duke accepted the challenge. It briefly looked at a drone program before determining that it would be too challenging for drone operators to monitor the entire extent of its pipeline system on a regular basis. Fixed-wing solutions offered other problems in terms of timing and scheduling.
Then came the idea of satellites. The technology has been used by production companies in open drilling areas. The question was whether it would work as well in an urban area with homes and trees.
Duke partnered with a satellite company to launch a year-long pilot in Greenville, South Carolina, during which a satellite would capture images of the utility’s pipeline system every month, to determine how well algorithms could pick up known leaks in the system. Three months in as of October 2021, “we’re just amazed at what we can see with satellites,” said Weintraub.
The processing of the image data is key, he said. The company is working with Ohio-based Satelytics to marry satellite images of methane plumes with GIS data. The satellite can detect methane at 200 parts per million, says Weintraub, and currently the hit rate for known leaks is over 93%, but he expects that to get “better and better” as algorithms continue to improve.
Meanwhile, the pilot also discovered unknown leaks that occurred since the utility’s most recent inspection.
“These are very, very small leaks,” he added. “In some cases as we were going through this pilot, it took a while for our technicians to realize how small a leak we’re looking for … One of the challenges is you really have to dedicate resources, that you are going to find leaks and that you are going to have to take some time to find those leaks … Keep looking, because they’re there.”
However, as a result, Duke could now redirect its manpower from laboriously walking its distribution system with a handheld device, to instead walking to the area of a leak, locating it and fixing it. “This really is a different mindset … no more grading, no more backlogging of leaks,” said Weintraub. “What we want to do now is when the technician is dispatched to that leak, he’s being dispatched to fix it, not to find it. It’s a big mentality [change] from ‘find it’ to ‘fix it.’”
The leak data is also being combined with new technologies being put in place around stationary assets such as compressor stations or LNG facilities to create a platform to measure the utility’s entire value chain of methane emissions, “[which] we hope will be more refined than the EPA emission factor calculation that the industry uses today,” said Weintraub. The Advanced Methane Leak Detection Platform is a joint pilot with Duke, Accenture and Microsoft.
Duke plans to extend its satellite pilot into the Charlotte area in 2022, then ultimately throughout its service territories. “From what we understand, we are the only gas utility company doing this, and from the amount of interest we’ve seen from others,” said Weintraub.
Along with satellite technology for leak detection, utility is also eliminating flaring as much as possible during maintenance activities and offsetting emissions with renewable natural gas, including a project with Smithfield Foods. “We’d love to be able to show others the blueprint through which you can go about getting to net zero so the whole industry can go there.”
Mobile at Work
In 2013, CenterPoint Energy piloted its first Picarro Surveyor, a vehicle-mounted leak detection technology. Since then, it says, the vehicles – which run four nights a week – have helped reduce the amount of natural gas rising into the atmosphere across the eight states where its natural gas business is located. In Minnesota, for example, emissions were reduced by 25%, and in Texas, by 53%.
Improved methods for identifying and eliminating methane leaks are one strategy in the utility’s long-term goal to reduce operational emissions by 70% by 2035 and emissions attributable to natural gas usage in heating appliances and equipment within the residential and commercial sectors by 20% to 30% by 2040, based on 2005 emission levels.
As an early adopter of the technology along with utilities such as PG&E, CenterPoint found that using the Picarro mobile solution “enabled earlier detection of leaks – before they could be detected by traditional leak survey methods,” said Jeff Goetzman, CenterPoint Energy manager of technical field operations in Texas. Adoption rates are continuing to rise: Other utilities have recently begun employing the same or similar technology, including Consumers Energy and Ameren Illinois.
At CenterPoint, detection of leaks during initial surveys led to a burst of repair activity, which has contributed significantly to CenterPoint’s ongoing decline in repair activity, a 2.9% reduction from 2019 to 2020 alone, according to an S&P Global Market Intelligence analysis of federal data from natural gas utilities with at least 5,000 miles of distribution mains and service lines.
Goetzman describes the technology as a paradigm change from accepted and traditional leak survey methods. “The tendency is to see the Picarro Surveyor as a leak find device,” he said. “In [and] of itself, [it] doesn’t find leaks. It provides very valuable data that when used as a tool in your leak survey program provides a significantly better leak survey.”
Goetzman says the tool specializes in field data collection, helping to augment existing map- and instrument-based tools. That data has been proven to “substantially increase our find rate of leaks during our Department of Transportation Leak Surveys, which are required under 192.706 and 192.723,” he said. “With the Picarro Surveyor, leak survey techs are provided with data to which of our assets have a likelihood of having a leak on them.”
As a result, “we have been able to eliminate leaks that traditional industry and regulatory leak survey methods likely would have not found. We are finding leaks earlier in their lifecycle than ever before.”
The Picarro technology is also being used in CenterPoint’s distribution integrity management asset replacement programs to help identify needed pipeline replacements.
CenterPoint’s focus on ongoing innovation also includes work by its tool and equipment team to test newer handheld leak survey instruments, such as one that provides better detection of ethane, a marker that can differentiate natural gas released by transmission and distribution systems from gas created by biogenic sources such as sewers or material decay. Goetzman also points to interest in satellite surveys as well as low-cost methane detectors.
In future, as integrity management and improved leak survey continue to drive a drop in leak repairs across the industry, Goetzman says he envisions the frequency of leak surveys increasing substantially.
“You might see a day when technology such as Cavity Ring-Down Spectroscopy, or CRDS, utilized in the Picarro Surveyor is in third-party vehicles such as Uber or public transportation, and that data would come back to the utility in close to real time,” he said. “Over the last 10 years, the technology improvements in leak survey have accelerated. I would expect that evolution to continue.”
Real Time at Home
Meanwhile, in densely populated urban areas, methane leaks take on even greater importance. For New York’s Con Edison – which scans its gas system for leaks 12 times a year, is in process of swapping legacy pipe with plastic, and has reduced its leak backlog dramatically as a result – the next step was enhancing safety closer to home.
In 2017, the utility laid the groundwork for a residential methane detector pilot program, which would examine technologies with the potential to quickly detect gas near the point where the service line enters the building and notify both the utility and first responders.
After issuing an RFP and testing various detectors with the Gas Technology Institute, Con Edison launched a pilot in lower Manhattan and several Westchester County communities, with 9,000 detectors developed by New Cosmos USA with Itron’s Milli 5 battery-optimized communications module, which operates on the utility’s existing industrial IoT network from Itron.
If methane is detected, the device sounds both an alarm and a voice warning and can only be silenced by the utility. It also alerts operators at Con Edison’s Gas Emergency Response Center, who notify the local fire department.
The field test successfully showed that the technology could be used for mass deployment, said Con Edison spokesman Allan Drury.
“Customers were receptive to having the detectors, and we found that they were effective in notifying us of gas leaks with few false positives,” Drury said. “They are also convenient for home and building owners, which is what we want. It takes our gas technicians less than hour to install a detector, [and] it requires no maintenance.”
Itron also earned a 2020 Gold Stevie Award in the industrial products and services category at the 18th annual American Business Awards for the use of its technology in this project.
The pilot has now moved into deployment of 376,000 detectors – one for each of the utility’s service lines in New York City and Westchester County, which serve 1.1 million natural gas customers. Under the $130 million program, the utility plans to install all detectors by 2025; more than 73,000 have been installed, with 850 alarms produced, as of October 2021.
“We think the detector program is a big leap forward for safety,” said Drury. “We see no cons. They are a way to quickly detect leaks, notify occupants and get the local fire department and Con Edison on the scene to make the leak safe.”
Con Edison also encourages its customers to install additional methane detectors, as its device is located at the area where the gas enters a building, often a basement.
A handful of other utilities have or are piloting methane detectors, including National Grid. GTI is also continuing to work on residential methane detection, including helping to establish nationally recognized standards.
“A number of other gas utilities have contacted us for information on this technology,” said Drury. “We are happy to share our knowledge and experience with these utilities. Their goal is the same as Con Edison’s: the safety of the public we serve.”
Final Thoughts
As technologies improve, costs continue to fall. Smaller companies can also skip the burden of the learning curve. “The learning is done,” said Duke’s Weinbtraub. “It’s really just a matter of being able to understand what needs to be done.
“It’s only going to get better from here. That’s what’s amazing to me. This is the start of something, and it will be really interesting to see how it progresses and unfolds. And I really think it’s only going up new windows of use cases and benefits for our customers and benefits for our system.”
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