Duke Energy Corp. aims to achieve net-zero methane emissions from its gas utility business by 2030, an ambitious deadline that vaults the Charlotte, N.C.-based company ahead of many of its peers on the issue of tackling fugitive methane.
The company announced the target Oct. 9, roughly a year after Duke said it would attempt to hit net-zero emissions across its entire business by 2050. To meet the goal, the company plans to embrace new technologies, step up damage reduction and leak survey initiatives, fine-tune operations and address remaining emissions through methane offsets through solutions such as renewable natural gas, or RNG.
Net-zero-by-2030 goals remain rare in the gas utility space, an industry focused on distributing a product composed almost entirely of methane, a more potent greenhouse gas than carbon dioxide. Like many utilities, Duke has chiefly reduced methane emissions through safety-oriented pipeline replacement programs. Over the last 15 years, the company has invested $1 billion in eliminating leak-prone iron and bare steel pipes from its system and replacing them with plastic and coated steel mains, particularly in its Midwest Duke Energy Ohio Inc. territory.
"The capital investment side of this, a lot of that is in the rearview window, and to really keep making strides to net zero, it's more around operational practices," Sasha Weintraub, Duke's senior vice president and chief commercial officer of natural gas said in an interview.
Duke sets initiatives to reduce emissions
These operational practices will include more closely scrutinizing Duke's compressor stations and valves for fugitive emissions, as well as creating processes to avoid venting or flaring gas during pipeline maintenance, according to Weintraub. To more quickly locate and repair leaks, the company plans to survey its distribution systems every three years instead of its current five-year schedule.
The company is also piloting new technology-enabled leak-detection procedures, including a project that pairs fixed-wing aircraft with a satellite. The company is also analyzing whether drones and real-time measurement devices affixed to gas infrastructure can help the company more quickly pinpoint leaks.
"We're trying to figure out what are we not counting that we are responsible for, or we should be addressing in this net-zero methane goal," Weintraub said.
To prevent third-party strikes on its gas lines, Duke has deployed artificial intelligence and data analytics to identify high-risk excavations when it receives notifications through the 811 call-before-you-dig system. The company can then contact excavators to remind them of their responsibilities or send staff to supervise the dig.
Duke continues to see a long-term role for natural gas but acknowledges the need to tackle methane emissions beyond its distribution system. To help achieve net-zero methane emissions, the company will seek to procure gas from producers that aim to reduce their own emissions.
Renewable gas a solution for the 2020s
Duke sees RNG playing a crucial role in addressing its nearly 60,000 miles of transmission, distribution and service lines across the footprint of Piedmont Natural Gas Co. Inc. in the Southeast and Duke's service territories in the Midwest. The alternative fuel is produced by breaking down methane waste sources at farms, landfills and other sites that would have otherwise emitted the greenhouse gas.
Weintraub said the company is "blessed" to distribute gas in the heart of a robust agricultural region, where swine, dairy and cattle farms provide ample opportunities to refine and distribute RNG. In July, Duke announced an investment in and partnership with SustainRNG to process RNG from Southeastern farms and ship it through gas pipelines. In September, Piedmont announced it had begun selling RNG through its Nashville compressed natural gas fueling station.
The RNG market is still in the early stages. But Weintraub pointed to Oregon's recent regulations as a model for policy support. The rules established guidelines for the amount of RNG that utilities are allowed to blend into distribution systems, and they allow the utilities to recover costs for procuring RNG supplies. The latter provision could help ease the burden of investment that makes interconnection to distribution systems infeasible for some potential RNG suppliers, according to Weintraub.
As for green hydrogen, a gas alternative produced through electrolysis that uses electricity from renewable sources, Weintraub sees potential. But he noted that the hydrogen economy is just getting off the ground. "RNG is here this decade," he said. "Hydrogen will be ready the decade beyond."