NEWPORT, R.I. — Fortifying and upgrading the natural gas pipeline network could prepare existing infrastructure to transport zero-carbon fuels, but that is an “enormous task,” according to Erin Blanton, a senior research scholar at Columbia University.

It “looks exceedingly likely” that a significant volume of natural gas will flow for the next couple of decades, Blanton said during a panel Thursday about the future of natural gas at the 73rd New England Conference of Public Utilities Commissioners Symposium.

Blanton co-authored a report this spring from Columbia’s Center on Global Policy that said the U.S. must reduce the burning of coal, oil and natural gas to achieve decarbonization targets, which seems intuitive. Investing more in the natural gas pipeline network, however counterintuitive it might appear, could help the U.S. reach net-zero emission goals more quickly and cheaply, the report said.

National Grid, which has gas customers in Massachusetts, Rhode Island and New York, is trying to take innovative approaches to decarbonize its system by 2050. The utility outlined net-zero ambitions in a 10-point plan in October, including decarbonizing its network with renewable natural gas and hydrogen, according to Sheri Givens, vice president of U.S. regulatory and customer strategy at National Grid (NYSE: NGG).

“We’ve actually been injecting renewable natural gas into our system since the 1980s,” Givens said. 

National Grid is participating in a hydrogen blending study in conjunction with Stony Brook Institute and the New York State Energy Research and Development Authority to explore the performance and use of its existing gas infrastructure to integrate and store renewable hydrogen.

National Grid, Givens said, is also thinking about different kinds of heating systems. 

“Electrification is going to be a key component of future heat,” she said. “We recognize air source heat pumps are going to be needed and necessary to help us meet our decarbonization goals, but there might be opportunities for dual-fuel heating as well, where you have an electric heat pump that has a gas backup to ensure you have that resilient, reliable energy heating source in your home.” 

Geothermal alternatives might be part of National Grid’s future solutions as well. For example, Givens said a small-scale project in New York on Long Island that connected 10 homes and a senior community center has been operating since 2017. The utility has several similar proposals pending in Massachusetts and New York.

In addition, Givens said the utility recently conducted a study with the New York City mayor’s office on decarbonization that revealed that 30 to 60% of the building stock in the city could be electrified, which opens the door for alternatives. 

“This gives you an idea of some of the policy levers that regulators and lawmakers can push and pull in the coming years,” she said. 

Gas utilities face several problems, including decarbonizing gas, which is difficult because it is a fossil fuel, according to Audrey Schulman, co-founder and co-director of the nonprofit Home Energy Efficiency Team (HEET).  

“What happens to the gas system is important because millions of people rely on it,” Schulman said. “What we need is a system that safely delivers decarbonized heat at the same or lower cost than gas.” 

HEET envisions a GeoGrid — a street-segment loop of shared water pipes with boreholes and thermal loops going to buildings.  

“Like Lego blocks, they can gradually grow into a GeoGrid over time,” Schulman said. “It does not take up new land; it’s installed in the street.” 

Gas utilities, she said, are perfect for installing this type of system, adding that Eversource Energy (NYSE: ES) could pilot a GeoGrid and has been working toward an initial installation.

“They have the customers, the right-of-way in the street and the expertise of pumping energy through pipes, and they can basically socialize the cost of that energy for all of us and decades into the future,” she said. 

Any building connected to the GeoGrid would reduce its emissions by about 60%, according to Schulman. In addition, the installation cost, if done by incumbent utilities, would be spread across decades and deliver “renewable lower-cost energy to all and not just those with money.” 

“This is an equitable system,” Schulman said.