How the gas system can adapt to net zero future

THE FUTURE of natural gas is now at the forefront of state and local climate planning as it has become clear that the combustion of fossil methane and the leakage of methane from the pipeline system at current scales are incompatible with net zero goals.

Understanding the future role of gas is essential for another reason: new clean technologies are disrupting the historical prominence of pipeline utility gas in a way that will have consequences for the economic viability of the gas system even in the absence of policy.

Gas faces real competition in the new value being created by electric alternatives. Electric heat pumps offer customers more comfort due to their ability to zone heating and cooling more easily and lower heating costs most days of the year. Induction cooking enhances the culinary experience while reducing indoor air pollution. The flexible operation of electric water heaters allows them to soak up excess low-cost electricity.

For various reasons, a few customers, and the energy system, may still benefit from the modest use of combustible fuels in some situations. A cook may value sautéing over a propane flame next to an induction cooktop that rapidly boils a pot of water. While air-source heat pumps can heat whole buildings in our climate, having a backup pellet boiler or propane furnace could provide cost and reliability benefits during cold snaps.

Such hybrid arrangements are steppingstones toward electrification that aim to defer intensive upgrades to buildings and the grid and preserve some element of customer optionality. Eventually, improvements in other strategies, such as thermal storage, drilling of ground-source heat wells, and building efficiency retrofit practice, will make it easier for more buildings to leave combustion altogether.

Modest use of combustible fuel is consistent with our current understanding of a net zero emissions energy system, but it does not need to rely on a sprawling, leaky, and expensive gas distribution system. The economic value of the gas system was based on its ability to distribute large amounts of energy rapidly. That is now under threat as a growing number of non-pipeline alternatives will steadily eliminate the bulk of that demand even on peak heating days. As a regulated monopoly, this raises significant concerns for those connected to the system, especially those with less agency to leave it.

With climate goals and technology improvements in mind, it is critical to ask if we should be investing $20 billion into an increasingly underutilized and redundant system. It is also essential to ask: given the potential for an uncontrolled exit of customers, how should the Commonwealth, municipalities, and the gas utilities manage the potential cost, operational, and equity implications of the pending downsizing of the gas system?

These questions inspired the Massachusetts Department of Public Utilities’ investigation into the future of gas (Docket 20-80). They were raised in the Massachusetts 2050 Decarbonization Roadmap and were asked by stakeholders at the inception of and throughout the 20-80 process. They have yet to be satisfactorily answered.

The utilities’ responses, such as the one presented in an April 19 column by Rob Rio and Stephen Woerner, describe a future of gas not too different from today – one in which the gas system maintains its current size, albeit with lower gas sales. Rather than right-sizing the gas system to meet the needs of a net zero future, this vision places the gas system financially on a knife’s edge and risks not achieving climate goals.

The utilities’ study presented some crucial insights into the pending decarbonization of heat. Notably, the practical and economic benefits of heating hybridization – arrangements such as those described above where electric heat pumps are used when they perform most efficiently and are supplemented by wood pellets, pipeline gas, oil, or propane on a handful of days when temperatures are well below freezing, and renewable electricity supplies are low. Many buildings currently utilize this approach to varying degrees.

Heating hybridization solves several transitional challenges, notably the cost and practicality of performing whole-home heating retrofits and lessening the impact of larger seasonal electric peaks. However, the benefits of gas heating hybridization may be overstated relative to other strategies investigated by the utilities. In their analysis, the utilities simulated the combined impact of hybrid gas and oil arrangements rather than separately. To those unfamiliar with energy system modeling, this modeling choice serves as a thumb on the scale for the cost savings observed in that analysis and that are used to justify the utilities’ plans.

The utilities’ study also emphasized the potential of targeted decommissioning or the pruning of leak-prone and expensive-to-maintain parts of the gas system. In many cases, it is cheaper to take homes off the gas system than to replace the pipes they are dependent on. With the strategic use of non-pipeline fuels in hybrid systems and whole building electrification, targeted decommissioning allows for the rightsizing of the gas system over time while minimizing customer impacts. We can accommodate individual choices and meet resiliency goals while making responsible decisions to manage expensive shared infrastructure.

The utilities’ strategies are also over-reliant on limited bioenergy resources to produce renewable natural gas (RNG). While it is possible such resources could be allocated to produce RNG, doing so would compete with efforts to decarbonize other sectors and remove carbon from the atmosphere. Hydrogen is better suited to decarbonize other sectors, and blending it into the gas system is simply a waste of energy and money.

Notably, non-pipeline renewable fuels may be a better use of bioenergy resources. Pellet stoves are a more efficient use of waste biomass than producing RNG. “Renewable propane” is a byproduct of sustainable aviation fuel pathways.

Ultimately, the more ambient heat we can pump from local air, water, and earth will yield more significant economic benefits for consumers and the Commonwealth. As the Massachusetts 2050 Decarbonization Roadmap demonstrated, strategies that reduce reliance on energy imports result in more local jobs and reinvestment.

The gas utilities can play a role in maximizing this potential by selling heat through district systems that integrate various energy resources. Doing so will require regulatory reform but can leverage their current knowledge, capabilities, and workforce. Their current geothermal pilots are an excellent first step, but the utilities will need to accelerate their efforts to remain competitive.

Finally, the study and utility plans underestimate the impact of gas leaks and fail to address this pernicious problem. A recent study found that methane emissions from leaks in the Boston region have barely budged despite six years of accelerated replacement of leak-prone-pipe. This is partly because half of the leaks appear to be coming from inside the buildings. No one has yet to propose a practical strategy for fixing such leaks.

The utilities’ plans seek to further entrench the gas system in the face of competition, technological progress, and more effective climate strategies. Doubling down on the gas system at its current scale puts its customers, workforce, and society’s climate goals at risk. The Commonwealth and its utilities need a better strategy for managing this transition.

Michael J. Walsh is an independent decarbonization researcher and consultant.