Eight Key Findings, Part One: Renewable and Low-Carbon Gases
The following is the first part of an eight-part series to dive deeper into the eight key takeaways from the Net-Zero Emissions Opportunities for Gas Utilities report. If you are interested in the full report, you can learn more at https://www.aga.org/netzero.
In February 2022, the American Gas Association (AGA) released a bold vision for the future along with a seminal analysis detailing how America’s natural gas, natural gas utilities and delivery infrastructure will be essential to meeting our nation’s greenhouse gas emissions reduction goals, including achieving net-zero emissions. Building on the industry’s ambitious Climate Change Position Statement from January 2020, this new study “Net-Zero Emissions Opportunities for Gas Utilities,” presents a national-level approach that leverages the unique advantages of gas technologies and distribution infrastructure. Several modeled pathways are analyzed to underscore the range of scenarios and technology opportunities available as the nation, regions, states and communities develop and implement ambitious emissions reductions plans. The study details eight key findings in the Net-Zero Emissions Opportunities for Gas Utilities Study includes:
Each pathway starts with an exploration of the options to reduce natural gas demand per customer, accommodating for the rapid growth in the number of natural gas customers. We will cover this in a subsequent installment of this series, but the industry has a stellar track record in this area. The total number of residential natural gas customers in the U.S. has grown by 86 percent in the past 40 years, but overall residential natural gas demand has remained steady. Residential customers today use half of the volume of natural gas that they used in 1970 despite consistent growth in the average size of homes.
The pathways then explore decarbonizing the remaining gas demand to support deeper customer emissions. There is a tremendous amount of feedstock for renewable natural gas (RNG) and hydrogen to meet new gas demand. These are split into the following five supply options:
- Geologic natural gas: Gas supply from shale/conventional natural gas production
- Renewable natural gas (RNG): This includes methane produced by Anaerobic Digestion and Thermal Gasification from a variety of feedstocks
- Methanated hydrogen: This portion represents RNG (carbon-neutral methane that can be blended without limit in existing infrastructure) that was produced from a clean hydrogen feedstock and biogenic CO2.
- Hydrogen blending into gas supply: Hydrogen that is assumed to be mixed into existing gas infrastructure without requiring significant infrastructure upgrades
- Dedicated hydrogen infrastructure: This represents the build-out of new infrastructure to enable targeted customers/clusters to convert to higher levels of hydrogen use.
An American Gas Foundation study of RNG in 2019 estimated that up to 3,780 trillion Btu of RNG can be produced annually for pipeline injection by 2040. Based on technological innovation and advances in production efficiency, “Net-Zero Emissions Opportunities for Gas Utilities” estimates even more potential RNG production than originally thought in 2019. Interestingly, the feedstock stays the same. There is the same number of farms, landfills, water resource recovery facilities and renewable electricity, but the study estimates a greater yield of gaseous fuel from that feedstock because technological advances are leading to greater potential efficiencies
In addition to RNG, several of the pathways employ a readily available supply of hydrogen. The study assumes that power generation by 2050 will be zero-carbon, with a combination of nuclear, solar, wind and natural gas with carbon capture and sequestration. Excess electricity from intermittent renewable sources could be turned into hydrogen using electrolysis, a process of using electricity to split water into hydrogen and oxygen.
The gas system’s ability to integrate high-value sources of energy like renewable natural gas and hydrogen is a critical component of our nation’s ability to reach ambitious greenhouse gas reductions goals. One advantage hydrogen has over battery storage is that it does not require costly, nonrenewable, and environmentally destructive heavy earth elements like lithium, unlike battery storage. These methods can be coupled with other decarbonization options like energy efficiency and methane abatement throughout the value chain to achieve net-zero emissions.