Compilation of RNG and hydrogen reports

Many reports detail the pitfalls of increasing fossil gas infrastructure investments that use RNG and hydrogen instead of prioritizing electrification for heating and clean energy for electricity demand. Below are a few recent reports:

At Scale, Renewable Natural Gas Systems Could Be Climate Intensive: The Influence of Methane Feedstock and Leakage Rates | August 2020

According to a 2020 published report in Environmental Letters by Emily Grubert, assistant professor of Civil and Environmental Engineering at the Georgia Institute of Technology, expanding RNG could be climate intensive due to methane leakage:

“RNG is not inherently climate friendly. Based on consideration of both the source of methane used to produce RNG and the likely alternative fate of that methane, and using reasonable assumptions about likely system methane leakage, it is unlikely that an RNG system could deliver GHG-negative, or even zero GHG, energy at scale.”

The Challenge of Retail Gas in California’s Low-Carbon Future | April 2020

The California Energy Commission’s Energy Research and Development Division found that “building electrification is likely to be a lower-cost, lower-risk long-term strategy compared to renewable natural gas (RNG, defined as biomethane, hydrogen and synthetic gas, methane produced by combining hydrogen and carbon).” The division’s report built off of a 2018 report that modeled decarbonization pathways prepared by Energy + Environmental Economics (E3). E3’s analysis detailed that even with “aggressive technology learning” the RNG needed to decarbonize the state’s gas system would be both wildly expensive and insufficient.

Decarbonization of Heating Energy Use in California Buildings | October 2018

A Synapse Energy study found that heat pumps are the primary technology to deploy for a “cost-effective pathway to deep decarbonization” in the California building sector. In new construction projects, clean electric heating is lower than conventional gas alternatives due to the savings from avoiding the costs of plumbing the building and connecting it to the gas main in the street – even though heat pump equipment still costs more than gas furnaces. The study also found that while retrofit lifecycle costs vary from home to home, clean heating can be economical when a combination of energy efficiency and load management is deployed. 

New Jersey Charts a Practical, Affordable Course to a Decarbonized Economy | November 2019

Evolved Energy and RMI modeled pathways for New Jersey to achieve an 80 percent reduction in carbon emissions by 2050. The model found that the scenario of keeping fuel use in buildings costs more than the high electrification scenario: “We found that these alternative fuels are not competitive today at the scale required to decarbonize direct fuel use, and are likely to stay comparatively expensive.”

The Economics of Electrifying Buildings | 2018, 2020

In 2018, RMI analyzed the economics of electrifying residential buildings in several locations across the country. RMI found electrification reduces costs over the lifetime of the appliances when compared to fossil fuels for most new home construction in Oakland, Houston, Providence, and Chicago. The RMI report, similar to the Synapse study, also found the cost of a retrofit of an existing home already connected to the gas grid will vary depending on what gets replaced (furnace, water heater, air conditioning). But many customers with existing homes heated by propane or heating oil will find electrification cost-effective when replacing both a furnace and air conditioner simultaneously.

In October 2020, RMI updated and expanded the report to include seven new cities: Austin, Boston, Columbus, Denver, Minneapolis, New York City, and Seattle. RMI found all-electric homes in all the cities result in substantial carbon emissions savings, and new all-electric single-family homes have a lower net present cost than the new mixed-fuel home in every city.

Reclaiming Hydrogen for a Renewable Future | August 2021

In 2021, Earthjustice examined the claims of hydrogen as a clean energy source for homes and business. The report explains that while green hydrogen – made using 100% renewable electricity to split hydrogen from water molecules – could be used in some sectors and be a public health and climate benefit, its use in the gas distribution network is a deadend. The report highlights how safety hazards increase when increasing hydrogen flow in gas pipelines:

“Distribution pipelines cannot be retrofitted to deliver pure hydrogen. The gas-burning appliances in homes and commercial buildings cannot burn hydrogen without an unacceptable risk of explosion … the transmission pipelines that carry fossil gas from production centers to storage facilities and industrial users could conceivably be retrofitted to carry pure hydrogen. This retrofit would require significant costs, including replacing all of the pipeline’s compressors.”

Additionally, the report highlighted how frontline communities bear the brunt of hydrogen production since the fossil fuel industry is the largest producer and consumer of hydrogen – with the majority used in crude oil refining: “If gas-power plants were to be retrofitted to run on hydrogen, the air pollution impacts in frontline communities could be even more devastating. One group of researchers predicted that burning pure hydrogen would emit more than six times as much NOx as burning methane, the main component in fossil gas.”

Hydrogen: Future of Clean Energy or a False Solution? | January 2022

Sierra Club’s recent report details the limited justifications of deploying “green hydrogen” throughout the economy. Green hydrogen is hydrogen made through electrolysis that is powered by renewable energy. The report also explains that “blue hydrogen” – hydrogen produced from gas power plants equipped with carbon capture – increases overall emissions due to the emissions intensity of creating the blue hydrogen. In other words, power plants will increase their lifecycle emissions when using increasing amounts of blue hydrogen mixed with methane gas. Sierra Club cites an August 2021 report authored by Robert Howarth and Mark Jacobson, “How green is blue hydrogen?“.

Assessing The Viability Of Hydrogen Proposals: Considerations For State Utility Regulators And Policymakers | March 2022

According to Energy Innovation, utilities have proposed at least 26 hydrogen pilot projects across more than a dozen states and some are starting to file requests with state regulators to have ratepayers pay for these projects. The Energy Innovation report cautions utility regulators and state policymakers, and says public officials “should exercise skepticism when considering ratepayer-funded proposals to blend hydrogen with natural gas for distribution in pipelines or use in power plants, and they should place a high burden of proof on utilities to demonstrate viability.” The authors point to research that has found hydrogen projects increase consumer costs, exacerbate air pollution, and cause safety risks while minimally reducing greenhouse gases. Additionally, the authors recommend that regulators focus on “proven, least-regrets alternatives” such as building electrification, renewable energy and storage, and approving gas utility proposals that identify and seal methane leaks.

Methane emissions along biomethane and biogas supply chains are underestimated | June 2022

Researchers at Imperial College London, who published their findings in the environmental science journal One Earth, found “methane emissions could be more than two times higher than previously estimated, and the digestate-handling stage contributed to the largest CH4 emissions along the supply chain.” The authors emphasize that it is critical to avoid biomethane supply chain emissions in order to achieve net zero goals.

Hydrogen Blending Impacts Study | July 2022

According to a study by University of California, Riverside sponsored by the California Public Utilities Commission, injected hydrogen into the existing gas pipeline system “becomes concerning as hydrogen blending approaches 5% by volume. As the percentage of hydrogen increases, end-use appliances may require modifications, vintage materials may experience increased susceptibility, legacy components and procedures may be at increased risk of hydrogen effects.” The study noted additional concerns, including increased emissions of nitrogen oxides (NOx), potential flashback fires in household appliances, hydrogen embrittlement, and leaks. The study recommended further research and studies to address knowledge gaps in leak detection, leak flow rates, hydrogen embrittlement process, blending strategies, and more.

Hydrogen Blending into Natural Gas Pipeline Infrastructure: Review of the State of Technology | October 2022

Researchers at the National Renewable Energy Laboratory (NREL), a national laboratory of the U.S. Department of Energy, conducted a literature review on blending hydrogen into the gas network. NREL’s report details the knowledge gaps of hydrogen blending even though many gas utilities are conducting pilot programs and claiming hydrogen can help achieve net zero emission targets. NREL found “the presence of hydrogen significantly affects both fatigue crack growth and fracture resistance” on pipeline steel used throughout the transportation and distribution system. Additionally, the researchers found “hydrogen can impact the physical properties, such as density and degree of crystallinity, of polyethylene materials.” In other words, hydrogen blending can impact the physical properties of plastic pipes installed throughout the gas distribution network.

Hydrogen: Not a solution for gas-fired turbines | August 2024

A recent Institute for Energy Economics and Financial Analysis (IEEFA) report found hydrogen-related power projects require significant additional investments and will be extremely costly for ratepayers. Specifically, IEEFA found that “hydrogen-ready” gas plants will:

• Not have an adequate supply of hydrogen fuel to run a consistent methane gas blend at the methane gas plants.
• Face enormous hurdles to connect to a hydrogen pipeline network because of blending and siting issues.
• Not have the infrastructure capabilities to store hydrogen for the methane gas plants.

IEEFA urged state regulators to scrutinize utilities’ assertions and require companies to complete a full analysis comparing the costs of hydrogen plans with zero-carbon resources. 

A review of challenges with using the natural gas system for hydrogen | August 2024

This peer-reviewed study published in Energy Science & Engineering, authored by engineers and scientists associated with the Hydrogen Science Coalition, Environmental Defense Fund, and Environmental Defense Fund Europe, finds that because of the large, fundamental physical and chemical properties between hydrogen and methane, every component on the gas infrastructure value chain is “challenged by reuse.” Using hydrogen in the existing gas system is mostly unusable without de-rating to lower pressures, which leads to decreased energy flow rates, or substantial investments, retrofits, and replacements. Additionally, the reductions in greenhouse gas emissions are minimal. The authors write, “Overall, while repurposing the natural gas system for use with hydrogen may, at first, seem appealing, the limited practicality, risks and data gaps strongly suggest that like-for-like gas substitution proved limited benefits for increased risks, even if major technical and economic hurdles are overcome.“