Climate think-tank casts doubt on hydrogen blending

A new white paper released by San Francisco climate policy think-tank Energy Innovation is casting new doubt on green hydrogen blending in natural gas pipelines, used to help mitigate greenhouse gas (GHG) emissions in the United States.

Energy Innovation helps utilities move away from fossil fuels in favour of renewable energy and helps them build electrification in their projects. Hal Harvey, the firm’s CEO, previously served on executive energy panels under Presidents George H. W. Bush and Bill Clinton.

The paper, published at the end of March, comes as 26 utility pilot projects across a dozen states have begun injecting hydrogen into existing gas pipelines. Some of these gas utilities include Center Point Energy, Dominion Energy, National Grid, Puget Sound Energy, Southern Gas Co. (SGC), New Jersey Resources Corp. (NJR) and Sempra Energy.

Green hydrogen development and blending into gas pipelines has garnered media attention and excitement, in addition to financial backing from Washington.

Last year, the bipartisan Infrastructure Investment and Jobs Act (IIJA) allocated some US$8 billion to support regional hydrogen hubs, including at least two for heating and power generation.

Taking the hydrogen initiative a step further, the US Department of Energy (DOE) said in April it had committed $500 million to help build a 300GWh hydrogen storage project in Delta, Utah.

The U.S. natural gas system is a highly integrated network that comprises around 3 million miles of mainline and other pipelines that link natural gas production areas and storage facilities with consumers.

Green hydrogen blending hurdles

The Energy Innovation paper finds that plans for large-scale green hydrogen blending using existing natural gas infrastructure is at best a “highly inefficient solution for power generation and heating.”

In the worst case scenario, it could lead to what the report calls “dead-end investments” that actually raise GHG emissions, instead of lowering them, adding that over-reliance on green hydrogen could also increase energy costs for users, both industrial and residential.

“Theoretically, [green] hydrogen offers an appealing path for gas utilities to continue business-as-usual without major disruption to their financial models in the face of the decarbonization imperative,” it says.

“In the face of growing momentum and enthusiasm for hydrogen, state utility regulators and policymakers should be highly scrupulous and discerning of hydrogen blending proposals and avoid costly dead ends on the road to a decarbonized future,” the report cautions.

The study focuses only on green hydrogen, which is produced from renewables, and as such has no CO₂ emissions. Other forms of hydrogen range from blue hydrogen – that’s produced using natural gas and supported by Carbon, Capture and Storage (CCS) technology – to the end of the spectrum, so-called brown hydrogen that’s made by burning coal and is a major CO₂ emitter.

However, the report runs counter to prevailing beliefs in the viability and feasibility of hydrogen blending.

A report by the National Renewable Energy Laboratory (NREL), part of the DOE, finds that there are upfront costs associated with hydrogen blending into gas pipelines and modification to existing pipeline infrastructure, but these can be weighed against alternative means of bringing more sustainable and low-carbon energy to consumers on a case by case basis.

It adds that “as a hydrogen delivery method, blending can defray the cost of building dedicated hydrogen pipelines or other costly delivery infrastructure during the early market development phase.”

While the Energy Innovation authors critique several potential green hydrogen applications, it’s most critical of blending hydrogen with fossil fuels in pipelines that supply buildings with gas for heating, cooking and other indoor usage, calling it “highly inefficient,” while it “does little to reduce GHG emissions.”

Instead, they suggest, “it might thwart more viable decarbonization pathways while increasing consumer costs, exacerbating air pollution, and imposing safety risks.”

The report says the problem stems from hydrogen’s inability to be readily swapped for use in heating or consumer appliances above a 5% to 20% blend with gas without enormous cost and disruption.

Moreover, it adds, low blends achieve very few GHG emissions reductions while increasing nitrogen oxide (NOx) pollution. NOx forms a family of poisonous, highly reactive gases.

Differing perspectives

The NREL report also offers a different perspective on these claims, finding that hydrogen blending into natural gas pipelines provides a more sustainable and low-carbon gas product to consumers.

“Any social or environmental benefits associated with sustainable hydrogen pathways could arguably be attributed to natural gas with a hydrogen blend component in proportion to the hydrogen concentration,” the NREL finds.

Other industry players, including the American Gas Association, AGA, which represents more than 200 gas utilities across the country, also sees hydrogen blending as a way for utilities to implement a clean energy transition strategy.

AGA released a study in February that focused on combining natural gas infrastructure with solutions like renewable natural gas and hydrogen technologies to put utilities on a faster and less expensive path to GHG reduction.

SouthWest Gas Corp., a natural gas distribution company that serves more than two million customers in Arizona, California and Nevada, also sees hydrogen blending as a way to mitigate harmful emissions.

Amy Washburn, a SouthWest Gas spokesperson, told GasOutlook that the utility is teaming up with the University of Nevada, Las Vegas (UNLV) to study how hydrogen-blended natural gas can further reduce carbon emissions while still providing clean and reliable energy.

“The pilot programme is expected to signify major advancements in using a natural gas and hydrogen blend,” she said, adding a second pilot programme is underway to study the use of hydrogen blending with natural gas for household cooking.

Energy Innovation’s hydrogen blending critique for the power sector is less severe but still cause for what it calls concern for both utilities and policymakers.

Green hydrogen “might be suitable to provide long-duration energy storage in the power sector to help it decarbonize,” it says. However, “the fuel has limited value until such grid services are needed.”

Overall criticism is levied at hydrogen’s chemical make-up, since hydrogen is the smallest known molecule that exists. As such, its use “creates pipeline integrity and leakage challenges throughout the existing US natural gas infrastructure system.”

These leaks would require more upgrade, maintenance and investment than utilities are now considering, the authors claim.

The NREL report disagrees with this finding as well. “Hydrogen usage in gas pipelines can actually prevent gas pipeline leaks since hydrogen is more mobile than methane in many polymer materials, including the plastic pipes and elastomeric seals used in natural gas distribution systems,” it says.

“The permeation coefficient of hydrogen is higher through most elastomeric sealing materials than through plastic pipe materials,” the NREL says, adding that pipes have much larger surface areas than seals, so leaks through plastic pipe walls would account for the majority of gas losses.