JOURNAL ARTICLES
Geospatial variation in carbon accounting of hydrogen production and implications for the US Inflation Reduction Act
Valeria Vallejo, Quoc Nguyen & Arvind P. Ravikumar
Date published: October 14, 2024
Low-carbon hydrogen is considered a key component of global energy system decarbonization strategy. The US Inflation Reduction Act incentivizes low-carbon hydrogen production through tax credits that vary based on life-cycle greenhouse gas emissions intensity of hydrogen. Blue hydrogen or hydrogen produced from natural gas coupled with carbon capture and sequestration is one such pathway. Here we develop a geospatial, measurement-informed model to estimate supply-chain specific life-cycle greenhouse gas emissions intensity of blue hydrogen produced with natural gas sourced from the Marcellus and Permian shale basins. We find that blue hydrogen production using Permian gas has a life-cycle emissions intensity of 7.4 kg carbon dioxide equivalent per kg hydrogen (kgCO2e kg−1 H2), more than twice that of hydrogen produced using Marcellus gas of 3.3 kgCO2e kg−1 H2. Eligibility for tax credits should therefore be based on life-cycle assessments that are supply-chain specific and measurement informed to ensure blue hydrogen projects are truly low carbon.
Determining Life Cycle Emissions of Hydrogen Production Using the 45VH2-GREET Model for the 45V Hydrogen Production Tax Credit
Date published: August, 2024
This study provides an analysis of life cycle greenhouse gas (GHG) emissions associated with hydrogen
production pathways in the context of the 45V clean hydrogen production tax credit (45V PTC) under the 2022 Inflation Reduction Act (IRA) and underscores the importance of integrating zero-carbon electricity (ZCE), implementing CCS technology and co-product valorization, and careful selection of feedstocks to maximize eligibility for the 45V PTC. Additionally, it provides insights into the various limitations of the latest 45V-GREET model, identifying opportunities for future research to further evaluate the model’s fixed assumptions and constraints. The findings are valuable for stakeholders in the hydrogen production industry aiming to leverage the 45V PTC to promote low-carbon hydrogen production.
Model to Inform the Expansion of Hydrogen Distribution Infrastructure
Date published: July 22, 2023
A growing hydrogen economy requires new hydrogen distribution infrastructure to link geographically distributed hubs of supply and demand. The Hydrogen Optimization with Deployment of Infrastructure (HOwDI) Model helps meet this requirement. The model is a spatially resolved optimization framework that determines location-specific hydrogen production and distribution infrastructure to cost-optimally meet a specified location-based demand. While these results are useful in understanding hydrogen infrastructure development, there is uncertainty in some costs that the model uses for inputs. Thus, the project team took the modeling effort a step further and developed a Monte Carlo methodology to help manage uncertainties.
Influences on Hydrogen Production at a Wind Farm
Date published: January 13, 2023
If an affordable infrastructure for low-carbon-intensity hydrogen can be developed, then hydrogen is expected to become a key factor in decarbonizing the atmosphere. This research focuses on factors an existing wind farm operator would consider when weighing
participating in the electricity market, the hydrogen market, or both.
The solutions depend on the state of technology, which is changing rapidly, the local market structures, the local natural resources, and the local pre-existing infrastructure. Consequently, this investigation used an assessment approach that examined the variation of net present value. The investigation identified profitability conditions under three different scenarios: 1) Make and sell what makes economic sense at the time of production, 2) Use electrolyzer and fuel cell to consume power from the grid at times of low net demand and to produce electricity at times of high net demand, 3) Same as #2 but also market hydrogen directly when profitable.
On the Climate Impacts of Blue Hydrogen Production
Date published: November 19, 2021
Natural gas based hydrogen production with carbon capture and storage is referred to as blue hydrogen. If substantial amounts of CO2 from natural gas reforming are captured and permanently stored, such hydrogen could be a low-carbon energy carrier. However, recent research raises questions about the effective climate impacts of blue hydrogen from a life cycle perspective. Our analysis sheds light on the relevant issues and provides a balanced perspective on the impacts on climate change associated with blue hydrogen. We show that such impacts may indeed vary over large ranges and depend on only a few key parameters: the methane emission rate of the natural gas supply chain, the CO2 removal rate at the hydrogen production plant, and the global warming metric applied. State-of-the-art reforming with high CO2 capture rates combined with natural gas supply featuring low methane emissions does indeed allow for substantial reduction of greenhouse gas emissions compared to both conventional natural gas reforming and direct combustion of natural gas. Under such conditions, blue hydrogen is compatible with low-carbon economies and exhibits climate change impacts at the upper end of the range of those caused by hydrogen production from renewable-based electricity. However, neither current blue nor green hydrogen production pathways render fully “net-zero” hydrogen without additional CO2 removal.
Scalable, Highly Stable Si-based Metal-insulator-semiconductor Photoanodes for Water Oxidation Fabricated Using Thin-film Reactions and Electrodeposition
Date published: June 25, 2021
Metal-insulator-semiconductor (MIS) structures are widely used in Si-based solar water-splitting photoelectrodes to protect the Si layer from corrosion. Typically, there is a tradeoff between efficiency and stability when optimizing insulator thickness. Moreover, lithographic patterning is often required for fabricating MIS photoelectrodes. In this study, we demonstrate improved Si-based MIS photoanodes with thick insulating layers fabricated using thin-film reactions to create localized conduction paths through the insulator and electrodeposition to form metal catalyst islands. These fabrication approaches are low-cost and highly scalable, and yield MIS photoanodes with low onset potential, high saturation current density, and excellent stability. An onset potential of 0.7 V versus reversible hydrogen electrode (RHE) and saturation current density of 32 mA/cm2 under simulated AM1.5G illumination. In stability testing in 1 M KOH aqueous solution, a constant photocurrent density of ~22 mA/cm2 is maintained at 1.3 V versus RHE for 7 days.
Hydrogen Infrastructure Expansion Requires Realistic Framework
Date published: May 3, 2021
With expected improvements in hydrogen generation technologies (most notably electrolysis) and reduction in costs, the supple of hydrogen will grow. Modeling and assessing supply- and demand-driven market scenarios will provide the framework through which to better for realistic infrastructure and storage requirements.
REPORTS
A Framework for Hydrogen in Texas: Demonstration and Framework for H2@Scale in Texas and Beyond
Date published: March 2024
Building on its existing hydrogen infrastructure, experienced workforce, and natural resources, Texas is poised to be a global leader in the quest for an economical, at-scale hydrogen economy. A 2022 study estimated that a hydrogen-rich, net-zero Texas economy would have an economic benefit (business-as-usual) of more than $120 billion and create over 750,000 new jobs by 2050.
This material is based upon work supported by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) under the Hydrogen and Fuel Cells Technologies Office (HFTO), H2@Scale Initiative, Award Number DE-EE0008850.
Don’t Mess with Texas: Getting the Lone Star State to Net-Zero by 2050
Date published: April 2022
The world is decarbonizing. Many countries, companies, and financial institutions have committed to cutting their emissions. Decarbonization commitments have been issued by: 136 countries including Canada, China, and the UK, at least 16 U.S. states including New York, Louisiana, and Virginia, and a third of the largest 2,000 publicly traded companies in the world, including Apple, Amazon, and Walmart, and numerous Texas companies like ExxonMobil, American and Southwest Airlines, Baker Hughes, and AT&T.1–9 These decarbonizing countries, states, cities, and companies are Texas’s energy customers. If Texas ignores the challenge to decarbonize its economy, it may eventually face the more difficult challenge of selling carbon-intensive products to customers around the world who do not want them. We are already seeing this scenario beginning to play out with France canceling a liquified natural gas deal from Texas gas producers and both U.S. and international automakers announcing shifts to electric vehicles. Proactive net-zero emissions strategies might allow Texas to maintain energy leadership and grow the economy within a rapidly decarbonizing global marketplace.
Thankfully, Texas is uniquely positioned to lead the world in the transition to a carbon-neutral energy economy.
Global Renewable and Low-Carbon Gas Report (2021 Edition)
Date posted: November 18, 2021
Over the recent years, the momentum of supportive policy commitments toward reaching the goals of 2015 Paris Agreements has been growing – including, in no small part, plans and strategies to develop low-or-zero carbon hydrogen and renewable gas.
While natural gas, which currently provides around 25% of global primary energy supply, is the lowest carbon fossil fuel, there is growing recognition of the importance of low-carbon gases, as key decarbonisation actors. These include biogas, produced by anaerobic digestion and typically used for combined heat and power near the point of production; biomethane (also known as renewable natural gas) from upgrading biogas, and low-carbon hydrogen. A key question, however, is whether these low-carbon gaseous fuels can be developed fast enough and at a reasonable cost. Against that background, the International Gas Union, with support from the Oxford Institute for Energy Studies and its partners from Imperial College London and University of Texas, Austin, started launched this global renewable gas database project to track development of low-carbon and renewable gas supply around the world. As more projects are developed, and scope and coverage of the databases increases in parallel, this will provide the ability to track the extent to which actual project developments are consistent with ambitious goals which have been set.
WHITE PAPERS
Determining Life Cycle Emissions of Hydrogen Production Using the 45VH2-GREET Model for the 45V Hydrogen Production Tax Credit
Date posted: August 28, 2024
This study provides an analysis of life cycle greenhouse gas (GHG) emissions associated with hydrogen production pathways in the context of the 45V clean hydrogen production tax credit (45V PTC) under the 2022 Inflation Reduction Act (IRA). The 45V PTC mandates a well-to-gate system boundary for assessing life cycle GHG emissions, focusing on emissions up to the point of hydrogen production, including feedstock-related emissions. Central to this study is the use of the 45VH2-GREET model to determine the well-to-gate life cycle GHG emissions. The study focuses on three hydrogen production pathways:
– Low-temperature electrolysis (Case 1)
– Natural gas steam methane reforming (SMR) (Case 2)
– Natural gas autothermal reforming (ATR) (Case 3)
Texas’ Role in the Future Global Demand for Hydrogen
Date posted: September 13, 2023
Future decarbonized economies will still include sectors that will be hard to electrify. Some countries such as Japan and Germany, that are targeting net-zero emissions by 2050 and 2045 respectively, are counting on hydrogen to play a key role in their respective energy strategies. Many others are also beginning to see hydrogen as a form of energy security and are launching agreements to facilitate hydrogen use and trade networks. As hydrogen demand around the world increases, leading hydrogen-producing countries, such as the US, stand to gain by developing a global hydrogen export strategy.
Hydrogen Blending in Texas Natural Gas Power Plants at Scale
Date posted: January 31, 2022
Hydrogen is a potential solution to help decarbonize the economy, including electricity. Once hydrogen is produced, it can be used in industrial processes or to produce electricity from fuel cells and gas turbines. Hydrogen can also be a long-term storage solution for excess electricity produced by other clean sources.
This study sought to assess the carbon emissions reduction value, if any, in utilizing low levels of hydrogen blending in existing power plants. This study finds that blending even relatively small amounts of hydrogen in the fuel streams of existing natural gas power plants can reduce carbon emissions. Furthermore, the results suggest that the levels of tax credits currently being considered at the federal level are likely necessary and sufficient to make hydrogen blending economically competitive in the short term.
Analysis of Hydrogen Fuel Cell Class 8 Trucks
Date posted: January 7, 2022
This paper specifically focuses on hydrogen fuel cell class 8 trucks. Class 8 trucks are vehicles that weigh over 53,000 lbs., which are most commonly 18-wheeler trucks. Heavy duty vehicles contribute to 23% of transportation emissions of greenhouse gases and a quarter the fuel consumed annually due to long traveling distances and heavy cargo. Therefore, sizable reduction of transportation sector emissions could be accomplished by using alternative fuels, such as hydrogen, for trucks.
Renewable Electrolysis in Texas: Pipelines versus Power Lines
Date posted: August 3, 2021
Using wind and solar generation to power electrolysis facilities and produce “green” hydrogen at scale would require infrastructure investment. Using current technology, we identify at least one situation in which producing hydrogen at the point of electricity generation and transporting it to the point of use via pipeline costs about one third that of transmitting the electricity and generating hydrogen at the point of use. This raises the possibility that hydrogen pipelines might provide an alternative to high voltage transmission lines for connecting renewable generation with demand. In this white paper, we explore the tradeoffs of those two options.
Market Competitive Electrolysis in ERCOT
Date posted: July 1, 2021
Across US and global markets, demand for hydrogen is increasing. Simultaneously, the cost of producing hydrogen via electrolysis using electricity is decreasing, creating new market opportunities for this low-carbon hydrogen production process. To assess this opportunity, three key cost factors for hydrogen production using an electrolyzer need to be considered: capital, operating, and electricity cost. Of these three, the electricity cost can be assumed to vary most widely by location due to local availability of generating sources and local market rate structures. Although conventional wisdom holds that electrolyzers can only operate profitably if given very low electricity prices, this paper highlights an existing electricity market where electrolysis could be an attractive and profitable option for hydrogen production today.
Since electricity prices vary over time, an electrolysis facility can choose when and to what extent to adjust its hydrogen production to target lower electricity prices and consequently reduce its hydrogen production costs. This white paper uses historical electricity price data from the Electric Reliability Council of Texas (ERCOT), the grid that serves 90% of Texas, coupled with a basic techno-economic model of electrolysis to explore the costs and benefits of flexible electrolysis operation considering variable wholesale electricity prices. With strategic operating schedules, cost reductions, and efficiency improvements, electrolysis shows promise as a low-carbon, cross-sector, market competitive, and flexible source of hydrogen.
