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.
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.
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.