Blue, green, gold — what do all the colors of hydrogen even mean? Photo via Getty Images

Repeated association of specific colors in defined contexts deeply reinforces themes in the human brain. It’s why most students and alumni of Texas A&M University scoff at the sight of burnt orange, and you’d be hard-pressed to find the home of a Longhorn adorned in shades of crimson or maroon.

The color-coding of hydrogen energy production exemplifies one such ambiguous classification methodology, as the seemingly innocuous labeling of hydrogen as green (for hydrogen produced from renewable sources) and black (for hydrogen produced from coal) initially helped to quickly discern which sources of hydrogen are environmentally friendly or not.

But the coding system quickly became more complicated, as the realization that hydrogen extracted from natural gas (aka grey hydrogen) or coal (again, black hydrogen, or sometimes, brown hydrogen, depending on the carbon content and energy density of the source coal) could be extracted in a less harmful way, by introducing methods of carbon capture and storage.

These cleaner methods for hydrogen extraction earned the lofty color coding of blue, just one shade away from green in the rainbow spectrum and a safe distance from the less delightful and inspiring colors grey, brown, and black.

Then along came pyrolysis — a method for producing hydrogen through methane cracking, plainly, the decomposition of methane, CH4, into solid carbon and hydrogen gas, without the introduction of oxygen. This method results in significantly less (if any) creation of carbon dioxide as a by-product. Logic would lead one to categorize this process with a color that lies further away from black than exalted cousin, green hydrogen.

However, the solid carbon that remains after pyrolysis retains over one-third of the original energy available from methane and could tip the GHG scales negatively if not utilized in an environmentally responsible manner, so it’s not a clear-cut winner in the game of lower-carbon energy production. Thus, it is nestled between green and blue and often referred to as “turquoise hydrogen” production.

Other hydrogen production methods — pink, purple, and red — defy rainbow logic as they have all proven to result in higher GHG emissions than the original “clean” queen, green hydrogen, despite following a similar electrolysis process to separate hydrogen and oxygen from one another in its original composition as water. The source of electricity used in the electrolysis process determines the color-code here, as pink hydrogen is generated from nuclear power, red hydrogen is generated from nuclear thermal power, and purple hydrogen is generated from a combination of nuclear power and nuclear thermal power.

Yellow hydrogen seems to not yet have found a clear definition. Some argue it refers to green hydrogen produced exclusively from solar-powered electrolysis, while others claim it to be the child of mixed green/gray hydrogen. Artists should probably keep a far distance from this conversation, unless the energy produced from the steam coming out of their ears could perform electrolysis more cleanly than any of the green hydrogen solutions.

Finally, we have white hydrogen, the naturally occurring, zero-carbon emitting, plentiful element found in the earth’s crust – which is also the least understood of all the hydrogen extraction methodologies.

Remember, hydrogen is the first element in the periodic table, meaning it’s density is very low. Hydrogen knows no bounds, and once it escapes from its natural home, it either floats off into outer space or attaches itself to another element to form a more containable compound, like water.

Many believe white hydrogen to be the unquestionable solution to a lower-carbon energy future but there is still much to be understood. Capturing, storing, and transporting white hydrogen remain mostly theoretical, despite recent progress, which includes one recently announced Houston lab dedicated to hydrogen transport. Another Houston company, Syzygy has raised millions with its light-based catalyst for hydrogen production.

For example, Cemvita, a local Houston chemical manufacturing company, predicts a future powered by gold hydrogen: white hydrogen sourced from depleted oil and gas wells. Many wildcatters believe strongly in a new era of exploration for white hydrogen using techniques refined in oil and gas exploration, including reservoir analysis, drilling, and fracking.

Without a doubt, investigating further the various hydrogen extraction theories is surely a craveable new challenge for the sciences. But perhaps the current color-coding nomenclature for hydrogen needs refinement, as well.

Unless used in the scientific context of wavelength, color-based labels represent an ambiguous classification tool, as the psychology of color depends on modern societal norms. The association of colors with the various hydrogen production methodologies does very little to distinguish the climate impact each method produces. Additionally, the existing categorizations do not consider any further distribution or processing of the produced hydrogen — a simple fact that could easily negate any amount of cleanliness implied by the various production methods — and a topic for a future article.

For now, hydrogen represents one of the front-running sources for a lower-carbon energy future, but it’s up to you if that’s best represented by a blue ribbon, gold medal, white star, or cold-hard greenbacks.

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Lindsey Ferrell is a contributing writer to EnergyCapitalHTX and founder of Guerrella & Co.

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UH's $44 million mass timber building slashed energy use in first year

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The University of Houston recently completed assessments on year one of the first mass timber project on campus, and the results show it has had a major impact.

Known as the Retail, Auxiliary, and Dining Center, or RAD Center, the $44 million building showed an 84 percent reduction in predicted energy use intensity, a measure of how much energy a building uses relative to its size, compared to similar buildings. Its Global Warming Potential rating, a ratio determined by the Intergovernmental Panel on Climate Change, shows a 39 percent reduction compared to the benchmark for other buildings of its type.

In comparison to similar structures, the RAD Center saved the equivalent of taking 472 gasoline-powered cars driven for one year off the road, according to architecture firm Perkins & Will.

The RAD Center was created in alignment with the AIA 2030 Commitment to carbon-neutral buildings, designed by Perkins & Will and constructed by Houston-based general contractor Turner Construction.

Perkins & Will’s work reduced the building's carbon footprint by incorporating lighter mass timber structural systems, which allowed the RAD Center to reuse the foundation, columns and beams of the building it replaced. Reused elements account for 45 percent of the RAD Center’s total mass, according to Perkins & Will.

Mass timber is considered a sustainable alternative to steel and concrete construction. The RAD Center, a 41,000-square-foot development, replaced the once popular Satellite, which was a food, retail and hangout center for students on UH’s campus near the Science & Research Building 2 and the Jack J. Valenti School of Communication.

The RAD Center uses more than a million pounds of timber, which can store over 650 metric tons of CO2. Aesthetically, the building complements the surrounding campus woodlands and offers students a view both inside and out.

“Spaces are designed to create a sense of serenity and calm in an ecologically-minded environment,” Diego Rozo, a senior project manager and associate principal at Perkins & Will, said in a news release. “They were conceptually inspired by the notion of ‘unleashing the senses’ – the design celebrating different sights, sounds, smells and tastes alongside the tactile nature of the timber.”

In addition to its mass timber design, the building was also part of an Energy Use Intensity (EUI) reduction effort. It features high-performance insulation and barriers, natural light to illuminate a building's interior, efficient indoor lighting fixtures, and optimized equipment, including HVAC systems.

The RAD Center officially opened Phase I in Spring 2024. The third and final phase of construction is scheduled for this summer, with a planned opening set for the fall.

Experts on U.S. energy infrastructure, sustainability, and the future of data

Guest column

Digital infrastructure is the dominant theme in energy and infrastructure, real estate and technology markets.

Data, the byproduct and primary value generated by digital infrastructure, is referred to as “the fifth utility,” along with water, gas, electricity and telecommunications. Data is created, aggregated, stored, transmitted, shared, traded and sold. Data requires data centers. Data centers require energy. The United States is home to approximately 40% of the world's data centers. The U.S. is set to lead the world in digital infrastructure advancement and has an opportunity to lead on energy for a very long time.

Data centers consume vast amounts of electricity due to their computational and cooling requirements. According to the United States Department of Energy, data centers consume “10 to 50 times the energy per floor space of a typical commercial office building.” Lawrence Berkeley National Laboratory issued a report in December 2024 stating that U.S. data center energy use reached 176 TWh by 2023, “representing 4.4% of total U.S. electricity consumption.” This percentage will increase significantly with near-term investment into high performance computing (HPC) and artificial intelligence (AI). The markets recognize the need for digital infrastructure build-out and, developers, engineers, investors and asset owners are responding at an incredible clip.

However, the energy demands required to meet this digital load growth pose significant challenges to the U.S. power grid. Reliability and cost-efficiency have been, and will continue to be, two non-negotiable priorities of the legal, regulatory and quasi-regulatory regime overlaying the U.S. power grid.

Maintaining and improving reliability requires physical solutions. The grid must be perfectly balanced, with neither too little nor too much electricity at any given time. Specifically, new-build, physical power generation and transmission (a topic worthy of another article) projects must be built. To be sure, innovative financial products such as virtual power purchase agreements (VPPAs), hedges, environmental attributes, and other offtake strategies have been, and will continue to be, critical to growing the U.S. renewable energy markets and facilitating the energy transition, but the U.S. electrical grid needs to generate and move significantly more electrons to support the digital infrastructure transformation.

But there is now a third permanent priority: sustainability. New power generation over the next decade will include a mix of solar (large and small scale, offsite and onsite), wind and natural gas resources, with existing nuclear power, hydro, biomass, and geothermal remaining important in their respective regions.

Solar, in particular, will grow as a percentage of U.S grid generation. The Solar Energy Industries Association (SEIA) reported that solar added 50 gigawatts of new capacity to the U.S. grid in 2024, “the largest single year of new capacity added to the grid by an energy technology in over two decades.” Solar is leading, as it can be flexibly sized and sited.

Under-utilized technology such as carbon capture, utilization and storage (CCUS) will become more prominent. Hydrogen may be a potential game-changer in the medium-to-long-term. Further, a nuclear power renaissance (conventional and small modular reactor (SMR) technologies) appears to be real, with recent commitments from some of the largest companies in the world, led by technology companies. Nuclear is poised to be a part of a “net-zero” future in the United States, also in the medium-to-long term.

The transition from fossil fuels to zero carbon renewable energy is well on its way – this is undeniable – and will continue, regardless of U.S. political and market cycles. Along with reliability and cost efficiency, sustainability has become a permanent third leg of the U.S. power grid stool.

Sustainability is now non-negotiable. Corporate renewable and low carbon energy procurement is strong. State renewable portfolio standards (RPS) and clean energy standards (CES) have established aggressive goals. Domestic manufacturing of the equipment deployed in the U.S. is growing meaningfully and in politically diverse regions of the country. Solar, wind and batteries are increasing less expensive. But, perhaps more importantly, the grid needs as much renewable and low carbon power generation as possible - not in lieu of gas generation, but as an increasingly growing pairing with gas and other technologies. This is not an “R” or “D” issue (as we say in Washington), and it's not an “either, or” issue, it's good business and a physical necessity.

As a result, solar, wind and battery storage deployment, in particular, will continue to accelerate in the U.S. These clean technologies will inevitably become more efficient as the buildout in the U.S. increases, investments continue and technology advances.

At some point in the future (it won’t be in the 2020s, it could be in the 2030s, but, more realistically, in the 2040s), the U.S. will have achieved the remarkable – a truly modern (if not entirely overhauled) grid dependent largely on a mix of zero and low carbon power generation and storage technology. And when this happens, it will have been due in large part to the clean technology deployment and advances over the next 10 to 15 years resulting from the current digital infrastructure boom.

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Hans Dyke and Gabbie Hindera are lawyers at Bracewell. Dyke's experience includes transactions in the electric power and oil and gas midstream space, as well as transactions involving energy intensive industries such as data storage. Hindera focuses on mergers and acquisitions, joint ventures, and public and private capital market offerings.

Rice researchers' quantum breakthrough could pave the way for next-gen superconductors

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A new study from researchers at Rice University, published in Nature Communications, could lead to future advances in superconductors with the potential to transform energy use.

The study revealed that electrons in strange metals, which exhibit unusual resistance to electricity and behave strangely at low temperatures, become more entangled at a specific tipping point, shedding new light on these materials.

A team led by Rice’s Qimiao Si, the Harry C. and Olga K. Wiess Professor of Physics and Astronomy, used quantum Fisher information (QFI), a concept from quantum metrology, to measure how electron interactions evolve under extreme conditions. The research team also included Rice’s Yuan Fang, Yiming Wang, Mounica Mahankali and Lei Chen along with Haoyu Hu of the Donostia International Physics Center and Silke Paschen of the Vienna University of Technology. Their work showed that the quantum phenomenon of electron entanglement peaks at a quantum critical point, which is the transition between two states of matter.

“Our findings reveal that strange metals exhibit a unique entanglement pattern, which offers a new lens to understand their exotic behavior,” Si said in a news release. “By leveraging quantum information theory, we are uncovering deep quantum correlations that were previously inaccessible.”

The researchers examined a theoretical framework known as the Kondo lattice, which explains how magnetic moments interact with surrounding electrons. At a critical transition point, these interactions intensify to the extent that the quasiparticles—key to understanding electrical behavior—disappear. Using QFI, the team traced this loss of quasiparticles to the growing entanglement of electron spins, which peaks precisely at the quantum critical point.

In terms of future use, the materials share a close connection with high-temperature superconductors, which have the potential to transmit electricity without energy loss, according to the researchers. By unblocking their properties, researchers believe this could revolutionize power grids and make energy transmission more efficient.

The team also found that quantum information tools can be applied to other “exotic materials” and quantum technologies.

“By integrating quantum information science with condensed matter physics, we are pivoting in a new direction in materials research,” Si said in the release.