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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Houston Methodist leader on the push for sustainable health care and new local event

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Every industry can play a role in the energy transition, and Houston Methodist is leading the charge in the health care sector.

Culminating at this week’s inaugural Green ICU Conference, part of Houston Energy and Climate Startup Week, the health care system has spent the last three years taking a closer look at its environmental footprint—and showing other hospital systems and medical organizations how they too can make simple changes to reduce emissions.

The event, held tomorrow, Sept. 17, at TMC Helix Park, will bring together health care professionals, industry leaders, policymakers and innovators to explore solutions for building a more sustainable healthcare system.

In an interview with EnergyCapital, Dr. Faisal N. Masud, medical director of critical care at Houston Methodist and a champion for sustainability efforts across the system, shares the inspiration behind the event and what attendees can expect to take away.

Tell us about how the Green ICU Conference came to be.

Houston Methodist’s inaugural Green ICU conference is about three years in the making. It originated because Houston Methodist recognized the significant impact health care has on sustainability and the lack of similar initiatives in the U.S.

The Center for Critical Care at Houston Methodist launched a sustainability-focused ICU initiative, published a roadmap and became involved in international efforts to develop guidelines that many other organizations now use. Our work led to the creation of the first Green ICU Collaborative in the country, and the Green ICU Conference was established to share best practices and address the global impact of critical care on the environment.

What were some of the biggest takeaways from the collaborative, and how are they represented in this new event?

Through the Green ICU Collaborative, we’ve seen that health care professionals can make a significant impact on sustainability through simple, practical changes, and many solutions can be implemented without major costs or compromising patient care. Additionally, there’s a strong link between environmental stewardship and patient safety and quality. These lessons will be represented in the new Green ICU Conference by showcasing easy-to-adopt best practices, emphasizing the importance of sustainability in daily health care operations, and fostering a sense of shared responsibility among attendees to improve both patient outcomes and environmental impact.

Why are ICUs considered to be such carbon hot spots?

ICUs are considered carbon hot spots because they care for the sickest patients, requiring intensive therapies, numerous medications and a large amount of equipment, such as ventilators and pumps. This makes them the most resource- and energy-intensive areas in a hospital. A single day in the ICU can have a greenhouse gas impact equivalent to driving a car 1,000 kilometers.

The U.S. health care sector is responsible for approximately 8.5 percent of greenhouse gas emissions, and hospitals are the second-most energy-intensive commercial buildings in the country. With the Texas Medical Center being in the heart of Houston, it’s critical that health care organizations play a role in this area.

That’s why the Center for Critical Care launched a system-wide Green ICU Initiative with the Houston Methodist Office of Sustainability to help reduce our carbon impact and waste while continuing to provide unparalleled patient care. Innovation is part of our culture, and that extends into our sustainability efforts. Houston Methodist’s Green ICU initiative is the first-of-its-kind in the U.S.

What efforts has Houston Methodist taken to cut emissions?

The first step to cutting emissions is measuring an organization’s carbon footprint to determine the best path forward. Houston Methodist’s Office of Sustainability has aggregated two years of baseline emissions data pending third-party validation. The hospital has taken several steps to cut emissions, including implementing composting programs, installing solar panels, improving energy utilization and participating in global plastic recycling initiatives. These efforts are part of a broader commitment led by our Office of Sustainability to reduce the hospital’s environmental footprint.

Tell us a little more about the event. Who should attend? What do you expect to be some of the highlights?

The Green ICU Conference, taking place during Houston Energy and Climate Week, is focused on health care sustainability, bringing together health care professionals, engineers, experts and anyone interested in reducing health care’s environmental impact. With participants and speakers from six countries, the conference brings together leading experts who aim to raise awareness, share best practices and offer practical, easy-to-adopt solutions for making health care more sustainable.

Highlights include perspectives from leading voices in health care sustainability, real-world examples of successful sustainability initiatives and opportunities for networking and collaboration. Anyone interested in health care, sustainability,or making a positive impact in their community should consider attending.

And, because of increasing interest, we’ve opened up the opportunity for attendees to join virtually at no cost or in person.

What do you hope attendees take away? What are your major goals for the event?

The main goals of hosting the Green ICU Conference for the first time are to raise awareness about the environmental impact of health care; engage and empower attendees to implement easy, practical sustainability solutions; and foster a sense of shared community and responsibility.

I hope attendees leave the event feeling motivated and equipped to make meaningful changes in their own practices, whether that’s improving patient care, supporting their colleagues, or leaving their organization and environment in a better place for future generations.

Texas House Democrats urge Trump administration to restore $250M solar grant

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Eight Democratic members of the U.S. House from Texas, including two from Houston, are calling on the Trump administration to restore a nearly $250 million solar energy grant for Texas that’s being slashed by the U.S. Environmental Protection Agency (EPA).

In a letter to Lee Zeldin, head of the EPA, and Russell Vought, director of the federal Office of Management and Budget (OMB), the House members urged the two officials to reinstate the nearly $250 million grant, which was awarded to Texas under the $7 billion Biden-era Solar for All program. The Texas grant was designed to assist 28,000 low-income households in installing solar panels, aiming to reduce their energy bills.

“This administration has improperly withheld billions in congressionally appropriated funding that was intended to benefit everyday Americans,” the letter stated.

The letter claimed that numerous court rulings have determined the EPA cannot repeal already allocated funding.

“Congress made a commitment to families, small businesses, and communities across this country to lower their utility bills and reduce harmful pollution through investments in clean energy. The Solar for All program was part of that commitment, and the EPA’s actions to rescind this funding effectively undermine that congressional intent,” the House members wrote.

The six House members who signed the letter are:

  • U.S. Rep. Sylvia Garcia of Houston
  • U.S. Rep. Al Green of Houston
  • U.S. Rep. Greg Casar of Austin
  • U.S. Rep. Jasmine Crockett of Dallas
  • U.S. Rep. Lloyd Doggett of Austin
  • U.S. Rep. Julie Johnson of Dallas
  • U.S. Rep. Marc Veasey of Fort Worth

The nearly $250 million grant was awarded last year to the Harris County-led Texas Solar for All Coalition.

In a post on the X social media platform, Zeldin said the recently passed “One Big Beautiful Bill” killed the Greenhouse Gas Reduction Fund, which would have financed the $7 billion Solar for All program.

“The bottom line is this: EPA no longer has the statutory authority to administer the program or the appropriated funds to keep this boondoggle alive,” Zeldin said.