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 energy tech platform Molecule closes series B funding

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Houston-based energy trading risk management (ETRM) software company Molecule has completed a successful series B round for an undisclosed amount, according to a July 16 release from the company.

The raise was led by Sundance Growth, a California-based software growth equity firm.

Sameer Soleja, founder and CEO of Molecule, said in the release that the funding will allow the company to "double down on product innovation, grow our team, and reach even more markets."

Molecule closed a $12 million Series A round in 2021, led by Houston-based Mercury Fund, and has since seen significant growth. The company, which was founded in 2012, has expanded its customer base across the U.S., U.K., Europe, Canada and South America, according to the release.

Additionally, it has launched two new modules of its software platform. Its Hive module, which debuted in 2022, enables clients to manage their energy portfolio and renewable credits together in one scalable platform. It also introduced Elektra, an add-on for the power market to its platform, which allows for complex power market trading.

"Four years ago, we committed to becoming the leading platform for energy trading," Soleja said in the release. "Today, our customers are managing complex power and renewable portfolios across multiple jurisdictions, all within Molecule.”

Molecule is also known for its data-as-a-lake platform, Bigbang, which enables energy ETRM and commodities trading and risk management (CTRM) customers to automatically import trade data from Molecule and then merge it with various sources to conduct queries and analysis.

“Molecule is doing something very few companies in energy tech have done: combining mission-critical depth with cloud-native, scalable technology,” Christian Stewart, Sundance Growth managing director, added in the statement. “Sameer and his team have built a platform that’s not only powerful, but user-friendly—a rare combination in enterprise software. We’re thrilled to partner with Molecule as they continue to grow and transform the energy trading and risk management market.”

D.C. energy company secures $233M for ERCOT battery storage projects

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The Electricity Reliability Council of Texas’ grid will get a boost courtesy of Lydian Energy.

The D.C.-based company announced the successful financial close of its first institutional project financing totaling $233 million, backed by ING Group and KeyBank. The financing will support three battery energy storage system (BESS) projects in Texas.

Lydian is an independent power producer that specializes in the development, construction and operation of utility-scale solar and battery energy storage projects. The company reports that it plans to add 550 megawatts of energy—which can power approximately 412,500 homes—to the Texas grid administered by ERCOT.

“This financing marks an important step forward as we continue executing on our vision to scale transformative battery storage projects that meet the evolving energy needs of the communities we serve,” Emre Ersenkal, CEO at Lydian Energy, said in a news release.

The projects include:

Pintail 

  • Located in San Patricio county
  • 200 megawatts
  • Backed by ING

Crane

  • Located in Crane county
  • 200 megawatts
  • Backed by ING

Headcamp

  • Located in Pecos county
  • 150 megawatts
  • Backed by KeyBank

ING served as the lender for Pintail and Crane projects valued at a combined total of approximately $139 million.

KeyBank provided a $94 million financing package for the Headcamp project. KeyBanc Capital Markets also structured the financing package for Headcamp.

The three projects are being developed under Excelsior Energy Capital’s Fund II. Lydian’s current portfolio comprises 20 solar and storage projects, totaling 4.7 gigawatts of capacity.

“Our support of Lydian’s portfolio reflects ING’s focus on identifying strategic funding opportunities that align with the accelerating demand for sustainable power,” Sven Wellock, managing director and head of energy–renewables and power at ING, said in the release. “Battery storage plays a central role in supporting grid resilience, and we’re pleased to back a platform with strong fundamentals and a clear execution path.”

The facilities are expected to be placed in service by Q4 2025. Lydian is also pursuing additional financing for further projects, which are expected to commence construction by the end of 2025.

“These financings represent more than capital – they reflect the strong demand for reliable energy infrastructure in high-growth U.S. markets,” Anne Marie Denman, co-founding partner at Excelsior Energy Capital and chair of the board at Lydian Energy, added in the news release. “We’re proud to stand behind Lydian’s talented team as they deliver on the promise of battery storage with bankable projects, proven partners, and disciplined execution. In the midst of a lot of noise, these financings are a reminder that capital flows where infrastructure is satisfying fundamental needs of our society – in this case, the need for reliable, sustainable, domestic, and affordable energy.”