Hydrogen is widely recognized as a promising energy carrier for global decarbonization efforts, offering a path to reduce carbon emissions across transportation, industry, and power generation. However, the environmental benefit of hydrogen depends entirely on how it is produced, leading to a complex classification system. The source dictates its carbon footprint, which is why the energy industry uses a “color-code” to distinguish production methods. This distinction is paramount for shifting away from carbon-intensive sources toward cleaner, more sustainable options.
Defining Gold Hydrogen and the Color Spectrum
The industry uses a spectrum of colors to quickly categorize hydrogen based on its manufacturing process. The most common varieties include Grey hydrogen, which is produced from natural gas using steam methane reforming (SMR) and releases carbon dioxide into the atmosphere. Blue hydrogen uses the same SMR process but captures and stores the resulting carbon emissions, making it a lower-carbon option. Green hydrogen is considered the cleanest, as it is created through the electrolysis of water powered exclusively by renewable energy sources like wind or solar.
Gold hydrogen, also referred to as “natural” or “white” hydrogen, stands apart because it is not manufactured. Instead, it is molecular hydrogen gas (\(\text{H}_2\)) that occurs and accumulates naturally in underground geological reservoirs, much like oil or natural gas. The “Gold” designation signifies its perceived value as a clean, naturally occurring energy source. Its existence represents a potential shift away from synthetic production methods toward geological sourcing.
How Gold Hydrogen is Sourced from the Earth
The formation of Gold hydrogen deep within the Earth is attributed to two primary geological processes: serpentinization and radiolysis. Serpentinization is a chemical reaction that occurs when water interacts with iron-rich, ultramafic rocks, such as olivine, under high temperature and pressure conditions. This reaction, often occurring at depths between 10 and 50 kilometers, causes the water molecules to split, releasing free hydrogen gas.
The second major process is radiolysis, where the natural radioactivity from elements like uranium, thorium, and potassium-40 within certain rock formations splits water molecules into hydrogen and oxygen. The resulting hydrogen gas then migrates upward and becomes trapped in porous rock layers beneath an impermeable caprock, forming a geological reservoir. These natural processes are ongoing, suggesting that Gold hydrogen could potentially be a continually renewing resource.
The extraction of Gold hydrogen leverages existing technologies developed by the oil and gas industry. Exploration uses specialized geophysical techniques to locate these subterranean reservoirs. Once a deposit is identified, drilling taps into the reservoir to bring the gas to the surface. Unlike some fossil fuel extraction, Gold hydrogen deposits often do not require well-stimulation techniques like hydraulic fracturing. The primary challenge upon extraction is purification, as the hydrogen gas is frequently mixed with other gases like nitrogen or methane, requiring specialized separation units.
Economic and Environmental Viability
The economic viability of Gold hydrogen is its most compelling advantage, as it bypasses the massive capital expenditures (CAPEX) associated with synthetic production methods. Producing Green hydrogen requires expensive electrolyzers, while Blue hydrogen necessitates costly carbon capture and storage (CCS) equipment. Since Gold hydrogen is simply extracted, the main costs are limited to geological exploration, drilling, and gas processing. Early industry estimates suggest that Gold hydrogen could be produced for less than $1 per kilogram, a cost that is highly competitive with the least expensive fossil fuel-derived hydrogen and aligns with government targets for clean hydrogen. This low potential price point could accelerate the adoption of hydrogen as an energy source across various sectors.
The ability to repurpose existing oil and gas infrastructure and expertise further reduces initial investment and deployment time. From an environmental standpoint, Gold hydrogen has the potential to be a near-zero-carbon energy source because its formation does not rely on fossil fuels or external energy input. The carbon intensity of the final product depends heavily on how any associated gases, such as methane, are managed during the extraction process. Proper handling, including sealing or sequestering these co-produced gases, is paramount to maintaining a low-carbon footprint.
Despite its promise, the industry faces hurdles, most notably the uncertainty of resource scalability and location. While the U.S. Geological Survey estimates there may be as much as five trillion metric tons of natural hydrogen globally, mapping subterranean reservoirs remains difficult, resulting in few proven commercial reserves. Because the industry is nascent, significant research is still needed to understand the long-term sustainability and extraction efficiency of these natural systems, even as pilot projects are underway.