Understanding Hydrogen Colors

Recently, there has been a surge of interest regarding a new category of hydrogen—white hydrogen. However, given my color blindness, I find the entire spectrum of hydrogen colors rather amusing; it seems we now have 23 shades beyond what’s necessary. In reality, hydrogen can be classified into two main types: low-carbon and high-carbon. If we must categorize them by color, let's stick with green and black. The founders of the Hydrogen Science Coalition, who possess extensive expertise in the field, debated the appropriate carbon intensity threshold for hydrogen production, ultimately settling on a target of one kilogram of CO2 or equivalent (CO2e) for every kilogram of hydrogen produced. This standard suggests that any production resulting in one kilogram of CO2e or less qualifies as green, while anything beyond that is black. I can agree with that distinction; at least it’s simpler.

The focus should be on the full lifecycle carbon intensity of hydrogen rather than the methods or raw materials involved in its production. The multitude of color classifications stems from various production methods, which complicates the conversation even for those without color vision deficiencies, leading to inconsistent definitions.

Section 1.1 The Carbon Intensity Debate

To understand what a carbon intensity of one kilogram per kilogram means, consider that it requires approximately 55 to 60 kWh of electricity to produce a kilogram of hydrogen through electrolysis, a figure unlikely to decrease due to physical constraints. This process does not follow Wright's law, which suggests that increasing production leads to lower costs per unit. While economies of scale exist in hydrogen production, they primarily come from creating larger plants, which remain capital-intensive.

Using the one kilogram of CO2e benchmark, each kWh of electricity effectively carries a carbon burden of roughly 18 grams of CO2e. This metric works well in regions like British Columbia, Canada, where the grid electricity has a carbon intensity of 12.9 grams CO2e per kWh. Vermont enjoys even lower CO2e emissions, and thus could produce green hydrogen by this definition using its grid electricity, whereas Washington State falls short at around 84 grams CO2e/kWh. In Europe, Sweden is the closest contender but still exceeds the cutoff at 45 grams CO2e/kWh.

Comparatively, I would prefer hydrogen from the grid in Vermont or Sweden over that derived from natural gas, which typically results in carbon emissions of around 10 kilograms of CO2e per kilogram of hydrogen. Even blue hydrogen, a more 'sustainable' option, would only reduce emissions to between 2 and 4 kilograms of CO2e per kilogram, necessitating rigorous management of methane emissions in the process.

Subsection 1.1.1 The Lobbying Landscape

The discourse surrounding what qualifies as 'green' hydrogen is heavily influenced by lobbying. For instance, the European Union's criteria for renewable hydrogen set the acceptable carbon intensity at 3.38 kilograms of CO2e per kilogram of hydrogen— a threshold that the Hydrogen Science Coalition argues is inadequate. This discrepancy raises concerns, as it does not align with the urgent climate targets we aim to achieve, especially when the EU's current obsession with hydrogen as an energy carrier seems misguided.

Chapter 2 Title: The Economics of Hydrogen Production

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In terms of costs, producing hydrogen via electrolysis represents a balancing act between capital expenditures (capex) and operational expenditures (opex). High capex necessitates high utilization rates, which in turn requires reliable electricity sources available over 60% of the year. Unfortunately, relying solely on a single wind or solar farm does not guarantee this level of availability.

The majority of the components in an industrial-scale electrolysis facility are standardized industrial parts, leaving little room for significant cost reductions aside from the electrolyzer itself. Consequently, we shouldn’t expect electrolysis plant costs to drop dramatically over time.

On the flip side, we have a reliable source of firmed electricity: the grid. Connecting large demand sources to the grid is more cost-effective than constructing remote wind or solar farms. However, using grid electricity incurs utility administration costs, raising operational expenses.

In conclusion, my perspective is that most hydrogen production facilities should ideally be located at existing demand points, particularly ammonia production facilities, and powered by grid electricity. While consolidating massive electrolysis plants at new demand centers may make sense in some cases, the scale of current proposals driven by hype and unrealistic demand forecasts is largely misguided.

White Hydrogen: A Misguided Hope

The recent excitement over white hydrogen—natural deposits of gaseous hydrogen—has drawn attention but remains largely unfounded. Claims of unlimited hydrogen reserves are prevalent, particularly following a notable announcement from France’s Lorraine region, which estimated a deposit of 46 million tons of hydrogen. While impressive, this amount only meets about 40% of the annual global hydrogen demand of 120 million tons.

Moreover, the discoverability of these deposits raises several questions. For instance, one site in Spain has approximately 1.2 million tons of hydrogen, which is less than 1% of yearly demand and is mixed with other gases. Extraction methods, costs, and potential environmental impacts remain largely unclear, making it difficult to assess the viability of these resources.

The French site’s hydrogen is trapped in an underground aquifer, with concentrations varying significantly with depth. The extraction process’s costs, potential gas leaks, and other unanswered questions complicate the narrative further.

In summary, while some hydrogen resources exist underground, they are often not close to demand centers, and we lack clarity on extraction costs. While there’s potential for decarbonization in some hydrogen usage, the notion that white hydrogen can significantly support a hydrogen economy is overly optimistic.

Ultimately, the Lorraine find merits exploration, especially considering its potential revenue against the backdrop of $1–3 per kilogram black hydrogen from natural gas. However, it is crucial not to divert hydrogen resources toward transportation or heating without careful consideration.