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Enum: HydrogenType

Color-coded classification of hydrogen based on production method and carbon intensity. This informal industry taxonomy differentiates hydrogen by its carbon footprint and energy source.

URI: valuesets:HydrogenType

Permissible Values

Value Meaning Description
GREEN_HYDROGEN None Hydrogen produced via electrolysis powered by renewable energy sources (solar...
BLUE_HYDROGEN None Hydrogen produced from natural gas via steam methane reforming (SMR) with car...
GREY_HYDROGEN None Hydrogen produced from natural gas via steam methane reforming without carbon...
BROWN_HYDROGEN None Hydrogen produced from brown coal (lignite) gasification without carbon captu...
BLACK_HYDROGEN None Hydrogen produced from black coal (bituminous) gasification without carbon ca...
PINK_HYDROGEN None Hydrogen produced via electrolysis powered by nuclear energy
TURQUOISE_HYDROGEN None Hydrogen produced via methane pyrolysis, producing solid carbon instead of CO...
WHITE_HYDROGEN None Naturally occurring geological hydrogen found in underground deposits
YELLOW_HYDROGEN None Hydrogen produced via electrolysis powered by solar energy specifically
ORANGE_HYDROGEN None Hydrogen produced from plastic waste gasification or pyrolysis

Slots

Name Description
hydrogen_type Type of hydrogen classified by production method and carbon intensity

See Also

Identifier and Mapping Information

Schema Source

  • from schema: https://w3id.org/linkml/valuesets

LinkML Source

name: HydrogenType
instantiates:
- valuesets_meta:ValueSetEnumDefinition
description: Color-coded classification of hydrogen based on production method and
  carbon intensity. This informal industry taxonomy differentiates hydrogen by its
  carbon footprint and energy source.
title: Hydrogen Type (Color Classification)
from_schema: https://w3id.org/linkml/valuesets
see_also:
- https://www.energy.gov/eere/fuelcells/hydrogen-production
- https://www.nationalgrid.com/stories/energy-explained/hydrogen-colour-spectrum
contributors:
- orcid:0000-0002-6601-2165
- https://github.com/anthropics/claude-code
status: DRAFT
rank: 1000
permissible_values:
  GREEN_HYDROGEN:
    text: GREEN_HYDROGEN
    description: Hydrogen produced via electrolysis powered by renewable energy sources
      (solar, wind, hydro). Zero carbon emissions during production.
    annotations:
      production_method:
        tag: production_method
        value: electrolysis
      energy_source:
        tag: energy_source
        value: renewable
      carbon_intensity:
        tag: carbon_intensity
        value: zero
    title: Green Hydrogen
    aliases:
    - Renewable Hydrogen
    broad_mappings:
    - sweet:matrElement/Hydrogen
  BLUE_HYDROGEN:
    text: BLUE_HYDROGEN
    description: Hydrogen produced from natural gas via steam methane reforming (SMR)
      with carbon capture and storage (CCS). Low carbon intensity.
    annotations:
      production_method:
        tag: production_method
        value: steam_methane_reforming
      energy_source:
        tag: energy_source
        value: natural_gas
      carbon_intensity:
        tag: carbon_intensity
        value: low
      requires_ccs:
        tag: requires_ccs
        value: true
    title: Blue Hydrogen
  GREY_HYDROGEN:
    text: GREY_HYDROGEN
    description: Hydrogen produced from natural gas via steam methane reforming without
      carbon capture. Most common production method currently.
    annotations:
      production_method:
        tag: production_method
        value: steam_methane_reforming
      energy_source:
        tag: energy_source
        value: natural_gas
      carbon_intensity:
        tag: carbon_intensity
        value: high
      co2_per_kg_h2:
        tag: co2_per_kg_h2
        value: 9-12
    title: Grey Hydrogen
    aliases:
    - Gray Hydrogen
  BROWN_HYDROGEN:
    text: BROWN_HYDROGEN
    description: Hydrogen produced from brown coal (lignite) gasification without
      carbon capture. High carbon intensity.
    annotations:
      production_method:
        tag: production_method
        value: coal_gasification
      energy_source:
        tag: energy_source
        value: lignite
      carbon_intensity:
        tag: carbon_intensity
        value: very_high
    title: Brown Hydrogen
  BLACK_HYDROGEN:
    text: BLACK_HYDROGEN
    description: Hydrogen produced from black coal (bituminous) gasification without
      carbon capture. High carbon intensity.
    annotations:
      production_method:
        tag: production_method
        value: coal_gasification
      energy_source:
        tag: energy_source
        value: bituminous_coal
      carbon_intensity:
        tag: carbon_intensity
        value: very_high
    title: Black Hydrogen
  PINK_HYDROGEN:
    text: PINK_HYDROGEN
    description: Hydrogen produced via electrolysis powered by nuclear energy. Zero
      carbon emissions during production.
    annotations:
      production_method:
        tag: production_method
        value: electrolysis
      energy_source:
        tag: energy_source
        value: nuclear
      carbon_intensity:
        tag: carbon_intensity
        value: zero
    title: Pink Hydrogen
    aliases:
    - Purple Hydrogen
    - Red Hydrogen
  TURQUOISE_HYDROGEN:
    text: TURQUOISE_HYDROGEN
    description: Hydrogen produced via methane pyrolysis, producing solid carbon instead
      of CO2. Lower carbon intensity than grey hydrogen.
    annotations:
      production_method:
        tag: production_method
        value: methane_pyrolysis
      energy_source:
        tag: energy_source
        value: natural_gas
      carbon_intensity:
        tag: carbon_intensity
        value: low
      byproduct:
        tag: byproduct
        value: solid_carbon
    title: Turquoise Hydrogen
  WHITE_HYDROGEN:
    text: WHITE_HYDROGEN
    description: Naturally occurring geological hydrogen found in underground deposits.
      Zero production emissions.
    annotations:
      production_method:
        tag: production_method
        value: geological_extraction
      energy_source:
        tag: energy_source
        value: natural
      carbon_intensity:
        tag: carbon_intensity
        value: zero
    title: White Hydrogen
    aliases:
    - Natural Hydrogen
    - Geological Hydrogen
    - Gold Hydrogen
  YELLOW_HYDROGEN:
    text: YELLOW_HYDROGEN
    description: Hydrogen produced via electrolysis powered by solar energy specifically.
      A subset of green hydrogen.
    annotations:
      production_method:
        tag: production_method
        value: electrolysis
      energy_source:
        tag: energy_source
        value: solar
      carbon_intensity:
        tag: carbon_intensity
        value: zero
    title: Yellow Hydrogen
  ORANGE_HYDROGEN:
    text: ORANGE_HYDROGEN
    description: Hydrogen produced from plastic waste gasification or pyrolysis. Emerging
      technology addressing both energy and waste challenges.
    annotations:
      production_method:
        tag: production_method
        value: waste_gasification
      energy_source:
        tag: energy_source
        value: plastic_waste
      carbon_intensity:
        tag: carbon_intensity
        value: varies
    title: Orange Hydrogen