Glossary

Anion Exchange Membrane electrolysis is an emerging technology that combines advantages of both alkaline and PEM systems. AEM electrolyzers use a solid polymer membrane that conducts hydroxide ions (OH⁻) rather than protons. This allows the use of non-precious metal catalysts (like alkaline systems) while maintaining the compact, pressurized cell design of PEM systems. AEM technology is less mature than AEL or PEM but is attracting significant R&D investment due to its potential for low-cost, high-performance hydrogen production.

The most mature and widely deployed water electrolysis technology. Alkaline electrolyzers use a liquid potassium hydroxide (KOH) electrolyte, typically at 25–30% concentration, and operate at temperatures of 60–90°C and pressures up to 30 bar. They use non-precious metal catalysts (nickel-based) and a porous diaphragm separator. AEL offers low capital costs, long operational lifetimes (60,000–90,000+ hours), and proven large-scale deployment. Limitations include lower current density, slower dynamic response to variable power input, and minimum load requirements of typically 10–40%.

A well-established hydrogen production technology that operates using a potassium hydroxide (KOH) electrolyte at 30–80°C. AWE features low-cost materials, long system lifespans, and proven large-scale deployment. Key challenges include moderate current densities, gas crossover between electrodes, and sensitivity to CO₂ contamination of the electrolyte. AWE is functionally equivalent to AEL (alkaline electrolysis) and the terms are often used interchangeably.

A hydrogen-derived compound (NH₃) produced using the Haber-Bosch process, which combines hydrogen and nitrogen under high pressure and temperature. Ammonia is one of the world's most widely produced chemicals, primarily used as a nitrogen-based fertilizer feedstock. Increasingly, ammonia is also recognized as a hydrogen carrier for long-distance energy transport (it is easier to liquefy and transport than hydrogen), a potential zero-carbon fuel for maritime shipping, and a feedstock for power generation. Green ammonia, produced from renewable hydrogen, is a key target for decarbonizing global agriculture and shipping.

The company providing ammonia synthesis technology and process design for a project. Major ammonia technology licensors include Haldor Topsøe, KBR, ThyssenKrupp Industrial Solutions, Casale, and Stamicarbon. Technology selection determines synthesis loop design, energy efficiency, and integration with the upstream hydrogen supply.

An energy scenario framework developed by the International Energy Agency (IEA) that models the impact of countries fully implementing all of their declared climate commitments, including Nationally Determined Contributions (NDCs) and net-zero targets. APS serves as a benchmark between current policy trajectories and the more ambitious Net Zero Emissions 2050 scenario.

The positively charged electrode in an electrolysis cell where oxidation occurs. In water electrolysis, oxygen gas is produced at the anode as water molecules lose electrons. The anode environment is highly oxidative, requiring corrosion-resistant materials — iridium oxide catalysts in PEM systems, and nickel-based materials in alkaline systems.

Asia Pacific — a geographic market segmentation covering Asia and Australasia, typically excluding the Middle East. In hydrogen market analysis, APAC is a critical region due to major hydrogen demand centers (Japan, South Korea, China) and export-oriented green hydrogen producers (Australia, India).

Application Programming Interface — a standardized set of protocols and specifications that allows different software systems to communicate and exchange data. In the context of Delphi Data Labs, the Serapis API provides programmatic access to structured infrastructure market data, enabling clients to integrate project, company, and supply chain data directly into their own analytics platforms, business intelligence tools, or custom applications.

The classification of a project based on its primary function in the value chain. Delphi Data Labs classifies assets into categories including: H2 Production & Utilization, H2 Export, H2 Import, H2 Storage, H2 Power Generation, Refinery/Petrochemical, Steel Plant, Green Refinery, Hydrogen Pipeline, Equipment Manufacturing Plant, and others. Asset type determines how the project is contextualized within the broader infrastructure landscape.

A hydrogen production process that combines partial oxidation and steam reforming of natural gas in a single reactor. ATR uses oxygen and steam to convert methane into hydrogen and CO₂. Compared to SMR, ATR produces a more concentrated CO₂ stream, making carbon capture easier and more cost-effective. It is increasingly favored for blue hydrogen projects targeting high capture rates (>95%).

A volumetric flow rate metric expressing production capacity in barrels of product per day. Used primarily for projects producing hydrogen-derived liquid fuels, synthetic hydrocarbons, or biomass-derived liquids. One barrel equals approximately 159 liters. This metric allows direct comparison with conventional petroleum refining capacity.

Energy storage systems using electrochemical batteries (primarily lithium-ion) to store and discharge electricity. Battery storage capacity is measured in MW (power rating — how quickly energy can be discharged) and MWh (energy capacity — total stored energy). In hydrogen projects, battery storage is used to stabilize renewable power supply to electrolyzers, compensate for short-term grid fluctuations, and optimize electrolyzer utilization by buffering variable renewable generation.

A flag indicating whether a hydrogen project serves as a comparative reference or industry benchmark. Benchmarking projects are typically notable for their scale, technology choice, cost structure, or milestone achievements, and are used by analysts and investors as reference points for evaluating other projects in the pipeline.

Hydrogen uses in the beverage industry, including carbonation processes (where CO₂ co-produced with hydrogen may be utilized), packaging, and clean energy for brewing and bottling operations. Hydrogen can serve as an energy source for production facilities and provide an inert gas atmosphere for product storage.

Renewable fuels produced from biological feedstocks (crops, algae, agricultural residues, waste oils), with hydrogen playing an important role in upgrading and refining processes. Hydrotreatment uses hydrogen to remove impurities (sulfur, nitrogen, oxygen) from bio-based feedstocks, improving fuel quality and compatibility with existing engines and infrastructure. Hydrogen is also a critical input for hydrotreated vegetable oil (HVO) and hydroprocessed esters and fatty acids (HEFA) production.

A thermochemical conversion technology that converts organic material of biological origin (e.g., agricultural residues, forestry waste, municipal solid waste) into a synthesis gas (syngas) containing hydrogen, carbon monoxide, and other gases. The syngas can be further processed to extract pure hydrogen. When combined with carbon capture, biomass-based hydrogen production can achieve negative emissions (BECCS pathway).

CO₂ capture from the combustion or processing of biomass feedstocks, creating the potential for net-negative emissions (bioenergy with carbon capture and storage, or BECCS). Since the biomass absorbed CO₂ from the atmosphere during growth, capturing and permanently storing the CO₂ released during its conversion effectively removes carbon from the atmosphere. BECCS is considered a key negative emissions technology in many climate scenarios.

Structural components in electrolysis stacks that conduct electrical current between adjacent cells, distribute reactant water and product gases, manage heat, and provide mechanical support. In PEM electrolyzers, bipolar plates are typically made from titanium or coated stainless steel to resist the highly oxidative anode environment. Material choice, surface coating, and flow field design directly affect stack performance, durability, and cost.

Key structural components in fuel cell stacks that serve as current collectors, distribute reactant gases (hydrogen and air) across the electrode surfaces, manage heat dissipation, and provide mechanical support. Fuel cell bipolar plates are typically made from graphite, metal alloys (stainless steel, titanium), or composite materials, and must be corrosion-resistant with high electrical conductivity. Flow field design (serpentine, interdigitated, or pin-type patterns) directly affects gas distribution, water management, and cell performance.

Hydrogen produced from natural gas via steam methane reforming (SMR) or autothermal reforming (ATR), with CO₂ emissions captured and permanently stored underground through carbon capture and storage (CCS). Blue hydrogen is positioned as a transitional solution that leverages existing natural gas infrastructure while significantly reducing the carbon footprint of hydrogen production. Capture rates typically range from 85% to 95% of CO₂ emissions, depending on the technology and configuration.

Competitive procurement mechanisms where energy capacity or production volume is awarded through bidding processes. In the hydrogen sector, capacity auctions are being implemented by several governments (Germany, EU Hydrogen Bank, India) to allocate subsidies for green hydrogen production. Producers bid the subsidy level they require (e.g., EUR per kg H₂), and the lowest bids are awarded contracts. The T-4 auction (held four years before delivery) and T-1 auction (one year before delivery) are common structures in electricity capacity markets.

A financial metric that evaluates a company's ability to fund capital expenditures from its operational cash flow. Calculated as operating cash flow divided by capital expenditures. A ratio above 1.0 indicates the company generates sufficient cash to fund its investment program without external financing. This metric is particularly relevant for assessing the financial strength of capital-intensive electrolyzer manufacturers, project developers, and industrial companies transitioning to hydrogen.

The systematic measurement, quantification, and reporting of greenhouse gas (GHG) emissions from an organization, product, or activity over a defined period. Carbon accounting follows standards such as the GHG Protocol, ISO 14064, and increasingly the EU Corporate Sustainability Reporting Directive (CSRD). Accurate carbon accounting is essential for tracking the emissions impact of hydrogen adoption and verifying claims of carbon-neutral or low-carbon production.

The process of capturing carbon dioxide (CO₂) emissions from industrial sources or power generation, transporting it (typically via pipeline or ship), and injecting it into deep geological formations for permanent storage. Storage sites include depleted oil and gas reservoirs, deep saline aquifer formations, and basalt formations. CCS is essential for blue hydrogen production and for decarbonizing hard-to-abate industrial sectors like cement and steel. While CCS can significantly reduce atmospheric CO₂ releases, it requires substantial energy input (increasing the energy consumption of the source facility by 10–40%) and permanent, leak-proof storage integrity.

An extension of CCS that adds the option of utilizing captured CO₂ as a feedstock for commercial products or processes rather than (or in addition to) permanent geological storage. Utilization pathways include enhanced oil recovery (EOR), production of synthetic fuels, chemicals (methanol, urea), building materials (carbonated concrete), and carbonated beverages. CCUS broadens the economic case for carbon capture by creating revenue streams from CO₂, though the permanence of carbon sequestration varies significantly across utilization pathways.

A policy mechanism that guarantees a fixed carbon price to industrial emitters investing in low-carbon technologies (including hydrogen-based production). The government pays the difference between the guaranteed strike price and the actual EU ETS carbon price when the market price is lower. If the market price exceeds the strike price, the company pays back the difference. CCfDs de-risk low-carbon investment decisions by providing price certainty during the transition period when carbon prices may not yet justify the investment alone.

A colorless, odorless gas produced by the incomplete combustion of carbon-containing fuels. In the context of hydrogen and chemical production, carbon monoxide is a key component of synthesis gas (syngas), which is produced by steam methane reforming, autothermal reforming, or gasification. CO is converted to additional hydrogen via the water-gas shift reaction, or used as a building block for Fischer-Tropsch synthesis of liquid fuels and chemicals.

A physical product with verified and certified greenhouse gas emissions data covering its entire lifecycle — from raw material extraction through production, transportation, and end-use. Carbon-accounted hydrogen or ammonia allows buyers to make procurement decisions based on verified emissions intensity, supporting corporate decarbonization targets and regulatory compliance. Certification schemes are being developed by organizations including CertifHy, TÜV SÜD, and the International Partnership for Hydrogen and Fuel Cells in the Economy (IPHE).

A material that accelerates the electrochemical reactions in an electrolyzer (hydrogen evolution at the cathode and oxygen evolution at the anode) without being consumed. In PEM electrolyzers, noble metals are used: platinum for the cathode (HER) and iridium oxide for the anode (OER). Alkaline systems use lower-cost nickel-based catalysts. Reducing noble metal loading and developing earth-abundant catalyst alternatives is a major focus of electrolyzer R&D.