Platform-Level Integration: Co-Locating Hydrogen Production and Storage Offshore
The most structurally impactful way to reduce balance-of-plant (BOP) complexity in offshore wind hydrogen systems is to physically integrate the electrolyzer, storage, and ancillary subsystems directly within the floating structure — eliminating the inter-system piping, power conversion stages, and safety interlocks that proliferate when these functions are distributed across separate modules or connected to shore. According to IRENA, offshore green hydrogen projects face disproportionately high system integration costs compared to onshore equivalents, making BOP reduction a primary engineering priority.
The Korea Marine Equipment Research Institute’s 2023 patent for an independent-type floating offshore wind turbine system with solid-state hydrogen storage exemplifies this multi-functional architecture. The invention uses Power-to-Gas (P2G) technology to produce hydrogen onboard a floating offshore wind structure using surplus renewable power, then stores the hydrogen in a solid hydrogen storage alloy tank positioned in the sub-float hull space. Seawater and waste heat manage the thermal cycles — eliminating the need for a dedicated refrigerant circuit or external heat source generation device. The solid-state tank placement beneath the centre of flotation simultaneously functions as ballast, removing the need for a separate ballast control system. One design decision therefore eliminates three discrete BOP subsystems: the refrigerant loop, the high-pressure compression train, and the ballast management system.
Solid-state hydrogen storage alloy tanks integrated into the sub-float hull of a floating offshore wind structure simultaneously eliminate the refrigerant circuit, high-pressure compression train, and supplementary ballast systems — three distinct BOP subsystems — as demonstrated by the Korea Marine Equipment Research Institute’s 2023 patent filing.
A 2023 patent by inventor 최병렬 describes a pontoon-based floating plant integrating freshwater treatment, seawater treatment, and green hydrogen production cell stacks within a single structural platform, alongside liquefied hydrogen and ammonia production subsystems. The use of a mooring drag anchor and a three-leg vertical pontoon structure accommodates all production functions within a compact, self-contained marine unit — removing the need for separate production vessels or subsea umbilicals linking production stages. Integrating water treatment and electrolysis on the same deck eliminates a full process fluid transport loop.
The Korea Institute of Ocean Science and Technology’s 2021 ammonia platform patent illustrates the deepest level of BOP integration available in the reviewed dataset. This platform combines a water electrolyzer, a solid oxide fuel cell (SOFC), compressed hydrogen storage, an air-based nitrogen production unit, and an ammonia synthesis unit in a single offshore marine platform powered entirely by marine renewable energy. The SOFC subsystem recovers hydrogen from the electrolysis output stream and uses it to supply the thermal and mechanical energy required for the ammonia synthesis loop — replacing what would otherwise require dedicated heaters, compressors with external power feeds, and heat exchangers as standalone BOP items. The SOFC’s waste heat recovery is coupled directly to the Haber-Bosch synthesis loop requirements, eliminating multiple auxiliary energy conversion devices in a single architectural decision.
“By coupling the SOFC’s waste heat recovery directly to the Haber-Bosch synthesis loop requirements, the system eliminates multiple auxiliary energy conversion devices — replacing standalone heaters, compressors, and heat exchangers with a single integrated thermal recovery pathway.”
Modular Electrolyzer Control and Demand-Responsive Operation Cut External Buffer Requirements
Offshore BOP complexity grows substantially when systems must manage the wide dynamic range of wind power input. Systems that cannot modulate electrolyzer output efficiently must rely on large power buffers, dump loads, or extensive energy storage — all significant BOP additions. Modular, demand-responsive control of the electrolyzer stack itself is an alternative architecture that absorbs variability at the process level rather than at the BOP level, as recognised in offshore hydrogen system design guidelines published by the IEA.
A control architecture in which parallel electrolyzer modules are individually managed by a unified control unit. The unit continuously records total product stream demand and each module’s efficiency ratio, then dynamically assigns target operating currents to ready modules. The electrolysis system itself becomes the power-absorbing buffer, removing the need for external energy storage, DC smoothing banks, or dump resistors.
Thyssenkrupp Nucera has filed two active patents — in 2023 and 2025 — establishing a dedicated IP portfolio targeting the elimination of external power buffering BOP in variable renewable-powered electrolysis. The 2025 patent describes a control architecture in which each electrolyzer module receives a module-specific operating current; the control unit continuously records total product stream demand and individual module efficiency ratios, then dynamically assigns target operating currents to ready modules to meet total demand while maximising system efficiency. The multi-year commitment to this approach — confirmed by the companion 2023 filing — signals a strategic position rather than a one-off invention.
Thyssenkrupp Nucera’s 2025 demand-based closed-loop electrochemical plant control patent describes parallel electrolyzer modules individually managed by a control unit that continuously records total product stream demand and individual module efficiency ratios, allowing the electrolysis system itself to absorb power variability and eliminating the need for external energy storage systems, DC smoothing banks, or dump resistors.
The wind-hydrogen coupling system described in a 2022 Chinese patent from State Grid Zhejiang/Ningbo uses a direct-drive permanent magnet wind generation system connected through a multi-interleaved buck converter (MIBC) structure to multiple PEM electrolyzer stacks. A chain distribution strategy allocates wind curtailment power across PEM electrolyzer single stacks in real time, ensuring stable and efficient electrolyzer operation without requiring a central AC bus, frequency regulation equipment, or large intermediate battery banks. By converting the high-voltage wind output directly to stable low-voltage DC input for the electrolyzers through the MIBC stage, the architecture removes grid-interface transformers, rectifiers, and associated protection relay trains from the BOP — a significant mass and volume reduction for an offshore installation.
A multi-interleaved buck converter (MIBC) architecture connecting direct-drive permanent magnet wind generators directly to PEM electrolyzer stacks — as described in a 2022 patent from State Grid Zhejiang/Ningbo — removes AC bus infrastructure, grid-interface transformers, rectifiers, and frequency regulation equipment from the offshore balance-of-plant.
Kellogg Brown & Root’s 2025 patent addresses stabilisation of hydrogen flow to downstream processes under variable renewable power availability. The method uses hydrogen density and pressure profiles within a storage unit across time intervals to determine optimal combinations of direct hydrogen flow and buffered storage flow, avoiding oversized compression and storage assets that would otherwise be needed to guarantee constant downstream supply pressure. Reducing the installed hydrogen storage size and compression duty is a direct BOP simplification — fewer vessels, smaller compressors, and reduced instrumentation scope.
Explore the full patent landscape for offshore wind hydrogen BOP reduction in PatSnap Eureka.
Explore Patent Data in PatSnap Eureka →Ammonia and Hydrogen Carriers Remove the Most Weight-Intensive BOP from the Offshore Export Chain
One of the most significant BOP burdens in offshore hydrogen systems is the hydrogen export chain — compression to high pressure, cryogenic liquefaction, or pipeline infrastructure. Converting hydrogen to ammonia at the point of offshore production substantially reduces the compression and containment equipment required for offshore storage and ship-based export, a pathway that the IEA and IRENA have identified as commercially viable for long-distance green hydrogen trade.
Ammonia can be stored as a liquid at 8–10 bar at ambient temperature, compared to compressed hydrogen requiring 350–700 bar or liquefied hydrogen requiring storage at −253°C. Converting offshore wind-derived hydrogen to ammonia at the production site eliminates cryogenic cooling trains and ultra-high-pressure vessel systems — both major balance-of-plant elements.
Siemens Aktiengesellschaft has filed multiple overlapping patents in the Korean jurisdiction addressing this strategy. Both a 2018 and a 2019 filing describe converting wind-derived hydrogen and nitrogen into ammonia for storage and subsequent gas turbine combustion. From a BOP perspective, ammonia storage operates at modest pressures of 8–10 bar at ambient temperature compared to compressed hydrogen at 350–700 bar or liquefied hydrogen at −253°C — eliminating the cryogenic cooling trains and high-pressure vessel systems that represent major BOP elements. The Siemens approach further integrates a hydrogen injection subsystem that extracts hydrogen from an upstream system stage and blends it with the ammonia gas turbine feed, improving combustion characteristics without additional fuel processing equipment.
Gentech E&C’s 2025 patent describes an ammonia production system where high-temperature, high-pressure steam generated in the heat exchanger of the ammonia synthesis loop is recycled to supply energy back to the compressor stage. This internal waste-heat recovery loop reduces external utility demand — steam generation, cooling water circuits, and auxiliary power feeds — that would otherwise constitute BOP equipment. By integrating energy recovery within the reactor-compressor-heat exchanger train, the system reduces the number of utility service connections required, a principle endorsed by process integration frameworks documented by ISO for industrial energy efficiency.
Ammonia storage at 8–10 bar (ambient temperature) versus compressed hydrogen at 350–700 bar represents a pressure ratio of up to 87.5:1. This difference eliminates the need for ultra-high-pressure vessel certification, multi-stage compression trains, and associated safety shutdown systems — each a distinct BOP item — on the offshore platform.
The Korea Institute of Ocean Science and Technology’s ammonia platform similarly centralises nitrogen air separation, hydrogen storage, and ammonia synthesis within one marine structure, avoiding the need for nitrogen supply ships, high-pressure hydrogen transport pipelines, or separate synthesis plant vessels — each of which would require its own BOP infrastructure including instrumentation, safety shutdown systems, and utility supplies.
Topside Utility Integration and Standardised Module Consolidation Shrink Structural Load and Control Overhead
Beyond the primary hydrogen process, BOP complexity in offshore plants is heavily driven by the proliferation of independent utility subsystems — hydraulic power units, nitrogen generation, instrument air, fire and gas detection, chemical injection, and their associated control panels. Consolidating these into integrated utility modules is a parallel, hardware-level simplification strategy that reduces module count, interconnection piping, structural support requirements, and the number of independent control systems.
Sejin Heavy Industries’ 2020 patent for an integrated utility module for offshore plant topsides directly demonstrates this approach. By combining the hydraulic power unit (HPU) and nitrogen generation system (N2G) — previously installed as separate independent modules — into a single integrated utility module on a common baseplate with a shared integrated control panel, the invention reduces module count, interconnection piping, structural support requirements, and the number of independent control systems. This principle is directly transferable to offshore hydrogen platforms, where utility modules for electrolyzer cooling, gas detection, instrument air, and water treatment represent a substantial fraction of total BOP complexity and weight.
Ulsan National University’s 2023 patent illustrates the control-layer analog of physical consolidation. Rather than controlling each BOP component individually with separate PID controllers in a single-input, single-output (SISO) architecture — the prior art approach — the invention employs a hybrid adaptive MPPT-based multiple-input, multiple-output (MIMO) controller that simultaneously optimises the oxygen excess ratio and other fuel cell BOP parameters based on measured system-wide state variables. Applied to offshore electrolyzer BOP control, this principle delivers fewer control loops, unified optimisation, and reduced sensor and actuator count compared to component-by-component approaches.
A 2024 patent from State Grid Fujian Economic Research Institute provides a complementary electrical BOP simplification: by optimising submarine cable topology using a full life-cycle cost model that encompasses reliability and cable energy losses, the number of cable strings, junction boxes, and switching stations in the offshore power collection system can be minimised. Reducing the electrical BOP between wind turbines and the hydrogen production platform directly reduces the number of subsea components requiring maintenance, protection, and control.
Map the full IP landscape for offshore hydrogen BOP innovation with PatSnap Eureka’s AI-powered patent analysis.
Analyse Patents with PatSnap Eureka →Key Players and Innovation Trends: Korean Institutions Lead, Global Engineering Firms Establish Strategic Positions
The patent dataset of approximately 60 records spanning Korean, Japanese, and Chinese jurisdictions reveals a concentrated cluster of Korean institutions driving the most directly relevant innovations for offshore wind-powered hydrogen BOP reduction, with global engineering and industrial firms establishing parallel strategic positions.
- Korea Marine Equipment Research Institute (KMERI): Focuses on eliminating refrigerant and heat source subsystems from the floating hydrogen production BOP through alloy-based solid storage integrated into the hull structure (2023).
- Korea Institute of Ocean Science and Technology (KIOST): The ammonia production platform patent (2021) represents one of the most complete visions of integrated offshore hydrogen-to-ammonia BOP simplification, combining electrolysis, SOFC-based thermal recovery, nitrogen production, and ammonia synthesis on a single marine platform.
- Thyssenkrupp Nucera: Two active patents (2023, 2025) for demand-based modular electrolyzer control constitute a dedicated IP portfolio targeting the elimination of external power buffering BOP in variable renewable-powered electrolysis.
- Siemens Aktiengesellschaft: Multiple parallel Korean filings covering wind-to-ammonia conversion (2018–2019) establish a consistent strategic position in using ammonia as the BOP-simplifying hydrogen carrier for offshore and grid-balancing applications.
- Sejin Heavy Industries: The integrated utility module patent (2020) represents a hardware-focused offshore BOP consolidation approach relevant to any offshore process plant.
- Ulsan National University: Active in both floating offshore wind platform design and MIMO-based BOP control strategies, with patents in 2020 and 2023 respectively.
- Incheon University: A 2018 decision-making method for wind-powered hydrogen supply system design provides a systems-level optimisation framework for minimising total daily cost, which when applied to offshore contexts inherently drives reduction of BOP capital expenditure.