The industrial science of offshore wind
A doctoral research project at NTNU quantifying the trade between standardization and structural over-design in offshore wind substructures — bottom-fixed and floating — at the FEED stage.
Standardization is the path to commercial-scale offshore wind. It comes at a price.
The substructure is the cost and industrial pivot of an offshore wind project. It accounts for roughly 13.5% of capital expenditure for bottom-fixed installations and approximately 24.4% for floating — nearly three times higher. Material and mass are the most volatile cost driver within that share.
Standardization — holding one design common across a portfolio of sites — is how fabrication yards achieve serial production, learning curves, and lower unit cost. But a common design must be sized for the most demanding site in the family. Every other site carries excess material: an over-design penalty. Standardization buys a manufacturing benefit at the price of structural over-design.
At the front-end engineering design (FEED) stage — where this trade is effectively locked in — it is currently made by judgment rather than computation. The industry already agrees it must narrow a pool of over one hundred competing substructure concepts. No published, reproducible model couples both sides of this trade for offshore wind substructures.
The research builds that model: a coupling framework that produces a Pareto front of over-design penalty versus manufacturing benefit, so the standardize-or-customize decision becomes a location on a curve — chosen for a given site spread, order volume, and fabrication setup — rather than a judgment call.
24.4%
of floating CAPEX in substructure & foundation
2.8×
floating vs. bottom-fixed substructure cost
100+
competing floating substructure concepts globally
Six interconnected research threads
The program spans structural engineering, production management, and optimization. Each theme is active — not archival.
Offshore Wind Substructure Design & Optimization
Parametric sizing of monopiles, jackets, semi-submersibles, spars, and tension-leg concepts across metocean and site classes. Physics-compliant and material-agnostic, with steel as the primary path and concrete and hybrid variants as bounded extensions.
Standardization vs. Over-Design
Standardizing a substructure across a site family forces excess material mass at every site that falls short of the worst case. Quantifying that over-design penalty — in mass, cost, and embodied carbon — is the central structural research question.
Design-for-Industrialization
Applying Design-for-X methods — manufacturability, assembly, installation, logistics, supply-chain readiness, O&M, and circularity — to load-bearing offshore wind structures. A domain where DfX theory is mature but application to structural components is absent from the literature.
FEED-Stage Decision Support
Front-end engineering design locks in manufacturability, port fit, installation sequence, and local content before most cost-reduction levers are still open. The research targets this stage specifically — making the standardize-or-customize call computable rather than a judgment.
Configure-to-Order Product Families
Reframing substructures from engineer-to-order one-offs to configurable product families. One common platform tuned per site or site cluster. The research extends product-family and commonality theory — mature in discrete manufacturing — into the project-production domain.
Production Economics & Supply Chain Readiness
Serial fabrication, learning curves, yard and port readiness, and balance-of-system cost — translated from programme-level models into a layer that scales with substructure geometry and order volume. This is the manufacturing-benefit side of the Pareto front.
From one-off engineering to configurable product families
Today an offshore wind substructure is engineered as a one-off: a bespoke design for a specific site, optimized for that site's metocean conditions, and produced in low volume with frequent design change. The result is near-optimal mass per structure, but one-off fabrication economics with no learning, no supply-chain stability, and high unit cost.
The research reframes this. A substructure family is treated as a configurable product platform — one common design configured per site or site cluster. The question stops being how to engineer it and becomes how far to standardize it.
Bottom-fixed substructures offer a validation anchor: the market iterated its way to a de facto standard — the monopile now accounts for roughly 80% of installed bottom-fixed foundations — at a mature substructure cost of around 788 USD/kW. That convergence took fifteen years and a price signal to accomplish. Floating wind has no such time. The framework compresses that market-selection logic into a reproducible computation.
The approach is design science: the central output is a useful artefact — a coupling framework — that must be both rigorously built and demonstrably useful. Three computational layers are assembled: a material-agnostic structural engine that sizes physics-compliant substructures and outputs the over-design penalty; a production-economics layer that translates geometry into fabrication and balance-of-system cost; and a multi-objective optimizer that searches the design family and returns the Pareto front.
The standardize-or-customize Pareto front
No single design wins on both axes. The Pareto frontier is the menu of best compromises.
The standardize-or-customize decision becomes a location on this curve — chosen for a given site spread, order volume, and fabrication setup.
Structural Engine
Material-agnostic parametric sizing across metocean classes. Outputs over-design penalty as extra material mass. Built on WISDEM, RAFT, OpenFAST, MoorPy.
Production Economics
Translates geometry into serial-fabrication and balance-of-system cost. Captures the manufacturing benefit of standardization. Calibrated with ORBIT and NREL cost models.
Multi-Objective Search
Trades penalty against benefit across the design family using NSGA-II via pymoo and OpenMDAO. Returns the standardize-or-customize Pareto front.
What exists, what is in progress, what is planned
A clear distinction between formalized outputs and active exploratory work.
Papers
Design-for-X and the standardize-or-customize trade-off in offshore wind substructure industrialization
In preparationA systematic, multivocal literature review integrating the DfX, product-family and commonality, substructure-optimization, and production-economics streams. Establishes the coupling gap and the decision-criteria set for FEED-stage standardization.
Target: IJPE · Submission window Q4 2026
Material-agnostic structural engine and the over-design penalty across metocean classes
In developmentA parametric structural engine that sizes physics-compliant substructures — monopile, jacket, semi-submersible — across metocean and site classes. Reports the over-design penalty as extra material mass from holding a design common. Validated against open IEA 15 MW reference structures.
Target: Wind Energy Science / Applied Energy · Q2–Q3 2027
Coupling framework: over-design penalty versus manufacturing benefit as a Pareto front
PlannedThe structural engine coupled to a production-economics layer via multi-objective optimization. Generates the standardize-or-customize Pareto front. Includes a retrodiction test: does the framework reproduce the monopile convergence the bottom-fixed market found over 15 years?
Target: IJPE / Applied Energy · Q4 2027–Q1 2028
Evaluation and material extension: concrete and hybrid variants on a representative case
PlannedFramework evaluation through structured expert assessment, sensitivity analysis, and comparison with known designs. Extends the engine to concrete and hybrid as mass and cost proxies, treating material and substructure type as decision variables.
Target: IJPE / Production Planning & Control · Q2–Q3 2028
Demonstrators & Prototypes
Material-agnostic parametric structural engine
In developmentA Python-based computational engine for sizing offshore wind substructures across site and metocean classes. Built on open tools: WISDEM, RAFT, OpenFAST, MoorPy, OpenMDAO. Adds the novel concrete and hybrid sizing and cost layer, and the production-economics coupling, that the open stack does not provide.
Open-source stack · IEA 15 MW reference validation target
Standardize-or-customize Pareto front visualizer
ConceptAn interactive visualization of the over-design penalty versus manufacturing benefit trade-off surface, parameterized by site spread, order volume, and material choice. A research demonstrator for FEED-stage decision support.
Post-engine prototype
Research Notes
The bottom-fixed convergence as a retrodiction benchmark
In developmentThe monopile reached ~80% market share over roughly 15 years of commercial deployment, with a mature substructure cost of approximately 788 USD/kW. This provides a rare ground truth: a framework that cannot reproduce this convergence computationally is a framework with wrong parameters. This note documents the retrodiction logic and calibration targets.
Working note · feeds Paper 3
Why FEED is the right intervention point
ConceptManufacturability, port fit, installation sequence, supply-chain readiness, and local content are all committed at FEED — the cheapest point to change them. This note maps which decisions are still open at FEED versus locked, and why the standardize-or-customize trade is particularly acute at this stage versus later project phases.
Working note · feeds Paper 1
One candidate, one question, three years
Evgeny Ramenskiy
PhD Candidate, NTNU
Evgeny's work sits at the intersection of production and operations management, structural engineering, and multi-objective optimization. The research follows a design science approach: the central output is a usable artefact — the coupling framework and its computational tools — that must be both rigorously built and demonstrably useful to practitioners.
Research domain
Production management, design-for-industrialization, engineer-to-order project production
Technical focus
Structural optimization, parametric modelling, multi-objective methods, offshore wind substructures
Application
FEED-stage decision support tools, configure-to-order product families, standardization frameworks
The project is a three-year doctoral fellowship (2026–2029) at the Norwegian University of Science and Technology (NTNU), supervised within the Production Management group at the Department of Mechanical and Industrial Engineering, Faculty of Engineering.
Discuss the research, explore collaboration, or follow the work
I welcome conversations with offshore wind developers, fabrication yards, research institutions, and engineers working on related problems — whether for collaboration, technical exchange, or early input on framework assumptions.