After two years of continuous operation, DemoSATH has established itself as a key reference in floating offshore wind demonstration off the Basque coast. Located at the BiMEP (Biscay Marine Energy Platform) test site, approximately 2 miles offshore in 85 m water depth, the project features a 2 MW turbine mounted on a prestressed concrete twin-hull platform, built by Saitec Offshore Technologies in collaboration with RWE and The Kansai Electric Power Co. Inc.
The Cantabrian Sea, with its demanding marine and wind conditions, has provided the ideal environment to put the SATH technology to the test. Each wave, gust, and current has challenged the platform, while a comprehensive system of sensors, SCADA, and condition monitoring tools has continuously validated its performance against real-world conditions.
Meticulous engineering and planning
From the very beginning, careful engineering planning has been key: defining all systems and components, developing high-quality as-built BIM models, calibrating numerical models with early WTT data, and anticipating long-term issues such as durability, accessibility, and splash-zone risks. Robust and redundant communication systems, combined with early engagement with certification bodies, have streamlined operations and reduced workload throughout the project lifecycle
Beyond power generation, DemoSATH was conceived as a research and development platform. Its mission is to gather empirical data, validate the SATH technology, refine Operations & Maintenance (O&M) strategies, and assess environmental interactions.
Streamlined project management and operations
Effective management has relied on minimizing contracts, accurately estimating engineering hours across all phases, and emphasizing meticulous planning and monitoring. Marine operations follow step-by-step plans with early involvement from stakeholders including port authorities, tugs, and mooring teams, supported by virtual simulations to address challenges such as crew transfer limits, station-keeping demands, and precise weather forecasting. Construction success has been built on clear responsibilities, interface coordination, careful contractor selection, and contingency planning to navigate potential disruptions like COVID-19 or supply chain delays.
Key achievements and learnings
⚙️ Innovation in design – the twin-hull concrete platform and single-point mooring system improve stability and allow natural alignment with sea and wind forces.
🔎Knowledge for the future – real-time operational monitoring, hybrid O&M strategies and risk-based spare parts supply have generated insights that will shape larger commercial projects.
🌍Environmental responsibility – marine biodiversity, underwater noise studies, bird and bat monitoring are helping prove that offshore renewable energy can grow in harmony with ecosystems.
📊Economic relevance – OPEX tracking, supply chain involvement in Bilbao and surrounding areas, and financial modelling are strengthening the case for competitive, scalable floating wind.
✔️Credibility – Bureau Veritas prototype certification adds confidence to the pathway from demo to industrial scale.
What began in Bilbao as a prototype has evolved into a reference for floating wind. By combining local expertise with international collaboration, DemoSATH contributes both to regional industrial growth and to the global pathway toward decarbonization.
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