|A Concrete Semi-Submersible Floating Wind Platform Produced with Proven Industrialized Concrete Construction Methods


The University of Maine’s patented VolturnUS is a transformational floating concrete hull technology to harness offshore wind energy with the potential to significantly reduce the cost of offshore wind. VolturnUS can support wind turbines in water depths of 45 meters or more.


  • $40m Investment from the Department of Energy for technology demonstration
  • $100m Investment from Diamond Offshore Wind, a subsidiary of the Mitsubishi Corporation, and RWE Renewables
  • State of Maine – Gulf of Maine Research Array
    The Governor’s Energy Office submitted an application to BOEM to lease a 15.2 square-mile site in the Gulf of Maine for the nation’s first floating offshore wind research site in federal waters.


Concrete construction gives benefits over steel

  • Industrialized pre-cast bridge construction techniques that can be made anywhere in the world using locally sourced material and labor
  • Lower cost per ton; lower overall Levelized Cost of Energy (LCOE)
  • Higher corrosion resistance than steel; lower Operation and Maintenance (O&M) costs and longer design life
  • Heavier than an equivalent steel system; low center of gravity and high center of buoyancy yield excellent wave motion resistance

Optimized & Simple Design

  • No complex features like active ballast systems, heave plates, or hanging masses
  • Rectangular bottom beam sections are easier to construct and add more wave motion resistance than cylindrical sections

Mobility & Ease of Deployment

  • Low tow-out draft allows for deployment in shallow water harbors around the globe. VolturnUS can be disconnected and returned to port for maintenance or turbine upgrades

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Media Gallery

NEAV 1 Rendering

Volturnus 1:8 Castine Deployment

Volturnus 1:8 Tow Out

2013 Volturnus 1:8 Launch

Volturnus 1:8 Castine Deployment

Consensus Digital Media Story

2013 Volturnus 1:8 Launch

DeepCLiDAR Metocean Buoy

Volturnus 1:8 scaled 500 year storm conditions, 2013

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