BATSO Project

Optimising heavy maintenance for floating offshore wind turbines

The project

Major Component Replacement (MCR) on a floating wind turbine is currently a complex operation, typically requiring heavy lifting equipment and towing the turbine back to port. These solutions are costly, both financially and environmentally.

The BATSO project aims to study the feasibility of carrying out this heavy maintenance directly at sea, drawing on a technology already proven in onshore wind: nacelle-mounted crane lifting. The objective is to reduce floating wind maintenance costs and improve its competitiveness in terms of levelised cost of energy (LCOE).

A major component replacement operation is planned at the SEM-REV test site, off Le Croisic. The project will also feed into the sizing studies needed to replicate this type of operation on commercial wind farms.

Funded to the amount of €2.9 million by ADEME under France 2030, in response to the DEMO Tase call for projects, BATSO runs over three years (2024-2027).

Partners

• BW Ideol: designer and builder of the Damping Pool® floater technology, and operator of the FLOATGEN prototype
• Centrale Nantes (LHEEA and LS2N laboratories): basin testing and design of cable-driven robot system models
  EDF Power Solutions: offshore wind farm developer and operator, also involved in their maintenance
• OPEN-C Foundation: leader in offshore testing, operator of the SEM-REV test site

The 2026 basin testing campaign

The first year covered feasibility studies, and during the second year, now underway, a 1:33 scale model of the BW Ideol floater was designed, built, and installed in Centrale Nantes' ocean engineering test basins. Deployment in the water was followed by a set-up phase: balancing, installation of the trajectory-tracking system, mooring adjustment, and camera setup.

The first test campaign began with characterising the seakeeping behaviour of the floating turbine for 15+MW turbines, allowing analysis of its response to hydrodynamic loads and to swell conditions representative of the offshore environment. This data provides an essential basis for validating numerical models and refining experimental protocols.
The next step will focus on integrating the crane and winches, a prerequisite for the test campaign dedicated to lifting operations under realistic conditions.

The SEM-REV test site

SEM-REV is a multi-technology offshore test site dedicated to marine renewable energy, operated by the OPEN-C Foundation since September 2023. Located off Le Croisic, it offers a 1 km² grid-connected area equipped to test and validate prototypes under real conditions — the same site that has hosted Floatgen since 2018.

News

Launch of the BATSO Project to Optimize Heavy Maintenance of Floating Offshore Wind TurbinesLa

unch of the BATSO Project to Optimize Heavy Maintenance of Floating Offshore Wind Turbines