FAQ

Orcelle Horizon is a Horizon Europe research and innovation project that aims to develop and demonstrate wind as the main propulsion source for large commercial ships. The project combines real-world demonstration of wing sail technology with advanced simulation tools and operational and regulatory analysis. Funded by the EU, the project builds on years of research and development and is backed by a broad consortium covering the complete maritime value-chain.

International shipping faces increasingly stringent GHG reduction targets, and wind is a carbon-free energy source available at global scale. While energy-efficiency measures and alternative fuels are progressing, they are not sufficient on their own to meet long-term decarbonisation goals.

Recent advances in wing sail technology, automation, weather forecasting, and digital simulation now enables wind propulsion technologies to be integrated into large commercial vessels in ways that were not previously feasible.

Wind-assisted propulsion systems (WAPS) describe the integration of wind propulsion units (WPUs) onto vessels. Wind propulsion units refer to specific technologies, for example rigid wing sails, rotor sails or suction sails, that are installed on the deck of a vessel to use wind energy for propulsion. These technologies are already in use and provide measurable energy-efficiency and emission reductions in commercial operation. According to industry and class-level assessments:

• WAPS typically deliver fuel and CO₂ reductions in the range of 1–10%, and up to around 20% in favourable conditions
• They support compliance with existing GHG regulations
• They can be retrofitted to existing ships with conventional or hybrid engines covering the remaining propulsion energy needs

These systems represent an important and proven step, but do not yet enable wind to act as the main propulsion source.

Orcelle Horizon specifically targets wind as the main propulsion source for the vessel, rather than a supplementary source to the main engines. For Orcelle, this means:

• 50% or more of average propulsion energy provided by wind over a full year of operation on routes with good wind potential
• energy efficiency gains of up to 100% are possible at lower operating speeds and on wind-favourable routes
• engines are retained for manoeuvring, navigating confined waters, low wind conditions, and safety in extreme weather events

The project addresses the integration throughout the ship’s systems, combining physical and digital demonstrators, logistics, simulation platforms, weather routing, wing system and vessel design optimisation, safety analysis, and regulatory gap assessment to support large-scale adoption in various shipping segments.

Orcelle uses a rigid wing sail system, the Wing 560, developed by Oceanbird. The technology is selected because rigid wing sails:

• provide high aerodynamic efficiency and thrust potential,
• can be completely automated or actively controlled,
• and are suitable for high wind contribution, including wind as main propulsion.

The wings can be folded down in port and in extreme weather conditions, supporting safe operation on large commercial vessels.

Wallenius Wilhelmsen’s PCTC vessel Tirranna is being retrofitted with one rigid wing sail and will serve as a large-scale demonstrator.

Its role is to:

• validate wind propulsion performance in real operation,
• collect operational data for simulation and safety validation,
• test automation, procedures, and crew interaction,
• and reduce risk for future high wind-contribution designs.

Expected energy savings are 5–10%, comparable to existing WAPS, but with significantly enhanced learning value.

The vessel is equipped with extensive sensor systems to validate models, safety assumptions, and operational concepts.

Orcelle Wind is a multi-wing Pure Car Carrier (PCC) newbuild concept with the capacity to transport 7,000 cars. It is designed to demonstrate wind as main propulsion for commercial operation.

The vessel is expected to:

• achieve more than 50% CO₂ emission reduction,
• operate safely on trans-Atlantic routes,
• and be delivered as a class-compliant, contract-ready design.

It represents the culmination of Orcelle’s technical, operational, and regulatory work.

Orcelle explicitly addresses safety, recognising that wind propulsion changes operational conditions and design loads. Safety measures include:

• automated wing control and procedures for extreme wind conditions,
• structural load monitoring and integrity assessment,
• operational limits supported by prediction systems,
• and redundancy that always enables the wing to be lowered, even in loss of power situations.

Engines remain available at all times to ensure safe manoeuvring and minimum powering.

The project investigates how wind propulsion interacts with:

• ship manoeuvrability in adverse weather,
• minimum powering requirements,
• and crew training and operational procedures.

These aspects are explicitly linked to potential impacts on SOLAS, COLREG, and STCW, and are addressed through operational studies and regulatory gap analysis.

Wind as main propulsion introduces new design and operational complexity that cannot be captured by conventional methods.

Orcelle therefore develops an industry simulation platform that:

• integrates aerodynamic, hydrodynamic, and operational modelling,
• uses demonstrator data to improve prediction accuracy,
• and supports design, routing, and operational decision-making.

This is essential for design optimisation of wind-powered ships, their life-cycle assessment, and safety of operation, as well as their regulatory approval and acceptance by the wider maritime industry.

Orcelle provides evidence and methods to support the evolution of regulations and standards for wind propulsion.

The project:

• identifies regulatory gaps at IMO level,
• supports the development of ITTC and ISO performance and safety standards,
• and demonstrates feasibility across multiple ship types beyond RoRo.

The ultimate goal is to enable scalable, safe, and commercially viable uptake of wind as main propulsion across a large share of the world fleet.