WIND POWER - Renewable Energy Research

Sailing ships may stage a comeback with the proper investment in research



  The Archinaute is a rotary sail or wind turbine powered catamaran

Eleven years after the launch of the project, the prototype of the first Archinaute wind powered boat is under construction at the Brittany South shipyard in Belz. This is a culmination of years of effort for its designer, Charles-Henri Viel, who was looking to present it from June 29 to July 10 at the La Mer XXL show in Nantes in 2018. The boat is 11 meters long, 6 wide and weighs 10 tonnes, built of aluminum. A wind turbine 6 m in diameter will be placed on the boat.

Unthinkable ten years ago, the project finally came to fruition. The transition from idea to design did not happen overnight. In 2014, the first investigations were carried out on a model. Two years later, Charles-Henri Viel participated in a contest: clim action. The principle of which was to propose projects in harmony with the environment.




DESIGN DRAWINGS: Peter Worsley and Brad Blackford's conceptual design drawings for boats powered by rotary sails. There are several ideas along these lines. More development is needed until a practical vessel may be achieved.




Peter is an amateur yacht designer and an incredibly inventive and productive experimenter. All of his designs work to some degree - which, as he has refined his ideas, they are getting better. We love the rotary sail boats. Not quite so keen on the wing-sail designs, which were pioneered by Walker Wingsail Systems many years ago, but never really took off :)  The idea seems to be a development of a fan ship proposal exhibited in 1935 at a patentees exhibition in London, although, we know that Peter developed his ideas independently from scratch. Nevertheless, there is a remarkable similarity, which supports the old adage that "great minds think alike." See Peter's nicely converted catamaran "Twice Lucky" below and compare that to Brad Blackford's Hobie catamaran further down. 



Rotary sail powered land yacht


AEOLUS DRAG RACING - It works on land too. This is the Baltic Thunder, a land yacht that competed in 2019 in the Netherlands where they hold an event each year for students to pit their wits against each other and nature trying to get more speed from their wagons than the prevailing wind.


On July 2, 2010, the Blackbird land yacht set the world's first certified record for going directly downwind, faster than the wind, using only power from the available wind during its run. The yacht achieved a dead downwind speed of about 2.8 times the speed of the wind, sponsored by Google.

On June 16, 2012, Blackbird set the world's first certified record for going directly upwind, without tacking, using only power from the wind. The yacht achieved a dead upwind speed of about 2.1 times the speed of the wind.



Peter Worsley's Twice Lucky rotary sailing catamaran








A number of windmill powered boats have been built over the years, with varying degrees of success. Some of the smaller ones were built from scratch, larger ones were converted production boats. However, the idea has not caught on beyond a few amateur one-off designs. So why build a windmill powered boat? The main advantage of a windmill boat is its ability to "sail" in any direction, regardless of wind direction. Because it is never necessary to tack, this ability can make it a long distance performer. Therefore, a moderate-speed boat can outperform a speedier counterpart. Further, they can be effortlessly maneuvered in tight quarters where winds are not fair. This would include rivers, estuaries, narrow lakes and shoal infested areas.



The trend towards using renewable and alternative energy sources on land has gathered momentum over the last decade as the general public and policy makers tackle the issues of pollution, energy security and climate change. However at sea the shift towards the widespread adoption of alternative energy is only now beginning to take shape.

Over recent years the shipping industry has begun to seriously look at ways to reduce fossil fuel consumption and operate in a more environmentally friendly way. The concept of Green Shipping or Sustainable Shipping is now becoming an important issue for ship owners, shipping lines and ship builders globally.

In the 1970's and 1980's there were several ships fitted with rigid sails of various types with the aim of reducing fuel consumption. This was driven largely by the oil crisis in the 1970's which resulted in oil shortages and the price of oil soaring. However the oil crisis passed and as the prices fell in the 1980's the viability of rigid sails in terms of cost was undermined. 

However Japanese ships such as the Shin Aitoku Maru and Usuki Pioneer did prove that rigid sails reduced fuel consumption. The rigid sail concept has also been applied to a range of smaller vessels but it has not gained widespread acceptance to date on either large ships or smaller vessels.

Another way to reduce fuel consumption on-board ships is through the use of solar power. Recent advances in solar cell and photovoltaic module technologies have lead to solar power becoming a cost effective fuel reduction option on pleasure boats, ferries and tourist vessels. However on large ships the amount of fuel saved through the use of solar power alone is relatively small. So the idea of a commercially viable solar ship seems impractical at the moment. Or is it?



JAMDA - A computer controlled, sail assisted merchant ship.


JAMDA - A computer controlled, sail assisted merchant ship.



Perhaps rather than having a ship with rigid sails or a ship with solar panels a better approach would be to design a system that could tap into the power of the wind and sun together. The challenge in developing such a solution is to overcome many of the practical problems entailed in trying to use sails or solar panels on large ships. 


But there is a solution on the horizon - the Eco Marine Power (EMP) Aquarius MRE System. This innovative wind and solar marine renewable energy (MRE) solution is designed so that the practical limitations of using rigid sails and solar panels on ships are overcome.


A ship fitted with the Aquarius MRE System such as a bulk carrier, oil tanker or cargo ship will be partly a solar ship and partly a sail ship. These ships will be able to use wind and solar power together as a source of energy and propulsion (along with the ship's main engines) in order to reduce harmful emissions and lower fuel consumption. On a large ship, 1000 tonnes or more of bunker fuel could be saved a year by using the Aquarius MRE System. This means that using renewable energy on ships is not only good for the environment but also good for business.


The power of the wind & sun is harnessed via EMP's own rigid sail technology called the EnergySail. This unique unit can incorporate a number of renewable energy technologies and can be installed on wide variety of ships. The EnergySail can be used alone or as part of an array and positioned automatically by a computer control system.


The Aquarius MRE System will offer ship owners and operators an attractive return on investment (ROI) which combined with the environmentall benefits, will help this technology gain widespread acceptance across the maritime industry.


Note: Aquarius MRE System & EnergySail are trademarks of Eco Marine Power Co. Ltd.




WIND PROPELLER SAILS FOR LINERS - Giant fan blades whirling rapidly in ocean breezes are proposed by an English inventor as a substitute for both sails and engines on ocean-going vessels. Mounted high above deck, the whirling propeller would transfer the wind’s unlimited power to the marine screw propellers of the boat. A working model of the windmill ship was on demonstration at the Inventions Exhibition sponsored by the Institute of Patentees at Westminster, England. Since the propeller could face into the wind regardless of the direction the ship is traveling, it is believed highly probable that windmill boats could travel directly into the wind. A generator mounted on the windmill tower could develop current for electric motors mounted on the propeller shafts, or a shaft could be used to transmit the power.


ROTARY WIND POWERED BOAT PROPULSION - PATENT ABSTRACT: A propulsion drive system for boats that is operated by wind power is disclosed. Upon initial observation of a boat equipped with the invention, it looks like a conventional boat. However, after closer inspection, it can be seen that a mast located at the rear of the boat supports a windmill structure. The windmill operates in a horizontal manner, similar to that of an anemometer. The central drive shaft is routed down the mast where it terminates in a gear box which increases the revolutions per minute by a factor of approximately 20 to 1. The output of the gearbox, complete with a clutch, is then routed to a propeller on the rear of the boat which is then used in a conventional manner. The features of the invention provide all of the advantages of a wind-powered boat without any of the disadvantages.




ROTARY WIND POWER: Test rig that works beautifully in the Youtube below. The aerofoil design of Peter Worsley's rotary sail is seen in the centre picture, with chain drive that matches the wind input torque to the water propeller rpm at the correct ratio to provide forward thrust. The problem with a fixed fan is that the boat will only work well directly into the wind and not at all with a side wind, etc, thus is not practical. It does though demonstrate the principle and Peter's model making and engineering skills. The efficiency of the air and water propellers determines the gearing - all in relation to the hull drag on course. In this case it looks like the catamaran is based on cycle parts. To convert the wind energy from a vector to an energy source, it is necessary to harvest the energy independently to the direction of travel of the host vessel.




ROTARY WIND POWER: A daring conversion; wind turbine powered catamaran, the Revelation II. We'd like to feature this vessel if the owner would care to get in touch.


AEROGEN 6 wind turbine generators. It won't power the vessel very far, but it's a start and we admire the effort by the owners of Exit Only.



As part of a €9m EU funded FP7 project, Marinet is offering SMEs, research groups and entrepreneurs working in the area of marine renewable energy and based in the EU or in FP7-associated States access to free renewable energy testing facilities.

Project MARINET aims to accelerate the development of marine renewable energy (wave, tidal and offshore wind) by coordinating marine research and development at all scales (small models through to prototype scales from laboratory through to open sea tests) and allowing researchers and developers access to specialist marine renewable energy centres and facilities across Europe. Access is open to companies and research groups of any size who wish to test at facilities outside of their own country.

This fourth call is specifically targeting access to test facilities specializing in the fields of offshore marine renewable energy, cross-cutting technologies (electrical, mechanical and moorings) and scaled prototype sea testing. 


 Popular Mechanics, Anton Flettner rotor wind powered ship   

ROTATING SAIL: More correctly a large tube that rotates and in so doing generates pull in one direction. This is called a Flettner rotor after Anton Flettner, the inventor.



Costs of accessing the facility are covered by the EC through the 7th Framework Programme for defined periods of access, and a contribution is made towards travel costs.

The National Renewable Energy Centre (Narec) at Blyth UK will be available for 24 weeks of total allocated use under the project.

An applicant team must be based in the EU Member States or States associated with the 7th Framework Programme. Team members based outside the EU can also participate as long as they do not form the majority in the team. The team must apply for a facility which is located outside their home country. MARINET also provides a financial contribution to assist the team with travel and accommodation costs.

Anyone interested in using Marinet to access Narec’s facilities should contact Alan Waggott, Chief Engineer – Wind & Marine at Narec on Tel:  +44 (0)1670 357616, Email:

To apply to the call or for further information visit: This call closed on the 20th August 2013.







The aim of the Wind Challenger Project is to substantially reduce fuel consumption by large merchant vessels. Under development by a group including members from the University of Tokyo and ClassNK, the idea is to utilize giant retractable sails, 20m wide by 50m high, to make maximal use of wind energy. The group has done simulations for shipping routes such as Yokohama-Seattle. The results indicate that hybrid ships with sails and engines could reduce annual fuel consumption by about 30% on average.


"Using today's technology, it's possible to make big sails, and to control them automatically. Also, navigation technology includes networked maritime information and weather forecasting, so ships like this can travel safely. Using wind energy, as in old-fashioned sailing ships, is actually feasible."


The angle of each sail is controlled individually, to obtain the maximum propulsive force. Also, each telescoping sail consists of five parts, so the sail can be contracted when the ship is at anchor or during rough weather conditions.




WIND CHALLENGER: Development model in black at a boat show (left) and a working model of the autonomous sail mechanism in the raised position (right) and folded away for stormy conditions (below).




WIND CHALLENGER: Artists impressions of the Wind Challenger docked, with its autonomous sails folded, and at sea with the mechanically operated sails raised. 



"The sails have a curved surface, and they need to be hollow, so they can expand and contract. So they don't use canvas, like conventional sails. Instead, they use aluminum and Fibre-reinforced plastic, which makes them rigid. In other words, with this concept, a ship has wings, like an aircraft."


Computer simulations and wind-tunnel tests using scale models show that this method is especially effective at saving energy if there's a crosswind. In other words, rather than taking the shortest route, this method makes it possible to travel faster and consume less fuel, by choosing an optimal route that takes account of wind strength and direction and the weather.


"These sails cost about US$2.5 million each, but they can reduce fuel consumption by over 25%. In that case, the cost of these sails can be recovered in 5-10 years. We've finished our basic research, so over the next two years, we'd like to build a half-size prototype, to check that this structure is practical. Ultimately, we're aiming for a sea voyage from 2016 onward."


Marine energy partnerships for offshore Atlantic power generation


This is not vessel based energy generation for transport, but rather a European partnership for the development of offshore electricity generation from wind.

The Atlantic regions have a huge potential in renewable energy which can be useful for the EU to meet the goals of its energy strategy, while contributing to the prosperity of their industries and populations, and meeting the objectives of economic, social and territorial cohesion. The Atlantic Power Cluster project builds on the Marine Energy Working Group set up in the CPMR (Atlantic Arc Commission) and is intended to implement a transnational marine energy strategy so the partner regions can seek complementarities to tackle the crucial challenges for the development of marine energies in the Atlantic Area (AA).



Wind energy harvesting devices are still the subject of intense research


The APC project seeks to develop cooperation and joint approaches to facilitate the identification of new market niches in the renewable energy sector and the redefinition of educational and training programs as per the needs of the offshore and marine energy sector in the AA. The project is likewise is expected to contribute to a "greener" model of energy development, while enhancing the competitiveness and innovation capacities in the Atlantic regions.

APC aim to build a transnational marine energy strategy in the Atlantic Area with a supportive political and social environment for marine energies, designed to enhance the competitiveness and innovation capacities of the industrial community in the Atlantic regions.

A miniature wind turbine for the SeaVax robot


MODEL WIND TURBINE BLADES - Just like their full grown offshore counterparts, the swept blade area determines how much electricity you can generate. We've been out in the wind testing the blade angles and comparing with the results as part of the SeaVax development project. Size matters.



BLUEFISH ZCC DEVELOPMENT: A hybrid, wind and solar powered vessel with computer controlled harvesting and a modular SWASH hull design that provides development platforms for both civil and military applications without having to redesign the whole vessel each time. The above diagram is for 4 x 2kW wind turbines = 8kW. A turbine boat will sail directly upwind exactly as a sailboat beats upwind through the manipulation of vector forces. The difference is that a sailboat must physically tack back and forth, whereas on the turbine boat the turbine alone tacks back and forth along with the underwater part the prop. None of the propeller blades go directly into the wind. They all follow angled paths relative to the wind, meanwhile the boat takes the overall (average path) In this case directly into the wind. It's possible because the driving surfaces are now no longer rigidly attached to the boat.



HOW MUCH FASTER THAN THE WIND CAN A TURBINE BOAT GO? - The above diagram shows 3 x 10kW turbines = 30kW (40hp) propulsion. The energy extracted by the turbine goes towards propelling the boat and the vessel reaches a steady speed (0 acceleration or equilibrium) once all the energy extracted is being converted to overcome air and water drag. We already know that sailboats can sail faster than the wind when close hauled. Even a good monohull can sail faster than the wind in light wind. Very efficient sailing systems, such as iceboats which have very little resistance, consistently achieve higher than windspeed.

EVOLUTION - The limiting factor for sail craft  is the sum of the aerodynamic and interface lift to drag ratios. However, in the case of a turbine boat, the powering surfaces are moving along different paths to the entire boat so this is no longer an issue. In fact if there would be zero resistance, zero drag, zero losses of any kind, the turbine system would accelerate indefinitely, straight into the wind, with an acceleration a function of the initial real windspeed. In the real world the ratio (Boat speed straight into the wind wrt substrate)/(real windspeed over the substrate) is entirely a function of efficiency. A very efficient system might go twice or more the windspeed into the wind.

Going downwind is more limiting. Traveling in the direction of the wind the apparent wind drops until you reach windspeed by which point apparent wind is zero, and the boat slows down to (as it were) let the wind "catch up with you again." Basically this is the turbine boat's slowest point of sail and it cannot outrun the wind, unless it deviates from dead downwind. Consider though, that as the cruising speed of the Bluefish ZCC is around 10 knots, if the wind is blowing at anything over 6 m/s the vessel will benefit.




ABOVE LEFT: The Bluebird™ yacht shown above has mid-range (partially) raised turbines in a high beam wind, the vector causing roll to port. The autonomous trimming system compensates for this running condition using the active outriggers, by raising the starboard outrigger out of the sea and lowering the port into the sea. The main hull of the vessel then remains vertical.  ABOVE RIGHT: A similar situation applies in this depiction, except that the wind is faster, as in a storm and coming from the other side. For this reason the turbine boom has been lowered to reduce roll, while the port outrigger has been raised out of the sea, to effect vertical running. By this means the ship can trim itself to harvest as much energy from the wind as it is safe to do, while still maintaining comfortable conditions for a crew. The design of this vessel is © August 2014 and the technology is patent applied for.






















International Windship Association












Blackcurrant 1  |  Blackcurrant 2  |  Catamaran  |  SWASH  |  SWATH  |  Trimaran




This page is Copyright © 2020 Bluebird Marine Systems Ltd. The names Bluebird™, Bluefish™, SeaVax™, and the blue bird & fish in flight  

Bluebird trademark legend, blue bird in flight logo Bluefish flying fish autonomous robotic ships navigation system  

logos are trademarks. All other trademarks are hereby acknowledged.