-- Pure Energy Systems Wiki -- your publicly editable site about new energy technologies. Power to the people!

Directory:Bulge Wave Anaconda by Checkmate Sea Energy

From PESWiki

Checkmate Group has formed Checkmate Seaenergy Ltd to develop the Anaconda Wave Energy Converter. The project is still in its early stages but already Anaconda has shown considerable promise compared with other WECs. Anaconda’s method of operation and construction mean that it has enormous potential, potential which exceeds all other wave energy converters and many other renewable energy sources.

Table of contents


This is a new page!
This is a new technology-related article needing expansion. You can help PESWiki by expanding it and are invited to help us add to its contents.
After logging in, click the "edit" link above. Further information might be found in a section of the talk page. Please remove this message once the page has become more mature and adequately developed.

Official Websites


  • Download ( (13 Mb; mp3) - On July 21, 2008, Sterling D. Allan conducted a live, 1-hour interview with Tom Roach, Project Director of Checkmate Sea Energy regarding the Anaconda technology.

How it Works

Quoting from

Anaconda uses an entirely novel concept to harvest wave energy. This resource is free and widely available to the UK and Eire as well as other countries with west facing ocean seaboards. The inventors (Professors Rod Rainey and Francis Farley FRS) have developed the concept of a distensible rubber tube, floating head to sea, in which bulge waves are excited by passing sea waves. The bulge waves are then used to drive a turbine generator. It is the long ocean swells which have most energy; developed by winds over hundreds or thousands of miles; these are the ones Anaconda uses. This is a particularly rich, but as yet untapped, energy resource which Government studies state could produce 3% - 5% of our electricity initially and up to 20% eventually.

The Anaconda team has now developed the concept in the most rigorous way to produce information which shows that Anaconda has the potential to be one of the most cost effective sources of renewable energy. We are now embarking on a research and development programme which will develop the system and demonstrate what Anaconda is capable of.

Essentially, it is a very large (perhaps 200m long and 5m diameter) water filled distensible rubber tube floating just beneath the ocean surface at right angles to the waves, with a power take off at the stern. As a long wave passes the bulge tube is lifted with the surrounding water and this causes a bulge wave to be excited which passes down the tube’s walls like a pulse in an artery, gathering energy from the ocean wave as it goes. Continuous energy gathering is caused by resonance between the bulge wave frequency and the sea wave’s so energy is drawn in towards the tube from the width of the sea wave crest as it progresses along the tube . Energy from the sea wave is stored in the rubber as potential energy by it being stretched (in a sea wave it is stored as potential energy due to gravity). The bulge wave travels just in front of the wave rather like a surfer, picking up energy as it increases progressively in size. At the end of the tube the bulge wave energy is converted to a surge of water which drives a turbine in the power take off after the flow has been smoothed.

It is a closed circuit system so issues with ingestion of marine animals will not arise. Because it is under the surface and rubber can be formulated to be non polluting, environmental impact will be minimal.

The idea of the excitation of bulge waves is novel and is the essential intellectual property from which comes many of Anaconda’s advantages over other WECs. A more detailed description of the theory of the device is included in a paper delivered to the 7th European Wave and Tidal Energy Conference in September 2007.

Water from each bulge wave flows under pressure into the upper reservoir of the Power Take Off through a one way valve. Energy storage is due to potential energy against gravity because the reservoirs are at different heights. The space above the free surface in each reservoir is occupied by a variable volume air bag. These are interconnected and used to maintain a positive pressure in the system. Pressure compensation due to the system pressure being higher then the surrounding sea allows the water to flow under gravity trough the turbine and into the lower chamber. As water leaves the upper chamber, air from the lower chamber’s air bag goes in the opposite direction to fill the upper chamber’s so the total volume of the two reservoirs remains the same. The water is then drawn back into the bulge tube through the other one way valve during the low pressure phase of the bulge wave. Since they are inter-connected, pre-pressurisation of the bulge tube is achieved by the compensation system used in the PTO. This allows the bulge tube to contract beyond its resting state without becoming flaccid. Another benefit of the pre-pressurisation is that it keeps the distensible portion of the bulge tube in tension, greatly increasing its fatigue life. Pressurisation also affects tuning to the sea wave length. Reactor mass is provided by the water in the PTO and there is an additional keel weight which is also used for stability.


  • Video (

(.56 Minutes) Giant rubber snake could be the future of wave power

  • The rippling "Anaconda" produces electricity as it is squeezed by passing waves. (YouTube (; July 4, 2008)

- - - -

  • Pictures ( (Inhabitat; July 8, 2008)


1MW wave-generated electricity at US$0.12 per kWh.


  • Anaconda has the potential to save many millions of tonnes of carbon dioxide production around the world.


Unlike other devices which may only have some detailed features protected by patents, Anaconda uses a new principle of operation which is itself protected by patent.


Company: Checkmate SeaEnergy

A division of The Checkmate Group.

  • Team (
  • BulgeWave (

Inventors Francis Farley and Rod Rainey

Professor Francis Farley ScD nst P, FRS – Co-inventor is an experimental physicist with wide experience of making things work; wartime microwave radar which controlled the Dover guns, innovative experiments in particle physics at CERN and Brookhaven and new wave energy devices. He is a fellow of the Royal Society which awarded him the Hughes medal. Francis has worked on wave energy since 1976 and has filed 14 patents in this area. He initially developed the Triplate (Farley et al., 1978; Altmann & Farley, 1979), which was funded by ETSU. Whereas model tests showed excellent performance, full-scale design by consulting engineers proved it to be too costly and the project was shelved. He then moved on to attenuators. Farley developed the mathematics of a buckling beam floating on water and discovered that, independent of length, it buckles at a preferred wavelength. This can be set equal to the wavelength in the sea, with the result that a large resonant oscillation is excited. Model tests confirmed the concept (Farley, 1981, 1982; Farley et al., 1981) and showed good capture width. The idea was later taken up by Wavegen Ltd under the name Hydra, but again engineering problems led to abandonment. An alternative design (Farley & Rainey, 2006) with an internal tension cable could prove more attractive. Meanwhile Ocean Power Delivery (Now Pelamis Wave Power) realised that by forcing the beam to vibrate at a steep angle to the vertical, the restoring effect of gravity would be reduced, and it could be made to resonate with the waves without a compressive cable. This concept has led to Pelamis.

Professor Rod Rainey MA MSc DIC CEng FIMarEST – Co-inventor is Head of Floating Structures at WS Atkins Oil and Gas Division. Rod is one of the UK’s leading experts on floating offshore structures, and has a unique combination of practical and theoretical know-how in this field. He has been employed by WS Atkins for over thirty years. Prior to this, he was employed by Yarrow Shipbuilders and was a research fellow at Imperial College. He is an internationally recognised authority in the field of hydrodynamic loading, and hosted the International Workshop on Water Waves and Floating Bodies, at Peterhouse, Cambridge. He has published extensively in the international technical literature, with well-known publications on wave loading, freak waves, and wave energy converters. Rod is a visiting professor at University College London and at Southampton University. He is also a recognised expert witness in the London Courts, on all aspects of marine structures.


In the News

  • SiloBreaker Pagefilter (
  • Simple 'Anaconda' Device Could Address Wave Power Cost ( - BulgeWave ( Anaconda is a simple closed end rubber tube that promises 1MW wave-generated electricity at US$0.12 per kWh. Although around twice as much as coal-fired power stations, this compares very favorably with other leading wave energy concepts. (Green Car Congress; July 3, 2008)
  • Rubber Snake Could Help Wave Power Get a Bite of the Energy Market ( - Invented in the UK, the ‘Anaconda’ is a totally innovative wave energy concept. Its ultra-simple design means it would be cheap to manufacture and maintain, enabling it to produce clean electricity at lower cost than other types of wave energy converter. Cost has been a key barrier to deployment of such converters to date. (Mendo Coast Current; July 3, 2008)

Other Coverage

  • list here


See Discussion page

Informative and Clear

On July 21, 2008, Francis Farley wrote:

Sterling ....... I am so impressed with the website you have put together in virtually zero time. It is very informative and clear.

How do you do it ?????? [Thanks ]

Meanwhile I am hoping our engineers will build a small Tesla tube to try out.

How do I download ( Tom's talk ????

best wishes ......... Francis

Related Technologies


Checkmate Seaenergy
Unit 6, Pegasus Way
Wiltshire SN12 6TR
Phone:+441225 705 465
Fax:+441225 705 497

  • Contact Form (

See also

- Other Directory listingsLatestA-IJ-RS-ZTreeNews
- PESWiki home page