Crestwing Development Vision Status Home Company Contact
The development of Danish WEC's are typically started with tests of very small test models in AAU wave tank typically at a scale 1:40 and 1:50. From these small scale concepts they usually go directly on the test off shore (NissumBredning) in a 1:10 scale. As it has proved; in practice a very expensive, time consuming and inefficient procedure.
Test of WEC´s have been focused around Aalborg University's testing facility and its capacity of development of concepts have been directed towards off shore test at Nissum Bredning and Hanstholm.
Waveenergyfyn experience in working with development (both from the renewable energy sector and, not least, the experience from Odense Steel Shipyard) has made it natural with a maritime approach for the development of wave energy concepts.
Though Frederikshavn has historically been a maritime center, it has only an insignificant part in the development and construction of the previous wave energy concepts. With knowledge of Frederikshavn status in the maritime field it was natural for us to contact the Energy City Frederikshavn back in 2009. We have since had an intensive andgood cooperation, which in cooperation with the Energy City has established interdisciplinary consortium cooperation with a number of maritime businesses in North Jutland.
The Floating concept Crestwing is in principle two barges hinged together why the main structure is regarded as unproblematic by the consortium. Focus is directed at three areas; hinge, PTOsystem (power takeoff) and anchoring.
Anchoring and hinge
Anchoring and hinge is tested under DHI test trials and is currently being tested off shore in a scale of 1:5 by Frederikshavn where it has undergone a wave environment matching the wave modes the upcoming prototype will be burdened with (scale considered).Powertake off-PTO
The Powertake off (PTO) system has been tested at DHI, while test offshore has not yet been accomplished. We have finished testing the main structure and anchoring offshore. Crestwings PTO system is mechanically designed with the target that the PTO efficiency must match ocean wind PTO´s efficiency. Waveenergyfyn has, from energinet.dk, for several years tried to get a testbench for PTO system established at AAU. We are now in partnership with Wave Star and AAU, whom have received grants for a test bench.
Crestwing concept developmentWe have applied for funds for the design of a 40 m Crestwing for the laying out of Hanstholm (DanWEC).We expect the following developments:
Overall Development Plan for Crestwing ConceptWe have applied for funds for the design of a 40 m Crestwing for layering on site at Hanstholm (DanWEC) We expect the following development.
Testing the Crestwing energy converter at Aalborg University
The first official test of the Crestwing concept was carried out on AAU in the period 13-03-08 to 30-02-09 and was done by Jens Peter Kofoed and Michael P.Antonishen AAU in collaboration with Henning Pilgaard Waveenergyfyn.
Waveenergyfyn reporting includes both the final report from Waveenergyfyn 2008/2009 “CrestWing-2nd test phase” and Study Report “The CrestWing Wave EnergyDevice -2nd phase testing” from AAU.
Status Testing the Crestwing energy converter at Aalborg University
Status theory of atmospheric influences
During preliminary tests at AAU there were performed tests with variation of the plants weight for detection or rejection of the theory of atmospheric pressure effect on the plant. The weight of the model was tested in the range between 17.5 to 40 kg. If the system worked in cording to Archimedes displacement principle the force on the pontoon going downward, should increase with larger pontoon weight. The test revealed that the plants own weight had little or none impact on the plants efficiency.
The concept has evolved during the test run compared to the original design and experience, but the principle of utilization of the atmospheric pressure remains central to Crestwingens function.
Status Crestwingens ability to absorb energy from the waves.
Estimated efficiency after the second cycle (December2008), based on the retail development of concepts and especially on the optimization of scale (PowerMatrix), has lifted absorber efficiency by 50% so that Crestwing's efficiency are assumed to be in the range 40 to 50 %.
Estimated energy production after the second cycle (December2008), based on the retail development of the concepts and especially on the optimization of scale (PowerMatrix), has lifted the potential annual energy intake, from a full scale plant North Sea location for approx.1000 MWh.'
In summary,the conclusion is positive with a test result which shows that Crestwing concept is among the most efficient flow concepts World Wide.
Testing the Crestwing energy converter at DHI, Hoersholm, Denmark
PSO project " The Crestwing final test "PSO R&D project nr. 10465 were carried out from February 2010 to March 2011 conducted by Bjarne Jensen M.Sc.Eng.Hydraulic Engineering & CFD expert Ports & OffshoreTechnology, DHI in collaboration with James Russell Brice Senior Naval architect K E H and mechanical engineer Henning Pilgaard Waveenergyfyn.
Waveenergyfyn reporting includes both the final report from Waveenergyfyn "project Wing Crest final test" PSOR & D project No. 10465 "and DHI's report" Crest Wing Wave Energy Converter Wave Tank 3D model tests. "
Status Testing the Crestwing energy converter at DHI, Hoersholm, Denmark
Most floating concepts for wave energy operate with forces from buoyancy from the upward movement where the plants downward movement is ensured by a high pontoon weight. With Crestwing the downward movement is achieved from the atmospheric pressure and not from the pontoons weight, which gives a light pontoon with a large upward movement, and a subsequent large and powerful downward movement.
The function was demonstrated during the initial trials in AAU's wave tank in 2008 when the pontoons gravity affect on the plant was studied. The pontoon weight had little or none effect on the efficiency.
During the present test procedure at DHI in 2010, the pressure conditions were measured under the plant to test the estimated negative pressure or vacuum below the hinge.
Measurement of pressure under the pontoons confirmed the estimated pressure conditions and documented that it is the atmospheric pressure which ensures the pontoons downward movement.
Status power take off
The PTO System was during the DHI tests based on the construction of a single frame for gradual expansion of the system. As a first step in building a linear gear with disc brake for use in Phase1 (mooring test).For the current test sequence there was fitted a hysteresis brake (electromagnetic) and flywheel arrangement.
The PTO systems hysteresis brake was controlled from the command bridge. The concept with a hysteresis brake gave a good simulation of an electricity-producing PTO system. The PTO system was in a 5:1 scale compared to the model.
The PTO system's gear and scale were tested in a test bench.
Test period phase 4 was optimized based on the experience from the previous three phases and those results presented here are made using Power Matrix Vorupør. Vorupør Phase 4 test No. 290,289,291 was characterized by only being anchored from the front pontoon; also, most of the tests are done with setups anchored from front pontoon.
Energy production is based on a PTO efficiency of 85 % which is the level we expect to achieve with the present mechanical PTO system.
We estimated energy production from three locations Hanstholm, Hornsrev and BillaCroosite
Status for Crestwingens economy.
Estimated capital investment
During the summer of 2010 a pre-design of a prototype full-scale Hanstholm was conducted. Below, there is a price calculation based on offers of building main items including hull, PTO system and electrical settlement price. The prototype which is assumed built in composite, built in Denmark and was
The estimation is based on a fixed length of 60m and is up/ down scaled with a power scale of 2.5, found by balancing the individual budget items.By estimation of the steel version there is exclusively adjusted in the prize on the hull and partly on material and labor costs compared to the composite version.
Estimate the simple payback time
The estimated simple payback periods are based on a settlement price for the produced electrical energy at 1kr /kW and operating costs per kWh of 0.1 Dk. kr. per kWh.
The estimated employment effects
Over the summer of 2010 the pre-design of a proto type full-scaleHanstholm with the main dimensions L= 60m and B =13.5 m was completed included the calculation of the employment effect.
Crestwing final test follow-up offshore
Crest Wings, at a scale of 1:5, are tested on site at Frederikshavn in the period October 2011 to June 2012.
The purpose of the project "Crestwing final test follow-up offshore" is to demonstrate Crestwing off shore with starting point in the recently completed DHI project "project Crestwing finaltest".
The aim of the trials are testing offshore and completing the DHI test 2010/2011 through; testing of the mooring system off shore under the influence of currents and wind testing the hull off shore under the influence of the currents and wind testing and adjustment of the developed PTO system and finally testing of the electricity-producing PTO system offshore.Through "Project Crestwing final test", we have developed a planning and design tool, and one purpose of "Crestwing final test follow-up offshore" is the calibration of this tool through the offshore process.
The purpose of the project "Crestwing final test follow-up offshore" is to demonstrate Crestwing off shore based on the recently completed DHI project "project Crestwing final test".
Status Testing the Crestwing final test follow-up offshore
CrestWingmodelFladstrandhavebeen throughthe first twomonth testperiodwitha good result.This firstperiodwas favored by thestrongsouth/south-eastwinds, whichis the areathat provides thestrongestwaveenvironment atthe site.Afterthe first testisanchoringsystemadaptedtoconditions at thesiteand the strongnorthward currenton the spot.Crestwingensability to remainperpendicular to thewavefront hasbeen shown tobe consistentwith the resultsfrom DHItests.Conceptsurvivabilityisconfirmed.CrestWingisequipped for the finalof-shoretesting processwhich takesplace from March toAugust 2012.
