Power for Change - 2 (of 13) The Duck wave energy device

An 8-minute compilation on the experimental development of the Duck, a wave energy device invented by Prof Stephen Salter in 1974 at the University of Edinburgh in Scotland.

• Category

  Science & Technology

[levanteIRL67592]

A quick question; From around 3:10, when the compliance of the support was increased in the surge direction, was there a power takeoff mechanism on the support to utilise its motion, or was the increase in efficiency purely due to a better response from the duck in pitch?

[Jamie Taylor]

The meter is showing efficiency based purely on the power converted from the 'nod' motion. ( 'pitch' : rotational motion of the spine. 'Nod': rotation of duck about the spine). Here the Surging-Heaving rig was not providing any (significant) damping on the heave and surge axes. We are showing how variation of the stiffness of the spine (controlled by joints), affects power capture. We went on to include power capture at the spine joints - as later realised in Pelamis.

[levanteIRL67592]

Thanks for the quick reply. Do you think that the duck will ever go to sea as a viable wave energy device? It seems like the industry is moving towards more less efficient, but more mechanically simple devices.

[Jamie Taylor]

In this context its inventor, Stephen Salter, sees one of itsmajor advantages being that it makes the best use of the available sea-space - so you can get more power out of given area of sea. There is great deal of novel, but very well thought out, technology in the Duck - some of which is currently being developed. My hope is that, in time, this comes together to make the Duck viable. We always felt that simplicity is not an option - otherwise it would have been done already!

[levanteIRL67592]

Do you think that the cost of implementing the Duck could be lowered if it was combined with an already-existing reference frame, like the tower of an offshore wind turbine, perhaps using a support structure similar to that of the Surging-Heaving rig? Or would scaling that sort of support up to operational size be impractical?

[Jamie Taylor]

A feature of a string of Ducks is that it is 'self-referencing' (i.e. no power take-off reactions are required from the sea-bed), so the mooring loads are relatively very small and no external structures are required. We tried various forms of solo ducks. In contratst to the Duck-string, these need some kind of external constraint and you can see an example in the YouTube video 'Desalination Duck tests'.

[NHẤT GIA BEST.CO CTY TNHH]

There might generate electricity... but there can not develop on industrial scale.

[NHẤT GIA BEST.CO CTY TNHH]

Have only family.... character can not develop According to industrial Form.....

[sailingsolar]

3 pence per unit? OK I can figure out the value of 3 pence at any given time. What is a unit? 1kw?