We've argued for awhile that hydrokinetic power -- tidal power, wave power, ocean current power and the like -- is the potential dark horse winner in the race to build breakthrough clean renewable power generation. Hydrokinetic power can avoid much of the "intermittency" problem of wind and solar (i.e., that the power source isn't always available) as well as the NIMBY "visual pollution" argument brought up by wind opponents. It's further back along the cost and development curve than wind and solar, but it's moving along swiftly.
Latest example: the Scottish firm Ocean Power Delivery -- the current leader in hydrokinetic technology -- is set to build the world's first commercial wave farm off of Portugal. When deployed in 2006, the three wave power generation units will provide 2.25 megawatts to 1,500 homes. And if all goes well with the initial build, OPD is set to deliver an additional 30 units, for a total of 20 megawatts of generation.
The wave power unit is called the "Pelamis:"
The Pelamis is a semi-submerged, articulated structure composed of cylindrical sections linked by hinged joints. The wave-induced motion of these joints is resisted by hydraulic rams, which pump high-pressure oil through hydraulic motors via smoothing accumulators. The hydraulic motors drive electrical generators to produce electricity. Power from all the joints is fed down a single umbilical cable to a junction on the sea bed. Several devices can be connected together and linked to shore through a single seabed cable.A novel joint configuration is used to induce a tuneable, cross-coupled resonant response, which greatly increases power capture in small seas. Control of the restraint applied to the joints allows this resonant response to be 'turned-up' in small seas where capture efficiency must be maximised or 'turned-down' to limit loads and motions in survival conditions.
Each Pelamis unit generates up to 750kW of power, although actual output will vary with wave intensity. The Portugal wave farm will run about €8 million (roughly $10 million) -- not cheap by any means, but a worthwhile investment in a promising source of clean power.
(Thanks, Paul at Eyeteeth!)
Comments (11)
It sounds great, but how would they do in a Category Five Cyclone/Hurricane/Typhoon and would they not be more difficult to service than land based solutions? Just asking.
Posted by Tavita | May 22, 2005 4:16 PM
Posted on May 22, 2005 16:16
Portugal is not a place where cat 5 hurricanes occur. :)
Posted by JIm Bailey | May 23, 2005 12:58 AM
Posted on May 23, 2005 00:58
I expect in more storm likely regions a wavefarm will be able to automaticaly retract itself below the surface till the storm calms.
Posted by wintermane | May 23, 2005 8:10 AM
Posted on May 23, 2005 08:10
Ideal place for one of these wave farms:
North/NorthEast coast of Bonaire. Gets hit direcly by all the carribean waves, very intense waves. Bonaire is about 50 miles north of Venezuela.
Posted by tyler | May 23, 2005 8:42 AM
Posted on May 23, 2005 08:42
Is the wave farm friendly to ecosystems? Because I know Dams/hydroelectric powerplants are not since they turn shallow river into deeper water and change the ecosystem.
Posted by Thomas | May 23, 2005 9:19 PM
Posted on May 23, 2005 21:19
Tavita, the systems are designed to go into a "survival" mode if the waves get too heavy. You won't get any power during the putative Class 5 Hurricane, but the wave power generators should survive it.
Thomas, the wave/tidal power systems appear to be much, *much* less disruptive to ecosystems than dams. They aren't walls so much as big "rolling pins" floating on the surface. They just don't take up a large amount of space.
Posted by Jamais Cascio | May 23, 2005 11:21 PM
Posted on May 23, 2005 23:21
Thanks Jamais, I live on an island in the South Pacific and Category Five Cyclones are all too real down here; surviving one of those would be quite impressive. I find this technology very intriguing and hope the Portugal project succeeds.
As far as effecting ecosystems, I wonder if they would act as fish attracting devices (fads) and, if so, what effect that would have on ecosystems if there were a large number of such farms.
Posted by Tavita | May 24, 2005 10:33 AM
Posted on May 24, 2005 10:33
The only problem for this in Portugal are the local political conditions. Hope this project is a sucess. EU imposes a 39% renewable energy quote by the year 2010. Studies indicate that natural conditions here permit an 70 to 80% of electrical power from Renewable Energies. Is there any political desire to this? Off course notÂ…
Posted by Carlos Sant'Ana | May 24, 2005 3:16 PM
Posted on May 24, 2005 15:16
The only problem for this in Portugal are the local political conditions. Hope this project is a sucess. EU imposes a 39% renewable energy quote by the year 2010. Studies indicate that natural conditions here permit an 70 to 80% of electrical power from Renewable Energies. Is there any political desire to this? Off course notÂ…
Posted by Carlos Sant'Ana | May 24, 2005 3:24 PM
Posted on May 24, 2005 15:24
This sounds fantastic. I do have some questions. The oil used as a hydraulic, what kind of oil is it? How much oil is there? What happens if it leaks out and/or ruptures and spills?
I really really really want this kind of thing to work.
Posted by Colin J. | May 27, 2005 9:54 AM
Posted on May 27, 2005 09:54
And what is needed to extract hydrogen from sea water quickly and efficiently?
Why a little electricity of course. So with but a few modifications one could use the same mechanisms to convert sea water into hydrogen for other purposes. This layered with some osmosis tanks and a few filters would put out fresh potable drinking water. And so on.
Posted by IXLNXS | May 27, 2005 5:00 PM
Posted on May 27, 2005 17:00