Someone suggested on my last diary (
Think Hot, Not Watt) that I post a few smaller diaries to gain a "reputation." Usually I post such material over at
DUs E/E group but heck I can paste it here too. Not sure if a reputation is what I want, I'm more a "leave breadcrumbs around and they'll get found by a bird much louder than I" kind of guy. But heck, I suppose a little promo work can't hurt.
Wave Power isn't one of the technologies that folks usually list off the top of their head along with solar and wind. It is starting to gain traction, though. It's nice that the idea is getting enough support that there is now a fledgling industry to live vicariously through. Here's the latest significant news.
What's it look like? Well, there are shoreline impact models like the below photo, as well as offshore ocean rig plans, under-dock bouys, and who knows what else. Maybe the lack of a consistant icon like a big white turbine on a hillside is one reason why they go unnoticed.
On to the news:
New Jersey-based Ocean Power Technologies (OPT) announced that it recently received additional funding of US $2.8 million for its ongoing contract from the US Navy to build a wave power station off the Hawaiian island of Oahu.
OPT's wave energy converter consists of a vertically oriented column that absorbs the rising and falling motion of ocean waves to cause the buoy mechanics to move freely up and down. This movement in turn drives an electric generator that creates AC power. The AC power is then converted to high voltage DC, which can be cabled to the mainland for use. The company expects a typical 1 MW project such as this to cost (US) 7-10?/kWh.
http://renewableenergyaccess.com/rea/news/story?id=37418
OK so maybe that was last week, but deployments are so much more newsworthy than technical research IMO, that it deserved mention.
Bourne has successfully completed tank testing a scale model of its OceanStar (OS-1MW) ocean energy harvester which is designed to be cost-competitive, self-contained and highly scalable. The OS-1MW is designed to pump energy on shore to existing electrical power grids. The technology, machinery and manufacturing system are patented by Bourne Energy. The OceanStar project represents four years of research, design and testing and includes optimizing the structure of the wave, refining the hydraulic response of the device, developing an efficient energy absorber for variable speed and extreme stresses, developing an efficient power transmission system, optimizing design for assembly manufacturing and reducing the energy component of construction, maintenance and operation.
http://www.prweb.com/releases/2005/10/prweb297855.htm
...another renewables company sparse on technical details on their website. So what they are up to engineering-wise is anyone's guess, other than their stated goals of low construction and maintenance costs/energy input.
Engineers have tried a range of different techniques to tap the power of the sea, but none has yet seen large-scale use. Most rely on channelling water over turbines, pushing air through pipes or harnessing the gentle rocking motion of a buoy. Although prototypes have shown promise, scaling up these devices has proven tricky.
...
His invention uses the up and down motion of a floating buoy to move an electrical coil along a stack of magnets, which generates an alternating current in the coil.
http://www.nature.com/news/2005/051010/full/051010-6.html
For the genset geeks: likely a close match to the "stacked magnet" generator mentioned (PDF!):
http://www.lancs.ac.uk/staff/bakern/papers/pemd2004.pdf