Wave Energy Converter - why not more of these?

[argentox]

Pelamis Wave Energy Converter generating electricity into the Portuguese grid off the coast of Aguçadoura, Portugal, October 2008. Can anyone tell me why we do not do more of these projects?

http://www.youtube.com/watch?v=JYzocwUfpNg
http://www.youtube.com/watch?v=F0mzrbfzUpM
http://www.youtube.com/watch?v=mcTNkoyvLFs

Eric W. Schreiber, BSc(EE), MBA

http://www.ericwschreiber.com

http://www.linkedin.com/in/eschreiber

 

[MikeHalloran]

For one thing, it's a hazard to navigation.

For another, it's got a lot of mechanical parts moving in seawater continuously, and just as many popping in and out of the water, which is probably worse.

For another, it's going to attract idiots, who will inevitably be maimed in one of the many pinch points.

The idiots will arrive in their boats, sometimes the hard way, e.g. at night, steering between the navigation lights at full speed. Don't tell me it won't happen; it happens to submarines, which have lights on the sail and the fin, and non- navigable water between them.



Mike Halloran
Pembroke Pines, FL, USA

 

[GregLocock]

Wave energy has a long and inglorious history. I think one problem is that wave energy is not especially reliable, and once in a while too often you'll get a hundred year wave to really check the system design out.

Another thing to think about is the energy density, by which I mean the size of machine you need to get a certain power output.

The sea is a pretty tough environment.

You often need a rectifier which is either inefficient or expensive.

Finally you are generating power in the wrong place, so you have transmission losses.

I think tidal barrage or tidal current systems make far more sense.





Cheers

Greg Locock

SIGlease see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[stevenal]

How many should we be doing? The technology is still new. Here is a map of the preliminary permits that have been issued in the USA. Many more have been applied for.

http://www.ferc.gov/industries/hydr...okinetics/issued-hydrokinetic-permits-map.pdf

Gotta disagree with it being in the wrong place. Population centers tend to lie along the coasts.

As far as energy density, like wind it is a nice concentrated form of solar; using the whole area of the ocean for collection. It is more steady and dispatchable than wind, since there are existing bouys to let you know what is coming. Best for winter peaking areas.

 

[IRstuff]

While populations tend to live near the coast, they're not there solely for the beaches. The waters surrounding Los Angeles are jam-packed with large shipping and small vessels. This would be relatively typical of most coastal population centers.

TTFN

FAQ731-376

 

[stevenal]

LA is a good example in one way. Part of their power comes from the Columbia River hydro system via the DC link. The waves are a tad closer. On the down side, the waves are much smaller in the summer when the loads are highest.

I'm sure the skippers will be able to avoid well marked and charted wave parks. The largest concerns are coming from crab fishermen and surfers.

 

[IRstuff]

Reality is otherwise. Some knucklehead captain managed to crash his cargo ship onto one of the Golden Gate Bridge's supports:

http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2007/11/08/MNUKT85I3.DTL

and:

http://cbs5.com/local/tanker.ship.aground.2.919597.html

TTFN

FAQ731-376

 

[stevenal]

Okay, let me re-phrase. If the wave parks are properly marked and charted, the owners will be able to bill the carrier and their insurance for the damaged caused when collisions occur. Better?

Perhaps we can eventually reduce the number of petroleum carrying tankers with technologies like the one under discussion.

 

[IRstuff]

Actually, it'll make it worse. Reducing the demand for oil will drop the price, allowing cargo shipments to be more cost effective, thereby increasing overall shipment volumes.

TTFN

FAQ731-376

 

[argentox]

Thank you for the comments and contributions. I certainly learned something...and makes me wonder further on the pros and cons of the popular renewable energy technologies (tidal, wave, wind, solar, hydro, etc.) Personally I think that solar power has big disadvantages (asset that works only during daylight just for starters) hence, I can visualize a sort of "energy park" with tidal wave and wind assets confined in an area out at sea.
Thank you again for the insights.
Sincerely,


Eric W. Schreiber, BSc(EE), MBA

http://www.ericwschreiber.com

http://www.linkedin.com/in/eschreiber

 

[L4189]

You forget the most reliable renewable energy source of all- garbage. Long Island has 2 large incinerator/generators that run day and night.

 

[argentox]

I certainly did forget about it.
Do you have any good references on what is the cost/MW for these renewable energy sources. Not only asset installation, but also life cycle cost. I think that the incinerator/generators need "costly" garbage, no? (Meaning that they do not burn just anything).
Thank you for the post.





Eric W. Schreiber, BSc(EE), MBA

http://www.ericwschreiber.com

http://www.linkedin.com/in/eschreiber

 

[L4189]

The Hempstead unit is about 30 years old and they charged $^& a ton tipping fees. There was an amusing lawsuit brought against the independent collectors by the Town of North Hemstead for goung to the incinerator instead of the town landfill because it was a few bucks cheaper. I think the unit was built by American Ref-Fuel and is now operated by Covanta Holdings. They plan a expansion at the Hemstead Plant probably to get garbage from Brooklyn and Queens. So they get money up front to take the stuff then make electricity that they sell to LIPA. I think they claimed that the garbage reprensented 5000 btu/lb. as fuel. The whole thing is a God send to Long Island as they still have problems with the North Hemstead Mount Trashmore.

 

[IRstuff]

That's certainly an option, but comes with tons of carbon dioxide, so there's a rather gigantic footprint in all of that.

TTFN

FAQ731-376

 

[L4189]

They sell the electric power to LIPA for "avoided Costs" primarily the oil of gas that LIPA would burn to produce the same electricity. Not to mention the fuel burned to transport it to where ever so that it ca rot and produce CO2 anyway. By the way where is Global Warming when you need it.

 

[IRstuff]

It's been here in southern California for the past 3 weeks, running 100+ temps on many days.

TTFN

FAQ731-376

 

[L4189]

It was a little better than half that up here in Seattle this morning. I using up next winters bio fuel to take the chill off. Getting back to the subject of using tidal energy, the town I grew up on long island has at least 3 sites along shore road where there were mills that used water impounded behind a dam to run the mill at or near low tide. I think they filled the pond on a rising tide, closed the gate then opened the gate at low tide to run a water wheel. Roslyn still has their mill intact. I thought I saw somewhere, maybe in the ASME magazine that there was a proposal to use something like the azupod (?) propulsion device to generate electric power in deep water from tidal current. There was something similar for use in fast flowing rivers. A poor man's hydro power plant. GE is building a plant to develop and build sodium salt batteries to store energy produced intermittently and producing AC power with inverters such as they already use on AC locomotives. Tidal currents at least are pretty predictable at least.

 

[MikeHalloran]

Submerged propeller turbines seem to be nearing installation in the lower Mississippi. It will be interesting to see how they do in fast flowing mud.



Mike Halloran
Pembroke Pines, FL, USA