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Seaweed Power

Use the power of nature and the vastness of the ocean for our energy needs.
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This idea has 3 parts, which I will describe seperately:

1. Giant floating nets. Made of a strong material that is coated with a seeded substrate that can support seaweed life.

2. Autonomous solar-powered ships. These ships slowly tow the floating nets into the ocean where they won't obstruct ship traffic.

3. Harvesting plant. When seaweed is fully grown, the ships bring the giant nets to the harvesting plant. The plant strips the seaweed and adds new substrate to send the nets back to the ocean. The harvested seaweed is dried then burned as a fuel source. Pollutants are scrubbed from exhaust using existing technology.

The net effect is a renewable solar plant that has no significant ongoing costs other than maintenence. All carbon released into the atmosphere was absorbed from the atmosphere by the seaweed in the first place. Seaweed grows quickly and will likely support sealife. The number of nets is only limited by the intake capacity of the plant.

(later) Could also be used for biodiesel. I'm thinking of stainless steel nets with floats, but [kbecker]'s seaweed rope nets may work as well.

This could also be used as a food source for food-poor countries.

Worldgineer, Jan 13 2004

Seaweed Power http://www.geocitie...symail/HB/nets.html
Yes, an actual drawing, by me. Feel free to print it out and frame it. [Worldgineer, Oct 04 2004, last modified Oct 06 2004]

Seaweed grown in mass quantities http://www.irishscientist.ie/UCGSK128.htm
62 tonnes of kelp were produced in a year - sounds like a fast enough growth cycle. (elsewhere I found that it takes nori a bit over a month to fully mature, but the site wasn't very linkable) [Worldgineer, Oct 04 2004, last modified Oct 06 2004]

Kudzu (Pueraria lobata (Willd.) Ohwi) http://www.vnps.org/invasive/invpuer.htm
"Almost any disturbed area is suitable habitat for this vine. Roadsides, old fields, vacant lots and abandoned yards are all prime spots for new kudzu growth." [phoenix, Oct 04 2004, last modified Oct 06 2004]

The Green Plague Moves North http://www.lib.niu.edu/ipo/oi000208.html
"By the 1980s, kudzu had covered an estimated 7 million acres of land...and each year, this amount was estimated to increase by another 320,000 acres...The vines develop from starchy tubers which can grow to depths of 10 feet and weigh 200 to 300 pounds. Kudzu also has extraordinary growth rates of up to a foot a day and 60 feet in a year." [phoenix, Oct 04 2004, last modified Oct 06 2004]

The House Aquatic http://www.halfbake...e_20House_20Aquatic
Your sytem could be integretated into my flaoting home... imagine a wreath-like circular carpet of kelp extending for a huge distance constantly rotating and sustaining the homes food and energy needs. [Leotardo Da Vinci, Oct 04 2004, last modified Oct 05 2004]

Carrageenan http://philexport.o...bers/siap/intro.htm
You probably had some today. [waugsqueke, Oct 04 2004, last modified Oct 06 2004]

biodiesel from algae http://www.unh.edu/...l/article_alge.html
Biodiesel from algae [maxwellian, Oct 04 2004, last modified Oct 06 2004]

Japan to create prototype Worldgineer Seaweed Power plant http://www.timesonl...,,3-1611170,00.html
[Worldgineer, Nov 08 2005]

[link]






       Why seaweed? Why not kudzu or hay or something easier to come by?
phoenix, Jan 13 2004
  

       Because hay and kudzu don't grow in the ocean. We are overfarming our land - there just isn't much room to grow crops for energy. The sea, however, is mostly empty.
Worldgineer, Jan 13 2004
  

       //The plant strips the seaweed and adds new substrate to send the nets back to the ocean.// That may be an expensive process and hard on the net. Also nets tend to tangle up. It may be easier extract some fiber from the harvested seaweed and use it to make a new nets. The old net is burnt together with the rest of the harvest. If the right seaweed is bred (still some GM magic here) fibers could also be used as cotton replacement.   

       This may not be a solution for all energy problems because that may take too much surface area in the ocean, but several percent of the demand could probably be done.
kbecker, Jan 13 2004
  

       Does CO2 for seeweed come from the atmosphere? I had thought that it came from dissolved CO2 in the water. I am sure this equilibrates with the atmosphere to some degree, but I have also heard that the oceans could function as a CO2 sink. If that is the case, we might be pulling CO2 out of the ocean and putting it into the atmosphere.   

       But I still like it. This could be done in that dead area by the arctic that is starved for iron. A little iron supplementation and voila - there's your seeweed harvest. Plus I like to think that this scheme would help fish, which we eat and eat and never try to assist in any way.
bungston, Jan 13 2004
  

       //Does CO2 for seeweed come from the atmosphere?// Yes, lot of it does, but you are right about being careful. Start small and watch what happens.
kbecker, Jan 13 2004
  

       How do you dry it? You'd need a vast area to spread it out in the open air. Sun-drying, especially in cold climates, will take a long time.
kropotkin, Jan 13 2004
  

       I will dry it using its own heat. This is a common technique for biomass plants. Here are the steps I currently envision (this all happens in the yellow building in my drawing - the building should actually be much longer than I've drawn it):
1) Rollers press seaweed to make somewhat dry
2) Steam-heated pipes heat seaweed to dry
3) Seaweed is burned, heating steam
4) Steam both drys seaweed and powers turbines
5) Nets are coated and returned to sea
Worldgineer, Jan 13 2004
  

       How fast does sea weed grow? I was considering something like this for the house aquatic -- see link... but for the fish farm and for eating/nutrients.   

       Could your system be used to power my floating home?
Leotardo Da Vinci, Jan 13 2004
  

       //Could your system be used to power my floating home?//
Perhaps. I'm not sure of the process of turning seaweed into biodiesel, but it is not unimaginable that it could be done in small batches. It could definately be used as a food source.
Worldgineer, Jan 13 2004
  

       [bung] You're right that CO2 is in equilibrium between the oceans and atmosphere but the oceans have huge amounts of C locked in as marine carbonates - hence they represent the largest global carbon sink.
hazel, Jan 13 2004
  

       [px], I don't get your point. If you had a mechinized way of harvesting kudzu that would be something. Even then you'd be using valuable land. If we could only get them to drink seawater...
Worldgineer, Jan 13 2004
  

       Isn't this essentially solar power? I mean we need to use bio-diesel for autos because we can't put huge solar arrays on our cars. But aren't kelp beds esentially solar collectors that turn that energy into living material? So... would you get more power just by putting your money into solar panels rather than kelp beds? Considering all the energy you would lose in the process of harvesting and extracting the energy from the kelp...   

       Another possible idea is to actually have the harvesting machine/the factory itself be the moving part...
Leotardo Da Vinci, Jan 13 2004
  

       Yes, this is solar power. The problem is that the cost of photovoltaics is prohibitive and is not generally paid back by energy savings. To produce thousands of square miles of PV panels and float them on the ocean would not be feasible. However, floating plants that grow themselves should be much cheaper.
Worldgineer, Jan 13 2004
  

       I don't know or care much about seaweed, but I am concerned about the hazard posed to sea dwelling creatures by your giant floating nets.
waugsqueke, Jan 13 2004
  

       Isn't kelp almost entirely made of water though? Not much mass? So while it grows fast and weighs a lot when hydrated there is very little material there when dehydrated/dried.   

       I hope I am not sounding negative. I like this idea. If it works it would be awsome.
Leotardo Da Vinci, Jan 13 2004
  

       [waugs] I agree - we'll have to be careful about that. Properly planned, this will greatly increase sealife population. Poorly planned and we'll end up with a bunch of dead dolphins.
Worldgineer, Jan 14 2004
  

       So what do we do now? Worldgineer may have saved the world with this idea... but what do we do with it?   

       I still fear that when you actually tried to put this idea into action that the amount of energy you got from the seaweed wouldn't be worth the trouble you had to go through to get it.   

       Can anyone convince me that these fears are unwarranted?   

       What types of creatures eat seaweed? I know that kelp is used in a lot of things... but could either humans or animals live on a diet almost solely of kelp? If this idea doesn't solve our energy problems it could solve the worlds hunger problems..
Leotardo Da Vinci, Jan 14 2004
  

       We constantly fight drift nets, even where their use is illegal. The intended kill catches EVERYTHING, and the ghost nets lost and left to drift take all from whales on down. Redesign concept, please.....
normzone, Jan 14 2004
  

       The difference here is a strong monofiliment net that doesn't float (or at least not horizontally) and either a stainless steel or organic net that does. In the case of the stainless steel we can make the holes very big, and with the organic net we can make it weak. In both cases it will float, and in both cases we could change it to a set of ropes instead of a net if this is still a problem.
Worldgineer, Jan 15 2004
  

       Kelp is also harvested on the east coast of Canada. I'll try to find you a link, world. They had a harvester of sorts.The locals told me the rockweed (common green stuff, Ascophyllum nodosum if memory serves) is used mainly for fertiziler. There is a red one harvested off the coast of Grand Manan island that is dried and sold as a snack food called "dulse". Quite nasty tasting unless you like rotten fish I suppose.
lintkeeper2, Jan 15 2004
  

       Maybe someone has already said this, but there is sixty times as much CO2 in the oceans as in the atmosphere, so the net non-equilibrium result of burning seaweed will be to transfer CO2 out of the oceans and into the atmosphere.
ldischler, Jan 15 2004
  

       Don't go messin' with my oceans, man. Where there's seaweed, there's algae, and too much algae is a bad thing.
RayfordSteele, Jan 15 2004
  

       //where there's seaweed, there's algae// Are you sure of this? And isn't the main problem with algae blooms is that they rob the ocean of oxygen? If so, doesn't seaweed completely counteract this effect?
Worldgineer, Jan 15 2004
  

       There's also the matter of sunlight, coral reefs, native vegetation, etc.   

       I dunno, I'm just against screwing with the oceans any more than we already have. Too much that we don't know yet. Check out what can go wrong by looking up 'caleurpa taxifolia.'
RayfordSteele, Jan 15 2004
  

       True, there are many issues with any new large-scale innovation. However, nothing you've listed is a significant challange. Just for fun I'll list potential solutions:
1) sunlight: I assume you mean stealing sunlight from plants below? The ocean's a big place - we can vary our path for each automated boat.
2) coral reefs: If there's an issue, then don't locate this near coral reefs.
3) native vegetation: We can use native vegetation as the plant material. Even if non-native species grow on nets, they are purified each cycle (through burning).
4) 'caleurpa taxifolia': Same as 3. If these start growing on nets, they won't for long.
Worldgineer, Jan 15 2004
  

       Start with a kelp seeded hemp nets/mats as surface drifting hanging gardens. These rafts would be constrained by leash to a brackish un-navigable tidal river outlet area with sufficient depth beneath the raft so as not the impede nature. This assumes that surface saline concentration of brackish water supports health kelp growth. The rafts would be held dispersed and would change position with the tides and wind to minimize any localized impact on the local river bed life while also providing bait fish habitat. The rafts might actually feed filter some land waste pollutants from the water and would be sized so that they can be rolled and manually lifted for on site harvest to an auger driven extruder. Most of the water is remove during extrusion before the mass degrades (smells). The quick money product is still an environmentally friendly (Yes… fire accelerates the carbon cycle) renewable hemp and seaweed biomass fuel pellet supply with a secondary potash (fertilizer) product from the burnt waste.
Caplin Cove, Mar 30 2004
  

       Simpler Algae is the answer as opposed to kelp. Algae oil could meet all fuel needs for the US using a rather small amount of area and recources, Special algae that are about 50% oil by weight can be grown in salt water ponds, or covered ponds that recycle water, and fertilized with sewage, getting rid of another problem. The algae is easily harvested, just suck it up and press the water out, the oil can then be extracted easily. The Algal oil could then be used as a feedstock for biodiesel, and potentially for other things petrol is used for.
maxwellian, Jun 27 2004
  

       Great ideas, [max] and [Caplin].
Worldgineer, Mar 10 2005
  

       I was thinking about that variant clone Caulerpa seaweed that is taking over the Mediterrranean - there is a fast way to generate biomass in the ocean. Faster than kelp. I was also thinking about the dead zones at the mouth of the Mississippi and elsewhere - presumably because of an excess of fertilizer, subseqeunt algal bloom and dieoff, then rot. Caulerpa barges there could benefit from the high fertilizer content of the water. They would be harvested before the dieoff, and would serve to attenuate the deadzone as well.   

       One can always burn biomass for fuel. I recently saw an article about ConAgra and their attempts to devise an enzymatic system which would ferment corn waste into ethanol, for use as fuel. Apparently this is not a trivial undertaking.   

       The corn waste thing makes me wonder if there is already surplus waste biomass around which is not currently being burned for fuel, maybe for good reason. For example: human poop. Lots of it and steady supply, but I know of no operation which chucks the stuff into an incinerator like coal.
bungston, Aug 10 2005
  

       It's value is too high as fertilizer for that. I've heard of burning elephant dung, though I don't remember the reason or the context. Quite a bit of biomass is used for fuel, when economics dictates. Peach pits, for example, have little use and must be put in a dump (pricy) or burned (also pricy, to comply with clean air regulations). I've been to a plant that takes peach pits from nearby peach canneries and uses it as free fuel to generate electicity.
Worldgineer, Aug 10 2005
  

       //I've heard of burning elephant dung, though I don't remember the reason or the context. //   

       Heh. Since I wrote that I've been to India, and no cow dung seems to be wasted there. It's hand-collected, rolled into balls, then thrown against rocks to flatten. They dry the patties in the sun, and the result is a fuel they use for fires. I believe one of my meals was cooked over a dung fire.
Worldgineer, Apr 04 2008
  
      
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