Very simple idea: hydrothermal vents spew hot sulfur-rich water into the ocean. There are ever better maps of the biogeography of these vents, so we know where many of them are, how hot they are, and which kind of minerals they contain.
Harvesting the energy from this super hot water should not have to be that difficult.
You let a stirling engine, encased in or made from strong steel, sink to the bottom of the ocean, and put it on stilts, over the vent. The "hot" part of the engine is put onto the vent. The "cold" part is facing up, into the colder water above.
The stirling is connected to a generator.
Everything is attached to a strong electric cable which reaches your ship at the surface.
Now you have electricity which you can use for several purposes.
1. desalinate water. A way of embedding the energy into a useful product.
Ship out the fresh water in big plastic bags to shores where it can be used to green deserts or for consumption by humans.
The big plastic bags are a cheap, existing technology. But it didn't come true that easily, because the sources of water that some of these companies wanted to tap, were off-limits (rivers, protected by conservationists, rightly so).
2. Alternatively, you can use the electricity to make hydrogen from desalinated water and ship that out.
3. Still a better alternative might be to use the electricity locally, to power remote underwater vehicles and drills to explore for minerals.
Apparently, the rocks of many of these hydrothermal vents (and the rocks in the vicinity) show high concentrations of valuable metals (gold, silver, copper, zinc, etc...) [see link].
EDIT: I just noticed there's a post titled "geothermal from hydrothermal vents". My idea is a tad different and more focused on ways to get the energy out. It's also less aggressive in certain respects. So I'd want to keep it instead of deleting it.-- django, Sep 12 2008 Nautilus Minerals http://www.nautilus...rals.com/s/Home.aspGold, silver, copper, zinc - for grabs [django, Sep 12 2008] Fascinating. http://www.ted.com/...he_deep_oceans.html [2 fries shy of a happy meal, Sep 15 2008] The problem is that the vents change locations often. [link]-- 2 fries shy of a happy meal, Sep 15 2008 Hey, look - a whole new ecosystem for us to fuck up.-- Loris, Sep 15 2008 Use Seebeck-effect generators. [+]-- 8th of 7, Sep 15 2008 //Hey, look - a whole new ecosystem for us to fuck up.//
It's not like we would tell you where our bots are drilling.
We will only sell you our goodies. I'm sure you'll buy.
Seriously, though, the drilling is not necessary, we might just want to use the electricity to desalinate water and ship it to places where we can use it to restore ecosystems that have been 'fucked up' by desertification and drought.-- django, Sep 15 2008 Try the UAE - they'd buy it. Fuck knows how they are going to get drinking water once their cheap electricity generators powering their desalination plants are too expensinve to run. But given they live in the desert they might actually realise there is such a thing as solar power.-- williamsmatt, Sep 16 2008 In case you are talking about highly efficient multi-junction photovoltaic cells, I offer my services to go out to mine the gallium, the arsenide, the indium and the germanium at the sea floor. :-)
In case you're talking solar-thermal, I'm duly screwed (we were using the word 'fucking' too often anyways.)-- django, Sep 16 2008 Yeah - if only you could be there at the right time, eh?-- david_scothern, Sep 16 2008 Supplying water, I'm afraid, will not help. Somalia, and especially Mogadishu, once the pearl of the horn of Africa, are now the place of deforestation and desertification. It is not water they need. It is the need to realize what planting trees will do for them. Until then, it will be hotter, and people will smile less, and shoot each other more.-- pashute, Mar 17 2011 random, halfbakery