# An Answer to the World's Energy Problems **URL:** \ **Category:** Factual Questions\ **Created:** [June 8, 2001, 12:29am UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991 "2001-06-08T00:29:16Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![roryaxis](https://avatars.discourse-cdn.com/v4/letter/r/8dc957/32.png) [@roryaxis](https://boards.straightdope.com/u/roryaxis)\ **Post date:** [June 8, 2001, 12:29am UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/1 "2001-06-08T00:29:16Z")
Okay, why can’t we build windmills in the ocean? These, sea-mills I guess you would call them, would work exactly like windmills, except that they would use the ocean’s currents instead of wind. The big problem with windmills is that there isn’t always an steady supply of wind, but in the ocean the current is as consistant as clockwork. Would there be a problem with habitat? I don’t think so, but I’m no marine biologist, but windmills don’t seem to be a big problem for birds, and the fish in the ocean already deal with the current. The sea mill turbines themeselves wouldn’t generate any new current, just use that which was already there. They could be build out of high tech, space age, state of the art materials that wouldn’t rust. So…so what’s the problem? Seaweed clogging the moving parts? Fish pureed? Anyone out there know if these things wouldn’t work, or know some basic problem I havent’ thought of? If not, anyone wanna fund some experiments? ---
**Author:** ![IBBen](https://avatars.discourse-cdn.com/v4/letter/i/85f322/32.png) [@IBBen](https://boards.straightdope.com/u/IBBen)\ **Post date:** [June 8, 2001, 12:58am UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/2 "2001-06-08T00:58:37Z")
Instead of tapping the ocean’s currents, why not tap into the most powerful (and predictable) force: Tides. I know that tidal damns exist but I have always wondered why this is not a legitimate source of power. My best guess as to why the _water-mill_ you propose above would not work is because the blades would become encrusted with marine life and not function properly. Also, salt water would wreak havoc on any and all moving parts. Tidal damns: Twice a day, the ocean rises and falls. Unlimited power in my humble opinion. Here’s a site: [http://waterpower.hypermart.net/tidal.html](http://waterpower.hypermart.net/tidal.html) ---
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [June 8, 2001, 1:02am UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/3 "2001-06-08T01:02:59Z")
We can. There have been a lot of proposals for various schemes for ocean energy using currents, thermal transfer, tides and waves. Some references: [http://www.eren.doe.gov/consumerinfo/refbriefs/v116.html](http://www.eren.doe.gov/consumerinfo/refbriefs/v116.html) Here’s an item about the “World’s First Ocean Current Power Plant”: [http://www.futureframe.de/news/000117-4.htm](http://www.futureframe.de/news/000117-4.htm) ---
**Author:** ![Ringo](https://avatars.discourse-cdn.com/v4/letter/r/779978/32.png) [@Ringo](https://boards.straightdope.com/u/Ringo)\ **Post date:** [June 8, 2001, 1:09am UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/4 "2001-06-08T01:09:35Z")
Windmill farms must have an effect on the environment. I’ve heard things to the effect that they can be hard on the birds, but I know little about that. The other thing I wonder, which would be similarly applicable to the effects of an array of sea turbines, is what meterological effects are realized by the presence of the windmills? They withdraw some energy from the wind - what does that do down the line? Do they somehow pull a Peking Butterfly on the rainfall somewhere? Another thing you’d want to consider would be cost effectiveness. Can you implement such an array that will draw enough energy benefit to offset its costs (both in cash rendered and environmental)? As far as subsea structures go, fish actually seem to like oil platforms. But oil platforms don’t spin. > [@](#): > > My best guess as to why the _water-mill_ you propose above would not work is because the blades would become encrusted with marine life and not function properly. Also, salt water would wreak havoc on any and all moving parts. All just part of the cost effectiveness question, as these are things that can be dealt with through maintenance. I do vaguely remember someone having an idea about articulated floats the would harness wave energy. Anyone? ---
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [June 8, 2001, 1:23am UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/5 "2001-06-08T01:23:36Z")
The main stumbling block with most of these areas of research seems to be that they’ve been generally determined to be uneconomic. beatle - you may be thinking of Salter’s “ducks”, which were proposed in the 1970’s. ---
**Author:** ![bashere](https://avatars.discourse-cdn.com/v4/letter/b/779978/32.png) [@bashere](https://boards.straightdope.com/u/bashere)\ **Post date:** [June 8, 2001, 2:25am UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/6 "2001-06-08T02:25:23Z")
There was an article in the economist with in the last 3 weeks about this. There is thought to building several tide-powered bouys off the coast of australia (if memory serves). The article didn’t make the on line addition. If you’re interested I’ll summarize if I still have the issue at home. ---
**Author:** ![johnson](https://avatars.discourse-cdn.com/v4/letter/j/d07c76/32.png) [@johnson](https://boards.straightdope.com/u/johnson)\ **Post date:** [June 8, 2001, 2:46am UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/7 "2001-06-08T02:46:40Z")
The _Economist_ article was very interesting (as usual, though their redesign is crap). The bouys are driven by waves, not tides, and the only maintenance required is scraping barnacles off every now and again. An added bonus is the reduction in waves’ energy as they hit the shore, presumably reducing erosion. ---
**Author:** ![Phobos](https://avatars.discourse-cdn.com/v4/letter/p/3d9bf3/32.png) [@Phobos](https://boards.straightdope.com/u/Phobos)\ **Post date:** [June 8, 2001, 12:44pm UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/8 "2001-06-08T12:44:37Z")
As has been stated, such technologies have been considered (usually taking advantages of coastline tides). I’m not too familiar with the technology, but my impression has been that it is not cost-effective as compared to what is already in-place. At least not yet. Clogging, corrosion, weathering, and undercutting would be of concern. Consider the maintenance headaches (and expense) of working in the ocean. Power output per area would be a big consideration (would you need to suck up miles and miles of coastline waves to power a city? I dunno offhand but consider the environmental impacts of that!) Overall, there are engineering challanges, but it doesn’t seem so impossible that it may happen someday. ---
**Author:** ![xizor](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xizor/32/102_2.png) [@xizor](https://boards.straightdope.com/u/xizor)\ **Post date:** [June 8, 2001, 2:05pm UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/9 "2001-06-08T14:05:21Z")
One engineering problem I see with the OP’s proposal is location. To tap an ocean current, you would have to go miles into the sea (away from the coast) with your windmill device. How are you going to get the current back to land? Big long cables? And wouldn’t you need to anchor this thing to get maximum efficiency? If it was just floating the current would just push it around and most of the energy would be lost. Harnassing the tide as mentioned earlier sounds a lot more plausible. ---
**Author:** ![toadspittle](https://avatars.discourse-cdn.com/v4/letter/t/c0e974/32.png) [@toadspittle](https://boards.straightdope.com/u/toadspittle)\ **Post date:** [June 8, 2001, 3:10pm UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/10 "2001-06-08T15:10:31Z")
> [@](#): > > \*Originally posted by xizor \* > \*\*One engineering problem I see with the OP’s proposal is location. To tap an ocean current, you would have to go miles into the sea (away from the coast) with your windmill device. How are you going to get the current back to land? Big long cables? And wouldn’t you need to anchor this thing to get maximum efficiency? If it was just floating the current would just push it around and most of the energy would be lost. Harnassing the tide as mentioned earlier sounds a lot more plausible. \*\* Considering the insane efforts we go to now to get some black goop from the earth (Alaskan pipeline; oil tankers shipping crude from Saudi Arabia to Venezuela to the U.S.; plus, what maniac first thought it was a good idea to stick giant oil-drilling platforms in the middle of the stormy North Atlantic?), I’m sure we could overcome the problems of power transmission, etc., given enough interest/profitability. Of course, if fuel cell technology becomes more viable/commonplace, we could have an ocean-based power plant that used water motion to generate electricity to separate hydrogen out of seawater–and we certainly have plenty of expereince transporting gases/refrigerated liquids (see pipeline/oil tankers above). ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [June 8, 2001, 4:11pm UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/11 "2001-06-08T16:11:10Z")
[QUOTE] \*Originally posted by toadspittle \* \*\* > [@](#): > > Considering the insane efforts we go to now to get some black goop from the earth (Alaskan pipeline; oil tankers shipping crude from Saudi Arabia to Venezuela to the U.S.; plus, what maniac first thought it was a good idea to stick giant oil-drilling platforms in the middle of the stormy North Atlantic?), I’m sure we could overcome the problems of power transmission, etc., given enough interest/profitability. > \*\* That “black goop” has an impressive amount of energy per unit volume, and a windmill/watermill offers little in the way of competition. ---
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [June 8, 2001, 4:16pm UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/12 "2001-06-08T16:16:01Z")
> [@](#): > > \*Originally posted by roryaxis \* > **Okay, why can’t we build windmills in the ocean? These, sea-mills I guess you would call them, would work exactly like windmills, except that they would use the ocean’s currents instead of wind…** OK, you’re on the right track, but you’re missing an even greater source of free energy. The wind! Ocean breezes are virtually perpetual in some regions. If a bank of modern windmills (as found in the Western US) were built upon screw-pilings, for example, the wind could be harnessed with low set-up costs. Maintenance costs might be higher, however. As for harnessing tides, this is already done in places around the globe where tidal changes are frequently significant enough to make it an economical venture. As for harming fish with what you are proposing, don’t forget your waterwheel is simple a turbine. Basicall, you’re describing a type of hydro-electric power (without dams) such as power plants found along the Niagara River. I am not sure how they maintain these turbines due to the effects of the hostile operating environment. Proposals like these are NOT far-fetched. And, while individually they won’t solve the overall energy problem, they will help offset our dependenc on conventional means (and OPEC). Keep thinking! The answers are not reall beyond our grasp! - Jinx ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [June 8, 2001, 4:20pm UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/13 "2001-06-08T16:20:35Z")
I read somewhere that harnessing tides effectively brakes the earth’s rotation because the movement of the tides is as much a function of the earth’s rotation in relation to the sun as it is of the moon’s rotation around the earth. Interesting; a 25 hour day and 350 day year eventually? (probably not in my lifetime though) ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [June 8, 2001, 5:56pm UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/14 "2001-06-08T17:56:49Z")
Harnessing the wind is trickier and more expensive than you think. Wind power increases with the cube of the speed so you have a relatively narrow range in which a windmill is efficient. Below that speed you get little to no energy, above that speed the windmill has to be protected or it will destruct. Go to any of the sites reporting wind speeds at different sites and you will see one thing about wind speed is it ain’t constant. So basically you have to think in terms of designing a machine which will withstand _any_ wind speed, will generate useful energy part of the time, hardly ever at peak efficiency, and not generate anything useful a great part of the time. Now think that the machine generates when _it_ wants, not when _you_ want… Add to that siting the machine in the middle of the sea and I can see how it just is not cost efficient. heck, it’s not cost efficient on land. Besides, I can assure you as soon as these sea-wind farms started sprouting up, many environmentalists would oppose them and so would I. This sailor believes the sea was made for sailing it. ---
**Author:** ![Lemur866](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lemur866/32/434_2.png) [@Lemur866](https://boards.straightdope.com/u/Lemur866)\ **Post date:** [June 8, 2001, 6:16pm UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/15 "2001-06-08T18:16:34Z")
The trouble is that you get a very small amount of energy for a huge investment of resources and a maintenence headache. Yes, it is sustainable. But if you cost it out tidal/wave/ocean energy is many times more expensive than coal, hydro, or nuclear. Also, there are very few sites where this would work. It may be that we make the decision to construct these things regardless of the cost. But the cost is much higher than for conventional power. ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [June 11, 2001, 12:17am UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/16 "2001-06-11T00:17:02Z")
You know what bothers me? People with the attention span of a gnat, who start a thread by asking a question and never bother to return after a whole bunch of people have gone through the trouble of answering. Specially a question which has been asked and answered a number of times before. Anyway, for those who have an attention span a bit higher: I was looking through some web sites about eolic generators and found some pretty interesting stuff. For those who proclaim government subsidies are what’s required to promote alternative energies, one of the sites points out that until the 1920s there was a fairly good market for eolic and other forms of energy but it was effectively killed by the government’s program of subsidies for rural electrification. Anyways, here’s a bunch of sites related to this issue: [http://www.renewable-policy.com](http://www.renewable-policy.com/html/body_small_scale_wind_power.html) [http://www.windpower.dk/tour/index.htm](http://www.windpower.dk/tour/index.htm) [http://www.awea.org/faq/vawt.html](http://www.awea.org/faq/vawt.html) [http://www.sandia.gov/wind/](http://www.sandia.gov/wind/) [http://telosnet.com/wind/early.html](http://telosnet.com/wind/early.html) and successive pages - very interesting [http://www.windmillworld.com/links/verticalaxis.htm](http://www.windmillworld.com/links/verticalaxis.htm) [http://www.ug-contact.dp.ua/eng/sich20.php3](http://www.ug-contact.dp.ua/eng/sich20.php3) ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [June 11, 2001, 1:15am UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/17 "2001-06-11T01:15:01Z")
[http://www.risoe.dk/vea/](http://www.risoe.dk/vea/) [http://www.awea.org/](http://www.awea.org/) [http://www.nrel.gov/wind/](http://www.nrel.gov/wind/) [http://telosnet.com/wind/index.html](http://telosnet.com/wind/index.html) The danes seem to be experts on this: [http://www.windpower.dk/pictures/offshore.htm](http://www.windpower.dk/pictures/offshore.htm) [http://www.windpower.dk/pictures/mega.htm](http://www.windpower.dk/pictures/mega.htm) [http://www.windpower.dk/pictures/multimeg.htm](http://www.windpower.dk/pictures/multimeg.htm) [http://www.windpower.dk/tour/wtrb/powerreg.htm](http://www.windpower.dk/tour/wtrb/powerreg.htm) ---
**Author:** ![roryaxis](https://avatars.discourse-cdn.com/v4/letter/r/8dc957/32.png) [@roryaxis](https://boards.straightdope.com/u/roryaxis)\ **Post date:** [June 11, 2001, 2:02am UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/18 "2001-06-11T02:02:15Z")
So, have the attention span of a gnat, do I? Well, I have returned to this posting…several times in fact, obviously I just did again so that I could read your oh so cunning replies. Thank’s to all of you, except for sailor, who helped answer my question. Personally, my thought was that these “seamills” as I’ve called them were very capable of providing adequate power. My question dealt with the fact that they seemed to be too perfect of an answer, therefore, knowing that I am probably not a revolutionary Thomas Edison type genius, knew that there had to be a problem with them, something which I was not seeing. Economics is the most probable answer. They are probably a bit too expensive. However, fifty or sixty years ago splitting an atom was way too expensive, I seem to understand that today it’s still not too cheap a source of power. I also understand that it produces waste materials that have to be stored indefinitely. I also understand that coal, oil and other combustable power sources produce something called “pollution” which tends to wreak a tad bit of havoc on our little planet. Who knows? Perchance one day the idea of destroying the enviorment, even a slight bit, will be considered less viable than spending a bit of cash. Maybe then we can give “seamills” another look. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [June 11, 2001, 2:30am UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/19 "2001-06-11T02:30:24Z")
Another potential energy source would have us use the thermal differential between the top ocean layers and lower ones to drive turbines. This has the beneficial side effect that the effluvient from such a power source is cold, nutrient-rich seawater from the deep ocean. The effect would be a natural bloom of ocean life around the power plants, which could also be harvested for food. It’s been years and years since I last looked at this, so I don’t know if any progress has been made, or any new pitfalls have been discovered. But yeah, it all comes down to money. Which is why we don’t have an energy problem. We know with certainty that we will always be able to get enough energy to supply our needs, it’s just a matter of cost. As oil becomes harder to get, the price will eventually rise. When it rises enough, other forms of energy become cost-competitive, and we will start diverting power production into those areas. Alberta has tremendous reserves of tar sands just sitting around, waiting for the price of oil to rise enough to make it reasonable to produce it. In fact, we already started building plants to extract oil from tar sands, but they were scrapped years ago when the price of oil didn’t rise as expected. Our premier is currently in Washington to discuss our tar sands reserves with Dick Cheney. Right now, our wealth is growing faster than the cost of energy, meaning that even if our energy costs double 20 years from now, it’ll still be cheaper than it is today as a percentage of GDP. I expect that trend to continue for as long as there are free market economies around. ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [June 11, 2001, 2:42am UTC](https://boards.straightdope.com/t/an-answer-to-the-worlds-energy-problems/67991/20 "2001-06-11T02:42:14Z")
Hey, roryaxis, don’t be so sensitive my man! If the shoe doesn’t fit, then don’t wear it. How can I know you are around if you don’t post? And you can at least recognise I’ve put more effort into finding relevant info than anyone else. I have spent at least a couple of hours on the site that I already mentioned [http://www.windpower.dk/tour/index.htm](http://www.windpower.dk/tour/index.htm) and it has amzingly deep studies on the issue. Technical, engineering, financial etc. I highly recommend it. It has pages specifically dedicated to sea turbines which, surprisingly, have some advantages: [http://www.windpower.dk/tour/wres/offshore.htm](http://www.windpower.dk/tour/wres/offshore.htm) This stuff is more advanced than I thought.