AnonTechie writes:
"I could not let this one go uncommented by our resident experts. What do you make of this, yet another pipe dream?
Oceanic steam engines; Jules Verne imagined this limitless power source in Victorian times.Now, 21st-century engineers say heat trapped in the oceans could provide electricity for the world. IF ANY energy source is worthy of the name, 'steampunk,' it is surely ocean thermal energy conversion. Victorian-era science fiction? Check: Jules Verne mused about its potential in Twenty Thousand Leagues Under the Sea in 1870. Mechanical, vaguely 19th-century technology? Check. Compelling candidate for renewable energy in a post-apocalyptic future? Tick that box as well.
Claims for it have certainly been grandiose. In theory, ocean thermal energy conversion (OTEC) could provide 4000 times the world's energy needs in any given year, with neither pollution nor greenhouse gases to show for it. In the real world, however, it has long been written off as impractical.
(Score: 2) by frojack on Tuesday March 04 2014, @07:12PM
Won't somebody PLEASE think of the Clams!
https://php.radford.edu/~swoodwar/biomes/?page_id= 1027 [radford.edu]
Discussion should abhor vacuity, as space does a vacuum.
(Score: 0) by Anonymous Coward on Tuesday March 04 2014, @09:57PM
I'm always thinking of clams.
Oh, you mean those clams.
(Score: 5, Interesting) by jt on Tuesday March 04 2014, @07:22PM
Everything is impractical until we are sufficiently desperate and it is the easiest remaining option.
I'm not an expert in this field, so I have no idea whether we could really get all of our energy from this. But it certainly could be a useful component of a larger solution, and we're not going to run out sea any time soon.
(Score: 2, Insightful) by Anonymous Coward on Tuesday March 04 2014, @10:00PM
(unfortunately) we're not going to run out of coal any time soon either... and shovels are cheap
(Score: 3) by jt on Wednesday March 05 2014, @07:16AM
Good point. Maybe we will just have to wait until we cause enough climate change to wipe us all out, and the energy problem just goes away naturally.
(Score: 2, Interesting) by Anonymous Coward on Tuesday March 04 2014, @07:33PM
They claim that warming of the ocean of like 0.1° is superbad, this would cool the oceans and reduce carbon emissions, should be supergood?
(Score: 2, Interesting) by robind on Tuesday March 04 2014, @07:47PM
Reminds me of this piece of tech: http://en.wikipedia.org/wiki/Underwater_glider [wikipedia.org]
This is pretty cool, though personally I think the engineering challenges surrounding large bodies of salt water will make this very difficult.
(Score: 5, Interesting) by Angry Jesus on Tuesday March 04 2014, @08:10PM
As a kid I lived just up the hill from the premier OTEC facility in the world (which is not saying much). One semester in grade school my class took ~day long field trips there on a weekly basis - but it wasn't for the energy science so much as the marine biology.
One of the problems that the article hints at is that the deep ocean water is nutrient rich. It is one of the most fecund natural resources in the world, which is why there are concerns about algae blooms from dumping it at the surface. At the time, the plant dumped some of the deep water right into a system of tide pools next to the plant and the result was an amazing amount of ocean life. Tide pools are full of cool creatures all on their own and this rich water just amped everything up. We were mainly there to do grade-school biology fieldwork on that ecology (and more importantly spend a day at the beach). FWIW, when the funding dropped out of OTEC energy research the plant diversified and started using those deep-water nutrients to grow top-grade crops like strawberries and even a fish-farm in tanks.
But I did pick up a few things about the system while I was there. The first of which is that an OTEC plant is not very steam-punky. For one thing, the "steam" is really just a fully-contained working fluid like ammonia (as the article mentioned) which in a pure form boils at negative 28F/33C. The way OTEC works is that the surface water is as hot as the system gets, so roughly 80F/26C. So, what you've really got are a bunch of large diameter pipes (big enough to walk on) that are always cool to the touch.
Another thing that the article didn't mention is the enormous problem of biofouling. Both deep and surface water are jam packed with micro-organisms that will not only clog up the pipes but will also kill the efficiency of the heat exchanger. Even at high flow rates those little buggers will latch on and grow everywhere. Keeping the pipes clean without pumping them full of poison is a really hard problem. It seems like they haven't made much progress over the years, the best approach looks like it is still to build with titanium piping and stop the plant for a couple of hours each day to run a cleaning/poisoning cycle and even that isn't sufficient over the long-term.
(Score: 1) by captain normal on Wednesday March 05 2014, @01:06AM
That is one big problem. Another is the huge energy investment in pumping cold water from the depths. I din't see this taken into account in the production projections in the articles. Maybe I just missed it, did anyone see it?
(Score: 1) by Nesh on Wednesday March 05 2014, @04:55AM
OTEC plants take that in account. Typically the given energy output numbers are net output numbers: some energy that is produced is used for pumping fluids internally in the system.
Other soylentis have pointed out that it's not all roses though: marine environment is hard on equipment and installations (salt, micro-organisms). Maybe that's why there is only one working OTEC plant on the planet.
It's definitely an interesting take on energy production.
(Score: 2, Interesting) by MichaelDavidCrawford on Tuesday March 04 2014, @08:27PM
I remember quite clearly the 1973 Arab Oil Embargo.
At the time, a gallon of full-serve gas, with window washing, checking one's oil, coolant and so on, at Concord Naval Weapons Station in Concord, California, a ways over to the east from the Berkeley Hills, was thirty-five cents per gallon.
Now that had the military discount. I don't know what a civilian was paying in Concord, but I would guess forty-five cents or so.
There is a hilarious scene in Back to the Future, where they pull up to a gas station and half-dozen gas station attendants run out, all wearing clean, white uniforms, and start pumping gas, checking the fluids and the like. My first job out of high school, at Fairfield Shell, was at the tail end of that. I pumped full-serve gas and operated the car wash.
We did not sell anything other than gas, the car wash and motor oil. We did not have a convenience store. We did not have a point of sales terminal; I had to run credit cards manually; my last check was docked because I operated the credit card imprinter without placing the customer's card in it. We did not have a cash register, we had to calculate the change mentally. We had to check a rather large, fine-print paper booklet to check for bad credit cards. One of my coworkers actually seized a card that was listed in that book, and got a reward from Visa International.
Why is it do you suppose, that gasoline at that same station now costs four dollars per gallon, the car wash is manually operated, there is no longer any full serve, the cashier has a cash register, the customers swipe their cards at the pumps, and there is a convenience store?
That's because it is no longer possible for the owner of a gas station to actually earn any significant money from the sales of fuel.
Instead, just about every gas station these days serves only to facilitate sales in their convenience store, so as to earn their real money from tobacco, soda, candy, magazines, beer and the like.
Strange, don't you think, that shortly after the 1973 Embargo, I checked a couple of books on alternative energy out of the library, and made a parabolic solar reflecting hot dog cooker out of nothing but corrugated cardboard, glue, masking tape, aluminum foil and some pieces of welding rod?
I was experimenting with methane gas production by letting a gallon bottle of lawn clippings anaerobically digest in some water. One puts a rubber or cork stopper on the top, with a glass tube through a hole in the middle of the stopper, then a bent rubber hose into a small bottle of water, just like you're brewing beer.
I was looking forward to heating our home during the cold Northern Idaho winters, as my father was by then a grad student at the U of I in Moscow. We had a large lot and an abundant lawn. I am dead certain that if I'd carried my plan to fruition, we would no longer have required heating oil.
Unfortunately, while walking through the garage in the dark, my poor father kicked over and broke my glass jug of anaerobically digesting lawn clippings. He requested that I stop experimenting with methane generation.
The orthogonal solar flux - that is, the amount of power through a surface at right angles to the Sun's incoming rays - is about 1.5 Kilowatts per square metre at the equator.
Given that solar photovoltaic panels are getting quite cheap, as well as quite efficient, it's getting real easy to find electrical contractors to install them, why aren't all new homes required to have them?
What just about everyone does now is to sell excess power back to the power company, by running one's electric meter in reverse. That's just asinine.
So here we are generating DC current, most likely at twelve volts or so, running it through an inverter to produce AC current as well as to raise the voltage up to 110, or in Europe, 220.
After all of those conversion losses, due to heating of the coils in the inverter, some of the AC current leading to electromagnetic radiation going off into space, we use the power for 110 or 220 Volt AC incandescent light bulbs.
How about screwing the middleman by installing twelve-volt wiring in your house, and powering twelve-volt DC light bulbs? How about compact fluorescents or LED lights.
Quite a lot worse is that in most residential neighborhoods these days, as well as quite commonly through the countryside, the higher voltage power lines are buried underground. My father was absolutely appalled when we purchased our next home in Fairfield, California, because the power lines are buried throughout the entire city.
The problem is that dirt is electrically conductive. I expect those power lines are protected by metal pipes. What then happens is that the AC current induces electric current in the dirt and in the pipes, that is then lost as heat.
Just as bad, is that to transmit AC power for any significant distance over high-tension lines, also radiates a great deal of power into space. Whereever the high-tension lines transmit a great deal of power, as from the washington and oregon state hydroelectric dams to southern california, they always use two DC lines, rather than the three cables for three phase AC. That avoids the radiation losses, as well as heating losses from inducing current in the dirt and in the metal of the tranmission towers.
A while back some public agency here in Vancouver spent like twenty-five grand to install solar panels at taxpayer expense. Some letter to the editor writer was quite vehemently outraged, as he pointed out that recouping the cost of those panels by selling power back, as well as savings as it does not need as much power, would take like thirty years.
Strange don't you think, that the government of Canada not only encourages the cultivation of industrial hemp, for use in making paper, rope, food and so on, it also performs research into better ways to grow it, then shares the wisdom obtained with Canadian hemp farmers.
Whereas in the US, until very recently it was flatly illegal to grow industrial hemp at all. It is now permissible for scientists to perform hemp research, but you and I would go to federal prison were we to grow a field of hemp to make paper out of, this despite it being completely legal to grow dope so as to get stoned out if my tree here in Salmon Creek. While it is still against Federal law, the Obama administration has been quite clear that the Feds won't enforce their laws against the growth, sale and consumption of marijuana when used as a drug.
Now there is one significant difference between the US and Canada in this respect:
Despite the Canadian Charter of Rights and Freedoms, Canadians are NOT guaranteed the right to free speech or freedom of the press. They do have a great deal of freedom of expression, but not like the US does, for example when a sensational murder trial takes place, the presiding judge can order a press blackout throughout the entire nation, so as to guarantee the defendant a fair trial.
Here in These United States, on can donate pretty much as much as one damn well pleases to candidates or to political parties. "Interest groups" that are not affiliated with any candidate nor party can spend money on issues advertisements. There really is no limit on that money, as the Supreme Court regards the money spent as the free speech that is so vitally important to our democracy.
Strange don't you think, that in just about every state in the union, the dealers for gasoline-powered automobiles are working - with some success - to prevent Tesla Motors from selling cars directly to the public. I regard that as unfair restraint of trade.
The fact is, the US could easily have obtained energy independence by 1985, we could have stopped burning any coal at all by 1995, and by now we would no longer need to extract coal, oil nor natural gas, were it not for the fact that those who own or work for the traditional carbon- and hydrogen-based energy companies so damn wealthy.
The icing on the cake is that most of the world's nuclear power plants were only designed to last, and so only licensed to be operated for forty years. Most of america's plants have been in use for sixty years, the NRC is looking into extending their licenses to eighty years, there is speculation we may operate for one hundred.
One of my physics instructors at Caltech specialized in radiation damage. I was puzzled by that at first, but he showed is a microphotograph of a slice through an astronaut helmet. There were little craters in it, not concave hemispheres like meteorite craters, they looked rather like trombone horns. The high-energy particles of the solar radiation, as well as the primary cosmic rays which are far more damaging in space then the secondary cosmic rays that make it to the ground, bore holes into everything they impact.
In addition to that, exposure to radiation, especially the neutrons that are so abundant in nuclear reactors, will transmute most elements into some other element. For example, the Carbon-14 dating that's used by archeologists works because Nitrogen in the atmosphere is continually bombarded by Neutrons in cosmic rays. Plants and animals absorb this Carbon-14 in our food, water and air, but we stop absorbing it when we die. The longer ago we died, the more it will have decayed so the less radioactive we will be.
They use a lot of titanium and alloy steel in nuclear power plants, exotic varieties of concrete and so on. When one exposes all that to vast torrents of neutrons and gamma rays, all that stuff turns into a hole lot of different kinds of elements, plus it gets all those microscopic holes blasted through it like the astronaut helmets do.
The result of letting all our reactors run for sixty years rather than decommissioning them at forty, is that many cooland pipes are rusty and brittle. I myself have seen a photo of a twelve-inch water pipe, completely covered with rust, with a hole and inch across, spewing coolant water all over the place.
OK now explain to me how it is better to continue operating that rusty, brittle, radiactively-leaking power plant, rather than decommissioning it then spending the money that would otherwise be used to keep it in service, on photovoltaic cells, tax credits for rechargeable battery manufacturers, installing twelve-volt DC into homes and businesses, building windmill farms and now ocean thermal energy conversion?
It's because the people who have equity in the nuclear power companies, or those who work for them, have a lot of cash to donate to politicians but they do not own any equity in windmill companies.
Go look around a public library, it's quite likely you can find dozens of books that were published starting around 1973, that if you applied there lessons even in a half-assed way, using today's technology like 3-D printers, better, more compact, more efficient electronic chips and so on, you could make your entire nation stop burning coal, oil and natural gas in no time at all, and for very little expense.
HAY IS THIS THING ONE?
(Score: 2, Insightful) by MichaelDavidCrawford on Tuesday March 04 2014, @08:32PM
I should not drink and post.
I have a major product announcement [warplife.com] coming 5:01 PM 2014-03-21 EST.
(Score: 2) by jcd on Tuesday March 04 2014, @08:46PM
I started to wonder if that's what happened about 1/3 of the way through. Not bad!
"What good's an honest soldier if he can be ordered to behave like a terrorist?"
(Score: 3, Interesting) by EvilJim on Tuesday March 04 2014, @09:19PM
I thought you were Bennett Hassleton for 15 mins there... good rant but a couple of nitpics for you, 12v in the house isn't often done as when the voltage is lower the current is higher for a certain W draw, you would need larger diameter wiring in every house - easy to do coming out of a hydro power station to a substation but would cost homeowners a fortune in copper. line losses at high voltage AC are less than DC, AC is far more suitable for long distance power transmission even with the losses you suggest. what you say about biogas actually looks really good, I'm having my parents take a look at this for their retirement on their plot of land, wikipedia has a great article. http://en.wikipedia.org/wiki/Biogas [wikipedia.org]
(Score: 1, Offtopic) by MichaelDavidCrawford on Tuesday March 04 2014, @09:33PM
However, at one time, Thomas Edison was being DC, while Tesla was behind AC, with the result that until quite recently, in the older parts of big cities like New York City, the power company supplied both kinds.
I read on the DICE Holdings site maybe two or three years ago, that they finally, after I think more than a century, were satisfied that they no longer required the DC to power things that anyone was actually using, and so finally shut it all off.
Yes I do know very well that higher voltage means lower current. One must find a compromise, because it is expensive and impractical to alter the voltage of DC. For example most computers these days use I think 3.3 Volts, but I expect a compact fluorescent lamp would work a lot better at a higher voltage.
It does not make sense to me that each individual server in a data center is plugged into 110 VAC. Why not distribute all the same voltages that the computer actually uses? Like 5, +12 and -12 for IDE disk drives, 3.3 volts for the memory and CPU and so on.
There would be a lot less power supply losses, less heat from power supplies, one could use smaller, slower cooling fans, one would need to cool the data center less, one would need less cooling equipment, were one instead to run 110 VAC into each rack, have one Big Jesus power supply, that distributes all those different voltages to each of the servers in that rack.
I met a commercial Scuba Diver in Santa Cruz a while back, who had logged literally thousands of dives. That's just what you want if you want to someday earn $200.00 per hour as an underwater welder.
It turns out that he used to have the job of cultivating and harvesting kelp in the ocean there, for use in biogas generation! But that was all shut down by the time Reagan got elected.
(My old boss used to be a commercial diver too. He used a push-broom to clean the bottoms of swimming pools!)
I have a major product announcement [warplife.com] coming 5:01 PM 2014-03-21 EST.
(Score: 1) by EvilJim on Tuesday March 04 2014, @10:19PM
absolutely agree about the data center power supplies, in fact I think Google is working on this already. even in an office with 20 PCs I could see an advantage to running them directly from DC supplies to avoid all the losses from each individual PSU. IIRC some cities trains run DC don't they? where I live there aren't any electric trains so I'm not entirely sure. interesting about the kelp farming.
(Score: 2) by VLM on Wednesday March 05 2014, @09:50AM
"voltage is lower the current is higher for a certain W draw,"
The problem is my 5 watt or so cell phone charger is plugged into a 1800 watt rated outlet. It is against the building code and UL and tradition and who knows what else to install a generic AC power outlet incapable of at least 1800 watts minimum, and thats expensive but tolerable at 120VAC but unaffordable at 12VDC. If you wire 12V you'll need 10 times the current capacity of a 120V ckt IF you demand constant wattage.
But why demand constant wattage? I'd be just as happy with a 180 watt outlet, after all, again, I'm still only using 5 watts to charge my phone. Doesn't matter if its a 1800 watt AC outlet or a 36 watt three amp DC outlet.
Yes I know all the EE stuff and it doesn't scale quite that simply and there are issues with voltage drops being a larger fraction of a smaller voltage blah blah blah. But the general idea holds, that if you're drawing about a hundredth or thousandth of peak wattage for most outlets, supplying power is simply no great problem at 12V.
For a couple decades I've had 12V distribution in my house. Mostly because of ham radio stuff. Later essentially as a UPS. Its not a big deal. No, I don't run my toaster oven or hair dryer on 12 volts, and I REALLY don't care that I can't.
If you make a histogram of current drawn per outlet you'll get a mighty peculiar graph, with a couple outlets running the waffle iron and hair dryer and arc welder, but at least ten times as many outlets running an alarm clock, or a charger, or a cablemodem, or a wifi access point at about 2 to 12 watts. DC works pretty well for the small loads, pretty well indeed. Now that lighting has shifted from 600 watts of dual halogens to 10 watts of LEDs I'm gradually moving that over to 12V too. You end up with a lot of 12 volt "RV" stuff including small fans and even appliances.
(Score: 2) by EvilJim on Wednesday March 05 2014, @04:22PM
Good on ya, never said it was impossible, just difficult/expensive for the general population, nerds excluded, I actually had something similar when in my teens, I had a backyard shed full of chemistry gear and electronics fed by 12v from inside the house (good luck doing that with kids today, your whole family will be arrested), also ran cb's in those days so 13.8v if you want to get exact on those and generally all my electronic projects these days run on 12v or less but I have a grunty bench supply for those. I was actually looking to live on a boat for a while so was preparing for 12v everything, still have a 12v crt tv/vcr somewhere. I'm sure I would survive just fine if the mains power went out long term, dont eat waffles and have jack all hair to dry :) those high wattage devices are the only ones that'll give you grief at 12v
(Score: 1) by pjbgravely on Tuesday March 04 2014, @09:17PM
If the word terrorism is used those rights are gone in the US.
(Score: 1) by cybro on Tuesday March 04 2014, @10:14PM
You mentioned several times that we don't need coal.
Brown coal is a very dense source of energy, and as such is very useful for industrial heating, and also power generation, but I suppose it isn't necessary.
However metcoal is crucial for the economic production of steel from iron ore. No metcoal, no steel. As you can imagine, steel is an incredibly important resource and I don't think that we will ever see titanium or carbon fiber reinforced concrete or buildings and bridges and railway lines and towers and so on, so the mining of coal will continue so that human civilization can continue employing the wonderful material known as steel.
Like wise methane and oil are needed for plastic, another crucial material for modern human civilization.
(Score: 2, Interesting) by MichaelDavidCrawford on Tuesday March 04 2014, @10:41PM
- ore?
Somewhat like the aluminum sucking the oxygen from Ferrous Oxide in Thermite.
I expect that, were we to get rid of all other need for fossil fuels than refining iron or, we could at least do it with more-or-less pure graphite.
Want to know how to spend twenty years committing suicide an a slow and incredibly painful way?
Develop a taste for sushi, or at your option, sashimi.
Mercury in the oceans as a result of burning coal you see, but I am rather more concerned about Radon gas in the coal. Its radiation might well be undetectable, but we do get a lot more cancer than we used to.
More or less if you dig up just about anything from deep underground then spew it all over the atmosphere, we're going to get all manner of radioactive isotopes into our groundwater, topsoil, oceans and food.
I have a major product announcement [warplife.com] coming 5:01 PM 2014-03-21 EST.
(Score: 1) by TK on Wednesday March 05 2014, @05:41PM
The oxygen is sucked from the coal by essentially bubbling carbon monoxide (from coke) through molten/semi-molten iron oxide. I can't speak for pure carbon's affinity for oxygen, but carbon monoxide loves it (or at least more than iron oxides do). That and graphite doesn't melt until you get up to 3500 C, and at those temperatures, you're more than likely to form carbides, which you don't want in your steel. It would be energy expensive, and the furnace/kiln would cost a bundle to handle those temperatures.
Maybe heating pure carbon up to around the melting point of steel (varies, call it 1200 C) could give it enough energy to bind to the oxygen, or the reaction:
2C + Fe3O4 -> 2CO2 + 3Fe
could be exothermic, but IANA chemist or metallurgist, and my thermodynamics book is out of my reach at the moment.
The fleas have smaller fleas, upon their backs to bite them, and those fleas have lesser fleas, and so ad infinitum
(Score: 1) by xtronics on Wednesday March 05 2014, @03:30AM
Silly computation by folks that don't understand thermodynamics don't provide free energy.
Just read up on exergy --
http://en.wikipedia.org/wiki/Exergy [wikipedia.org]
(Score: 2, Informative) by mascot on Wednesday March 05 2014, @10:02AM
Power Systems Engineer here
Efficiency in the transmission of Electricity is, to a first approximation, proportional to Voltage. The higher the voltage the more efficient. This is because the dominant loss mechanism is Ohmic heating which is proportional to the square of current. The power transfer is given by the voltage times the current. Double the voltage- transfer twice the power for no additional losses!
Using cables rather than overhead lines is slightly less efficient for AC transmission but it's a small factor. There are no significant currents induced in the soil. All cables have a grounded sheath around them which equalises the electrostatic stress. There are induced currents in the sheath which are responsible for roughly an additional 5% losses over the normal thermal losses. This can be mitigated through cable cross-bonding where the sheaths on adjacent cables are joined to balance out the induced voltages.
A bigger problem is that high voltage cables are like big capacitors and generate a lot of reactive power which must be absorbed by reactors. The reactive power generation is proportional to the square of voltage so this is only an issue for very high voltage cables. At 400kV this is a big issue.
TL;DR
Cables for electric transmission are not inefficient, however they are expensive costing 6-10 times the price of an equivalently rated overhead line.