The Heavyweight Sea Snail 358
Roland Piquepaille writes "Scotland, like many European countries, must comply with regulations requiring that a mandatory percentage of the energy it uses comes from renewable sources. For Scotland, this percentage will be 18% in 2010 and 40% by 2020. One of the programs in development is Ian Bryden's sea 'Snail' program. The Snail is a 30-ton anchoring device which uses hydrofoils -- wings that 'fly' in the water -- to generate enough power from tidal waves to service 10,000 homes by 2007. This overview contains more details and a picture of a prototype of the Snail with its six wings." There are several mentions of this in UK newspapers and the Scottish government webpages.
Salter's Duck (Score:5, Interesting)
Re:When I saw heaveyweight... (Score:3, Interesting)
Lol. Good troll. Lots of countries get called something else in foreign countries. In English speaking countries we call it "Germany". In French speaking countries they call it "Allemagne". But in German speaking countries I believe they call it Deutchland. This is a very common phenomenon.
You can't really control what foriegners call you. I suggest you try to get
Whew. . . (Score:3, Funny)
I never tried escargot, and probably never will, but I saw snail, 30 ton and almost lost my lunch.
How does it work? (Score:2, Insightful)
Re:How does it work? (Score:2)
What's the advantage? You don't have to excavate at depth to make the thing stay put, just lower it into the water, and let the water hold it down. Why not just use weights? I don't know, I didn't design the thing.
Power supplies (Score:5, Interesting)
It seems that a fair amount of research into new power plants is coming to fruition - the latest New Scientist had an essay on the JET (Joint European Torus) breaking even on its power budget for nuclear fusion. The big argument now is not whether to build one that ought to provide 10x its input requirements, but where to build it (France or Japan, from memory).
With windfarms (popping up all over Scotland and the exposed areas of England - presumably Ireland as well, that's one hell of a windy place
Simon
Re: (Score:3, Informative)
Re:Power supplies (Score:2, Interesting)
Re: (Score:3, Informative)
Re:Power supplies (Score:2, Funny)
Re:Power supplies (Score:4, Funny)
Now if they could only capture all those lemmings and hook them up to little hamster wheel generators around the time they start running toward the sea, they'd have an energy surplus they could sell off cheap!
Re:Power supplies (Score:4, Interesting)
How about the ever increasing waste? And since this is slashdot: how about the ever increasing waste concerning desktop processors? When will technologies like AMD's Cool & Quiet become standard? I cringe when I think of all the new power hungry P4's that I see popping up at my hospital. The ones in ER registration sitting their ideling 24hrs a day, and for what? To access the UNIX mainframe via Rhumba. That's it.
They make great advances in the laptop arena, but this technology should trickle down to the desktop.
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Re:Power supplies (Score:3, Insightful)
I wonder if the push towards quiet computers will start to help. We've reached the point where the typical desktop computer user hasn't had to upgrade in several years; very few people have any desire to get the latest PowerSucker 4.0GHz. (Or whatever it is these days. I'm still using my Athlon 900, and the only time I've wished I had a faster computer was while ripping a DVD.) People are going to start looking for systems that are sma
Re:Power supplies (Score:2)
Last time I checked, the Irish government had put out to tender a plan to build one of Europe's largest windfarms on the Arklow bank, off the east coast, in the Irish Sea.
They must be stopped! (Score:4, Funny)
You got it backward. (Score:4, Informative)
Actually, tidal friction slows the rotation of the earth and raises the orbit of the moon. Extracting tidal power will increase the friction and thus the rate at which this happens.
(Of course if there WAS a chance of bringing down the moon that would make for QUITE the "environmental impact".)
Re:You got it backward. (Score:2, Funny)
Is this really renewable? (Score:4, Funny)
Re:Is this really renewable? (Score:3, Funny)
You read it here first, friends - a new way to transmit power halfway around the world without power lines! Giant solar powered gyroscopes in the desert adding to the Earth's rotation, and humongous sea-snails in Scottland removing it!
How does it work? (Score:5, Insightful)
Re:How does it work? (Score:3, Informative)
It seems pretty logical, and it makes me think - Most of the water generators I've read about seem to be tide based - where this is more using the force of the incomng water laterally. I wonder how practical it would be to set up these devices inside of the oceans currents, or fast flowing channels. Using these 'wings' to generate force that way seems to me lik
Foils as anchors. (Score:5, Interesting)
This is just from looking at it, obviously not from the plans. One of the challenges they would face with any form of tidal or current energy device is how to keep the thing in place. With the foils, I can see issues with keeping it in position, but it does seem like that's what they're trying to do.
There's probably also a hard mooring to keep it from drifitng away at slack tide, which would also allow it to change facing when the tides change direction or the currant shitfs.
Missing some of the potential of those foils (Score:4, Insightful)
Bonus points for tilting the turbine so as to generate a lift moment downward and use it to produce some of its own downforce.
Re:How does it work? (Score:4, Informative)
Re:How does it work? (Score:2, Informative)
5MW good for 10,000 homes? (Score:5, Insightful)
Re:5MW good for 10,000 homes? (Score:2)
Re:5MW good for 10,000 homes? (Score:5, Informative)
You're (at least in the US) usually billed in kilowatt-hours (kWh). I'm no expert, but I doubt most homes use more than 0.5kWh at anything other than peak times (weekday evenings and weekend afternoons).
Appliances (again, in the US) all come with a sticker saying how many kWh they use in a year. A refrigerator is usually around 1000. That's a little less than 3 kWh a day, or 0.125 kWh (period... in an hour). That's only 1/4th of your constant usage allowance. How many other household appliances run 24/7? Probably none.
A good storage mechanism would store that unused energy for use at peak times. A poorly designed system would just fail over to a traditional power grid at peak times. In any event, it still reduces the load on the main grid.
Of course, my experiences are from my house in the USA... maybe Scotland is full of wasteful, electricity-hungry, even-worse-than-American people... but I doubt it.
Re:5MW good for 10,000 homes? (Score:2)
Re:5MW good for 10,000 homes? (Score:2, Interesting)
Re:5MW good for 10,000 homes? (Score:3, Informative)
0.125 kWh per hour is equal to 0.125 kilowatts, or 12.5 Watts.
Over what period of time?
Oh my. "Watts" don't go over a period of time; the OP was perfectly fine.
zach
Re:5MW good for 10,000 homes? (Score:3, Informative)
I use mostly CF light bulbs, but do have an electric range and clothes dryer that runs pretty often (2 of the 4 occupants are small and generally muddy).
(I also buy a good portion of my electricity from a small local hydro plant for a small surcharge, thanks to my friendly municipal utility [concordnet.org]).
Re:5MW good for 10,000 homes? (Score:2)
Re:5MW good for 10,000 homes? (Score:3, Insightful)
Rule of thumb for the US is 1 KW/home "fleet average B-) ". A LOT of that is either air conditioning or (in the few remaining ones from the "it's going to be too cheap to meter" era) electric heating and/or electric water heating, in the houses so equipped.
Resistance heating is HORRIBLY expensive in terms of power consumption. (More than a factor of three inefficiency compared to burning the same fuel to apply heat
Tidal Waves!? (Score:2, Funny)
Really, how often do they have Tsunami there?
Re:Tidal Waves!? (Score:2)
Really, how often do they have Tsunami there?
When it's not being powered by tidal waves it is able to convert natural energy from earthquakes to electricity.
Re:Tidal Waves!? (Score:2, Funny)
maintenance (Score:2)
When they need to fix it, they'll be calling Christopher Lambert to walk under water and make the necessary repairs, right? Or will the maintenance crew be expected to ride one of those Scooby-Doobie things?
Yes, I have difficulties separating the real world from cinema.
Repost (Score:2)
The Heavyweight Sea Snail
Scotland, like many European countries, must comply with regulations requiring that a mandatory percentage of the energy it uses comes from renewable sources. For Scotland, this percentage will be 18% in 2010 and 40% by 2020. In "Tidal farming's new wave [redherring.com]," Red Herring explains this why Scotland is very supportive of Ian Bryden's sea "Snail" program. The Snail is a
America... (Score:3, Insightful)
Sad part is tanks and planes don't run on well wishes and rainbows, the US military and the non-efficient consumer vehicles have *got* to be brought under control. Go ahead and argue all you want. You are wrong and we have *got* to get off of energy sources that will run out.
Also, i'm happy this sort of thing is being done....just wish more and more stories of new energy studies (that don't involve how to make *more* money for oil companies) come from the US. We either need to get *everyone* behind this or it's not going to happen. People, in general, are lazy and won't change unless they have a personal interest or are forced to. Let's get some grants and scholarships for people doing this kind of work in the US.
Sorry for rambling and not spell checking.
-1, US-Centric (Score:2)
Re:America... (Score:4, Insightful)
The US seems to be like a spoiled child that wants all the remaining cheap energy to feed its ever-increasing needs. We need to use that energy to develop new methods of generating energy, not fueling 1 SUV for every 3 Americans, not to mention the immense, oil-swilling military.
I dread the day when the tap finally runs dry, which it must as oil is a finite, non-recyclable resource. What painful reorganizations will occur when we can only afford a tenth of the energy we used to consume?
Re:America... (Score:5, Insightful)
While the United States and other countries that don't produce enough oil to run their economies would obviously like the price to be as low as possilbe (and I agree that internalizing the enviornmental, military, and foriegn aid costs of oil would greatly drive up its price), the idea that the price of oil is where it is because the US forces it to be so is just plain bad economics.
The Sauids (and not just Bush's buddies the House of Saud, but whatever theoretical government might be in place there) have a lot more oil than anyone else and a much larger time frame for extraction. So, they fight with the rest of OPEC to keep the price in an acceptable range (lower than other members would want) and use their massive capacity to flood the market when others get out of line. This is precisely so that oil doesn't get so expensive that people start looking elsewhere. Furthermore, this type of behavior is inherant is the nature of oil (rentier) economies, not a result of anyone's policies.
Now, I am far from an expert in these matters, but those who express admiration for "natural market processes" shouldn't also demonstrate such complete ignorance of how those processes work.
Re:America... (Score:3, Insightful)
Re:America... (Score:2, Interesting)
There's a pilot plant outside Philly, and another in Montana or Missouri (don't remember).
With this available, I just wish we were far sighted enough to pop these up all over the country to process any and all recoverable waste. With this as an option, the need to drill for oil becomes greatly reduce
Re:America... (Score:3, Insightful)
As to WMDs in Iraq, surely you jest. This is just the way the Bush admin sold the war to the public, with the help of the news herd. If there were WMDs in Iraq, why didn't Hussein use them? If he had them and didn't use them, then why did we invade? The hypocritical use of WMDs as a justification for war is asinine. After all, we don't invade Israel when they bre
Re:America... (Score:3, Interesting)
However, a vocal minority of people complain that they look too ugly, are too big, ruin the view, etc, and have been able to use lawsuits and regulatory processes to prevent them from being built. As you might expect, they're also trying to convince the state legislature to pass strict regulations governing where and how they can be built.
I k
Re:America... (Score:3, Insightful)
Our planet now supports 6.3 billion people. To feed them, we industrially generate as much nitrogen (in the form of chemical fertilizers produced from natural gas) as the
Re:America... (Score:2, Insightful)
Get ready for environmentalists to complain (Score:2, Insightful)
I predict environmentalists will shit a brick because it might disrupt a few sea animals. Just like environmentalists hate wind power since some bird aren't intelligent enough to fly around the windmills.
Considering the cost of the alternatives (coal, natural gas, oil, etc) isn't even on their radar.
Re:Get ready for environmentalists to complain (Score:2)
Disrupting a sea ecosystem?
or
Continuing to use energy sources that disrupt air, sea and land ecosystems?
I think that the whole "drilling for fossil fuels, tankers spilling in the ocean, using a fuel that destroys the environment just from burning it" is far worse than this...
Re:Get ready for environmentalists to complain (Score:4, Insightful)
Re:Get ready for environmentalists to complain (Score:2)
Hmm... i pictured the sea turtles from Finding Nemo riding the currents, passing through a "snail farm", and ending up as minced meat on the other side...
Re:Get ready for environmentalists to complain (Score:2)
Tidal energy isn't new... (Score:5, Informative)
"Currently, although the technology required to harness tidal energy is well established, tidal power is expensive, and there is only one major tidal generating station in operation. This is a 240 megawatt (1 megawatt = 1 MW = 1 million watts) at the mouth of the La Rance river estuary on the northern coast of France (a large coal or nuclear power plant generates about 1,000 MW of electricity). The La Rance generating station has been in operation since 1966 and has been a very reliable source of electricity for France. La Rance was supposed to be one of many tidal power plants in France, until their nuclear program was greatly expanded in the late 1960's. Elsewhere there is a 20 MW experimental facility at Annapolis Royal in Nova Scotia, and a 0.4 MW tidal power plant near Murmansk in Russia. "
I also recall having seen articles talking about attempts in Norway to capture wave/tidal energy for electricity generation.
I'm always a fan of renewable energy. I just wanted to point out that this is more an attempt to do something in a new way than to do something new.
Just occurred to me (Score:3, Insightful)
If there are many of these units in deployment, what are the chances that they will begin to alter or somehow affect the normal flow of water beneath the surface? And what kind of effect will this have on the ecosystem?
actually the effect should be as minor (Score:2)
A new internet law (Score:3, Funny)
No energy technology supported by a UK government and reported on the internet will ever produce more power than was consumed in publicising it.
Corollary: No energy technology will be supported by a US government unless it can (a)power an SUV and (b) create explosions.
Doing well with renewable energy (Score:4, Interesting)
Re:Doing well with renewable energy (Score:4, Interesting)
Quite sensible fiscal policy, actually. It seems that you'll soon be in the eviable position of being able to sell a valuable comodity while not consuming any (very little) of it yourselves.
If the US politicians and oil producers could wrap their minds around that concept, there'd be quite a change in the amount of polution produced in the world, as well as curing our horrendous trade deficit, but I'm afraid that there's far too much power politics involved to see any useful change here. The oil conglomerates make far too much off of importing, the politicians use the promise of US dollars far too often as a diplomatic ploy, and the two groups have been in bed together far to long for them to see that the relationship is destructive. (It's somewhat like a couple that are always fighting each other, except when they are fucking, or have allied in order to fight someone else. Their neighbors are suffering from it, their children are suffering from it, they themselves are suffering from it, but they'll be damned if they'll allow anything to change it.)
Read the articles carefully! (Score:2, Informative)
Missing the Obvious (Score:2, Interesting)
Have servo motors move the wings to lift the entire structure upward. This would "arm" the device for the power stroke. The power stroke would come from tilting the wings dramatically downward. This would provide 200 tons of pressure to work a pump that could pressurize sea water that turns a more efficient turbine.
Distributed Would Be Better... (Score:3, Insightful)
Re:Distributed Would Be Better... (Score:3, Informative)
Most of the electricity consumed by a UK house goes to heat the hot water tank and provide central heating so the biggest bang for buck is to do that using a solar/thermal system. The thermal vacuum tube systems are far more efficient at extracting energy from the sun than photovoltaics, up to 80% efficient and they are far far cheaper, nearly 1/10th the price.
Sea Snake - Pelamis project seems more interesting (Score:4, Interesting)
Wrong - and quit linking to bloggers (Score:3, Informative)
An article in the Scottish press [scotsman.com] has more useful info.
It only generates 150KW. That's not much. Typical wind turbines generate 200KW to 700KW each, on windy days. (Average values are much lower.) Typical nuclear power plants generate 1,000,000KW. Powering a home takes about 1-2KW on average, so 10,000 homes require perhaps 15,000KW.
The SNAIL people want to move up to the 750KW range or so. That's more reasonable. As wind power people have discovered, having huge numbers of little turbines isn't cost effective. But somewhere around a few hundred KW per turbine, the economics start to work. If you can find a good site with steady wind. As with dams, there aren't that many good sites.
It will probably take several decades of operating experience to turn this into a reliable technology, just as it did with windpower. It's been half a century since the Grandpa's Knob loss of blade accident. The first big power-generating wind turbine oversped and threw a blade several hundred feet. For many years, nobody built one that big again. Gradually, the aerodynamics and control problems were figured out. It's taken that long to make large wind turbines work reliably and profitably.
Anything with moving parts in the ocean is likely to be high-maintenance. Making one of these things work reliably for decades will be tough. Maintenance will be costly. There's no guarantee of success.
In short, there's no breakthrough here until it's been running for a few years without breaking.
Renewable???? (Score:3, Insightful)
Re:Socialism at its best (Score:4, Insightful)
Who's to say that's not desirable - for the state. One's power increases with each person dependant on you, all the better to guarantee your position in government.
Re:Socialism at its best (Score:4, Insightful)
Re:Socialism at its best (Score:2, Insightful)
2. Come up with boondoggle, pork-laden solution
3. Profit!!
Re:Socialism at its best (Score:2)
Re:Socialism at its best (Score:5, Insightful)
But the impending bankrupcy of oil supplies is NOT a fairytale. I think it's obvious, or at least it should be, that getting power by burning or exploding several millions of barrels per day of a substance that exists only sparsely is not the sort of thing we can do forever. My relatively ecomoderate history professor liked to quote that oil supplies will start to run out around 2040, using 1992's numbers. And our consumption has increased vastly since then...not due to the SUV as some will tell you, but due to increased petroleum usage in the industrial development of second and third wave nations, as well as increased reliance by first wave nations.
Personally, I'm not too worried, because right around the time that oil gets really scarce, all of the hundreds of alternative solutions that are already fairly mature will suddenly become viable. At that point, whoever has the best, most efficient way to use the elements to make juice will stand pretty strong against the backdrop of nations scrambling to gather their their oil money.
Europe has these regulations to decrease the potential effects of oil greed. When the oil crunch comes, they're half way to neutrality. If the US had regulations and incentives, or rather, more of them (NY does offer tax credits for alternative fuel sources but they're break-even deals, not something to bank on), we wouldn't have to worry either. "Let the Arabs fight over their oil, we've got solar farms!" Unfortunately, America's caught between myopic politicians and a still strong petroleum industry trying to squeeze as much as possible out of their remaining power. The end result is -- well, war, high fuel prices and an intense media driven hatred of "green" politics.
Re:Socialism at its best (Score:3, Insightful)
And thanks to lax recycling practices, we've got tons of raw materials sitting in landfills. If costs increase high enough, it'll be cost effective to mine these.
I mean, when steel started to get expensive, we moved to plastic and aluminum. As plastic gets expensive, we'll move on from there. Like many environmentalists, you seem to imply that a reduction in a si
Re:Socialism at its best (Score:3, Insightful)
We are 36 years away from the oil pinch. That's more than a generation. We are just now starting to see oil prices go up. People have yet to realize that they aren't ever going to go back down into the $.80/gal region. Another year of $2 gas prices combined with decreasing wages, and we'll start to see more demand. The SUV thing isn't going to dry up based on oil costs, because currently the apparent safety and comfort override the concern of oil costs. As costs cont
Re:Socialism at its best (Score:2)
Better for whom is the question you need to ask... oh.. you meant the general population?
Re:Socialism at its best (Score:5, Insightful)
Re:Socialism at its best (Score:3, Interesting)
Except that there are distinct advantages to being second in such a case. Let the Euros make the huge investment in R&D for feasible alternatives, while the US continues to enjoy cheap energy via petroleum. Then, if/when oil becomes economically infeasible, the US simply borrows whatever magic solution the Euros have discover
Socialism, or a reality check? (Score:5, Insightful)
We already have a lot of fuel-saving technologies which will pay for themselves nicely at current prices (let alone future prices), yet adoption has been very slow. I can think of a number of causes:
- Tax subsidies which have the effect of paying users not to change.
- Outmoded regulations which slow or even block desirable change.
- Interest groups which resist changes which threaten their way of doing business.
- Simple inertia.
As an example of 3 and 4, I hold up the continued widespread use of stick-built construction when SIPs (Structural Insulated Panels) leak a lot less heat, have next to zero air leakage when properly installed, and save a lot of time and labor in the construction. They also reduce the use of wood. We should be promoting or mandating their use where feasible and training builders and building inspectors in their proper installatino. Are we? No. I'll bet there are a lot of union carpenters who like it that way.Another is the relative lack of CHP (Combined Heat and Power, or cogeneration) systems in the USA vs. Europe. This may be due to power regulations which make it impossible to obtain a market price for the production of small generators, or far too expensive to connect to the grid save as a pure consumer. Again, this is something which can be fixed with proper regulatory changes.
There are questions not answered in the article about the snail, such as the handling of the variable output of the tidal power systems versus the contrary schedule of grid demand. These things must be dealt with; unfortunately, they are beyond the scope of small news items. What's truly a pity is that news editors don't think they are sufficiently important to collect links for further study.
Affordable? (Score:5, Insightful)
Energy from petrochemicals is not sustainable. It might be cheap - right now - but it's not going to last. Moving to sustainability while we have cheap petrochemicals to help us get there makes sense. I think it's high time that environmental costs, lack of sustainibility, and other "externalities" were factored in when comparing "affordability". Cheers!
Re:Affordable? (Score:3, Insightful)
Steady, there -- you're sounding too reasonable (Score:3, Insightful)
C'mon, stop saying such reasonable things. Get out of the way and let the big energy interests scuttle their competition. They're powerful, and they'd like a market that's "free" to allow them to throw their weight around.
We're in very great danger of a socialist takeover because of this Sea Snail project. Honest. 'Cause there's never been an innovation encouraged by government that helped the economy at all.
Re:Affordable? (Score:3, Insightful)
Further, I think petrochemical supplies are already running too low, hence my support for the alternatives that are appearing. That's beside my original point, though: when you count the real costs (environmental/sustainibility
Re:Socialism at its best (Score:4, Insightful)
Private corporations are great at going the last mile, making a processor or a hard drive that's 10% better than last year.
They're less good at pumping in huge amounts of money to make a technology initially feasable or doing basic research.
The free market provides substandard information. There've been several studies of rogaine published in scientific journals. Those funded by industry (even though industry doesn't disclose their funding, sometimes in violation of the pubishing journal's standards ) often show a drug doing much better than government funded research shows it to be.
Besides, many countries try to lure venture capital, which creates jobs. Better infrastructure and more stable energy costs are considerations for major manufacturing concerns which help more developed countries compete with cheap labor.
Besides, if you have high unemployment projects like this can create jobs as well as contributing to the economy. And unemployment creates more problems than just people not working (crime, drug use, etc.)
Re:Socialism at its best (Score:2, Troll)
As if the US defence industry is any different. The US spends more than the next 5 biggest defence spenders combined. It's a form of welfare. If the government's going to spend money like this then I would prefer it to be for something useful like renewable energy than the military.
Re:Socialism at its best (Score:2)
I for one am a staunch supporter of the undemocratic influence on politics, the wholesale environmental damage, and the pronounced socio-economic striation resulting from overreliance on non-renewable resources controlled by massive corporate monopolies.
By continuing to allow petro-chemical interests to dominate political policy, we ensure that the natural, capitalist, laissez faire stagnation of innovation maintains the status quo, so I can buy another yacht, and poor children in cities a
Re:Socialism at its best (Score:4, Informative)
Socialism is bad when it causes the state to interfere in short-term market issues (ie, price fixing), because no single entity can affectively micromange such a complex system. But applying broad long-term pressures to the market is not socialism, its a smart policy that recognizes the deep complexity of the market system.
Re:Socialism at its best (Score:3, Informative)
The production tax credit (PTC) for wind in the US was 1.5c per kilowatt-hour because that was needed to have a level playing field with the heavily subsidized fossil fuel industry.
So instead of cutting the subsidies to polluting tech, we increase it for the next generation. Fusion and fission are both heavily subsidized as well. Meanwhile the PTC for wind has expired, and it is competing against unfairly subsidized incumbents.
Besides the obvious tax burden, this has a nasty counte
Re:Socialism at its best (Score:3, Insightful)
The standards have to be set somewhere by someone. Business isn't going to regulate itself. Besides, it isn't really anything unique to "socialism." Even in the US, we have certain standards (albeit low) for fuel economy, polution, etc. It isn't like they are saying exactly which technologies to pursue. They just say "This is the
Doh! (Score:2)
Re:Why? (Score:3, Insightful)
How was the parent post modded Score:0,Troll ?
It is a good point that if there were regulations like that in the US, things might be very different. I think few would argue that we depend on oil for to many of our energy needs.
The annoying part which neither the summary or the article address, is that a country is sovereign and is not *required* to follow regulations setup by another group. It may choose to take part in a treaty, or follow similar guidelines as other countries, but *required* is another s
Re:Why? (Score:5, Informative)
Re:Why? (Score:4, Informative)
Considering that our coal supplies will long outlast our oil supplies, I think that its still a good idea to invest in cleaner coal technologies. Linky. [energy.gov]
Re:Why? (Score:4, Informative)
Not to nitpick, but coal mining is the number 2 most dangerous occupation in the world IIRC. Commercial fishing is substantially more dangerous [oceansatlas.org].
Re:Made up statistic (Score:3, Informative)
City of Austin (Score:3, Interesting)
Austin renewables (Score:4, Interesting)
Re:30 Tonnes (Score:2)
Re:it's like the recycling bins (Score:2)
Of COURSE the pickup, processing, melting, and re-forming of materials is going to use a ton of energy. It does have other nice side-effects, though: less deforestation, less mining, etc...
It's a tradeoff. You spend energy to get material.
Re:Uh, what about the environment? (Score:5, Insightful)
These seemed like valid concerns at first glance, but the numbers just don't add up. It's something we often deal with in physics; it's very hard for humans to compare quantities which are very very large.
The amount of energy we're extracting from the water is miniscule. Take the 5MW sea power station. Water weighs 1 gram / cc, which means 1000kg per m^3. 5 MW in 1 second is the kinetic energy (using E=(1/2)m(v^2)) in 100 cubic meters of water moving at 10 m/s: E=(1/2)(1000gm)(100m/s)^2 = 5e6 joules. 100 cubic meters, even once a second, is NOTHING compared to the rest of the sea. 7/10 of the Earth's surface is covered by water; the seas have an estimated volume of 1.4*(10^18) cubic meters!
Huge solar plants will abosorb their energy from our sun. That energy would have heated our soil, been absorbed by plants, been reflected back into the atmosphere...
The amount of land affected is exactly that in the shadow of the solar array. No more, no less. Even the power we "extract" from that shadow returns to the environment in the form of heat, after it's used in the grid. Remember, energy is always conserved.
Geothermal generation will cool our planets core faster
This one really set me off. Come on people, the Earth is a GIANT BALL OF MOLTEN ROCK. The crust, with all the seas, life, solid rocks and mountain chains, is a few miles on top of it. The radius of the Earth is 4000 miles = 6400km. It has a volume of 1.1*(10^12 cubic KILOMETERS)! You could literally pour every ocean on Earth (10^9 km^3) into the mantle, boil it off into space, and barely make a dent in the temperature. There's a reason it takes billions of years for planets to cool.
Think about replacing a nuclear power plant with a tidal generator. You are sucking an entire nuclear power stations energy output from the ocean! Don't you think that might have some sort of consequences? And that's just one nuclear power plant. There are dozens!
This seems really logical, because to humans a nuclear power plant generates an enormous amount of energy, i.e. many orders of magnitude more than it takes to run your electric razor. But the power in the oceans (7/10 of the Earth covered by VERY dense material moving about) makes those power plants look like coin cells by comparison.
The only solution is to be more efficient, not to try and generate more power.
On this point I agree with you in spirit, but have to point out that it will simply never work. Google for "The Tragedy of the Commons" if you want to know why. Simply put, any person/organization which tries to consume less energy puts himself at a competitive disadvantage. It sucks, but it's the way economics work.
Formula correction (Score:3, Informative)
E=(1/2)(1000kg*100)(10m/s)^2 = 5e6 joules
The answer is the same; just a typo.