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The Heavyweight Sea Snail
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.
Isn't it great, where the State can mandate the advance of technology? This reminds me of that Simpon's quote "Young lady, in this house we obey the 2nd law of Thermodynamics!"
Who's to say that these energy mandates are even achievable, or desirable? Since they won't be affordable, all this does is create a new class of subsidized business, and executives to run the businesses, and higher taxes on (in the case of Scotland) an already under-performing economy.
I want to delete my account but Slashdot doesn't allow it.
What good is a "downward force" if it doesn't do anything? The article doesn't explain how this downward force from hydrofoils produces any energy.
The article mentions that the device is able to "generate more than 200 tons of downward force to the seabed", but nowhere does it state how that force is used. A static force does no work and therefore can generate no energy.
5MW is good for 10,000 homes, so a house in Scotland only uses 500 watts of electricity?
Things like this are amazing ideas and very, very, very important and will only be increasing more so. Oil won't last forever. You know it. i know it. Why beat around the bush (no pun) and say 10, 20, 50, etc years? Who gives a fuck *how* long we have....get on the ball and get renewable energy sources up past 95% of out uses.
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.
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.
Do you even lift?
These aren't the 'roids you're looking for.
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?
I don't know much about the initiative in question, so please don't read this as an unqualified endorsement. However, one factor that needs to be borne in mind when looking at the "affordability" of an alternate power source is its sustainability.
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!
Corruptissima re publica plurimae leges.
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 story. But alas, there is no supporting information on said regulations and/or their origin, so we must blindly accept everything that is said!
But I digress....
how about the ever increasing waste concerning desktop processors?
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 smaller and quieter, and those will generally have lower power consumption.
And, of course, with LCD displays improving and getting more affordable, we'll see a huge jump in efficiency. Although then I'll probably have to buy a seperate space heater for my room.
How can we continue to believe in a just universe and freedom to eat crackers if we have no ale?
The energy to power tides comes from the rotational
inertia of the earth and moon. Extracting power
from tides slows down the earth (making days long)
and makes the moon drive further away from the earth
(in order to preserve angular momentum.) Once all
the power is used up, the earth and moon will be
in tidal lock and a day on earth will last a
month. It will get very hot by midday, and very
cold at night. Most of life as we know it will
cease to exist on earth.
On the other hand, the power tied up in the rotation
of the earth is immense, and it is unlikely that
Scotland is going to reduce it by any measurable
amount. But still....
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. The British Government didn't encourage the development of chronographs by offering a "Longitude" prize, and don't you let those whiny liberals convince you otherwise.
(It's not like the government subsidized the nascent railway and airline industries, ever, by sending the mail through them, or anything like that. We'd never do something like that. Wouldn't be the good old American way. Nope.)
"Fundamentalism" isn't about divine morality. It's about human authority.
I don't know why we bother putting our money into these centralised energy projects. Why not just mandate that all houses must have photovoltaics and solar heating installed? We just had solar heating installed, which works great even in sunny Britain. Photovoltaics would be more expensive (20K UKP expensive) but we calculate that they could provide about 120% of our idle energy needs, so at night the grid would actually have to pay us! :) The payback period would be ~ 6 years we estimate.
Just a little more thought, and the government could easily reach their European targets at little cost to themselves, and with no new R&D.
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.
Time is Nature's way of keeping everything from happening at once... the bitch.
Bonus points for tilting the turbine so as to generate a lift moment downward and use it to produce some of its own downforce.
Time is Nature's way of keeping everything from happening at once... the bitch.
Like the tidal energy isn't coming straight out of the moon. Won't be very easy to renew when we've used this one up.
"Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
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.
Yes, I understand that waves are a function of the moon's gravity, but the energy extracted was going SOMEWHERE before the 30 ton snails moved in.