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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.
According to this site:
"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.
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Over what period of time?
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.
This link explans better how the sea snail works. http://www.friendsofscotland.gov.uk/education/rene wable.html
Basically, the foils are to keep the snail anchored while the turbine is moved by the water.
quis custodiet ipsos custodes
This is all part of an alien conspiracy to bring the moon crashing down on us! Awaken to the truth before it's too late!
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".)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
In this case it's not oil that we are dependent on but COAL. Now while we mine coal right here in the US remember that coal mining is by far the most dangerous occupation in the US, for each coal plant in the US one coal-miner is killed each year in an accident. This doesn't count the long term healt and psychological effects that mining has on a person. Nor does it take into effects the polution generated by a coal plant. Sorry, but oil fuels some of our energy needs (heating and automobiles) but very little oil is used in electrical power generation.
While it is true that coal mining is still a rather dangerous occupation, the polution generated by coal-fired power stations isn't as bad as many people belive. In the last few decades, coal has come quite a long way in reducing toxic emmisions. Modern coal plants combust the fuel much more completly, and are outfitted with high-tech (and very expensive) scrubbers to remove the really toxic byproducts (especially sulfer).
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.
Not to nitpick, but coal mining is the number 2 most dangerous occupation in the world IIRC. Commercial fishing is substantially more dangerous.
The fact is that private companies do not have the long-term interests of society in mind. They have a mandate to increase profits.
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.