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Green Energy Now, And On The Tide
thpr writes "The Electric Power Research Institute and its partners have completed their Offshore Wave Power Feasibility Demonstration Project, which defined potential wave energy projects off the shores of the United States. This is building off of work already done in Scotland (and elsewhere). San Francisco, New York and other areas are considering trial installations of the technology. It is interesting to note (table 1 in the report) that the energy density (kW/m^2) that can be achieved is much higher than wind or solar. In addition, harnessing 24% of available wave energy near the US at 50% efficiency is equal to all of the hydropower currently generated in the US (~7% of total electricity production). On a separate note, in the Office of Energy Efficiency and Renewable Energy's $1.2B 2006 budget the Department of Energy is closing out the Hydropower Technologies Program. Maybe that's why this technology is missing from our National Energy Policy?" Until it reaches maturity, though, U.S. readers can pay for other forms of green energy.
In other words, these projects affect the currents, at least locally which in turn *will* affect the biological systems that depend on these currents, to what extent? I don't think we know.
We need alternate energy, but we need to honestly compare the impact of each energy extraction method we consider. Personally, I think nuclear is the lowest impact energy tech.
I've made up my mind and now I've got to lie in it.
Yes, tidal forces DO cause the earth's rotation to slow down.
The tidal forces created by the earth on the moon have slowed the rotation of the moon down to the point that we only see one side of the moon. That is, the moon rotates about once a month. Similarly, the tidal forces of the moon are slowing the earth's rotation down, and it will eventually reach one about one rotation per month also. Assuming that the sun doesn't become a red giant first. And, speaking of the sun, there is also a tidal force that from the sun that will eventually cause the earth to rotate once per year. I'm not sure who this conflict between the moon's and the sun's tidal forces work out.
Conservation of angular momentum means that the tidal forces are causing the moon to orbit the earth faster, and thus further away.
While all these tidal forces are very small and only add up over very long periods of time, they can be measured. In particular, things like variations of the amount of snow on mountains, the amount of water in man-made lakes, the force of huricanes, and variations in the shape of the earth caused by earthquakes all add up to enough to cause the need for leap seconds.
Leap years keep the seasons from rotating through the calendar. Leap seconds keep the zenith of the sun ("noon") from rotating through the day. I forget the exact value, but there is something like an accumulated 20-30 seconds difference caused by these forces over the last 50 years, and therefore there have been 20-30 leap seconds added since then.
SPF support for most open source mail servers can be found at libspf2.
For those who want more, the best links on for intelligent green reading:
WorldChanging.com -- which also has an article about wave power.
TreeHugger, which is already linked in the story.
Dave Pollard, which writes very insightfully about lots of things including environmental philosophy.
Green Car Congress, where you can get the best news about green mobility, cool cars & industrial developments.
IDFuel, which is more about design but covers some of the same ground as TreeHugger.com
FuelCellWorks for all the latest news about fuel cells.
Grist Magazine, for news and a touch of humor, plus lots of interviews.
Treehugger? Treehugger... Treehugger!
Well, considering that burning coal puts out more radioactivity than nuclear energy (not to mention all the soot, CO2, CO, etc), I'd say that nuclear is pretty green. It could be made even more green if we didn't ban reprocessing. A recent discover (or was it wired?) had a nice article on it, pick it up, it can tell you a lot more than me.
There are 11 types of people in the world: those who can count in binary, and those who can't.
Waves are cool, but don't forget ... OTEC (Ocean Thermal Energy Conversion)
My father was a primary designer on this, so I had the "real scoop" on what was going on there in real time, it was real exciting stuff back then!
Mini-OTEC, 1979
In 1979, the first successful at-sea, closed-cycle OTEC operation in the world was conducted aboard the Mini-OTEC, a converted Navy barge operating in waters off Keahole Point.
This plant operated for three months, from August-October 1979, and generated approximately 50 kilowatts of gross power with net power ranging from 10-17 kilowatts.
Its turbine generator produced a gross output of up to 55 kW. About 40 kW were required to pump up 2,700 gallons/min of 42F water from 2200-ft depth through a 24-in diameter polyethylene pipe and an additional 2,700 gallons/min of 79F surface water, leaving a maximum net power output of 15 kW.
This was a joint effort by the State of Hawaii and a private industrial partner.
More linkage: NREL's OTEC site
Google
Wind power is also relatively non-disruptive I used to live near a wind turbine that is on the outskirts of a medium sized wind farm. They are the most disruptive energy producers I can think of to be near in terms of effect on people (and possibly animals). The low frequency noise produced by the machine played havoc on sleep (you got none) and can drive you to the point that you think of any stupid excuse not to go home. I had to sell up and move, it had got so bad, due to the fact it was starting to effect every part of my personal and professional life from sleep deprevation and stress. I realise you were referring to the environment, but some of these 'green' solutions to power generation produce an effect to its surrounds other than what is normally addressed when their impact is reviewed. Wind power is often viewed, here at least, to be one of the most cleanest methods of producing energy and I believe that to be true.....as long as you don't live near them.
And no, I couldn't give a shit what my karma is.
I'm not going to bother to check your math, I'll just quote from a January 2005 report of the Solar Energy Industries Association:
"Solar collectors on a 100-by-100-mile area in the Southwest could generate as much electricity as the United States consumes in a year. Alternatively, solar systems on roofs, parking lots, and other developed land across the nation could generate all the electricity we need--now, in 2030, and 2050--without building on the nation's open spaces."
I've seen similar figures from Sandia labs.
I'm really puzzled why people always try to figure out how much space would be taken up by a centralized solar power plant. The appealing thing about solar power (and fuel cells, and wind power) is that it's distributed--generating units are scattered wherever power is necessary. If you think about it that way, the space taken up by solar panels (or whatever) is negligible.
Go into an urban or suburban area and see how much space is taken up by buildings with flat roofs, parking lots, etc. Imagine that space covered by solar panels. Now realize that you can clad tall office buildings in solar panels that look like glass (and that let light through to the interior). There's an idea--make the buildings generate some of the power that they consume.
Aight, I've seen tons of misinformation and bogus speculation here, and I just perused the document!!
(1) The facility is out to sea. Hawaii is the closest at 2.5KM, while California is at 13 to 20 Km.
(2) They are in about 40M of water. Waves break in about 1-4M of water, depending on size.
(3) The things FLOAT on TOP of the water! (The "Pelamis" design does anyway.) They are mored with cable, and are no where near breakers.
(4) They are not so much "wave" energy as "swell" energy (ie waves = coastal, swell = deep ocean).
Huge variation in wave height makes near-shore uneconomical when waves are small (often), and SEVERELY dangerous when large. (Name a man made structure that has withstood BREAKING waves or a sustained period of time.)
Even when waves are small on the coast, deep sea swells still oscillate across the surface unhindered. The point is to harness these oscillations for energy (as far as I can tell).
The environmental impact will be truly negligable, except for moorings and swell energy depleted before it reaches the coastline.
The very environmentally-paranoid surfer in me says... Go for it!
-Pie
You're right, I'm incredibly frightened of what could happen as a result of the burgeoning nuclear weapons arsenals in Finland and Sweden.
Wow, what a fair and balanced analogy.
Expensive compared to what available alternatives? Japan's large and abundant reserves of coal and natural gas? Their mighty rivers? Broad expanses of unpopulated land for wind and solar?
Unproven compared to what? LWR technology may not be the latest hot, new concept in power generation, but it has a lot of advantages... not the least of which is that it is fairly well proven. Improvements are possible, yes... but look at the improvements over the past twenty years. US plants are now running 90% of the time, unplanned shutdowns are at a very low level, planned outages now take two weeks instead of two months, personnel exposures and radwaste are at all-time lows... what else do you want, free milk and cookies?
Complex, but manageable. It also has the benefit of extremely low fuel, operation, and maintenance costs. Oh, and it's reliable baseload.
Yeah, concrete and steel are pretty exotic, and so expensive.
That depends on where and when the plant was built, and in comparison to the available alternatives at the time. If your benchmark is coal, then nuclear usually doesn't look so great economically. If your benchmark is wind or solar, then nuclear looks much better. Oh yeah, go talk to Finland about how terribly expensive nuclear is compared to the alternatives... maybe they'll decide not to build a new 1600 MWe reactor.
Actually, there is a big difference betweeen US and UK nuclear. In the UK, you have old Magnox plants operating at very high cost relative to average LWR technology used in the US and elsewhere. Magnox was basically the first generation of nuclear power technology, and a lot of its design was dictated by the desire to extract plutonium for weapons production. Then you have AGR, which appears to be very good technologically, but was eventually dropped in favour of LWR technology. So, in the end, the UK has just one fairly modern LWR at Sizewell B, and a bunch of old, expensive plants based on technology that nobody else is using.
Jimmy Carter was a nuclear engineer, and he was President, but to say he stopped all building of nuclear power plants in the US is simply false. Old plant orders were
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