Sustainable Energy without the Hot Air- Great Read

[FinanceDude]

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Originally Posted by clifp The book has a lengthy chapters on Nuclear Energy, in which he covers pretty much every objection. Including how many resource required to build the things. He glossed over storage of wastes which at least in the US has proved to be a political problem. Although, from a strictly numerically view the problem seems quite manageable about a wine bottle of nuclear waste per person (in the UK) per year. One of my favorite charts in the book is death per Gigawatt which has both wind and nuclear being quite low and as he points out very small in comparison to driving deaths etc.

Doesnt' the govt own a bunch of deep salt mines for spent nuclear storage? Also, here's a mind twister: If a "breeder reactor" keeps making fuel, does it ever "get full"??

[HFWR]

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Originally Posted by FinanceDude Doesnt' the govt own a bunch of deep salt mines for spent nuclear storage?

They're full of SPR oil...

I've seen a snippet (on the Science channel?) about a university team working to reduce/remove inpurities from "spent" rods, which are only 95% used, but rendered impotent by impurities. As I recall, they were making good progress, in a research sort of way, meaning the technology might be ready in 10-20 years.

[FUEGO]

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Originally Posted by HFWR I've seen a snippet (on the Science channel?) about a university team working to reduce/remove inpurities from "spent" rods, which are only 95% used, but rendered impotent by impurities. As I recall, they were making good progress, in a research sort of way, meaning the technology might be ready in 10-20 years.

I just use em as nightlights for my kids. Nice glow to em, and as an added bonus they throw off some radiant heat in the winter. Gotta run - my 2 year old is trying to attack me with all eight of her tentacles!

[clifp]

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Originally Posted by FUEGO I just use em as nightlights for my kids. Nice glow to em, and as an added bonus they throw off some radiant heat in the winter. Gotta run - my 2 year old is trying to attack me with all eight of her tentacles!

LOL, spare the rod and mutate the child.

[samclem]

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Originally Posted by ERD50 In comparison, nuclear "waste" is contained (most is kept right where the plant is, I think). And since we've only known how to work with this stuff for 60 years or so, something tells me that in another 60 years we will know how to make good use of the remaining energy there. And it will be right where we left it. Perfect! If not, we will probably have better ways to deal with it than today.

Yep. Store the waste for now as we use conventional reactors. Then, in 30-50 years when we start to run low on easily-obtained uranium, we can use the spent fuel in breeder reactors that will provide power for hundreds of years. And, we can start using thorium reactors, too (there's lots of fuel for those).

[Zathras]

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Originally Posted by ls99 By the way until you spent time in the close vicinity of wind generators, you have no ide of the nerve wrecking WHOOSH of the giant blades make. They work fine in uninhabited areas like Mohave.

You have some interesting ideas. I spend a fair amount of time near wind generators (not on a day to day basis, but hours at a time).
At a few hundred yards, they can't be heard.
Even right underneath them it isn't a big issue.
I have yet to see anyone suggest building on in someone's back yard such that they would hear the blades. Many in the upper midwest are on farmland and not within a hundred yards of a residence.

As for solar being inneficient, that is true. Most panels don't get beyond 19% or 20% efficiency. However, considering that the 'fuel' for the panels is free, and generates no pollution in the generation of the power, it is a pretty good deal.
Financially, no, but on pollution, definately.

[HFWR]

Eight testicles...

[ls99]

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Originally Posted by Zathras You have some interesting ideas. I spend a fair amount of time near wind generators (not on a day to day basis, but hours at a time). At a few hundred yards, they can't be heard. Even right underneath them it isn't a big issue. I have yet to see anyone suggest building on in someone's back yard such that they would hear the blades. Many in the upper midwest are on farmland and not within a hundred yards of a residence.

Some relevant info on higher power turbines from page 17 bottom of the following document: http://www.town.manchester.vt.us/win...oiseIssues.pdf

Therein is some pretty darn good research for those with technical interest and the willingness to pore through and digest the information presented. Still not a lot of info megawatt rated systems.


A study of sound produced by a 10 kW Bergey wind turbine at Halibut Point State Park in
Rockport, MA, includes measured sound pressure levels under a variety of wind conditions and at
a variety of distances from the wind turbine base (Tech Environmental, 1998). The study showed
that under some conditions the wind turbine noise at 600 ft (182 m) from the wind turbine base
increased noise levels by 13 dB(A). The study estimated that a buffer zone of 1600 ft be required
to meet Massachusetts noise regulations! Finally, the study also mentioned that under high wind

My experience from up close is about 20 yrs old, near large wind generators. I presume blade design has gotten better over the years.

Here is some hard data:BWEA - Are wind turbines noisy?
For small farm sized wind turbines. They are reasonable.

For large commercial megawatt wind farms the story is different. Hard published data is not easy to find. Here is an excerpt from an article in the Grand Forks Herald.com

"A growing body of research, critics say, raises questions about the chronic health effects of noise and low-frequency vibrations caused by wind turbines.
In Europe, which has a much longer history of large-scale wind farms than the United States, some expert panels recommend much longer setbacks.
The French Academy of Medicine, for example, recommends setbacks of a mile, the minimum distance sought by the Stillings and others who raised concerns about the Luverne project.
Some researchers contend turbines can cause earaches, dizziness, heart palpitations and sleep deprivation with diminishing brain function, findings that are disputed by other researchers.
Documenting a possible causal link in chronic health conditions, which take years to develop, means people could be living at risk until results become conclusive, Dennis Stillings says.
“The studies on the sound are inadequate,” he adds. “You can tell when you study the literature they avoid a serious discussion. They avoid the noise issue.”"


The full article is:NOISY WIND: Residents near N.D. wind farm project raising voices over noise pollutions | Grand Forks Herald | Grand Forks, North Dakota

Cheers.

[Nords]

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Originally Posted by ls99 I often wondered why the spent fuel holding tanks could not be used via several heat exchangers to provide heat and water heating to adjacent neighborhoods. The spent fuel stays hot (in more ways than one) for a long time. Surely there might be a cost effective way to use the heat, instead of dumping it through the cooling tower or other waste type heat exchanger.

It ain't the free heat, it's the "extras" that come with it.

The problem is that the used core isn't producing heat from fission but from the decay of fission products. Decay heat does just that-- it decays away. In a few weeks you'd barely be able to boil water, but you'd still have all those yummy neutron-activated gamma-radiating isotopes running around the piping. Cobalt is a common component in stainless steel and the half-life of cobalt-60 is five years. Five half-lives of decay would still throw off detectable radiation, although not necessarily at harmful levels. As near as we can tell.

Even if the core & fuel is extracted from the pressure vessel and dumped in a big cooling pond you still have the same issue-- not enough heat and too much radiation. By the time you found someone who was willing to live close enough to the pond to get free hot water, they'd still be sweating (so to speak) the radiation levels. And they'd still be so far from the pond that the heat losses from the piping between the pond and their house would be enough to drop the water temp to ambient.

The advantage of water tanks is that hydrogen atoms (protons) are very effective at slowing down fission neutrons, while the tank is big enough that the neutrons just fizzle on out past the fuel elements and don't bounce back into uranium atoms to cause more fissions. So while the water helps with the decay heat transfer, its main role is preventing criticality.

And, as has been noted, it makes that cool nightlight glow.

[ls99]

Thanks Nords, appreciate the description. Kind of explains why divers in the tanks have to stay 5 or more feet from the spent fuel rods.

[Zathras]

The experience I have is spending 4-6 hours at the families farm down in Iowa. They have a comercial sized wind turbine in the field neighboring their house. Closest I have gotten is about 60-75 yards.
Again, no appreciable noise.
Now, I appreciate the data you have. If that number was 13 decibels, a whisper is rated at 15 decibels.
If you want annoying, I suggest you live within 2 miles of an airport

[ls99]

Yea 13 db incresase does not sound like much. All of the FAA, wind turbine, other noise standards are done using db(A) the "A" weighted scale. Which conveniently cuts out most of the annoying high energy low frequency noise. Which is why jet aircraft flying 1800' AGL (above ground level) produce "acceptable" noise level over populated areas.

There is a push by several noise abatement organiztioans to dump the "A" weighted scale for the more inclusive and accurate "C" weighted scale.

In addition there is band specific periodic noise which gets averaged over long time for "standards" purposes, yet is most disturbing.

So anyway our experience differs. That is Ok. I have lived in areas that were under final approach path to large metropolitan airport (BWI), had many discussion with the FAA reps regarding standards etc.. Needless to say I checked carefully for flight patterns in our new town, also for wind farms. We are better than 60 miles from any major airport/windfarm and 18 miles from any airport end even for those the approach landing pattern is such that they are more than 10 miles away.

Peace reigns, except for the occasional open pipe motorcyclist happening by.

But as they say YMMV.

Cheers.

[ERD50]

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Originally Posted by Zathras Now, I appreciate the data you have. If that number was 13 decibels, a whisper is rated at 15 decibels.

Gotta be careful with those numbers. A 13 dB *increase* is not the same as a 13dB *level*.

-ERD50

[Zathras]

Good point. Isn't there some sort of additive affect? But it isn't linear, is it?
For example, if two jet engines are running (120dB) is the resulting sound 240dB or 150dB or 125dB?
I am sure it isn't linear, as I have been out as close as I could get to the wind farm north of Palm Springs. 500 generators (easily) and at about 200-300 yards I could hear nothing (yes, they were moving).
I put this in the category of 'hot air' the book is talking about, right along side 'wind generators kill birds!' (house cats kill more) and 'Florida is going to disappear under the waves!'

All I am saying is that the noise from the wind generators is much less than most people think.

[Nords]

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Originally Posted by ls99 Thanks Nords, appreciate the description. Kind of explains why divers in the tanks have to stay 5 or more feet from the spent fuel rods.

Yeah-- human bodies make great neutron moderators too, for a limited time only.

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Originally Posted by Zathras Good point. Isn't there some sort of additive affect? But it isn't linear, is it? For example, if two jet engines are running (120dB) is the resulting sound 240dB or 150dB or 125dB? All I am saying is that the noise from the wind generators is much less than most people think.

It's a logarithmic power sum, so 120 db (+) 120 db = 123 db.

But when you double the transmitter power, you don't get double the range.

There's been a lot of research into reducing wind tower noise, so you guys may both be right.

[FUEGO]

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Originally Posted by Zathras Good point. Isn't there some sort of additive affect? But it isn't linear, is it? For example, if two jet engines are running (120dB) is the resulting sound 240dB or 150dB or 125dB? I am sure it isn't linear, as I have been out as close as I could get to the wind farm north of Palm Springs. 500 generators (easily) and at about 200-300 yards I could hear nothing (yes, they were moving). I put this in the category of 'hot air' the book is talking about, right along side 'wind generators kill birds!' (house cats kill more) and 'Florida is going to disappear under the waves!' All I am saying is that the noise from the wind generators is much less than most people think.

Noise in dB are reported on a log scale. For the 120 dB jet engine, adding another one would increase the noise level to ~123 dB. However a 3 dB increase is at the very limits of what is a perceptible difference in noise levels to the typical human ear. To double the perceived noise levels, you would need 10 jet engines which would produce 130 dB. There is ten times more noise energy, but only a doubling of the perceived noise.

In regards to the study mentioned above about the 13 dBA increase in noise levels due to the wind turbine, this was a maximum noise level increase with low wind speeds. The maximum observed increase in noise levels were observed with ambient noise levels at 44 dBA and with the wind turbine installed at 57 dBA for wind speeds under 7 m/s. Over 7 m/s and you get a barely perceptible increase of only a few dB.

The 13 dB is a noticeable increase in noise levels, but 57 dBA is not exactly uncomfortable. Plus, the type of noise is a more constant or repetitious noise and not intermittent like a plane flying overhead every few minutes or a loud diesel truck accelerating once per minute. In other words the quality of noise is much better.

This reminds me of a noise study I was conducting recently in a rural area where I measured approx 44 dBA in the woods where it was very calm and quiet. Just the leaves and trees rustling in a gentle breeze and some minor insect and bird noise, plus the occasional far distance noise of an airplane flying overhead at 30000 ft or a truck on the highway a few miles away. I move my noise detection equipment 1000 feet off into the woods near a small pond, and the noise levels jump up to 57-59 dBA. Frogs are loud. All of this out in the middle of nowhere. Yet natural ambient noises were measured over 57 dBA - louder than that wind turbine. When I teach my class on Noise Impacts Analysis, I always tell my classes (jokingly) that those darn frogs are violating the municipal noise ordinance!

Further, looking at the noise chart for the wind turbine, at wind speeds of 9 m/s and higher, the ambient noise readings (without the wind turbine) are actually greater than the "with turbine installed" measurements that showed the 13 dBA differential. In other words, a moderate breeze causes more noise than a wind turbine. That is pretty common - variable ambient noises often will trump man-made noises in non-industrial environments. Nature can be loud.

I'm sure the larger wind farms produce more noise. And the ground vibrations can be another problem, but I have almost zero experience with those.

[FinanceDude]

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Originally Posted by Nords Yeah-- human bodies make great neutron moderators too, for a limited time only. It's a logarithmic power sum, so 120 db (+) 120 db = 123 db. But when you double the transmitter power, you don't get double the range. There's been a lot of research into reducing wind tower noise, so you guys may both be right.

So, Nords, I am assuming you are in favor of more nuclear power plants? heck, they seem to work well for the military........

[Nords]

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Originally Posted by FinanceDude So, Nords, I am assuming you are in favor of more nuclear power plants? heck, they seem to work well for the military........

Well, don't ask the Air Force or the Army about their 1950s studies of nuclear aircraft & tanks. One of the more notorious fatalities of that era involved an Army prototype with a stuck control rod that the operator tried to yank free with his hands while standing on top of the pressure vessel. He succeeded beyond his wildest dreams.

The submarine force places a very high premium on operational safety and battle damage, as in "unaffordable". One of the reasons the fleet is so small is because it's being bankrupted by nuclear maintenance & refueling expenses. The VIRGINIA class was expressly designed to be the first submarine to be used for 25-30 years and then thrown away instead of refueled, but the core lasting the life of the boat means that you don't buy it all over again during a three-year refueling overhaul. But I'm sure the Navy will find a way to burn the fuel faster than Naval Reactors anticipated.

Commercial nuclear is more of a "right now" solution than solar or wind, believe it or not, and I'm impressed with the latest generation of pebble-bed reactors. Their physics allow for much better safety & maintenance designs than current pressurized-water or boiling-water systems, helium doesn't turn as radioactive as water-based systems, and the fuel pellets are a lot easier to handle than fuel bundles. Of course I don't have any personal operational experience beyond what I read about them. Maybe one of the commercial operators can add their experience here.

But instead of adding more power-generation capability, I think a higher ROI will come from modernizing the grid, imposing more stringent EnergyStar criteria, and offering more customer incentives. A funny thing happens when you pay people to use less energy: they use less energy. It's a lot cheaper than the cost of designing and building new infrastructure, whether it's nuclear or "green". If the auto manufacturers could respond to CAFE the way that appliance manufacturers respond to EnergyStar ratings, we'd all be throwing away our cars every 10 years in favor of the fuel-cost savings offered by the latest models improving their efficiency from 100 mpg to 200 mpg to 400 mpg.

Nuclear waste is still a long-term problem. A dirty little secret of retired Navy nukes is the lifetime employment offered by Washington's Hanford site, where nuclear fuel from all over (including submarines) is sent to be stored & processed. Every few years a retired nuke admiral takes a senior management job there to "clean the place up", and there's a regular stream of middle-management officer retirees & technicians. It's been going on for over two generations now, and the only noticeable benefit has been to greatly improve our knowledge of nuclear waste proliferation through the water table and the food chain. Years ago there were rumors of employees whose full-time job was to search for (with radiacs) and clean up (while wearing anti-contamination suits) mouse & rabbit droppings because their radioactivity (the mice & rabbits, hopefully not the employees) was above detectable limits. Then that radioactivity started showing up in the owls and other predators... I think the waste problem will be solved but when the true lifecycle costs are added to the design/building costs then today's conventional reactors will be deemed unaffordable.

[ERD50]

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Originally Posted by Nords .... we'd all be throwing away our cars every 10 years in favor of the fuel-cost savings offered by the latest models improving their efficiency from 100 mpg to 200 mpg to 400 mpg.

Wow, they would need to find amazingly affordable ways to go from 200mpg to 400mpg to get me to trade up!

Let's see, at 200mpg and 12,000 annual miles, that is 60 gallons of gas. Getting to 400mpg would save half of that, 30 gallons.

Even at $6/gallon, that is $180/year. A rough loan calculation says they would need to go from 200 to 400mpg for less than an $800 premium to break even over a 5 year loan.

-ERD50

[FinanceDude]

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Originally Posted by Nords But instead of adding more power-generation capability, I think a higher ROI will come from modernizing the grid, imposing more stringent EnergyStar criteria, and offering more customer incentives. A funny thing happens when you pay people to use less energy: they use less energy. It's a lot cheaper than the cost of designing and building new infrastructure, whether it's nuclear or "green". If the auto manufacturers could respond to CAFE the way that appliance manufacturers respond to EnergyStar ratings, we'd all be throwing away our cars every 10 years in favor of the fuel-cost savings offered by the latest models improving their efficiency from 100 mpg to 200 mpg to 400 mpg.

Give me a $15,000 tax credit to buy a Prius, and I might........