# Thread: Multiple A.C. Voltage Sources

1. I sat this morning out in front, looking westward while enjoying the warmth of the rising sun, our shack being oriented in an angular way, musing over a neighbor's wind generator, already beginning to spin it's little heart out, even though the winds are usually absent until late morning. This one, perhaps 1/4 mile distant, revealed the wind to be coming mainly from the northeast, and north, as it's head kept rotating back and forth between those directions. The props describe at least a 10-foot circle, perhaps more like 12 or 15; they are 3-bladed, their shape looking almost identical in miniature to the monstrous commercial generator blades we have seen being delivered on flat-bed trucks. This curvature and general contour must have been ascertained to be most efficient.

As I perceive it, the idea is either to provide adequate electrical power for a residential location, or to return power to the commercial "grid". The former appears technically easier than the latter, to me.

Having babbled my way through to the "chase" now:

What happens electrically when let's say, for simplicity, 2 voltage sources having sine-wave alternating characteristics are connected to the same load? Obviously, unless the outputs of both are synchronized "in-phase", current might be found to be flowing every which way, no?

Explain this to me, please. Then, maybe the wind generators can be tackled next. Thanks for reading! jocular

2.

3. Just combine each to a single unit then vector?

4. Originally Posted by Magic Pixel
Just combine each to a single unit then vector?
I have no idea what that answer is supposed to mean. So I'll supply one that I do understand.

The answer to jocular's question is that bad things -- perhaps very, very bad things -- happen if the two sources are not synchronous. As you surmised, power can flow between sources, not only to the load. To assure that power only flows from the sources to the load, the two sources must be of equal amplitude and equal phase before connecting them together.

It is possible to combine two unequal-amplitude but otherwise in-phase ac sources (e.g., using a multi-tap transformer).

In the most general case, special circuitry can allow the combining of sources of different amplitudes and even different frequencies, but these are not simple things.

5. The wind turbine is probably generating d-c, or a-c that is then rectified to d-c. Then you would have an inverter generating 60 Hz a-c, synched to the grid.

6. Originally Posted by tk421

The answer to jocular's question is that bad things -- perhaps very, very bad things -- happen if the two sources are not synchronous. As you surmised, power can flow between sources, not only to the load. To assure that power only flows from the sources to the load, the two sources must be of equal amplitude and equal phase before connecting them together.

It is possible to combine two unequal-amplitude but otherwise in-phase ac sources (e.g., using a multi-tap transformer).

In the most general case, special circuitry can allow the combining of sources of different amplitudes and even different frequencies, but these are not simple things.
When studying 3-phase A.C. Circuits at DeVry Tech. Institute, our instructor called such unwanted current flows "circulating currents". This can generate very undesirable effects, (unwanted harmonics, parasitic oscillation)?

I started the thread specifically aimed at learning more about (bold 2). Surely not simple things. Hundreds of enormous wind generators are now operating in many places. In the past few years, we saw many in Oklahoma and New Mexico while driving Interstate Highway 40; twenty years ago there were none to be seen along that route. Where many stood viewable side to side, one could almost swear they were all turning at very nearly the same rotational speed. If their speed is being synchronized in some way, to provide equal output frequency (assuming they were used as alternators), I see that process as pretty damn difficult and costly, wouldn't you agree?

I realize all such info is dig-outable by searching, but believe bringing it to public discussion may benefit a broad cross-section of technically-directed young adults, who might otherwise not encounter it. jocular

7. Its confusing to me as to why wind power was chosen as the alternative energy source. Alos I read up on wind power once, and ac and an inverter are used as I can recall.

8. Originally Posted by Harold14370
The wind turbine is probably generating d-c, or a-c that is then rectified to d-c. Then you would have an inverter generating 60 Hz a-c, synched to the grid.
This is how I pictured it. The problem I am having is how do we synchronize phase with the "grid"? More daunting to me yet, is the fact that these variously-located small wind generators are most likely placed by being sold to individual customers, without regard to which "legs" of the three-phase being supplied to single-phase customers they are "returning power" to. The unbalance created is no doubt pretty small, presently. But what if, let's say, 10% of single-phase power users were generating in this way?

I reluctantly admit to being sadly "behind the times" technically, regarding the newer advances in the Electrical Industry! I should be able to design circuitry which would "match" phase synchronization of two sources, but am not sure where I would start! joc

9. A grid phaser? Thats good question. How do all of those new power add ons connect up to the grid ?

10. Originally Posted by Magic Pixel
Its confusing to me as to why wind power was chosen as the alternative energy source. Alos I read up on wind power once, and ac and an inverter are used as I can recall.
Being confused by trends such as discussed here is not a "lonely" position! I am, myself, confused by all the aspects of Electrical Industry trends. I suspect wind is favored for several reasons, the main one likely being availability of long-term historical records of wind availability, by location. Huge monetary losses could result from installing these very expensive generators, only to then experience future lack of adequate wind.

So, geo-thermal? Ever visit Yellowstone National Park? Ungodly amounts of heat energy are simply wasted there. But, harness steam issuing forth from the ground? Difficult. Open great clefts in the earth and bury heat exchangers? Whew. Maintenance nightmare!

The tides? Untold amounts of mostly wasted energy there. Could we "wall-off" a large section near ocean coastline, say, to a depth of two-hundred feet below the natural ocean floor, not very far out from the shoreline? Make it like a huge submerged chimney, the top edge of which would lie at the sea's level during "low tide", build an underground facility at some depth below the deep end of this chimney, say two-hundred feet deeper still, to which penstocks would carry the chimney's contents to electric generators, each time the returning tide proceeded to re-fill the chimney with seawater.

What do you think of that? jocular

11. Earth motions, like earthquakes, mountains falling over, or anything of that nature, stored then transfered to generators. There are a lot of energy resourses, tides as you mentioned, even waves, and focused sunlight. Lots of rules with generator designs. They are propably isolated from the main grid. I hear there is money in supplying extra power to the grid.

12. The complex I refered to before was the harmonics.

13. Originally Posted by jocular
This is how I pictured it. The problem I am having is how do we synchronize phase with the "grid"?
Smaller wind generators generate DC. A grid-interactive inverter then synchronizes the power to the grid.

Many larger wind generators are synchronous machines. They are spun up to their synchronous speed by the grid. Additional torque from the wind results in current being fed to the grid.

14. If you were going to add power to the power grid yourself, using an alternative energy source, what would you use?

15. Originally Posted by Magic Pixel
A grid phaser? Thats good question. How do all of those new power add ons connect up to the grid ?
Harold gave the answer: Each wind generator operates independently and generates DC. Then a circuit called an inverter converts that DC into AC. If you are going to connect the AC output to the grid at large, the inverter must also contain circuitry that assures in-phase operation.

16. Originally Posted by billvon
Originally Posted by jocular
This is how I pictured it. The problem I am having is how do we synchronize phase with the "grid"?
Smaller wind generators generate DC. A grid-interactive inverter then synchronizes the power to the grid.

Many larger wind generators are synchronous machines. They are spun up to their synchronous speed by the grid. Additional torque from the wind results in current being fed to the grid.
This concept I really like! Once synchronous speed is met, any out put generated is at the same electrical frequency as the grid. 2 questions plague me: How is the generated phasing locked in to match the grid phasing? What about "slip" occurring between grid-spun rotational speed, and wind-produced rotational speed? joc

17. Originally Posted by Magic Pixel
A grid phaser? Thats good question. How do all of those new power add ons connect up to the grid ?
That is a good question. One which I am also struggling with. An analogy I experienced firsthand: The area in which my wife & I lived in the Missouri Ozarks experienced very frequent
(comparably) power outages, perhaps on average, once monthly. The "killer" occurred when once, the juice was off 5 days. The contents of our fridge had reached 60`F, the freezer, 45`F, real close to total loss. I went out and bought a 5000 watt generator, which, during the next outage (one never knew how long it would last), I connected in to the house circuits through a double-pole 240V. circuit breaker which "fed" the water heater. This was expedient, as I had installed a socket outside to use for an air compressor, or welder. Thus, the generator "back-fed" all the breakers in the house, the water heater being shut off at the heater itself. I could switch "on" only those breakers really needed, in order to not overload the gen: fridge, lighting, well-pump. I had no "transfer switch", and could not afford one. The main disconnect at the power pole, feeding the house, was the "transfer", and it was opened before starting the generator.

Here's the point of all this: Once, I forgot to open the main disconnect, started the generator, it ran like hell OK, but then I found no power available in the house, and the overload breaker on the gen. open. The generator was trying to power-up the entire feeder line serviced by the power poles "marching" across our property! In essence, it dumped it's entire ability to provide electric power into an "open hole", which gobbled up it's entire output!

I see this as a possibility with the scenario talked about in this thread. Harold & tk will check me if wrong: the individual power source, here being the wind generator, must have voltage output slightly higher than that prevailing at the time on the grid. Otherwise, the generator will consume power from the grid, instead of adding power to it. This will all work OK as long as the grid voltage does not fluctuate widely, which, normally, it will not. It may present "excursions" from the nominal, but usually these are predictable, as loads imposed are historically predictable, based on the utilitity's prior experience. joc

18. Originally Posted by billvon
A grid-interactive inverter then synchronizes the power to the grid.
Sounds like the means to the end. But, is this truly effective enough to warrant the enormous capital outlay, given the huge power production capability of fission? joc

19. Why are folks in general, here in America, so frightened and "edgy" about Nuclear Power Generation? jocular

20. Its incompatability with people and the planet in general. Altimers? Heroshema, nakasaki, threemile, chenobel, fucishima, cancer. Fission never cools after it melts down. As an alternative energy source choice, fission would be my last. In fact I wouldn't even give it consideration. Back to the drawing board.

21. Providing a brief comparison, by country, below, are percentage in numbers of power produced using Nuke:

France 75%
Belgium 51% (thrown in for comparative purposes)
U.S. 19%
U.K. 18%
Japan 18%
Russia 18%
Germany 16%
China 2%

Excluding China, the big-names are all approximately alike. Why? Surprisingly, after the U.S. and France (102,000 MW and 63,000 MW), the fourth in place is.....! South Korea! 21,000 MW!

No conclusive logical results may I draw from this. I am at a loss.

Who knows with any distinct accuracy, how much fissionable , i.e., bomb-making able materials are being constantly produced by all those concerned? jocular

22. In your humble yet highly regarded opinion, does that make any of them right? And by the way just kidding about the althimerze.

23. Originally Posted by Magic Pixel
In your humble yet highly regarded opinion, does that make any of them right? And by the way just kidding about the althimerze.
You obviously fear nuclear power generation. What do you base that fear upon? Given the tremendous amount of power generated day after day after day, by the nuclear industry, and in consideration of injuries/casualties incurred in the Nuclear Sector vs. that of the general power production sector, can you reasonably condemn nuclear power production as "unsafe"?

My wife & I lived without power, water, or 'phone for a year. (Best year of my life!). Given the "majority rules" concept, we need to establish, in order to implement strategic control over personal resources, what sort of governmentally-mandated regulation are universally acceptable to the population at large. In other words (those of the politician) will you accept our taking control over the: automotive industry, telephone/communications industry, healthcare industry, educational industry, petroleum production, banking, mining, Public Health. Natural Resources, immigration, emigration, food and drug safety, "Homeland Security"............... jocular

24. With a shielded case of uranium and a hand full of pencils for the graphite, would you replace your house backup generator with it. And why not?

25. Originally Posted by jocular
Originally Posted by Harold14370
The wind turbine is probably generating d-c, or a-c that is then rectified to d-c. Then you would have an inverter generating 60 Hz a-c, synched to the grid.
This is how I pictured it. The problem I am having is how do we synchronize phase with the "grid"? More daunting to me yet, is the fact that these variously-located small wind generators are most likely placed by being sold to individual customers, without regard to which "legs" of the three-phase being supplied to single-phase customers they are "returning power" to. The unbalance created is no doubt pretty small, presently. But what if, let's say, 10% of single-phase power users were generating in this way?

I reluctantly admit to being sadly "behind the times" technically, regarding the newer advances in the Electrical Industry! I should be able to design circuitry which would "match" phase synchronization of two sources, but am not sure where I would start! joc
Grid Tie Inverter Schematic and Principals of Operation
Any grid tie power source has to synchronize its frequency, phase and amplitude with the utility and feed a sinewave current into the load. Note that if inverter output (Vout) is higher than utility voltage, the GTI will be overloaded. If it is lower, the GTI may sink current rather than source it. In order to allow a limited current flow into the loads as well as back into the line, "Vout" has to be just slightly higher than the utility voltage. Usually there is an additional coupling inductor (Lgrid) between GTE and the mains that "absorbs" the extra AC voltage. It also reduces the current harmonics generated by the PWM. A drawback of "Lgrid" is it introduces extra poles in the control loop, which potentially may lead to the system instability. Because the grid acts as a source with a very low impedance, normally, a GTE is designed to work as a current controlled source, rather than a voltage source.
I agree that the grid can absorb a limited amount of renewable power, and after that it will start causing problems.

26. Originally Posted by jocular
Originally Posted by billvon
Originally Posted by jocular
This is how I pictured it. The problem I am having is how do we synchronize phase with the "grid"?
Smaller wind generators generate DC. A grid-interactive inverter then synchronizes the power to the grid.

Many larger wind generators are synchronous machines. They are spun up to their synchronous speed by the grid. Additional torque from the wind results in current being fed to the grid.
This concept I really like! Once synchronous speed is met, any out put generated is at the same electrical frequency as the grid. 2 questions plague me: How is the generated phasing locked in to match the grid phasing? What about "slip" occurring between grid-spun rotational speed, and wind-produced rotational speed? joc
It's great as long as the wind is blowing, providing torque to the generator. When the wind quits, then the synchronous machine turns into a motor, and the turbine is a giant fan. Not knowing much about wind farms, I would suppose you'd have to trip the breaker when that happens, and start it up later after the wind picks up.

27. Jock, don't do it .The grid doesn't need any more nuclear power.

28. Originally Posted by Magic Pixel
Jock, don't do it .The grid doesn't need any more nuclear power.
Actually, yes it does. Either that or fossil fuel and the greenhouse gases it produces. Renewable power sources are not reliable enough to supply a stable grid.

29. Originally Posted by jocular
This concept I really like! Once synchronous speed is met, any out put generated is at the same electrical frequency as the grid. 2 questions plague me: How is the generated phasing locked in to match the grid phasing?
A controller starts up the turbine with grid power the same way any induction motor is started. The blade pitch is set based on the wind speed and the turbine begins generating power. Not much different to how steam turbines are synchronized in power plants.

What about "slip" occurring between grid-spun rotational speed, and wind-produced rotational speed? joc
Salient-pole machines don't slip. They always spin at exactly the same speed; torque is limited via blade pitch to prevent jumping a phase during high winds. Pure induction machines do slip; the amount of slip is based on the relative torque and current in the windings. Since the induced field slips along with the stationary field windings there is no risk of "getting out of sync."

30. Originally Posted by jocular
Sounds like the means to the end. But, is this truly effective enough to warrant the enormous capital outlay, given the huge power production capability of fission? joc
Wind has the potential to generate hundreds of times the power available from fission plants. (10 terawatts of wind power is available within the US land and coastal waters as a conservative estimate; you would need 200 fission power plants per STATE to match that.) A nice addition is that it does not heat the planet as nuclear power does. It's not ideal, of course; they are noisy and require a lot of maintenance, and wind is not available all the time.

In both cases, it is harnessing the available power safely and efficiently that is the problem.

31. While driving down twoard mojave I see all these windmill things in the tehachapi hills. I can't see and devices for wind direction on them. Do they change directions according to the wind?

32. Originally Posted by Magic Pixel
If you were going to add power to the power grid yourself, using an alternative energy source, what would you use?
Solar. I generate about 10kw of solar power and feed it back to the grid via a grid tie inverter. Wind has the potential for higher powers per dollar spent but zoning is a lot more difficult (they're very obvious.)

Originally Posted by Magic Pixel
Its incompatability with people and the planet in general. Altimers? Heroshema, nakasaki, threemile, chenobel, fucishima, cancer.
Hiroshima and Nagasaki were nuclear weapons, not power plants. Completely different process (prompt critical fission vs. thermal neutron fission.)

Fission never cools after it melts down.
Where do you get that? It cools within months. That's what "cold shutdown" means in a nuclear power plant.

As an alternative energy source choice, fission would be my last. In fact I wouldn't even give it consideration. Back to the drawing board.
Fission is far from ideal - but it is better than many alternatives.

How quickly would you panic if you found out that a nearby nuclear power plant had just leaked 200 pounds of nuclear waste directly into the atmosphere? What would you do if the plant were 100 miles from you? Would you move? Ask for evacuation? Cover your vents with plastic and duct tape and get air filters?

A typical coal fired power plant puts about 200 pounds of nuclear waste (thorium, uranium) in the air every year, and puts tens of thousands of pounds of those materials into landfills, which of course then leach into groundwater. Yet no one bats an eye.

As another example, take Three Mile Island. It was a disaster! An apocalyptic event that almost killed us all! Yet the total death toll - zero. Radiation injuries - zero. Illnesses linked directly to the fallout from that incident - zero.

Now compare that to the natural gas pipeline explosion in 2000 that killed nine campers in New Mexico. It was a pipeline that fed a gas fired power plant. Why is this not many times worse than Three Mile Island? In real human cost it certainly was. But natural gas doesn't fuel the same paranoia that nuclear does, so it's not a big deal to a lot of people.

There is no ideal source of power. Nuclear fills an important niche - carbon-neutral power that runs all the time, even at night and even when the wind isn't blowing. It's not safe, but it's much safer than the alternatives which are coal and natural gas. We will need it for a long time.

33. Originally Posted by Magic Pixel
While driving down twoard mojave I see all these windmill things in the tehachapi hills. I can't see and devices for wind direction on them. Do they change directions according to the wind?
The devices are there; they are just very small compared to the turbine itself.

34. Thanks, I noticed some attachments on them.

35. Originally Posted by billvon
Originally Posted by jocular
Sounds like the means to the end. But, is this truly effective enough to warrant the enormous capital outlay, given the huge power production capability of fission? joc
Wind has the potential to generate hundreds of times the power available from fission plants. (10 terawatts of wind power is available within the US land and coastal waters as a conservative estimate; you would need 200 fission power plants per STATE to match that.) A nice addition is that it does not heat the planet as nuclear power does. It's not ideal, of course; they are noisy and require a lot of maintenance, and wind is not available all the time.

In both cases, it is harnessing the available power safely and efficiently that is the problem.
How do you figure that nuclear power heats the planet?

36. Originally Posted by billvon
Solar. I generate about 10kw of solar power and feed it back to the grid via a grid tie inverter. Wind has the potential for higher powers per dollar spent but zoning is a lot more difficult (they're very obvious.)

Fission is far from ideal - but it is better than many alternatives.

A typical coal fired power plant puts about 200 pounds of nuclear waste (thorium, uranium) in the air every year, and puts tens of thousands of pounds of those materials into landfills, which of course then leach into groundwater. Yet no one bats an eye.

There is no ideal source of power. Nuclear fills an important niche - carbon-neutral power that runs all the time, even at night and even when the wind isn't blowing. It's not safe, but it's much safer than the alternatives which are coal and natural gas. We will need it for a long time.
Your knowledge, as well as opinions, are well-founded! There are many fission reactions possible, and, as I understand it, the "split-out" elements are not always identical, just certain ones predominating. U-235 for example produces mainly, what, barium and krypton (?), my old memory processes are a bit dim, but also some other dangerous stuff, cesium maybe?

Since all sorts of radio-isotopes have been artificially made, some of those certainly must be fissionable and usable to produce lots of heat energy. Are any known which do that, while producing totally-predictable non-radioactive split-out elements, thus eliminating the serious waste problem? I suppose if there are, the cost of producing them in quantity would be prohibitive. Just a thought. joc

37. "Solar. I generate about 10kw of solar power and feed it back to the grid via a grid tie inverter. Wind has the potential for higher powers per dollar spent but zoning is a lot more difficult (they're very obvious.)"

10KW is a decent amount of power. However, given the need to heat a home in addition to providing the other usual electrical needs, it would be insufficient for a single-family residence. A typical water heater uses 4KW, for example. Do you use any of the solar output yourself, or simply sell it all back to the utility?

I haven't kept current on solar cell costs, but do know they are still expensive. Maintenance, however, must be low; are the arrays ever in need of washing off dust accumulation? Regarding "looks" of solar arrays vs wind generators, to me neither is the more attractive. Really large commercial arrays cover huge areas of land, that being of little consequence given the vast wasteland of desert with lots of available sunshine. There is one along US Highway 95 near Boulder City, NV, which covers a pretty large area. There are many above-ground "junction boxes", I guess they must be, the entire installation being quite far back from the highway. At a distance, I thought those were parked, no longer used airliners! An aerial view would look most intrusive to the natural surroundings, to many "bleeding hearts".

Wind turbines, especially the big commercials, are widely being condemned for chopping up "thousands" of birds, "Especially eagles". All birds are, to me, of equal importance. However, I view such scare tactics as largely bullshit, until I'm proven wrong. Some believe big installations "disrupt" normal wind patterns to the extent that they are causing downwind AG crop failures. More bullshit? Others claim "noise pollution". The installations I've seen are so far from any human habitation that only the birds could be upset by the sound. Maybe it's disturbing scorpions, though, as they navigate by vibrations, I think.

Finally, why would zoning for turbine use (or solar for that matter), be of much consequence if installation is on Public Lands? All ya gotta do is convince EPA, obtain all the impact info for the bureaucrats, publish publicly to ferret out public distaste for the project, then pay off the needed bribes to get the ball rolling! WTH IS the zoning of Public Land, anyway? joc

38. Originally Posted by jocular
Wind turbines, especially the big commercials, are widely being condemned for chopping up "thousands" of birds, "Especially eagles". All birds are, to me, of equal importance. However, I view such scare tactics as largely bullshit, until I'm proven wrong.
Bullshit because you don't think they kill eagles, or bullshit because killing eagles doesn't matter? They do kill eagles, and Duke Energy was fined a million dollars.
http://www.greatfallstribune.com/vie...les-wind-farms

39. Do they kill thousands? And over what period of time, if so?

40. Originally Posted by greatfallstribune.com
A study in September by federal biologists found that wind turbines had killed at least 67 bald and golden eagles since 2008.
The article is dated Nov of 2013.
Originally Posted by greatfallstribune.com
In 2009, Exxon Mobil pleaded guilty and paid \$600,000 for killing 85 birds in five states. The BP oil company was fined \$100 million for killing and harming migratory birds during the 2010 Gulf oil spill.
• Wind farms kill roughly 0.27 birds per GWh.
• Nuclear plants kill about 0.6 birds per GWh. (2.2x wind)
• Fossil-fueled power stations kill about 9.4 birds per GWh. (34.8x wind)
^is from; Wind Farm Bird Deaths vs Fossil Fuel & Nuclear Power Bird Deaths | Environment
And for good measure; Canada Ranks Top Bird Killers, Wind Turbines Not Even Close To The Top | CleanTechnica
It would appear that the fossil energy industry is still responsible for more bird deaths than wind. Not to mention that fossil energy bird deaths tend to be in conjunction with large ecological disasters that just can't physically happen with windmills. In fact, the whole bird/wind turbine controversy is as manufactured as the zombie myths of "birther bullshit" and that other "secret muslim" aseninity.

I'm going to put up some solar, just to piss Harold off. Maybe a homemade windmill or two, use some old alternators out of Cadillacs. I'll charge a ragtag collection of batteries with the DC and use a cheap inverter to operate house stuff from the batteries. I could also use a bank of supercapacitors to complement the batteries.
Renewable energy can and will work, and all the corporofascist, Koch loving shills can just go Judas off into the potters ground. Renewable denialists should go line up against the wall with their other own ilk. The climate change, holocaust, relativity, and big bang denialists.

41. Care to explain how nuclear plants kill birds?

42. 3. Collisions with houses or buildings: 25 million
As building collisions are number 3 on the list of bird killers, I would assume that most bird/nuclear deaths are a result of collisions with the cooling towers.

43. I've never seen a bird that collided with a cooling tower.
You've changed the subject from killing eagles to killing any birds. Nobody gets fined a million dollars when their cat kills a robin.

44. Bird vs power plant. The epa could shut it down for hurting the environment. Bird-1, nuke-0.

45. Originally Posted by Harold14370
I've never seen a bird that collided with a cooling tower.
You've changed the subject from killing eagles to killing any birds. Nobody gets fined a million dollars when their cat kills a robin.
The only thing that any individual ever does or doesn't see outside of a proper study is sample bias.
Just for GP I saw a Bald Eagle here the other day, and heard it's two Eaglets; Find A Park/Facility | The City of Portland, Oregon
"Fatalities of golden eagles at modern wind facilities represent only two percent of all documented sources of human-caused eagle fatalities, while only a few bald eagles have died in collisions in the history of the industry."
^; http://www.huffingtonpost.com/2013/0...n_3915629.html
More info; What AP left out of its latest story on eagles and wind power - Blog - Into the Wind

Let's move the goal posts even more, Human deaths; Forget Eagle Deaths, Wind Turbines Kill Humans - Forbes
In England, there were 163 wind turbine accidents that killed 14 people in 2011. Wind produced about 15 billion kWhrs that year, so using a capacity factor of 25%, that translates to about 1,000 deaths per trillion kWhrs produced (the world produces 15 trillion kWhrs per year from all sources)....
These are pretty low numbers. By contrast, in 2011 coal produced about 180 billion kWhrs in England with about 3,000 related deaths.
Perhaps you should attempt to go tilt with some of the Windmills there Harold, go be a modern Don Quixote.

Here is a report; http://wildlife.org/documents/techni...s/Wind07-2.pdf
Look at the table at the bottom of page 17. The highest rate of raptor fatality occurs at an older wind farm using the first generation of wind turbines. It is only 1 raptor death per MW produced per year.
This whole issue of wind turbine bird kills is a red herring conjured up by the fossil energy industry. Renewable, sustainable is viable and better than fossil. Renewable energy deniers need to go join the anti-vax nutters.

46. Originally Posted by GiantEvil
It is only 1 raptor death per MW produced per year.
"Only"? That would be comparable to a 1000 MW power plant, fairly typical for a nuclear or coal fired plant, killing 1000 raptors per year. That seems like pretty many to me.

This whole issue of wind turbine bird kills is a red herring conjured up by the fossil energy industry. Renewable, sustainable is viable and better than fossil. Renewable energy deniers need to go join the anti-vax nutters.
Calling people "deniers" is childish. You should really research the issue. The need for base load power plants is real. The people who know how to plan an electrical grid know what the problems are, and that's why they don't want that junk power on their grid. Set aside your "Koch Brothers" conspiracy theories and study the facts.

47. My intent when starting a thread is usually to learn things, or help others learn things which I might convey. Often, many peripheral ideas wind up (that's a long "I", not a short one) floating along with all of my detritus! Heartening!

Birds dying colliding with unmoving structures? Come on, now! Blind birds, perhaps, or some foolish enough to maneuver blindly in the darkness. More birds dying by fixed-object collision by a significant multiple over other causes of death? I note that "qualifiers" are present in the stats below: "roughly", "about". Would that be ALL wind farms combined, or a number taken at a certain installation, which might, or might not, be in or near a fly-way? Why would nuke plants kill 1/4 as many as fossil-fueled? GWH would be billions of watt-hours? Looks like ALL power plants other than wind-using should be decommissioned, and replaced by turbines, to favor the birds.

Then, as added precautionary measures, suitable screens should be applied as are on electric fans to protect youngsters' fingers, to save the birds! joc

•Wind farms kill roughly 0.27 birds per GWh.
•Nuclear plants kill about 0.6 birds per GWh. (2.2x wind)
•Fossil-fueled power stations kill about 9.4 birds per GWh. (34.8x wind)

48. "The highest rate of raptor fatality occurs at an older wind farm using the first generation of wind turbines"

What has changed from early gen. design to later, which would affect fatality rate? Rubber blades, off which they bounce harmlessly? jocular

49. Originally Posted by Harold14370
Bullshit because you don't think they kill eagles, or bullshit because killing eagles doesn't matter? They do kill eagles, and Duke Energy was fined a million dollars.
Duke Energy pleads guilty to killing eagles at wind farms | Great Falls Tribune | greatfallstribune.com
Since you post as a query, I am compelled to answer! Both questions posed are imponderable, as if they kill birds, then they kill eagles. Eagles are majestic birds, quite true, and have a patriotic aura attached to them; nonetheless, other birds are no less important. To me, it is unconscionable that a company providing a product for sale to the public be fined for reasons utterly beyond their control. Moreover, the fine will inevitably be amortized among the buyers of the company's product. joc

50. Dirty power can be filtered. Crystal Mountain Ski Area in Washington State uses power filters because the power comes off the line there "dirty". After it's been filtered it's good enough for multi-million dollar machines. I just Googled "power quality of renewable energy". I bet some reading will reveal that power quality is a readily surmounted issue. The whole freaking Earth as we know it is being irrevocably changed because of fossil energy! People are dying because of it! The attitude that we shouldn't try alternatives is entirely profit driven, murderous, and makes me sick to my stomach.

51. Dirty power isn't the problem. The problem is the reliability of the power. It is an undeniable fact that most renewable power sources are not constant. In the case of wind, it's due to the weather. The wind can subside over whole regions at a time for extended periods of time. So what happens is that you use wind power when it's available (due to government mandates), then when it's not available, you have to use a fossil powered generator. It's either that or have blackouts. Sure, you can use hydro, but that's not available everywhere.

This is an expensive alternative, because you have to build enough conventional power plants to power the grid, in addition to all the renewable generating capacity you are adding. The fossil plants have operating and maintenance costs, even while they are in standby mode.

I sympathize with your desire to reduce fossil energy. You're just going about it the wrong way. I think nuclear is the way to go.

52. Originally Posted by jocular
Thus, the generator "back-fed" all the breakers in the house, the water heater being shut off at the heater itself. I could switch "on" only those breakers really needed, in order to not overload the gen: fridge, lighting, well-pump. I had no "transfer switch", and could not afford one. The main disconnect at the power pole, feeding the house, was the "transfer", and it was opened before starting the generator.

Here's the point of all this: Once, I forgot to open the main disconnect, started the generator, it ran like hell OK, but then I found no power available in the house, and the overload breaker on the gen. open. The generator was trying to power-up the entire feeder line serviced by the power poles "marching" across our property! In essence, it dumped it's entire ability to provide electric power into an "open hole", which gobbled up it's entire output!
You have learned one reason for having an automatic transfer switch. If you forget to open the disconnect, then your generator is trying to power up the whole neighborhood or power grid back to wherever the circuit breaker opened, which it probably won't be able to do. There's another reason too. If the power lines are down, there might be a lineman working on the power lines. He thinks the line is cleared, but he doesn't know about some SOB running a generator with the main disconnect closed.

53. Originally Posted by Harold14370
I've never seen a bird that collided with a cooling tower.
Nor have I. But there are plenty of dead birds that collide with the outbuildings and powerlines near the San Onofre nuclear power plant. Where the power feed exits the plant, there are literally lines of dead birds who have run into the wires.

54. Originally Posted by Harold14370
Originally Posted by jocular
Thus, the generator "back-fed" all the breakers in the house, the water heater being shut off at the heater itself. I could switch "on" only those breakers really needed, in order to not overload the gen: fridge, lighting, well-pump. I had no "transfer switch", and could not afford one. The main disconnect at the power pole, feeding the house, was the "transfer", and it was opened before starting the generator.

Here's the point of all this: Once, I forgot to open the main disconnect, started the generator, it ran like hell OK, but then I found no power available in the house, and the overload breaker on the gen. open. The generator was trying to power-up the entire feeder line serviced by the power poles "marching" across our property! In essence, it dumped it's entire ability to provide electric power into an "open hole", which gobbled up it's entire output!
You have learned one reason for having an automatic transfer switch. If you forget to open the disconnect, then your generator is trying to power up the whole neighborhood or power grid back to wherever the circuit breaker opened, which it probably won't be able to do. There's another reason too. If the power lines are down, there might be a lineman working on the power lines. He thinks the line is cleared, but he doesn't know about some SOB running a generator with the main disconnect closed.
This actually happened to me one time; I had started the gen., turned it's switch "on", and it's overload immediately tripped. I had forgotten to open our main disconnect at the meter. The power line feeding our neck of the woods originated at a substation miles away, we were near it's far end. The line surely represented a "dead short" to my gen., thus I doubt that the line itself ever saw much more than a very low voltage level, certainly not enough to kill (I think!), though our transformer, being 7200/240, could, I suppose, have developed a jolt.

Trying to weasel out now, the guys I knew working for Black River Electric Coop always wore special insulating gloves regardless of presence of voltage or not.

Have you ever heard this one? Guy in Colorado, when my company's transformer was on the verge of breakdown due to overtemperature, told me when they work on "high-lines", they string a length of steel chain around the three conductors at the location work is being done. Was he pulling my leg? joc

55. Originally Posted by billvon
Originally Posted by Harold14370
I've never seen a bird that collided with a cooling tower.
Nor have I. But there are plenty of dead birds that collide with the outbuildings and powerlines near the San Onofre nuclear power plant. Where the power feed exits the plant, there are literally lines of dead birds who have run into the wires.
Ah, now I get it! Wires are relatively invisible to swooping flight, but do they actually run into the buildings, too? joc

56. Originally Posted by Harold14370
Dirty power isn't the problem. The problem is the reliability of the power. It is an undeniable fact that most renewable power sources are not constant. In the case of wind, it's due to the weather. The wind can subside over whole regions at a time for extended periods of time. So what happens is that you use wind power when it's available (due to government mandates), then when it's not available, you have to use a fossil powered generator. It's either that or have blackouts. Sure, you can use hydro, but that's not available everywhere.

This is an expensive alternative, because you have to build enough conventional power plants to power the grid, in addition to all the renewable generating capacity you are adding. The fossil plants have operating and maintenance costs, even while they are in standby mode.

I sympathize with your desire to reduce fossil energy. You're just going about it the wrong way. I think nuclear is the way to go.
I think nuclear is bloody complicated, but otherwise I'd much rather be in proximity to a nuclear plant than a hydrocarbon one. Most nuclear plants operate safely within a specified lifetime. After that lifetime the thing is a pile of toxic slag, but it's still a small pile compared to fossil wastes. Electric storage technologies are also improving, mitigating some concerns of peak demand and timing. In the interim, I can see no long term significant negatives to diving in and trying wind and solar solutions. I can experiment with wind and solar at home.
Ah, now I get it! Wires are relatively invisible to swooping flight, but do they actually run into the buildings, too? joc
See post #41

57. May I leave the birds and nukes for one post? Someone mentioned, I seem unable to find the passage, that a wind turbine, having had it's output suitably "processed", operates with the "grid" by having output equal in voltage to, or slightly higher than, the grid voltage. Obviously, if the voltages were dead equal, neither would contribute power to the other, correct?

Now, looking out my window, the guy down the road from us has a fairly large wind turbine, blades spanning about 15-foot circle. It's a single family home, but I do not know if he is set up to "put power back", or simply supply his home when the wind blows.

My view of "the grid" for this set-up, is the secondary winding of a single transformer on a pole, near the guy's house. Every home here has it's own transformer. Thus, his generator looking into the "grid" sees the transformer secondary, which, in essence becomes the "primary", when the gen. puts power back into the "grid". Now, using some guesswork, these transformers typically are sized for single residential use, so are likely smaller than 200 KVA in size, maybe more likely 100 KVA. I will assume the 240 volt secondary is capable of producing a very short term short circuit current of 10,000 amps. For simplicity, calling the trans. size as 120 KVA, that would equate to an impedance level of about 1/2 Ohm, using P = E^2 / Z. Assuming these numbers are in play (give or take several orders of magnitude), at a 10 volt differential, that is, 250 volts applied to the "grid", the gen. would be delivering about 20 amps., this equating to a net power back into the grid of only about 200 watts. 5 hours per KWH. At 10 cents per KWH, you're getting back 2 cents per hour thus operated. Not very much. The gen. would be developing, however, 250 X 20 = 5000 watts, that sounding fairly realistic for a home wind generator, my guess. This all assumes negligible loss in the process called "Grid Tie Inversion", so helpfully submitted by Harold. My conclusion based on this "baloney-figuring" is that using wind power to replace utility-supplied power is where the pay-back lies, not in shoving anything back against the "stream".

Am I missing the boat with my assumptions, or is it pretty damn hard, as I've roughly shown with guesswork, to "put back" a substantial amount of power into the "grid"? joc

58. Magnetic field moving across your wire
Connecting
Much larger source of electricity
In a wire
Guess the result
A great big
Magnetic field
This electricity thing here is running backword
How it threw the breaker is a good guess.
The generator turned into a motor
Running at high speed in the normal direction
Now would be the time to upgrade with a water radiator and a few random pieces of uranium
Set on it
To keep it from freezing
A well water pump might also be caused to run backward
Not sure? If it would run the generator.
If not then back to
The pad of paper and model it over again.

59. Originally Posted by Magic Pixel
Magnetic field moving across your wire
Connecting
Much larger source of electricity
In a wire
Guess the result
A great big
Magnetic field
This electricity thing here is running backword
How it threw the breaker is a good guess.
The generator turned into a motor
Running at high speed in the normal direction
Now would be the time to upgrade with a water radiator and a few random pieces of uranium
Set on it
To keep it from freezing
A well water pump might also be caused to run backward
Not sure? If it would run the generator.
If not then back to
The pad of paper and model it over again.
Perhaps I'm alone in this, but I appreciate your input. If only it made sense. For example:

3 buttercups paid homage to the extra electrons present.
with their vewcal group the crypt kicker five.
The dimwits were having fun,
The guests included Count Dracula,
Wolfman, and his son.

60. The partying Pirate D.J. in Mexico The Wolfman in the movie American Graffitii had popsicles not buttercups. Not sure about Wolfman jr. Dimwits,some. Zombies? This doesn't make any sense.

1 beta to electricity to 100 beta. It is simply arm wresling for your generator.

61. Originally Posted by jocular
Originally Posted by billvon
Originally Posted by Harold14370
I've never seen a bird that collided with a cooling tower.
Nor have I. But there are plenty of dead birds that collide with the outbuildings and powerlines near the San Onofre nuclear power plant. Where the power feed exits the plant, there are literally lines of dead birds who have run into the wires.
Ah, now I get it! Wires are relatively invisible to swooping flight, but do they actually run into the buildings, too? joc
The power lines are part of the distribution system, and will be there no matter what kind of fuel you are using to generate it. As a matter of fact, most plans for using wind power require building new electrical distribution system infrastructure to deliver the power from areas where the wind blows to the places the power will be used.
I think that when birds get killed running into buildings, it's most likely windows they are running into. This has happened sometimes at my house. I once found a grouse that had run into my breezeway door and broke its neck.

62. Originally Posted by jocular
Am I missing the boat with my assumptions, or is it pretty damn hard, as I've roughly shown with guesswork, to "put back" a substantial amount of power into the "grid"? joc
No, there's no particular problem. If the wind turbine generator is producing more power than you are using in your house, then you can feed that power back into the grid and turn your meter backwards.
Originally Posted by "Magic Pixel
That doesn't make sense.

It makes a lot more sense than what you posted. I thought I warned you about posting nonsense.

63. No, there's no particular problem. If the wind turbine generator is producing more power than you are using in your house, then you can feed that power back into the grid and turn your meter backwards.

This is how I pictured it. I really have no inkling of the capacity of these wind gens around here, but evidently some astute sellers have convinced locally that they are a boon to home ownership. The closer neighbor has a solar array, mounted on a big mast, the array being about 20 feet by 15 feet, the thing rotates and elevates, "looking" at the sun all day long. I have not had the opportunity to talk to him about it. The "trend", though, seems to be the sale of technological wizardry to the public, as potential dollar signs illuminate. I'm sure the "pitch" of running the meter backwards is beguiling! BTW, can (do) digital watt-hour meters record in reverse? joc

64. Originally Posted by jocular
Obviously, if the voltages were dead equal, neither would contribute power to the other, correct?
Correct although that is rarely the case.

Assuming these numbers are in play (give or take several orders of magnitude), at a 10 volt differential, that is, 250 volts applied to the "grid", the gen. would be delivering about 20 amps., this equating to a net power back into the grid of only about 200 watts. 5 hours per KWH. At 10 cents per KWH, you're getting back 2 cents per hour thus operated. Not very much. The gen. would be developing, however, 250 X 20 = 5000 watts, that sounding fairly realistic for a home wind generator, my guess.
If you generate 5000 watts you "get credit" for 5000 watts generation. Wind/solar grid tie inverters are around 90-95% efficient, so 5000 watts in (via solar DC or windmill DC/wild AC) would get you 4500-4800 watts back to the grid

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