Wind power...what a joke!

[DanG]

Long as they're producing 60cps AC, they can output any voltage they want.  Transformers ain't just for reduction, ya know.  High voltage is just for efficient transmission.  It's the current flow that meets the demand.

[Fla._Deadheader]

Please answer my questions  : : :  I did NOT mention current, amps.

[DanG]

  I did NOT mention current, amps.

I noticed that. :  Current is an inescapable part of Ohm's Law.  It doesn't matter what voltage the windmills generate, it can be stepped up or stepped down to any desired voltage.  I suspect you are just pulling my chain here, so I'll just play along.  The bottom line is power, stated in Watts.  That, in case you don't already know, is the product of the voltage multiplied by the current, or Amperes.  A million volts at one Amp is a megawatt.  One volt at a million Amps is a megawatt.  A transformer can be built to change either of these into 250,000 volts at 4 Amps, and it will still be a megawatt, less the loss that is present in any circuit, of course.

I'm fairly confident that the engineers that design those things have already dealt with the question, and can provide you with a unit that will put out the desired voltage. ;D

[SwampDonkey]

At times, I've seen the windmills here at a dead stop, even in a brisk wind. SO I assume that is what's going on.

Up on the hill it will be windy when it is calm down here. I've been up on big hills like that and the wind picks up by mid morning as the warm air rises upslope. Just one of those things in nature I'm sure everyone has read about.

[thecfarm]

Perfesser DanG will explain about the wind in his next class.   ;D  I like that. And all this time I thought he only knew how to run a sawmill.   ;D

[stonebroke]

Windmills will generally bid at a very low price because they have no control on when the wind blows. Their power will displace peak power plants output because they are not paying anything for fuel. But if the demand gets low enough they will have to stop the turbines because the baseload plants cannot be turned up or down much. Confused?

Stonebroke

[Brad_S.]

They also stop them for maintenence or mechanical issues. There are several turbines at Mars Hill which get stopped in the winter so that the danger of ice chunks being tossed onto skiers on the nearby slope is eliminated.

[Fla._Deadheader]

We all know about DanG and wind.  : : :  ;D

  I was serious about his answers to my questions. Ohm's Law is old news. I want NEW news. He started out like he knew something about this high-low output and I am interested in the OUTPUT voltage. I could care less about the current-amps- killerwatts, mega lurches, and what knot.

   Facts, man, we need FACTS. I know how these things work, and why they are shut down at times. I know more about Transformers than I care to mention. WHAT VOLTAGES, and, how are they connected to WHAT grid ???  I have never seen a substation in ANY of the wind farm photos ???  : :

[stonebroke]

Generally there are transformers built into the base or just outside.  Then the wind farms have a substation  where the line goes into the main line to adjust it to whatever voltage you have in the main.

Stonebroke

[TexasTimbers]

Okay Mr. say-what-you-mean-and-mean-what-you-say, since you are going to hold DanG to such a high bar, let's lead by example . . . .

I could care less about the current-amps- killerwatts, mega lurches, and what knot.

emphasis added

So do you mean to say you do care to some measurable degree about the ". . .  current-amps- killerwatts, mega lurches, and what knot.? Because if you mean to infer, or even clearly state, that you have no concern about the specific peripheral matters mentioned in this instant, you err greatly by saying you could care less, as this insinuates, even demonstrates, that you care about those issues. So which is it FHD? Would you like DanG to take you at your word, or read into it what you actually mean? :D

At least you do not use "irregardless", or confuse "then" for "than" or "than" for "then" or . . . . or, I just need to shutup and get back to work. :

[DanG]

Perfesser DanG will explain about the wind in his next class. 

Wind is caused by trees moving back and forth.*

*second-hand information from Charlie, via Tom.  It may be based solely on anecdotal evidence. ;D

FDH, in answer to your question, I don't know. ;)

Radar, I knew you already knew all that Ohm's Law stuff.  I just felt like giving a basic electricity lesson.   Now that I THINK I understand your question, I'll take another stab at it.  More current  being demanded causes the generators to be harder to turn, so more energy is used to turn them at the prescribed speed.  Most all power plants have multiple generators, and they share the load.  Say you have a 90mw plant consisting of 3 30mw generators.  Those are the peak figures, all they will do with maximum demand.  If the grid is demanding only 30mw, each of them only produces 10mw, making them easier to turn, and using less fuel.  The energy isn't being wasted, it isn't being produced.

[TexasTimbers]

Let's not forget, once the widespread use of superconducting tranmission cables and superconducting magnets are feasable it will change the game entirely.

i don't know how far off that is, but I remember a big ongoing to-do about it in the news back in 99 thru 2K. These kinds of technologies alwaysseem to  take longer than what is thought though. Same has been the case with solar and wind and CNG ad infinitum.

[Radar67]

With that in mind Dan, let's look at this scenario...

The states all require the grid tie systems I mentioned earlier. The load on the 3 30 mw generators drops to zero during off peak times because the grid tied systems are producing enough extra power. Do the generators just go to idle? Or do they shut down?

If they are like my portable generator, just on a bigger scale, when I'm not using electricity, the generator is still running and burning fuel. And, according to the meter on my panel, still producing electricity, or at least voltage. The current may be close to nil, but inevititably, there is still a "waste" of energy. If you figure the number of power stations we have in the country, that waste could be great.

As I said earlier, I don't think the power stations will even be in a zero need status, but it would be wise to have a system that shut down un-needed generators when the needs were low. I know a lot of the stations have a "peak power" generator that is only fired up when needed.

Now, back on topic, the home wind generators have to have a storage medium for the produced power. The power is generally not "clean" enough to be fed directly into the grid. It has to go through an inverter to clean it up, this is just one of the reasons the commercial alternators are so expensive. They are designed to produce the "clean" electricity.

TT, solar has progressed well over the past 20 years. The problem is energy has been so cheap in the past, it makes using solar look bad because the initial investment is so steep. If the prices for components would drop 50%, you would see a large increase in usage of solar products and see the price come down even further. I think battery technology and better storage solutions should be the biggest concern right now.

[TexasTimbers]

Yes those are good points Radar and I agree. Still, overall, there seems to be a general lag in bringing new technology online even under the best, and even under the most urgent of conditions. But your points are certainly valid. One of the IPSWH pamplets I have makes this relevant point several times.

On the battery technology, that seems to be going at light speed all the sudden. Li-ion technology is fantastic. i love them, but about the time they will become affordable on large scale and widespread use they will be trumphed by better technology most likely. Of course I have no idea how plausible Li-ion would be for solar and wind storage. Seems like a perfect fit except for the cost.

[Radar67]

I have about decided to use regular deep cycle marine batteries.

My main reason is the high dollar batteries have to be replaced every 5 to 7 years (according to my reading and maufacturer recommendations). One of those high dollar batteries can run $400. I can build a bank of batteries from the deep cycle for that kind of money. If the system is planned right, and you only discharge 25% of the overall bank at any given time, the marine batteries will last just as long as the big boys. I know a lot of people say to use forklift batteries, but you have to have a supply of them to use them.

[TexasTimbers]

I haven't made it to the batteries yet on my generator, other than to have a verbal commitment from a Clark technician that he can get me free batteries semi-reguarly free, and without stealing them. I asked him how it was that in these tight coroporate times he can get free batteries. He said they have to pay to have them hauled off. I've known this guy for about 17 years and have never known him to be dishonest, and he has nothing to gain otherwise, but I still don't see how companies cannot find a way to turn those old batteries into money.

[submarinesailor]

Let me see if I can address this generator issue just a little.

Power companies are required by NERC (North American Electric Reliability Corporation) to keep a certain amount of "spinning reserves" on line at all times.  These reserves are there so that "just in case" something happens; like another generator dropping off line or someone crashes a tractor trailer into a big substation. These are the stand by power sources that are ready to go and can pick up the load very quickly.  This is one of the big problems in California where the ratio of load demand vise total generation capacity is too narrow and if something happens (like one of the fully loaded generators drops off line) the whole grid can/could go down.

If I remember my (big) generation theory correctly, there are ways to control the "power" output.  One thing to remember, big generators spin that the same rotor speed (about 900 or 1800 RPM) no matter what the load is.  The rotational speed of the generator determines the frequency out from the generator.  But, if you control the exciter current/voltage to the rotor, you can control the amount of "power" being generated.  More power to the exciter circuit, the more power you get out of the generator.  This way you can have the required spinning reserve and control the voltage on the system.  BTW – big steam turbines don't necessarily like to be lightly loaded.  This could cause uneven heating of the blades and that's not a good thing.  Also the boilers that fire these things are turned down and when you get big boilers below about 65 to 70%, their efficiency drops way off – think big money losses when they become un-efficient.  So the power companies like to keep things loaded as best as possible.  But, if there is no demand, they turn it all back.

As for controlling the output from the windmills, I haven't quite got it figured out yet.  When I do, I'll let you know. 

Bruce

[TexasTimbers]

 In my short self-study thus far on wind generators, I know you can add a "stop" switch which shorts the windings together on the generator, and introduces resistance. The battery bank is the regulator until it is fully charged. After that any number of a variety of regulators can be introduced by the controlling circuitry such as a shunt regulator, or by using the aforemention stop switch to manipulate the windings.

Don't take this as fact. All from memory and I am sure there are dozens of methods beinf used/explored.

[farmerdoug]

Also shutting down and restarting those steam turbine generators is no easy task.  The generators are usually used like motors to bring the generator/turbine up to speed from stop.  It takes time and energy to do that.

Remember the eastern blackout?  They restarted our neighboring power plant from their peakers they have there.  Then they restarted their others plants and supplied power for other utility companies to do the same.  We were without of power for only three hours but others waited days to get theirs back on.

[Haytrader]

I stopped in my tire man to pay a bill this evening.
He was telling me about changing a tire on a trailer hauling a section of tower for a wind mill.
He said the driver told him he picks them up at the port near Houston. The point of origen is middle east.    >:(

Durn it. I was not pleased to hear that.

[Gary_C]

This wind energy is going to be back in the news as congress is back in session and will be dealing with alternative energy sources, specifically renewing the wind energy subsidies. One of the problems with these government subsidies is that foreign companies are investing heavily in these wind farms in the US. I have heard that a lot of money is coming from Italy and yes, the middle east. Now these investors are careful to set up companies in the US so they can collect these taxpayer funded subsidies, but make no mistake, these are foreign companies collecting money from US taxpayers.

I have also seen an ad on TV claiming that without subsidies, wind energy is not economically viable. Are these subsidies really a good idea or are we just sending more money overseas?

[farmerdoug]

I think they should drop the subsidies and just require a certain percentage of green power produced of the total energy produced. :