wind turbine generators

Your Questions About Wind Turbine Generators For Sale

Joseph asks…

Can i convert a solar charge controller into a wind turbine charge controller?

I am building a wind generator and it turns out the system needs a charge controller. There a some on sale but I’d rather build or modify one myself. I pulled one out of a solar lamp. It has two ports, one for the input, whose input voltage range was 6-12v and and the other, output, with 6 volt output.The lamp used a 4 volt battery. However, the generator is a 30 volt ametek (capable of supplying up to 28 volts on a good windy day), and the battery am going to use as a bank is a 12 volt UPS one. Am just wondering if this controller will deliver on my wind turbine system, and where to connect the dummy load because I’ve heard solar controllers don’t use dummy loads yet they are essential on wind turbine systems. Thanks

admin answers:

A solar lamp will likely simply be a small voltage regulator, not a good choice. I would use a power FET, a zener diode, two transistors, a capacitor and maybe some resistors but then again, I’m an electrical engineer and actually know what I’m doing.

The UPS batteries are lead acid batteries which you can buy for about $12.

I think, you should stop and get an education before you hurt yourself.

Richard asks…

Where to find detailed info: Alternate Energy connection to National Electric Grid?

I am interested in locating detailed equipment & system information on how Alternate Energy producers (e.g. Windfarms, HydroElectric, private turbines, etc.) go about connecting their generating source to the US national Electric Power Grid, and sell off their excess electricity capacity. What current Federal and State (e.g. California) regulations exist that encourage or require the major energy companies to purchase that excess electricity if available and meeting Voltage specifications?

admin answers:

Suggest you look at the American Wind Energy Association web site: awea.org

Large renewable energy facilities, such as large wind power plants, must meet the same interconnection requirements as a large power plant. Additionally, due to the nature of most wind turbine generators, there are some other requirements defined in FERC 661-A, that impact wind farm interconnection.

Sale of produced electric power is a very complex process that is highly dependent on the grid operator and the electric power transaction processes for a given regional reliability organization or independent system operator.

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Your Questions About Wind Turbine Generators How They Work

Jenny asks…

How to control the fluctuation of energy in wind turbine?

Due to the change in the wind speed, the speed of the wind turbine rotor changes, so at the output we get variable AC supply which means we do not get exactly constant voltage and frequency.

It can be control by controlling shaft speed and at the output by varying the load (Resistance).

I need to submit a case study about that so tell me about any site or e-book where I can find comprehensive details about that.

admin answers:

Basically there are two methods.

For small turbines (a few kilowatts) the turbine runs at whatever speed it likes, depending on the wind speed. There is a separate electrical converter to change the generated power into AC at mains frequency and synchronize it with the mains.

There may be a simple device to limit the max turbine speed just to prevent mechanical damage – for example a mechanical brake or lock, or spring-loaded turbine blades that spill the wind when the wind speed is high.

Large turbines (producing of the order of 1 MW or more per turbine) run at constant speed, generate power at mains frequency, and are directly coupled into the electricity grid when they are working. The speed is controlled the same way as for conventional power station generators. Without getting lost in the practical details, if the turbine tries to run at the wrong speed it is fighting against the whole of the rest of the power that is being generated in the electricity grid, so it loses the fight. As the wind speed changes, the amount of power generated changes. If the wind speed is too low, the generator acts in reverse as a motor to drive the turbine. (Of course in practice the turbine would be stopped completely, instead of doing that for a long period of time).

The rotational speed for large wind turbines is usually slow (10 or 20 rev/minute) with a gearbox to spin the generator at a higher speed. The blades are variable pitch so they can work efficiently at different average wind speeds.

Lisa asks…

Is there a forum for people who want to build their own wind turbines and generators and stuff?

I am looking for some website or forum where I can discuss the nitty-gritty of making wind turbines and building anything that enables people to go off the grid and build their own boats, heat sources, alternative fuels, all-natural materials, etc.
Would anyone know where to find that?
Thanks.

admin answers:

I’m putting together a small wind turbine. Check my web page for pictures, diagrams, and other information.

Http://members.rennlist.org/warren/wind.html

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Your Questions About Wind Turbine Generators For Home

Jenny asks…

How hard is it to build a wind turbine for home?

For a 5 month project at school I have to build a wind turbine for my home. How many hours will it take, will I get an efficent gadget, and how much will it cost? I’m thinking of getting help from a small wind turbine manufacturer. And I would just like to say my motor skills are very poor and I am not used to building things. Can I do it?

admin answers:

You can get kits.

However you need permission of your zoning board before you can do this, if it is any size at all.

But you can get small 1-2 ft kits. First reference is a 12″ one, but a toy, for $40. Second one is a 46″ 400 watt one that looks real and has a generator. You still need a battery and inverter. $630.

Search for “wind turbine kit” for more.

.

Ruth asks…

How are different AC generators linked in a power grid?

I’ve often wondered this. When you have two or more AC generators (say two different power plants) produce power, it seems like it would be impossible to be sure the two are in phase with each other. So how can the two be linked into a power grid? Is the same technique used when hooking up a home generator (from a wind turbine, for example) to supply the grid?

admin answers:

No. It’s actually rather simple to keep them running synchronously on the power grid. All it takes is a simple phase comparator and a feedback control system to regulate the generator.

Doug

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Your Questions About Wind Turbine Generators For Home Use

Sandy asks…

How can wind turbines tackle pollution problems?

Can you give me three points of how can wind turbines tackle pollution problems in the modern days?

admin answers:

They can’t and never will.

Since wind is unreliable and unpredictable, conventional generator plants have to be on constant standby for when the wind is calm. While on low efficient standby, they actually produce more CO2 than when in full high efficient operation.

Electricity can not be stored and has to be produced on demand. When the wind is calm, the coal and gas genertodrs have to be poised to power up in a minutes notice. Low power in the grid burns out motors and burns up equipment. Wind farms are being paid to shut down in Scottland and Germany, as well as other countries because wind urbines are unpredictable and are causing undervoltage and overvoltage problems since the wind is variable and unpredictable.

It only costs about $0.02 per KWH to generate (not including transmission and maintenance costs) for coal, and about $0.03 per KWH for gas. Wind turbines cost about $2.40 per KWH to generate power. We are already paying about 10% more for electricity to pay for the expensive wind turbines, and if more are used, electric rates will go even higher, like gasoline prices. We should only be paying about $1.80 per gallon for gasoline.

Since CO2 is now classified as a pollutant, we all need to stop breathing, and eliminate all animals on the planet, according to what the the ideologists are telling us.

Wind turbines have other flaws, as well as solar electric panels. I am a contractor and have turbines large enough to power 4500 homes or more, so I know all the problems with them that the government and ideologists are not telling us. It is all about eco-guilt and not much to do with real problems and solutions.

Sandra asks…

Would a wind generator trickle charge a couple of car batteries in 14 hours?

I’m just trying to get an idea of how long it takes a wind turbine to charge batteries with regular win, could you just provide some examples?

admin answers:

Hey Joesh, wind turbines come in all different sizes, but your biggest variable here is the rate at which those batteries will accept a charge. Typical car batteries will have a capacity of around 60 amp hours. If you had a 60 amp charger, or turbine, in theory you can completely charge that battery in one hour, but you can never get power into a battery that fast without damaging it. A good rule of thumb is not to charge your battery in less than 5 hours if it is completely discharged. A couple car batteries might hold 120 amp hours, which means anything that puts out more than 30 amps is oversized. You can take a larger than needed turbine and use a charge controller to keep from charging the batteries too fast, but that is like using an indy 500 race car to haul a camping trailer, most of the capability of your turbine would be wasted. The best thing is to get a turbine that is just big enough, or maybe a little undersized, to do the job. For 100 to 150 amp hours of 12 volt batteries, I would suggest something in the 200 to 300 watt range, like a Southwest Windpower Air 303. They cost just a few hundred dollars, are designed to work on a sailboat to keep the boat batteries charged, and they have their own internal charge controller. So you just mount one on top of a 1 and 1/2 inch diameter conduit pipe, then connect the two wires from the turbine straight to the batteries. We used one for a couple years here at our remote cabin, but later upgraded to a larger World Power Technologies 900 watt unit. There are lots of other turbines on the market that can do that job for you, just remember that even the best turbine will not pan out if you do not have good wind, or a tall enough tower to get to the wind above the tree tops.

There are some great places to learn more about this if you’re interested, but I’m curious, have you considered solar? Solar panels are so much easier to use, install and wire up, and they never need maintenance, you can take my word on this, I’ve had both for over 11 years now. A solar panel is basically a battery charger, they deliver their rated amperage when the sun shines, no more, so in a sense they are self regulating. If you really want to get up to speed on this stuff, get a sub to Home Power Magazine, we did 12 years ago, now our home is completely powered by the wind and sun.

If you get frustrated by all the numbers thrown around, remember that watts is voltage times amps. So a 300 watt wind turbine that runs at 12 volts will put out 25 amps at full power, 25 X 12 = 300. Solar panels are basically the same animal, but they are all usuallly set for 18 volts to charge a 12 volt battery, so a 36 watt panel will actually put out 2 amps in full sun, 36 divided by 18 volts is 2 amps. Hope this helps, take care, Rudydoo

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Your Questions About Wind Turbine Generators Types

Sharon asks…

What is the dollar cost of a megawatt wind turbine?

The megawatt size wind turbine seems to be a standard so why not have the cost of these machines available to compare with other type of electric generators?

admin answers:

In terms of the initial cost, just to purchase a commercial scale turbine, the usual price is roughly $1 million per megawatt of capacity. So, a GE 1.5 MW would cost around $1.5 million. Installation and development of the site would be additional costs.

Robert asks…

What type of bearings to use in a savonius wind turbine?

Hi all

I am currently building a savonius wind turbine that will be around half a meter tall. I have the general plan drawn up but just need some answers on what type of bearing to use – I really have no idea about different bearings/lubricants/size restraints etc. Would really appreciate any help that could be provided.

Thanks!

admin answers:

Basically you need a thrust bearing somewhere in the process to take the weight and another one or two bearings to take the wind force and keep it upright. If you are mounting above a generator, there might be a thrust bearing in the generator.
In your design, you have to provide for mounting the bearings. Lets suppose you were putting the unit on a shaft with a pulley on the bottom to drive a pump or generator off to the side via a belt. You would go to www.grainger com or local bearing firm and tell them you wanted a flat mount ball bearing for your shaft diameter – this would be the top support – and you wanted a flat mount thrust bearing for the bottom, as well as a shaft collar all to match the shaft. For your project these might total $15-20.
The simplest possible mount would be a stiff frame rectangle to which you mount the ball bearing in the middle of the top and the thrust bearing at the bottom. What the shaft collar does is screw to the shaft and rest against the bearing, transferring the weight. Since I have proposed a pulley, the shaft would have to be long enough to go through the frame to put the pulley below, so you didn’t have to take the unit apart to change the belt.
To be honest, most ball bearings even if not thrust, will take much more weight than your turbine and you could probably get the shaft collar and two bearings at your hardware store or home center where they are sold as replacements for wheel barrow and cart wheels
for another view
http://www.macarthurmusic.com/johnkwilson/MakingasimpleSavoniuswindturbine.htm

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