amps from a wind generator 2

[dkm0038]

I am considering if a wind generator can provide me enough amperage.

I have a graph of the annual energy production that shows the annual output in kWHr, and am a little confused in what that means (ie kWHr/year or average kWHr??) the values are 0-4000.

The bottom line is that I know that I can get 1000 kWHr (annual output) and I am opperating at 480 volts (3-phase)and I want to know how much amps I can get.

I was thinking that the equation A=W/V would give me my amps but I do not exactly know what is ment by that annual output kWHr. I am hoping that somebody is familiar with this and can give me some guidance

Thank You

 

[waross]

Well there are 365 x 24 hours in a year. That's about 8760 hours.
If you divide your 1000 kWHrs per year by 8760 Hours you get an average of .114 kW, or 114 Watts.
For 3 phase, divide that by 1.73 for 66 Watts per phase. Now divide by 480 volts and you get 0.137 amps.
If you want to provide a little more information someone may help you out with the difference between Peak output, Average output, kW, kWHrs, annual output, etc.
The most accurate answer to your original question

I am considering if a wind generator can provide me enough amperage.

It Depends.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[dkm0038]

Thanks Waross for the very helpful reply but can you please explain why you did -> "For 3 phase, divide that by 1.73 for 66 Watts per phase".

Also does this amperage seem reasonable to you, this is for a single wind generator (11 meters high with normal wind conditions).I am seeing if it is practical to power a warehouse with these I found that at peak operating time I need 450 amps.

If I am understanding the situation I will need 3000+ wind generators to handle my peak amp needs???

 

[rbulsara]

Annual kwhr means exactly that kwhr/yr.

Apms of a wind turbine can only be known if you know its kW rating and voltage.

How can you calculate amps from kwh??

You can run a 50 kW machine for 20 hrs and get 1000 kwh or a 100 kW machine for 10 hrs and still get 1000 kWh.

WTG only generates power when there is suitable wind. Do you have the wind data for a few years for the location?



Rafiq Bulsara

http://www.srengineersct.com

 

[dkm0038]

rbulsara,

I have average wind speed from the last 49 years at the site in question, and it is 10.7 mi/hr (this is where i get my 1000 kwHr from)

The 450 amps is actually amps per hour.

 

[Skogsgurra]

There is no such thing as "amps per hour". There are amphours and there are amps. Period.

Gunnar Englund

http://www.gke.org

--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

 

[rbulsara]

dkm:
Hire a consultant or talk to a WTG mfr at least. Leave electrical calcs to sparkies.

Average speed means nothing. WTG only works over a narrow rage of air speeds.

Rafiq Bulsara

http://www.srengineersct.com

 

[oldfieldguy]

dkm:

There are a lot of variables to look at, but the basic answer is "Probably not". Or "maybe". Your peak requirements may be handled by a battery bank charged by your wind turbine generator, but you're going to have to do some studying to answer those questions.

Like the others say, if you're working on this at a professional (for your business or employer) level, you need to get some engineering horsepower at the table to talk about all this.

I know of some folks who installed WTG's for home use that spent a lot of money for not much utility, but the "green energy" impresses their patchouli-smelling friends.

old field guy

 

[resqcapt19]

You are looking at a huge machine, one of about the size you see in the big wind farms, to get that amount of power and as others have said you only get power when the wind is blowing within the operating range of the wind turbine.

 

[jghrist]

The bottom line is that I know that I can get 1000 kWHr (annual output) and I am opperating at 480 volts (3-phase)and I want to know how much amps I can get.

I am seeing if it is practical to power a warehouse with these I found that at peak operating time I need 450 amps.

The answer is no.

 

[cranky108]

So what are you going to do when the wind isen't blowing?

Besides the KWHr value should be on you electric bill every month.

The amp VAR demand of a wind generator could be around as much as the amp WATT production, or even more (Depending on the machine type).

 

[rockman7892]

Waross

Why did you divide the 114Watts by 1.73? Shouldn't it be divided by 3 to divide amoungst the three phases of three phase power? Similar to a 1500KVA transformer being being rated for 500kVA on each phase.

 

[jghrist]

Why did you divide the 114Watts by 1.73? Shouldn't it be divided by 3 to divide amoungst the three phases of three phase power? Similar to a 1500KVA transformer being being rated for 500kVA on each phase.

It would have been more understandable to divide the 114 watts by 3 and then divide by the Ø-N voltage. Since the Ø-N voltage is 480/sqrt(3), and sqrt(3)/3 = 1/1.73, the answer is the same.

 

[wolf39]

Assuming you own a wind generator with a rated output of 10 kW. Annually you could generate a maximum of 87600 kWh, under the assumption that you get a utilization factor of 100 percent (utilization factor = average kWh generated per annum divided by rated kW output x 8760 hours). The average utilization factor for wind power worldwide is slightly above 20 percent and you have to bear in mind that this figure is valid for favourable wind conditions. So you can expect about 17500 kWh to generate with your 10 kW unit, if wind conditions at your site allow. This is equivalent to an average output of 2 kW over the year.

Regards

Wolf

http://WWW.HYDROPOWER-CONSULT.COM

 

[waross]

Hi Rockman7892;
If you connect three 500 KVA, 277 Volt transformers in star or wye, you will have 1500 KVA at 480 volts. 277/480 = 1.73

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[LionelHutz]

My quick calculation says you need about 3.3MWh so yes you'd need 3300 of those little toys to provide the power you need.

You need about 400kW continuous. At 20% utilization this means you need a 2MW turbine. As resqcapt19 already posted, you would need one of those large wind farm sized machines.

Or course, the above is assuming the warehouse is using that 450A for real power. There could be a poor power factor which means the actual wattage demand is lower.

Now, if the warehouse operates at much lower loads for a lot of the time you could install a smaller turbine and sell to the grid at lower load and buy back at high load. Combine load with possible power factor and you might be able to reduce that 2MW turbine down to a 500kW and still be practical. You might not generate all the power you need but you would still put a good dent in it.

Wind power varies approximately as a cubed function of the wind speed. So, just having the average wind speed is pretty much useless. Comared to 10mph, at 5mph you have 1/8 of the power available and at 20mph you have 8 times the wind power available. You need to know each wind speed along with the number of hours per year at that speed so you can do a better analysis of the possible wind power available.

 

[LionelHutz]

I should add that the 3.3mWh is the energy produced in one year.

 

[cranky108]

If you take a look at the pay back from wind generation, and compaire that with the value of other possible projects, you should be finding the wind generation as a very low priorty. Exception where the wind generation has a value for public display (Advertising or feel good factor).

An alternative is to buy green power block from your utility company and save all the overhead from these monsters.

Another better use of you money is look at solar heating to replace some of your heating costs. The payback is shorter, and the overhead isen't so difficult to get to.