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Off Grid windpark 1

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jckelly

Electrical
Sep 13, 2003
6
I want to set up an off grid windfarms where loads are mainly motors of total installed capacity of 300kw. I have no idea how many wind turbines I should install where average wind speed is 6.8m/s. What will be the ideal mix of generation and how it will be distributed. Can someone advise
 
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And when the wind stops?
I live near a 150 Mega-Watt wind farm.
It's quite a sight to see over 80 stationary wind turbines on a still day.

Bill
--------------------
"Why not the best?"
Jimmy Carter
 
Agree with Bill, if the loads must run at all times, then your biggest issue will be energy storage and conversion. Average wind speed isn't all that useful. Could be long periods of no wind punctuated by extreme winds that you can't utilize safely. You could get much more than 300 kW from a single turbine.
 
The idea is to install at least 4 150kw wtg so their output at average wind speed will cover the loads because at average wind speed their output could be 50%.is energy storage essential in off grid network? If motors run all the time, what if I install solar in parallel, the sun is always shining in that area.
 
How far apart are you planning to put these wind turbines so that one of them is always running? Several hundred kilometers, perhaps? Weather systems can be pretty big. Wind turbines that are a few hundred metres apart, are seeing very close to the same conditions at the same time. If one stops, probably they'll all stop within seconds of each other.

It somewhat works when many wind turbines spread over a thousand kilometers are all connected to the grid. Somewhat.

And I can guarantee you, that the sun is not shining at night.
 
It's quite a sight to see over 80 stationary wind turbines on a still day.
Hard to see at night but it happens.
If your motors are driving water pumps you may consider pumped storage.

Bill
--------------------
"Why not the best?"
Jimmy Carter
 
Yes, if the sun is shining 24 hours a day, I'd definitely go with solar.
 
Considering a base load of 250kw what if I install a hybrid plant having wind turbines, solar and energy storage(battery banks)
 
You really need to compute how much ENERGY you need - not just power levels. Battery banks would require inverters. If outages can be tolerated, then it is an easier problem.

What's the reason for wanting to be off-grid? Philosophical or economic?
 
Energy availability is site and installation specific.
National Renewable Energy Lab (NREL) has historical insolation tables tabulated for the US, AWEA.org has wind energy availability maps.

Beyond that site surveys would give you a better idea of light (shading study) and wind available (anemometer on a pole study)at your intended site(s). You could identify prelimenary solar panel and turbine selections to see if you can develop enough energy for your needs at the site or not.
 
I'd say windmills are next to impossible without energy storage. You must use all the wind energy the blades are converting to mechanical energy, which makes it rather hard to match the mechanical power to a fixed amount of electrical load.
 
Hi dpc
The problem is that the site is coal mines with no grid network in the area, we are using diesel engines to run motors which is costing us $2k/day in fuel. 2500kwhr is the energy requirement based on daily load consumption
 

Hi Lionel
Energy storage is the solution but at what ampere hour. Someone suggested 9600Ah with 400kw wind energy and 500kw of solar, but will the batteries sustain indutive loads beyond 2 hours
 
You can reduce your energy bill quite easily but the reduction may not be as much as you hoped.
2500 KWHr per day is an average load of 104 kKW. As I remember a 100 kW wind turbine will produce an average of 15% to 30% of the maximum rating.
Somewhere between a WAG and a loose rule of thumb, a 100 kW turbine working in parallel with the generators will save between $300 and $600 per day.
A larger turbine will save more but the relationship is not linear.
Another option is to install a much larger turbine and use the excess energy when the wind is blowing to produce a marketable by-product, on an energy available basis.
How is the market for ice in your area.
At times when the output of an oversized installation is more than the mine demand you may be making and selling ice.
ou will still need the generators when the wind is still.

Bill
--------------------
"Why not the best?"
Jimmy Carter
 
Jckelly; Your problem seems considerably less daunting with the additional info.

Solar panels are dirt cheap now. New 250W panels are only about $100 a piece. A 100kW array is not very big nor hard to install. Rule of thumb is 5hrs/day. A 100kW of panels alone will carve off 500kWHr per day. Multiply that to achieve as much non-sun running as desired. Of course you will need to purchase storage. Storage is the elephant of off-grid power. It's the main cost. There should be a sweet spot between storage and generator power that would provide the correct amount of storage to make it work.

Keith Cress
kcress -
 
There are companies now that do this sort of thing commercially for mine sites, such as this.
The fun in integration of renewables with diesel is maintaining stability and adequate loading for the diesels, although these days its more of an economic than technical argument than it used to be.
Solar is reasonably well understood, wind can also be fun as output can exceed load quite easily depending on turbine regulation and wind gusts. Storage can help, as can overgenerating and dumping the excess when required.

EDMS Australia
 
I find it ironic that you are wanting to use wind or solar to power needs for a coal mine. How about setting up a small coal powered generator? Runs day or night wind or not and fuel should be free. LOL
 
Hi Valvecrazy
That's a great suggestion, where cna I find such small coal fired generators, any reliable sources?
 
Google used steam turbines, used boilers, surplus turbines, surplus boilers.
I was consulting for a sawmill that wanted to generate their power from waste sawdust. The mill failed before we could go ahead but I found a lot of used equipment online.

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

Would there not be issues with designing a solid fuel fired plant capable of unattended overnight operation [lest staffing costs become a prohibitive consideration] that would satisfy the AHJ?

If my understanding of the matter is correct, the AsHJ generally take a very dim view of automated / guarded plants using bed-fired solid fuel [ IIRC unattended operation of pulverizers is prohibited ] since immediate tripping of the fuel source is not possible.

CR

"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
 
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