Author Topic: Where to buy Hi-Voltage PV panels?  (Read 1704 times)

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hamlet

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Where to buy Hi-Voltage PV panels?
« on: September 19, 2008, 09:21:25 PM »
Maybe you've seen my pump posting...


I want to run my 90v,1.5A pump with just

panels, no battery. To get the voltage I need,

I have to use 4 or MORE lower voltage panels,

but the extra watts are useless to me, and an

extra expense. I'm planning on using a linear

current booster.


Does anybody have any ideas?

« Last Edit: September 19, 2008, 09:21:25 PM by (unknown) »

richhagen

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Re: Where to buy Hi-Voltage PV panels?
« Reply #1 on: September 19, 2008, 04:23:17 PM »
A 40 Watt 12V panel typically has a current at charging voltage of about 2.4 Amps and a typical 30W panel has a current of about 1.8 Amps.   Voltage at maximum power of about 16 to 17V,  for both wattages depending upon the manufacturer.  If you string 6 typical mono or polycrystaline panels together you will have approximately the power you want.  I have noticed that sunelec.com has gepv-30 panels, 30 Watts 1.8Amps for U.S. $125 per panel here, they output 1.8 Amps.  


I still don't see how you are going to make it work on the fly, - although I recall the Dan's posting on a direct driven water pump before - see Ghurd's comment from your other story, but with a series string of panels you can match the power specifications you seek fairly closely.  Rich


Ok, actually Dan wrote it up and posted it under the heading 'water pumping' off of the main page here:  http://www.otherpower.com/otherpower_waterpumping.html

« Last Edit: September 19, 2008, 04:23:17 PM by richhagen »
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richhagen

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Re: Where to buy Hi-Voltage PV panels?
« Reply #2 on: September 19, 2008, 04:28:39 PM »
Just read up on the function of the linear current boosters.  Should actually be doable.  Rich
« Last Edit: September 19, 2008, 04:28:39 PM by richhagen »
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methanolcat

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Re: Where to buy Hi-Voltage PV panels?
« Reply #3 on: September 19, 2008, 09:00:00 PM »
   Sorry, not an idea, but a question.


What will you do on cloudy days or at night? How will you run your pump then?

« Last Edit: September 19, 2008, 09:00:00 PM by methanolcat »

dbcollen

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Re: Where to buy Hi-Voltage PV panels?
« Reply #4 on: September 19, 2008, 11:20:50 PM »
I have some new old stock First solar FS50 panels, they are 50 watt, 90VoC,  I will sell you some for $3.00watt plus shipping. you would need 4. if you are using a Grundfos SQFlex pump it would work well as 2 panels series, 2 parallel.


Madriverwind (at) gotsky.com


Dustin

« Last Edit: September 19, 2008, 11:20:50 PM by dbcollen »

hamlet

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Re: Where to buy Hi-Voltage PV panels?
« Reply #5 on: September 20, 2008, 01:29:20 AM »
I'll use a storage tank. Most of my water use will be garden/pasture/orchard, which is below the tank. I don't want spend the kW to pressurize it. I'll have booster pump for the house.
« Last Edit: September 20, 2008, 01:29:20 AM by hamlet »

hamlet

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Re: Where to buy Hi-Voltage PV panels?
« Reply #6 on: September 20, 2008, 01:53:52 AM »
Those are interesting panels, at a nice price. Would work well with a MMPT.

I made a mistake, my motor is 2.5A, and using


http://www.sierrasolar.com/articles/water_pumping/calc_water_pumping.html


I've calculated either 94 watts, or 199w, depending on which pump head I'll use

(procon 2.5gph/5.3gph)


I like this LCB:


Model # PPT 90 - 6

Features

Voltage Limited Output

Greatly increases water flow, even under reduced sunlight

        conditions (over 40% likely)

Transient Protected on the input and output

Float Switch input for on/off control

Ultra High Efficiency >94 %

Weatherproof NEMA enclosure

Nominal Voltage (V) 96

Nominal PV Input (V) 96

Maximum PV Input (V) 160

Maximum Output Voltage (v) 99

Maximum Output (A) 6 continuous

Maximum Output (A) 20 for ten seconds

Efficiency >94%


http://www.solarconverters.com/product_frame.html


QUESTION:  At a maximum PV INput of 160v, those 50w Panels have an Open Circuit Voltage

of 85v.  Would that be an over voltage? Or do I use the "Voltage at mpp" figure of 58v, which is still pushing things for the LCB, although the motor can handle it.

I have 1000 feet of 2/0 wire to the pump, so voltage drop isn't a problem.


Thanks

« Last Edit: September 20, 2008, 01:53:52 AM by hamlet »

Clifford

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Re: Where to buy Hi-Voltage PV panels?
« Reply #7 on: October 01, 2008, 01:08:07 AM »
Assuming you have a DC motor...

Most standard DC motors can run with a variety of voltages...   lower voltages mean they run slower, higher voltages mean they run faster.


Certainly they should be able to tolerate 20% or so higher or lower voltages.  But you can confirm with your manufacturer.  Also note, the more amps you draw, the lower the voltage at the panel will be, and it can fall off quickly near the peak power point on the panel (under the current conditions).


What about startup power?  You might be able to add some capacitors to aid with startup if necessary, but if your panels produce marginal voltage (including morning and evening times), then you might not be able to start the pump.  And one of the hardest things on electric motors is being stalled.


What about an old fashioned windmill for pumping water?


I was also reading about enphase micro-inverters.  240V AC, 175W with MPPT, and can daisy chain together if you need more power.  The basic unit is about $200 each.

« Last Edit: October 01, 2008, 01:08:07 AM by Clifford »

cylindar

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Re: Where to buy Hi-Voltage PV panels?
« Reply #8 on: December 10, 2008, 11:36:38 PM »
You might want to try "Build Your Own Solar Panels" they have instructions on how to build custom panels for any current or voltage output.
« Last Edit: December 10, 2008, 11:36:38 PM by cylindar »

spinningmagnets

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Re: Where to buy Hi-Voltage PV panels?
« Reply #9 on: December 11, 2008, 09:01:48 AM »
Here's a story with a posting about using high-voltage PV (170-VDC)


http://www.fieldlines.com/story/2008/8/31/202716/222

170-VDC solar PV to 144-VDC battery to 120-V inverter


The poster is "jacobs". I am not suggesting that anyone do this, but I saved it because it was interesting.

« Last Edit: December 11, 2008, 09:01:48 AM by spinningmagnets »