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Where to buy Hi-Voltage PV panels?


By hamlet, Section Solar
Posted on Fri Sep 19th, 2008 at 09:21:25 PM MST
I need 90 volts/2amps/200w, I'd like to do it with one or two panels

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?
Where to buy Hi-Voltage PV panels? | 7 comments (7 topical, 0 editorial)

Re: Where to buy Hi-Voltage PV panels? (3.00 / 0) (#1)
by richhagen (richhagen (a t) Juno.com) on Fri Sep 19th, 2008 at 04:23:17 PM MST
(User Info)

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
'A Joule saved is a Joule made'



Re: Where to buy Hi-Voltage PV panels? (3.00 / 0) (#2)
by richhagen (richhagen (a t) Juno.com) on Fri Sep 19th, 2008 at 04:28:39 PM MST
(User Info)

Just read up on the function of the linear current boosters.  Should actually be doable.  Rich
'A Joule saved is a Joule made'
[ Parent ]


Re: Where to buy Hi-Voltage PV panels? (3.00 / 0) (#3)
by methanolcat (methanolcat (at)yahoo(dot)com) on Fri Sep 19th, 2008 at 09:00:00 PM MST
(User Info)

   Sorry, not an idea, but a question.

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



Re: Where to buy Hi-Voltage PV panels? (3.00 / 0) (#5)
by hamlet on Sat Sep 20th, 2008 at 01:29:20 AM MST
(User Info)

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.

[ Parent ]


Re: Where to buy Hi-Voltage PV panels? (3.00 / 0) (#4)
by dbcollen on Fri Sep 19th, 2008 at 11:20:50 PM MST
(User Info)

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


Mad River Wind and Hydro



Re: Where to buy Hi-Voltage PV panels? (3.00 / 0) (#6)
by hamlet on Sat Sep 20th, 2008 at 01:53:52 AM MST
(User Info)

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

[ Parent ]



Re: Where to buy Hi-Voltage PV panels? (3.00 / 0) (#7)
by Clifford on Wed Oct 1st, 2008 at 01:08:07 AM MST
(User Info)

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.



Where to buy Hi-Voltage PV panels? | 7 comments (7 topical, 0 editorial)
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