Hybrid Car – More Fun with Less Gas

How many panels ? ( to run 230 volt sprinkler pump 30 minutes a day?) - Page 14

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Posted by wmbjkREMOVE on July 14, 2008, 12:10 am
On Sun, 13 Jul 2008 15:48:04 -0700 (PDT), bealiba@gmail.com wrote:


That quote does exactly nothing to prove your straw man claim that I
ever said that "you can reduce voltage drop by increasing the load".
Making things up is called lying.

So what? That also does nothing to prove your straw man. In fact,
arguing in circles only advertises your inability to think.

You might as well say "the sky is blue, therefore anything I write
must be correct".


Posted by bealiba on July 13, 2008, 6:15 am
On Jul 13, 10:47 am, wmbjkREM...@citlink.net wrote:

There are many things I have not done. This is of course true for all
of us. Some of the more notable things I have not done are:

1) I have never copied a system from a magazine and claimed that I
designed it. wayne has.

2) I have never copied a system from a magazine, found it did not meet
my needs and kept throwing money at it until it at least worked during
daylight hours. wayne has.

3) I have never hired a bunch of contractors to build my house then
claimed that I built  the house. wayne has.

4) I have never have never claimed to be the "General Contractor" and
blamed the subbies for failings of the "General Contractor". wayne

5) I have never taken an argument away form these groups or set up a
web site to harass someone. wayne has.

6) I have never stalked a person across the internet. wayne has.

7) I have never claimed that you can reduce line losses (Voltage Drop)
by by increasing the load. wayne has.

My goodness, what a dull life I lead.

OTOH I have designed and built dozens of systems, all of which worked
to spec from the moment they were turned on.

All of these systems were sized with the formula that has been
presented here. It works. It is correct. It is free, as is the
spreadsheet and backup via email.

Tweedledee and Tweedledum have yet to prove that the formula is
incorrect, and that will never happen.

Posted by wmbjkREMOVE on July 13, 2008, 12:46 am
 On Sat, 12 Jul 2008 08:55:26 -0400, Ron Rosenfeld

As is his habit, although in his defense he claims that over-sizing
allows for such things as "unexpected babies".  :-)

He's just a little behind the times. For example, Peukert's Law was
presented in 1897, but George simply ignores it, even when discussing
high-current loads. Like many of his other mistakes, it's rooted in
his lack of experience. He has no more idea about high-current loads
than he does about battery monitors, energy meters, inverter-chargers,
or MPPT controllers. Most are able to learn about things they don't
have any personal experience with, but George prefers to pretend that
whatever he can't afford or has never seen must be unnecessary,
wasteful, foolish choices of "yanks", etc.

That's just another thing he prefers to ignore. Posters have been
supplying links to PVWatts and HOMER for years, but you'll never see
the ghinius recommend those. He prefers to pretend that a GIGO
spreadsheet is best for every need.


Posted by bealiba on July 13, 2008, 1:45 am
 On Jul 13, 10:46 am, wmbjkREM...@citlink.net wrote:

Tell us about your system. What are the loads? How long are they run
and what they draw. While you are at it you can explain how increasing
the load reduces line losses (Voltage Drop)

Posted by Ron Rosenfeld on July 13, 2008, 11:20 pm
 On Sun, 6 Jul 2008 19:07:12 -0700 (PDT), bealiba@gmail.com wrote:

Let's get back to this challenge of yours, as to whether your
specifications will run the OP's 2500watt pump 1/2 hour per day, every day.

You give incomplete specifications, so it's a tough to run a simulation.
But perhaps, if you can fill in a few details, or agree with some of my
assumptions, we can proceed with a simulation:

With regard to your selected module:

Does this mean it has an STC nameplate power rating of 14*2.94 = 41.16
watts?  Or is the STC nameplate power rating something else?

I will round this up to 11.

Do you want to consider the effect of temperature on the module?

If you do, then we need to use some assumptions about the temperature
coefficient, NOCT and MPPT efficiency at std. test conditions.

I would assume
    Temperature coefficient of power = -0.5%/C
    NOCT                    45.2C
    MPPT Efficiency at std test cond     13%

but we can use different values if you like, or ignore temperature affects

With regard to the battery, you have supplied this information:

The real world battery I could find (in my database) closest to these

Trojan T105
    Maximum allowable depth of discharge = 70%
    Capacity at 100 hr rate             = 240
    Efficiency                85%

So I would use two of these in series to provide a 12V battery bank.

Let me know.


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