Author Topic: A beginner who so so confused .. help?  (Read 2257 times)


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Re: A beginner who so so confused .. help?
« Reply #30 on: November 30, 2016, 09:20:48 AM »
First something slightly off topic but still important:

I often see folks use KW and KWH interchangeably. I see it in this thread, as well.

That is just plain wrong and very confusing.

I saw a good analogy the other day that I want to pass on.

KW is like the speedometer on a vehicle.

KWH is like the odometer on the vehicle.

The units are the same but they mean very different things.

now, back to your project, SouthPacific:

This thread has gotten fairly long and with so many included quotes I get lost. I will just hit the high spots here:

48 volts is definitely they best commonly available voltage for an off grid system with batteries.

A true hard core off grid system will use 2 volt cells in a single series string. This eliminates the parallel strings issue.

I used to be an advocate of tracking arrays (follow the sun). I no longer am an advocate of tracking. Simply put, it is a pain in the backside to do unless it is automated. If it is automated it is another point of failure with moving parts. Plus solar modules have gotten so cheap that you can easily put in a lot more modules than you think you need if you were tracking. And, probably for less money.

Facing smaller arrays in different directions can boost output by working around your shade issues. Basically get as many modules in full sun as much as possible. This can mean throwing out commonly held "rules of thumb" like solar panels need face south (north in the other hemisphere). Solar panels need to face the sun as much as possible. Some locations might require panels facing East,West or both if multiple arrays are used. In these cases each array should be on its own charge controller.

For big loads you may need to bite the bullet and use a fuel powered generator. That way, you are never going to be backed into a energy deficit corner choice of either no power or a  battery killing over discharge as you can fire up the generator.

As stated earlier your big Jacuzzi load is pretty impractical for running from batteries.

Just from here.



« Last Edit: November 30, 2016, 09:23:08 AM by TomW »
Do NOT mistake me for any kind of "expert".

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Re: A beginner who so so confused .. help?
« Reply #31 on: November 30, 2016, 10:49:55 PM »
Hello everyone,

Instead of trying to do all the quotes from all the recent replies, I wanted to first thank everyone for the replies and all the great information.

I'm re-evaluating the entire system at this point.  I do understand that 48 volt is the definite configuration I will be building and the panels I have (CSUN 305's) should be good from that standpoint.

I am now looking at the battery bank system and found the Trojan L16RE-2V.  I wanted everyone's opinion on these.  In research I understand that flooded batteries are about to be a thing of the past and more efficient energy storage is coming into play.  So I would also like your opinions on this matter.  Should I begin to plan around the old flooded battery style or continue looking into the newer alternatives? 

I think this will be a good foundation point in the design from here.

Also, the 7.1 on the Kill-O-Watt is KWH and not KW, just to clarify that.  Is that still considered a lot on an off-grid system?

Your thoughts?   :)

On a side note, I'll be a little less available on the forum this week.  I began playing back in the market the first part of October and have some nice plays in the works, so a lot of research and watching is going into that atm.  Made just over 37% in the month of October playing some oil ETF's and picked up FNMA just before the election at $1.65 .. it closed today at $4.49 and looking to continue a hard climb.  So some good easy money to be made right now.   :)  Have to make the money for all this new PV setup.

Thanks again!
« Last Edit: December 01, 2016, 05:03:02 PM by SouthPacific »


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Re: A beginner who so so confused .. help?
« Reply #32 on: October 23, 2017, 12:39:34 AM »
So I just read this entire thread and gotta wonder.... Did you ever build the system... Or did the idea get scrapped?  I was really wanting to find out if u ever found a big enough battery bank to handle such large loads.
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