Author Topic: Back up power system  (Read 205 times)

Swbls12b

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Back up power system
« on: February 02, 2017, 10:28:20 PM »
Total noob and wanting a solar based back-up power system.
Here's what I want to build.

Solarworld  300 watt sunmodule X 4
Voc= 40.1
Vmp= 31.6
Isc= 10.23
Imp= 9.57

    2 in series X 2 parallel into a classic 150sl to start with and eventually either 4 parallel strings or 9 panels parallel to charge a 24 volt bank of Trojan T-105 re's.

I've used the classic string sizing tool but, I can't help but think that I am missing something or figuring wrong.

I'm sure that more info. will be needed so, please be gentle with me, as I said I am a TOTAL NOOB to all of this and want to learn all I can.

Westbranch

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Re: Back up power system
« Reply #1 on: February 02, 2017, 10:58:36 PM »
Hint:  once you have electrons in the battery you have to get them out and you need an (......er) to do that, and what is it going to power? How big are the loads ? How long will they run (min. or Hrs)?

more later
« Last Edit: February 03, 2017, 11:51:49 AM by Westbranch »
KID FW1811 560W >C&D 24V 900Ah AGM
CL150 29032 V.2126-NW2097-GP2133 175A E-Panel WBjr, 3Px4s 140W > 24V 900Ah AGM,
2 Cisco WRT54GL i/c DD-WRT Rtr, NetGr DS104Hub Hughes 1100 Sat. Modem
Cotek ST1500 Inv  want a 24V  ROSIE Inverter
OmniCharge3024  Eu1/2/3000iGens
West Chilcotin 1680+W to come

Resthome

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Re: Back up power system
« Reply #2 on: February 03, 2017, 12:33:03 AM »
First determine all your loads and for what period of time. That will tell you how many Ah of batteries you need. Then you can design the solar system that will charge that bank of batteries. You need to design in that order or you will be throwing away a lot of equipment and dollars.
John

10 x Kyocera KC140, Classic 150 w/WBJr, Link10 Battery Monitor, 850 AH @ 12v Solar One 2v cells, Xantrex PROwatt SW2000
Off Grid on Houseboat Lake Don Pedro, CA

Swbls12b

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Re: Back up power system
« Reply #3 on: February 03, 2017, 11:53:41 AM »
The main things I'm want to power are the fridge and freezer which from what I can find are 600 watts apiece. I'm unable to check with the kil-a-watt because of there size. The only other item would be a tv at 150watts and lighting in one room which is all led.

The longest we have been without power has been two days. It sux listening to a generator run all day and night.


Swbls12b

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Re: Back up power system
« Reply #4 on: February 03, 2017, 12:28:43 PM »
Maybe this will help, the energy guide for the fridge estimates 365kwh per year usage.
The freezer is estimated at 651kwh per year to run.

Westbranch

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Re: Back up power system
« Reply #5 on: February 03, 2017, 12:41:39 PM »
How old are the fridge and freezer? 

New ones use about 1  KWhr or less per day so the fridge, @ 1KWhr per day must be relatively  new. I am able to run mine on a 1500W inverter.

that freezer must be fairly old at 651KWhr/yr.. = 1.783KWhr / day and it probably has a large inrush at startup...  means a beafyer Inverter needed.

PS you need to add the time factor  to your usage figures. ie 150W x 5 hrs = 750Whr

I suspect you will need to be looking at a 2000W to 3000W inverter, or larger,  for those 2 large appliances... due to both kicking on at the same time
KID FW1811 560W >C&D 24V 900Ah AGM
CL150 29032 V.2126-NW2097-GP2133 175A E-Panel WBjr, 3Px4s 140W > 24V 900Ah AGM,
2 Cisco WRT54GL i/c DD-WRT Rtr, NetGr DS104Hub Hughes 1100 Sat. Modem
Cotek ST1500 Inv  want a 24V  ROSIE Inverter
OmniCharge3024  Eu1/2/3000iGens
West Chilcotin 1680+W to come

Swbls12b

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Re: Back up power system
« Reply #6 on: February 03, 2017, 01:06:20 PM »
They were both purchased brand new in 2013.