Solar Barn! Brand new, need some advise

[kathys]

Kathys

I have the same issue but I am only running 2 AC box fans. I understand I will need a constant power source to the battery. I am considering using a solar panel to keep the battery charged. I have been told to use a 5 watt Solar trickle charger panel and another person told me 5 watts is not enough and a trickle charger will not work. After reading this article I am hoping you can tell me what I need to convert DC to AC to run the fans 12 hours a day. The fans are 120V. Thanks you

[milezone]

Trust me take Sunking's advice. I had close to the same setup you have now. I since took the advice and went 24 volts, MPPT 60amp controller, and I have noticed a huge increase in my power.
This was keeping the same 480 watts of solar panels (4 - 120 watts each).

Milezone

[Sunking]

Location - Atlanta, Georgia

One 15W light bulb - .50 hr a day at most
Two Galazy 20" Box Fans 3 speed - 90 watts (on high), 1.1 amps each - 9 hrs a day usage
One Nucool 1.7 cu/ft Refrigerator - 130 watts, 1.6 amps - Continuous
Radio 120v, 60hz, 13 w - Maybe 2 hrs use a day.

OK that is exactly what I need to know to fully design the system. I assume the fans will only run from say May to October.

Power usage:
15 watt light x 1 hour = 15 WH
2 fans 180 watts x 9 hours = 1620 WH
1 frig 130 watts x 24 hours x .4 duty cycle = 1250 wh
1 Radio 13 watts x 2 hours = 26 WH

Total = 2911 watt hours.
Efficiency adjustment using MPPT Controller = 1.5 x 2911 wh = 4366 WH round up to 4400 watt hours daily usage.

Battery AH vs Voltage:
12 volts = 4400 wh x 5 / 12 volts = 1833 AH
24 volts = 4400 x 5 / 24 volts = 916 AH
48 volts = 4400 x 5 / 48 volts = 458 AH

Solar panel Wattage required:
4400 wh / 5 hours = 880 watts

MPPT Charge controller requires vs Battery voltage:

12 volts = 880 watts / 12 volts = 73 amps
24 volts = 880 watts / 24 volts = 36 amps
48 volts = 880 watts / 48 volts = 18 amps

Here is my suggestion. You will not like the first part. Sell whatever you have already because it is of no use.

Run the system at 24 volt battery with a 80 amp charge controller. This will allow you to grow the system up to 2000 watt panels @ 24 volts, or 4000 watts @ 48 volts.

[Spartan]

Location - Atlanta, Georgia

I just returned from our barn and I gathered my info. Please assist on these calculations:

One 15W light bulb - .50 hr a day at most
Two Galazy 20" Box Fans 3 speed - 90 watts (on high), 1.1 amps each - 9 hrs a day usage
One Nucool 1.7 cu/ft Refrigerator - 130 watts, 1.6 amps - Continuous
Radio 120v, 60hz, 13 w - Maybe 2 hrs use a day.

My (2) 12v batteries are deep cycle marine batteries - 685 Marine Cranking amps, 550 cold start amps, 140 Reserve amps.

I currently have the 3 panels = 90Watts
7amp charger controller

What do i need to make this work? Is there a different way to configure the batteries to get more out of them. Trying to stay within my means.

Any help would be appreciated.

Thanks,

Spartan

[Sunking]

Wow! Thanks for the information. About as rookie as it gets, but willing to learn.

So, what would be your minimal list of equipment to get what is needed, and recommendations? This also helps me understand the concepts better.

Spartan that is a very hard question to answer because I do not know your location or how many Kwh per day you need.

But here is a rough idea for a system that produces 1 Kwh of electricity per day which is about what your refrigerator uses.

Solar Panel wattage = 500 watts
40 Amp PWM charge controller
12 volt 400 AH battery

[Spartan]

Wow! Thanks for the information. About as rookie as it gets, but willing to learn.

So, what would be your minimal list of equipment to get what is needed, and recommendations? This also helps me understand the concepts better.

[Sunking]

Welcome aboard

Well you described the picture pretty good and very simple to troubleshoot. You simply do not have enough of anything to run what you want.

With you panels being miss matched more than likely cuts your power output from the panels way down. Even if they are matched up you are around 500 to 1000 watts short.

As for the batteries and charge controller, not even in the ball park to being close to large enough.

What you have is just about enough to run the 1 light and radio. Fridge and fans gotta go.

[Spartan]

Hey Everyone ~

Sorry if I'm about to ask stupid questions, but this solar project is fun, but confusing as heck. Brand new to this and need some help.

We have a two stall barn & tack room in Cumming, GA that I decided to go solar. Here's what I have running so far:

One 60W panel and Two 15W panels (Sunforce) 90 Watts in array on the roof
Two 400w Inverters
10 awg wiring (40 feet total)
One 7amp 105W Controller
Two deep cycle batteries in parallel

Here's what I'm trying to power up, to start:

One 1.7 Cubic Foot NuCool Refrigerator (sodas and MY Beer)
Two 20" Box Fans (one in each stall for the hot days) Run time from 7am to 5 pm, daily
One 15w Eco lightbulb in our tack room (only in the evenings when needed, minimal time)
One plug in radio (ballgames and some music)

Here's my issue -
I followed the directions installing all of the components. Checked volts of the panels (separately, and in array), it's at 18.5 volts. Checked it after the controller was installed, then began running the refrigerator and box fans. Within about four hours, the batteries were at 11.7 volts, so I shut everything down.

I initially had a 12 v 30 amp controller, but it would not charge, so I purchased a 7 amp to just try and get off the ground. It seems to be working, because the charge in increasing to 12.75 watts today.

I know that I'm probably leaving a bunch of important information out, but I'm trying to grasp the concept on how everything works and if what I have being powered is too much. Should my batteries conceptually be for backup?

Any help would be greatly appreciated. My beer is back in the grid refrigerator!
Thanks, Mr. Spartan