diy solar

diy solar

Three panels, three controllers, one battery. Optimum panel placement?

Freep

Solar Enthusiast
Joined
May 11, 2020
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Location
USA
At our off grid cabin in Canada we have 2 100 AH AGM batteries. They are currently separate, running separate circuits. Because of uneven loads and the solar panel situation I plan to put them in parallel and have all loads on the same circuit. This runs led lights, cell phone chargers, marine radio, water pump and cell phone booster.

For solar we have a 225 watt, a 90 watt and a 50 watt panel. There is one Epever MPPT controller and two PWM controllers. Right now all three panels face south.

I'm thinking I should face the 90 watt panel(with its PWM controller) east to provide some juice first thing in the morning if for some reason the battery gets low overnight, the 225 watt panel(with the Epever) south and the 50 watt panel west.

This cabin is only used in the summer so we get a lot of sun when it's not cloudy and in the fall we shut everything down and put the battery in storage.

What do you fine people think? Is there better placement for these panels?
 
All South will get you the highest yield, but the S/E/W combo may play better towards your actual usage. It's really about how you use it. If you want more power in the morning and more juice in the evening to keep your batteries charged later, then that may be the way to go.

FWIW, I have my whole array at 165° because weather patterns in my area tend to result in afternoon cloud cover, so I try to gather a bit more of the morning sun. My peak is at 11:30am instead of noon.
 
At our off grid cabin in Canada we have 2 100 AH AGM batteries. They are currently separate, running separate circuits. Because of uneven loads and the solar panel situation I plan to put them in parallel and have all loads on the same circuit. This runs led lights, cell phone chargers, marine radio, water pump and cell phone booster.

For solar we have a 225 watt, a 90 watt and a 50 watt panel. There is one Epever MPPT controller and two PWM controllers. Right now all three panels face south.

I'm thinking I should face the 90 watt panel(with its PWM controller) east to provide some juice first thing in the morning if for some reason the battery gets low overnight, the 225 watt panel(with the Epever) south and the 50 watt panel west.

This cabin is only used in the summer so we get a lot of sun when it's not cloudy and in the fall we shut everything down and put the battery in storage.

What do you fine people think? Is there better placement for these panels?
I have three arrays, 1 facing South and 2 facing West. So far producing good for two years. After my wife retired, she is at home every day so I am thinking of adding an array to the east just for that.
 
All South will get you the highest yield, but the S/E/W combo may play better towards your actual usage. It's really about how you use it. If you want more power in the morning and more juice in the evening to keep your batteries charged later, then that may be the way to go.

FWIW, I have my whole array at 165° because weather patterns in my area tend to result in afternoon cloud cover, so I try to gather a bit more of the morning sun. My peak is at 11:30am instead of noon.


One thing I was worried about with that is a controller not pushing in enough current because of higher voltage created by other controllers. I have already run into a situation where a smart charger(AC) wasn't bulk charging when it should because of the voltage coming in from the solar chargers. At least that's what I think was happening.
 
One thing I was worried about with that is a controller not pushing in enough current because of higher voltage created by other controllers. I have already run into a situation where a smart charger(AC) wasn't bulk charging when it should because of the voltage coming in from the solar chargers. At least that's what I think was happening.

If that's the case, then you either have one or more controllers configured incorrectly, or your battery is in the absorption phase of charging, and it can't take any more current, even if it's available.


If you configure the 3X SCC to the same absorption and float voltage, there should be no concerns.
 
I would do SE not E.
I’d be inclined to procure ~200W of panels to deploy to SW. Use the 225W south, and 90W SE.
Gift or sell the 50W
 
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