Solar Panel Location and Series Vs Parallel

[ddutton]

This is an off grid system. I plan on installing 2 300 watt panels with a mppt charge controller. My roof faces east west (not ideal). My question is which is better to install both panels on either the east or west side (will have to measure which side gets better exposure, I have a lot of trees) or one panel on the east side and one on the west side. Also series or parallel, I'd prefer series as I can save on wire costs.

[Logan5]

You need to provide more info. what size of battery bank, AH and voltage, size of wire you intend to run from panels to MPPT. What are your loads, Inverter? inverterless? any idea what your daily Watt hours will be?

[inetdog]

if you put one panel on each roof face you cannot put them in series.

[ddutton]

24 volt system 4 225 amp hour golf cart batteries in series. 1500 watt magnum invertor charger. Wire 10 gauge run of about 30 feet. Light load, lights, charging phone etc. Unsure of watt hours usage per day, cottage so mainly used July, August.

[Logan5]

no refrigerator? Why use an inverter at all? do you have a generator to equalize the batteries? Did you initialize the batteries before you set them into a solar charge situation?

[Logan5]

you must wire them in series to get as high voltage for the 30' run, this means you have to pick a solar exposure for them as a pair. You could later add 2 more panels on the other side.

[ddutton]

Fridge is propane, Solar charge controller equalizes batteries once a month, generator charges batteries when I need to run the well, I may use gen to equalize batteries once a year. Lights are all 120 volts and charging things would be a pain getting the correct voltage.

[Logan5]

You will learn a quick and heavy lesson if you expect a solar charge controller to equalize your expensive batteries.

[Logan5]

propane frige is good choice for weekend cottage. Do you have a hygrometer?

[ddutton]

My batteries are 12 years old and going strong.

[Logan5]

Then you already know all there is to know.

[Mike90250]

you must wire them in series to get as high voltage for the 30' run, this means you have to pick a solar exposure for them as a pair. You could later add 2 more panels on the other side.

UN-True, It depends on the voltage rating of the PV panels,. As long as you have 36 V for the MPPT controller to work with. Or if panels are only 31V, you could use a PWM controller.
Or it may be better to use 4, 150w , 30V panels , 2 in series to get sufficient voltage to run the MPPT.

Too many unknowns to decide so far.

[ddutton]

MPPT Charge controller rated charge current 30 amps, maximum solar input voltage 100 volts. Solar panel 36.7 volts and 8.18 amps.

[PNPmacnab]

I think you are a little shy on panels considering your batteries and how cheap they are. I'd do another pair. I feel your pain, almost all my panels aren't even on my land due to shading. You can't even find my house and garage on a google earth view.