Can someone check my math?

[hozer]

This is a 24 volt system I am thinking putting together

Panels:

LG Mono LG300N1C-B3 305 Watt Panel = ( 5 ) 1525 watts total

Batteries:

Rolls Batteries 24 volt S6-460ah = ( 8 )

4 Batteries in series & 4 Batteries in Parallel. Total AH 960

960ah X 24volts = 23040 watts / 1000 = 23.05 kwh

( using 30% max battery ) 23.05kwh X 30% 7.02 hrs per day of power max!

Thanks guys

[sensij]

commenting only on the math...

460 * 2 = 920 (not 960)

920ah * 24 V = 22.08 kWh * 30% = 6.6 kWh of energy (not "hrs" and "power").

Edit: I see the rest of the information is in this thread. Are the batteries 460ah or 480ah?

[hozer]

commenting only on the math...

460 * 2 = 920 (not 960)

22.08 kWh * 30% = 6.6 kWh of energy (not "hrs" and "power").

Edit: I see the rest of the information is in this thread. Are the batteries 460ah or 480 ah?

The Rolls Batteries are 460ah AGM's


Whoops lol Mistype lol Ok so I will get approx. 6.6 kwh per day correct?

[sensij]

The Rolls Batteries are 460ah AGM's

Whoops lol Mistype lol Ok so I will get approx. 6.6 kwh per day correct?

Looks right to me.

I'm not sure if it was pointed out to you yet, but those panels have STC ratings of 39.8 Voc, with a 9.98 Isc. That charge controller is rated for 150 V max, with a 48 A max Isc at STC. How are you planning on wiring those panels? 5 panels in series is too much voltage, and 5 in parallel would be too much current.

[Sunking]

The Rolls Batteries are 460ah AGM's


Whoops lol Mistype lol Ok so I will get approx. 6.6 kwh per day correct?

Wrong. The batteries are capable of supplying 6.6 Kwh per day, but no way can your panels generate that much in a day.

[sensij]

Wrong. The batteries are capable of supplying 6.6 Kwh per day, but no way can your panels generate that much in a day.

PVWatts for those panels in Grand Junction, CO estimates 6.7 kWh / day annually for south facing, 20 deg tilt. In December and January, the average day is only 4.3 kWh. That assumes the panels are properly matched to a grid-tied inverter. A bad match to a charge controller would, of course, result in less.

[hozer]

PVWatts for those panels in Grand Junction, CO estimates 6.7 kWh / day annually for south facing, 20 deg tilt. In December and January, the average day is only 4.3 kWh. That assumes the panels are properly matched to a grid-tied inverter. A bad match to a charge controller would, of course, result in less.

Thanks guy for all the input. Will check other controllers and let you know which one will work better

[SunEagle]

PVWatts for those panels in Grand Junction, CO estimates 6.7 kWh / day annually for south facing, 20 deg tilt. In December and January, the average day is only 4.3 kWh. That assumes the panels are properly matched to a grid-tied inverter. A bad match to a charge controller would, of course, result in less.

If he keeps his daily use to 20% DOD of the battery capacity (~4.4 kWh) he might be able to put back what he uses.

Better keep that generator handy to top off the batteries.

[Sunking]

PVWatts for those panels in Grand Junction, CO estimates 6.7 kWh / day annually for south facing, 20 deg tilt. In December and January, the average day is only 4.3 kWh. That assumes the panels are properly matched to a grid-tied inverter. A bad match to a charge controller would, of course, result in less.

Now go change the efficiency to 66% of a Battery system and see what you get. Battery systems are designed for worse case winter month, not yearly averages. I stand behind my comment.

[sensij]

Now go change the efficiency to 66% of a Battery system and see what you get. Battery systems are designed for worse case winter month, not yearly averages. I stand behind my comment.

I was only adding some data to your comment, not disagreeing. What the panels are capable of supplying is one thing, how much of that is useful energy in the battery system is another. That is why I included the qualifier about grid-tie, and also separated the yearly average from the worst case months. I don't see how our posts conflict.

[Sunking]

I was only adding some data to your comment, not disagreeing. What the panels are capable of supplying is one thing, how much of that is useful energy in the battery system is another. That is why I included the qualifier about grid-tie, and also separated the yearly average from the worst case months. I don't see how our posts conflict.

They don't my bad. My apology.