Overview: House System Only
System type: Grid-tie solar-electric with battery backup
System location: New Orleans, Louisiana
Solar resource: 5 average daily peak sun-hours
Production: 250 AC KWH per month (estimate by NREL PVWatts)
Utility electricity offset: 35%
Photovoltaic Array
Modules: 21 Uni-Solar PVL-136, 136 W STC, 33 Vmp, 24 VDC nominal
Array: Seven three-module series strings, 2,856 W STC total, 99 Vmp, 72 VDC nominal
Array combiner box: OutBack PV8 with seven 8 A breakers
Array disconnect: E-Panel, 60 A DC breaker
Array installation: Installed on north-facing roof at 5° tilt
Energy Storage
Batteries: Eight Deka 8G31DT-DEKA, 12 VDC nominal, 97.6 Ah at 20-hour rate, sealed gel
Battery bank: Two four-battery strings, 48 VDC nominal, 195.2 Ah total
Battery/inverter disconnect: 125 A breaker
Balance of System
Charge controller: OutBack Flexmax 80, 80 A, MPPT*, 150 VDC max Voc input voltage; 12, 24, 36, 48, or 60 nominal output voltage
Inverter: OutBack FX series, GTFX3648, 48 VDC nominal input, 120 VAC output
System performance metering: OutBack MATE2, bidirectional utility kWh meter
*When corrected for the site’s historical low temperature of 7°F, the array maximum system voltage could exceed the charge controller’s 150 VDC maximum voltage rating, damaging the controller and voiding the product’s warranty. String sizing should always account for both historical low and average high temperatures.
