Solar System & Battery Sizing for 1,225 kWh/Month in Perth (WA), Australia
Complete photovoltaic engineering breakdown for a 1,225 kWh/month (40.8 kWh/day) electricity profile in Perth (WA), Australia (5.8 Peak Sun Hours/day).
Technical Specification Table — 1,225 kWh/Month Solar System (Perth (WA), Australia)
| Monthly / Daily Electricity Consumption | 1,225 kWh/month (40.8 kWh/day) |
| Location Peak Sun Hours (PSH) | 5.8 hours/day (Perth (WA), Australia) |
| Required PV System Size (80% Performance Ratio) | 8.8 kWp DC |
| Number of Solar Panels (440W N-Type Bifacial) | 20 panels |
| Roof Area Required | 41.0 m² (441 sq ft) |
| Recommended Hybrid Inverter Rating | 7.9 kW AC |
| Recommended LiFePO4 Battery Storage (85% DoD) | 31.2 kWh Nominal (26.5 kWh Usable) |
| Estimated Annual Output | 14,904 kWh/year (~1,242 kWh/month) |
| Estimated System Turnkey Cost (Before Tax Credits) | A$11,440 |
| Annual Electricity Bill Savings (@ A$0.31/kWh) | A$4,620/year (A$385/month) |
Frequently Asked Questions
How many solar panels are needed for 1,225 kWh per month in Perth (WA), Australia?
With an average of 5.8 Peak Sun Hours per day in Perth (WA), Australia and an 80% system performance ratio, a monthly usage of 1,225 kWh (40.8 kWh/day) requires a 8.8 kWp solar array, which equals 20 standard 440W N-Type solar panels occupying 41.0 m² (441 sq ft) of roof space.
What size solar battery bank do I need for 1,225 kWh/month?
To cover evening and overnight loads (65% of daily consumption at 85% LiFePO4 depth of discharge), a 31.2 kWh nominal (26.5 kWh usable) LiFePO4 battery bank paired with a 7.9 kW hybrid inverter is recommended.
How much money will a 8.8 kW solar system save in Perth (WA), Australia?
Generating approximately 14,904 kWh per year at an average local tariff of A$0.31/kWh, the system saves A$4,620 per year (A$385/month) with an estimated payback period of 2.5 years.