Tech & Energy
Solar System Sizing Calculator
Right-size your solar array from your annual kWh usage and local peak sun hours. Most homes need 6-12 kW DC.
DC system size (kW)
—
- AC output expected
- —
- Panel count (400W)
- —
- Annual generation
- —
FAQ
What are peak sun hours? +
Equivalent hours of 1000 W/m² sunlight. Phoenix ~6.5, Boston ~4.0, Seattle ~3.5. Use NREL PVWatts for your zip.
Why derate 80%? +
Real losses: panel temperature, inverter efficiency, wiring, soiling, shading. PVWatts default is 86%; conservative is 75-80%.