Solar Panel Rechner
Berechnen Sie, wie many solar panels you need based on electricity usage und local sun hours. See system size und annual production.
Panels Needed
19 panels
Panels Needed vs Monthly Electricity Usage
Formel
## How to Calculate Solar Panel Needs Sizing a solar system depends on your energy consumption, local sunlight, and panel efficiency. ### Formula **System Size (kW) = Daily kWh / (Sun Hours * System Efficiency)** **Panels Needed = System Size * 1,000 / Panel Wattage** Peak sun hours vary by location: 4-5 hours in the northern US, 5-7 in the south and west. System efficiency accounts for inverter losses, shading, and panel degradation.
Lösungsbeispiel
A home using 900 kWh/month in a location with 5 peak sun hours, using 400W panels at 80% efficiency.
- 01Daily usage: 900 / 30 = 30 kWh/day
- 02System size: 30 / (5 * 0.80) = 7.5 kW
- 03Panels needed: ceil(7,500 / 400) = 19 panels
- 04Annual production: 19 * 400 / 1000 * 5 * 365 * 0.80 = 11,096 kWh
Häufig Gestellte Fragen
How many solar panels does a typical home need?
The average US home uses about 900 kWh/month and needs 15-25 panels depending on location, panel efficiency, and roof orientation.
What are peak sun hours?
Peak sun hours represent equivalent hours of full-intensity sunlight per day. Phoenix averages 6.5, New York about 4.5, and Seattle about 3.5 peak sun hours.
How much roof space do I need?
Each 400W panel is about 21 sq ft. A typical 8 kW system (20 panels) needs roughly 420 sq ft of unshaded south-facing roof.