Solar Panel Calculator
Estimate the number of solar panels needed and annual energy production based on your electricity usage and local sun hours.
Panels Needed
19 panels
Panels Needed vs Monthly Electricity Usage
सूत्र
## 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.
हल किया गया उदाहरण
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
अक्सर पूछे जाने वाले प्रश्न
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.