Panel Size Formula:
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Definition: This calculator estimates the required solar panel area based on power needs, panel efficiency, and solar irradiance.
Purpose: It helps homeowners, engineers, and solar installers determine how much panel area is needed to meet specific power requirements.
The calculator uses the formula:
Where:
Explanation: The power requirement is divided by the product of efficiency and irradiance to determine the necessary panel area.
Details: Proper sizing ensures your solar array meets energy needs, maximizes return on investment, and fits available installation space.
Tips: Enter your power needs in Watts, panel efficiency (default 0.18 for 18% efficient panels), and local irradiance (default 1000 W/m² for full sun). All values must be > 0.
Q1: What is typical solar panel efficiency?
A: Most commercial panels range from 15-22% efficiency (0.15-0.22). Premium panels may reach 23-24%.
Q2: How do I find my local solar irradiance?
A: Check NASA's solar database or local meteorological data. Average values range from 800-1000 W/m² in sunny areas.
Q3: Should I account for system losses?
A: Yes, consider adding 10-25% to the calculated size to account for temperature effects, wiring losses, and degradation.
Q4: How does panel orientation affect this calculation?
A: This uses ideal conditions. Adjust irradiance value downward for non-optimal angles or partial shading.
Q5: Can I use this for off-grid systems?
A: Yes, but you'll need to calculate your total daily power needs and account for battery storage and days of autonomy.