1. What Is Insolation?

Insolation refers to the amount of solar radiation energy received on a given surface area in a given time. It represents the power per unit area received from the Sun in the form of electromagnetic radiation.

2. How Does The Calculator Work?

The calculator uses the insolation formula:

Where:

• \( Solar\ Constant \) — Solar radiation received at top of atmosphere (1366 W/m²)
• \( zenith \) — Angle between the Sun and the vertical direction (0° = overhead, 90° = horizon)
• \( \cos(zenith) \) — Cosine of zenith angle, representing the reduction due to angle

Explanation: The formula calculates the solar energy reaching a horizontal surface, accounting for the angle of incidence. When the Sun is directly overhead (zenith = 0°), insolation is maximum. As the zenith angle increases, insolation decreases.

3. Importance Of Insolation Calculation

Details: Calculating insolation is crucial for solar energy system design, agricultural planning, climate studies, and understanding Earth's energy balance. It helps determine optimal solar panel placement and predict energy production.

4. Using The Calculator

Tips: Enter solar constant (typically 1366 W/m²) and zenith angle in degrees (0-90). The calculator will compute the insolation in watts per square meter. Zenith angle of 0° gives maximum insolation, while 90° gives minimum.

5. Frequently Asked Questions (FAQ)

Q1: What is the solar constant?
A: The solar constant is the amount of solar electromagnetic radiation per unit area that would be incident on a plane perpendicular to the rays, at a distance of one astronomical unit from the Sun (approximately 1366 W/m²).

Q2: How does zenith angle affect insolation?
A: As zenith angle increases, the same amount of solar energy spreads over a larger surface area, reducing the energy per unit area according to the cosine law.

Q3: What factors affect actual surface insolation?
A: Atmospheric absorption, scattering, cloud cover, altitude, and surface reflectivity all affect the actual insolation reaching the Earth's surface.

Q4: When is insolation maximum during the day?
A: Insolation is maximum at solar noon when the Sun is highest in the sky (smallest zenith angle) and decreases toward sunrise and sunset.

Q5: How is this used in solar energy applications?
A: This calculation helps determine optimal tilt angles for solar panels, estimate energy production, and design efficient solar energy systems.