What is Pyranometer in Solar Technology | New Topic [2024]

In this note, we are going to learn a topic called “What is Pyranometer in Solar Technology?”, its function and working principle as well. Welcome to Poly Notes Hub, a leading destination for polytechnic notes for diploma engineering students and as well as for engineering students.

Author Name: Arun Paul.

What is Pyranometer in Solar Technology?

A pyranometer measures total solar irradiance (TSI) or solar radiation flux density (W/m²) from the sun on a flat surface. It typically comprises of a flat sensor that absorbs solar energy and turns it into an electrical signal that the gadget subsequently measures. Pyranometers are widely used in meteorology, climatology, solar energy research, and environmental monitoring to better understand sun radiation levels and patterns throughout time. They play an important role in evaluating solar energy resources for a variety of uses, including solar power generating, agriculture, and construction.

Functions of Pyranometer

A pyranometer measures solar radiation flux density (W/m²). This measurement aids in understanding the quantity of solar energy that reaches a given point on Earth’s surface. Pyranometers are used for:

• Quantify Solar Irradiance: Pyranometers provide precise measures of sun irradiance, assisting researchers, meteorologists, and engineers in determining the availability of solar energy at a certain area.
• Solar Energy Assessment: They are critical in determining a site’s solar energy potential for purposes such as solar power generating, heating, and cooling.
• Climate and Weather Studies: Pyranometer data is used in climatology and meteorology to track long-term patterns in sun radiation and better understand its influence in climate dynamics.
• Agricultural and Ecological Research: Pyranometers capture solar radiation data, which is used to research plant growth patterns, agricultural yields, and sunlight-influenced ecological processes.
• Building Design and Efficiency: Pyranometer data helps designers create more energy-efficient buildings by maximizing the orientation and positioning of solar panels, windows, and other sun-sensitive elements.

Pyranometer Working Principle

Pyranometers are commonly used to measure the flux density of solar radiation using the thermoelectric effect or photovoltaic effect. This is how each kind functions –

1. Thermoelectric Pyranometer: Thermoelectric pyranometers use a thermopile sensor comprised of numerous thermocouples connected in series. Thermocouples are junctions of two dissimilar metals that produce electricity when subjected to a temperature gradient. When solar energy is absorbed by the sensor’s surface, it heats up, resulting in a temperature difference between the thermocouple’s hot and cold junctions. The temperature difference produces a tiny voltage output that is proportionate to the solar radiation flux density. The output voltage is then calibrated to ensure an accurate measurement of irradiance.
2. Photovoltaic Pyranometer: In order to directly measure solar irradiance, photovoltaic pyranometers use photovoltaic cells, which directly convert solar radiation into electrical energy. When sunlight strikes the surface of the photovoltaic cell, it generates a current proportional to the intensity of the solar radiation, which is then measured and calibrated.

Advantages of Pyranometer

Below we listed some pyranometer advantages –

• Measurement of solar radiation flux density with accuracy.
• For use in solar energy, agriculture, meteorology, and other fields.
• Monitoring in real time to analyze data right away.
• Analysis of long-term trends for studies on the environment and climate.
• Natural ecosystems are preserved by non-intrusive measurement.