Free-form surface-based polar-axis rotational direct solar radiation spectrum measurements

Area of Science:

• Atmospheric Science
• Climatology
• Solar Energy
• Agriculture

Background:

• Accurate direct solar radiation spectra are vital for multiple scientific and industrial fields.
• Current measurement systems often rely on expensive dual-axis trackers, leading to high costs and potential errors.

Purpose of the Study:

• To develop and validate a novel solar direct radiation spectrometer.
• To enable accurate, year-round spectral measurements across all latitudes without mobile tracking.

Main Methods:

• A free-form surface-based polar-axis rotating spectrometer was designed and implemented.
• The system operates in the 380-780 nm spectral range with a resolution better than 2 nm.
• Simulations and outdoor experiments were conducted for validation.

Main Results:

• Simulation results showed spectral curve area errors ranging from 0.68% to 1.22%.
• Outdoor experiments in Changchun, China, validated the system's accuracy against the AM1.5 G standard.

Conclusions:

• The developed spectrometer provides accurate direct solar radiation spectral measurements.
• The system eliminates the need for mobile tracking, offering a cost-effective and reliable solution for diverse applications.