The Term "Solar Simulation" and Definition
Solar simulation refers to the artificial replication of sunlight in the laboratory to test materials, systems, and processes according to standards. Two main types are distinguished:
- Optical/Physical Solar Simulation – using lamps and illuminator systems (the focus here).
- Computer Simulation – software-based calculation of energy yields for PV systems.
Aims and Applications
- Materials Testing:: Resistance to UV, visible, and IR radiation.
- Photovoltaics: Standard-compliant testing of solar cells and modules (efficiency, aging).
- Automotive: Climate chamber and solar roof tests.
- Life Sciences: Photobiological experiments, skin protection product testing.
- Photochemistry: Degradation and reaction studies.
Basics: Spectrum and Radiation Characteristics
| Range | Wavelength(nm) | Effect on materials |
|---|---|---|
| UV-C | 100–280 | Strong photochemical effect, rapid material aging |
| UV-B | 280–315 | Color change, polymer degradation |
| UV-A | 315–400 | Long-term degradation, visual aging |
| Visisble | 400–780 | Color appearance, photometry |
| Infrared (IR) | 780–4000 | Heat exposure, expansion, stresses |
Technical Implementation of the Solar Simulation
Light Sources:
- Xenon Lamps – best spectral approximation to sunlight (AM1.5G).
- Metal Halide Lamps (RSI/HRI) – high efficiency, large-area illumination.
- LED Systems – spectrally tunable, long lifespan.
- High-Pressure UV Lamps – targeted components for UV exposure tests.
Optical Elements:
- Filters (for spectral matching)
- Collimators (for homogenizing the radiation)
- Reflectors (for increasing power)Optische Elemente:
Performance parameters:
| Parameter | Significance | Standard requirement (IEC 60904-9) |
|---|---|---|
| Spectral match | Deviation from the reference spectrum | ≤ ± 25% per wavelength band (Class A) |
| Homogeneity | Uniformity across the test area | ± 2% (Class A) |
| Stability | Fluctuation over time | ≤ ± 2% in 10 min (Class A |
Classification according to standards
Example: IEC 60904-9 & ASTM E927
| Class | Spectral match | Homogeneity | Stability |
|---|---|---|---|
| A | ≤ ±25 % | ≤ ±2 % | ≤ ±2 % |
| B | ≤ ±40 % | ≤ ±5 % | ≤ ±5 % |
| C | ≤ ±60 % | ≤ ±10 % | ≤ ±10 % |
Tip: For photovoltaic testing, class A+A+A+ is recommended to achieve the highest accuracy.
Image Comparisons (Suggestions for Visual Content)
- Sunlight Spectrum vs. HRI Lamp – Diagram showing spectral power distribution (AM1.5G vs. HRI).
- Test Setup in a PV Climate Chamber – Photo of a chamber with an HRI lamp array.
- Homogeneity Test – Thermal image or lux meter mapping of the test area.
Advantages over Field Tests – Reproducibility
- Accelerated Aging
- Standard Compliance
- Combinability with Temperature, Humidity, Altitude
Conclusion
Solar simulators are essential for research, development, and quality assurance. With standard-compliant spectral quality, homogeneous irradiation, and high stability, they deliver reliable results – from PV module testing to material aging analysis. Radium TECH offers lamp systems such as HRI and Suprasol-HTC emitters, which are used for standard-compliant solar simulation.