Solar Irradiance Meters

Solar irradiance meters are portable instruments that measure the intensity of solar radiation striking a surface, typically expressed in watts per square meter (W/m²). They are an essential tool for solar energy professionals, enabling accurate assessment of the solar resource at a given location and time. By comparing measured irradiance with actual panel output, engineers can determine whether a PV system is performing as designed or identify underperformance caused by shading, soiling, module degradation, or wiring faults.

These instruments typically incorporate a calibrated photodiode or thermopile sensor matched to the solar spectrum, often paired with data logging capability for trend analysis and reporting. Many models also measure cell or ambient temperature, which together with irradiance allows calculation of the Performance Ratio (PR) — the key metric used in PV system evaluation, yield analysis, and warranty verification.

Typical Applications

Solar site surveys to assess resource availability and expected annual energy yield
Commissioning measurements to validate PV system output against design projections
Ongoing performance monitoring and benchmarking of operating PV plants
Input data for I-V curve analysis and performance ratio calculations
Field quality control and verification checks during solar panel installation
Research and development in solar energy resource assessment

Popular Brands

Seaward integrates irradiance measurement capability into their solar site survey tools and test kits. Fluke offers irradiance sensor accessories compatible with their solar clamp meter range. Specialist manufacturers such as Apogee Instruments and Delta-T Devices supply high-accuracy pyranometers and reference solar cells for research-grade and meteorological irradiance measurement in accordance with ISO 9060 standards.