LI-200R Pyranometer Performs Well in NREL Solar Radiation Assessment Tests

LI-200R Pyranometer Performs Well in NREL Solar Radiation Assessment Tests

Prior to the official product launch, LI-COR provided the National Renewable Energy Laboratory (NREL) with a set of LI-200R Pyranometers for their long-term solar radiation measurement project. The LI-200R is based on the proven LI-200 Pyranometer, but with a more robust cable and an improved seal against water vapor. The sensor is also detachable from the base/cable, simplifying installation and removal. Click here for a detailed comparison between the old and new sensor designs. 

NREL is a US government research facility that focuses on energy R&D and has among the highest standards for solar radiation measurement and instrument calibration accuracy in the world. They have a facility called the Solar Radiation Research Laboratory (SRRL) which facilitates a program called the Baseline Measurement System (BMS) for radiation sensors. 

As of April, 2015 the LI-200R Pyranometer has been deployed alongside other sensors at the BMS site. It wasn’t until last August that the sensor was labeled as the “LI-200R”, with data freely accessible and publicly viewable from the NREL SRRL website: 

You can identify, access, view, and download datasets from a variety of sensors, and even plot data using the web interface. Below is an example of a daily irradiance plot made using the NREL data viewing tool.

NREL plot
Daily irradiance as measured by the Eppley PSP, LI-200R, and LI-200 pyranometers, showing close agreement between the three. Source: NREL Solar Radiation Research Laboratory, Baseline Measurement System (

The LI-200R has provided excellent irradiance measurements when compared to the LI-200 (also at the NREL BMS site) and other more expensive designs, including the Eppley PSP.

Find out more about the NREL trials at

For more information about using the LI-200R Pyranometer for solar energy applications, visit

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