RT1 Rooftop PV Monitoring Sensor

The RT1 has both a pyranometer and back of module temperature sensors to measure solar irradiance and temperature.

It is an affordable monitoring system for commercial rooftop PV panel installations. Ideal when panel monitoring is critical but an SMP or CMP pyranometer is not cost-effective.


  • Designed to fit on all rooftop solar panels
  • Monitors solar irradiance and BOM temperature
  • ISO 9060 Class C performance
  • RS-485 Modbus output
  • Affordable solution for commercial rooftop installation


RT1 rooftop solar monitoring sensor

The RT1 is an affordable rooftop solar monitoring sensor designed for large rooftop solar panel arrays. It has both a pyranometer to measure solar irradiance and a temperature probe that monitors the back of panel temperature.

It is possible to install an RT1 onto a corner of every type of rooftop solar panel. As it is fitted on the corner the RT1 will measure the plane of array irradiance.

The RS-485 Modbus output allows integration into any SCADA or monitoring system. With the information and integration, operators are able to assess the solar array’s actual output against the expected output. The RT1 is ideal for planning solar panel cleaning.

Commercial-scale rooftop growth

The size of commercial-scale rooftop solar arrays is rapidly growing, some arrays are the size of small utility-scale solar farms. Unlike utility solar farms, performance monitoring has not always been a commercial priority. For most rooftop solar installations it would not be cost-effective to install a pyranometer such as an SMP6 or SMP10. However, with the RT1 operators can gain an understanding of their panel’s output, allowing them to plan and schedule panel cleaning and maintenance checks.

Irradiance 0 to 2000 W/m²
Resolution W/m2 1 W/m2
Spectral range (overall) 400 to 1100 nm
Non-stability (change/year) < 1 %
Non-linearity (0 to 100 W/m²) < 1 %
Operating temperature -40 to +80 °C °C
Calibration Against traceable reference pyranometer
PV panel temperature -20 to +100 °C, ± 1 °C
Power supply 5 to 30 VDC
Power consumption 60 mW
RT1 Rooftop Solar monitoring sensor Downloads: