The best rooftop solar pyranometer is easily the SMP22 from Kipp and Zonen. Boasting an incredible response time with exceptional accuracy the SMP22 is light years ahead of all other pyranometers.
However, at >$8000 the SMP22 doesn’t offer particularly good value to applications outside of high-level solar irradiance research. Even the largest of utility-scale solar farms would struggle to realise true value from the SMP22’s data.
Fear not, affordable and highly accurate alternatives that are ideal for rooftop solar monitoring are available. Which is best largely depends on the size of your panel array and budget.
When you have a larger budget, large solar array, and need a high degree of accuracy the SMP-10 pyranometer is a clear choice. It is the standard ‘go to’ pyranometer for utility-scale solar farms that need to conform to IEC 61724-1 standard. The fast response time and minimal drift allow complete performance calculations in almost real-time. However, even as rooftop solar arrays are increasing in size, it is unlikely the SMP-10 offers true value even for the largest facility.
Large solar arrays on rooftops are now reaching mW outputs. Consequently, full comprehension of the solar array’s output becomes a financially viable endeavor. More so when the facility largely relies on the output from the array for electricity. The SMP3 is a Class C pyranometer meaning it does not have the accuracy or response time of the SMP10. However, it is still incredibly accurate and will provide critical data to understand and compare a PV solar array’s performance. As the operating temperature range of the SMP3 is between -40°C to +80°C you can be sure it will withstand even the harshest of Aussie climates. The SMP3 has an RS-485 Modbus output. As such the SMP-3 is integratable to a SCADA system for real-time calculations. The SMP-3 would only be commercially viable for larger installations.
RT-1 – Rooftop Solar Panel Pyranometer with Back of Module Temperature Sensor
The RT-1 rooftop solar pyranometer has features specifically designed for monitoring rooftop array performances. Firstly, the RT-1’s unique design allows mounting to the corner of any make or model of solar panel, the clamping system ensures a snug and tight fit. Secondly, the back of module temperature sensor provides real-time panel temperature data. As panel temperature greatly affects output, such data is invaluable. As a final feature, the RS-485 Modbus output allows integration to SCADA systems. Best of all, RT-1’s provide high accuracy levels at a price where multiple sensor deployments across large sites are financially viable. In fact the RT-1 cost-effective for small to medium-sized commercial rooftop arrays.
If you would like more information on which pyranometer is best for your rooftop array then please do not hesitate to contact us.