Keeping solar panels clean is the only way to ensure that they function effectively. Dust, dirt and other assorted debris can block the sunlight that solar panels rely on to deliver power. Dirty solar panels can lead to a reduction in performance of up to 25% as well as potentially causing hot spots that damage cells. To assist in the quick monitoring of solar panels for dirt, Senseca has introduced their Dust Fall Monitoring System (MDFS) which has been designed to alert control centre operators at photovoltaic solar farms and other commercial developments utilising solar panels as to when their panels need to be cleaned.
“The MDFS system is easily added to the solar panel control system and compares the radiation collected by two-compensated reference cells with outputs either in voltage (Model MDFS2) or Modbus protocol (Model MDFS2-S). One cell (Clean Cell) must always be kept clean, while the other (Dirty Cell) is cleaned at the same time as the PV panels“ said Jan Grobler, Managing Director of Senseca South Africa.
“The device enables a quick identification of dirty solar panels which ensures that any drop in the performance of the panels is rectified timeously. The device is compact, lightweight and easy to install to existing systems“ said Grobler.
The MDFS can be used in two ways:
- Basic Mode: when manually comparing the Clean and Dirty cell readings, the operator can decide when cleaning is needed. In this mode, the Control Box is not required.
- Advanced Mode:Â with the optional Control Box, the system automatically calculates the soiling attenuation rate (%) of the PV panels. This value can be used directly to decide if cleaning is necessary whilst providing confirmation that cleaning and other maintenance tasks have been performed.
The MDFS system provides five data channels: sun elevation, clean solar cell rad, dirty solar cell rad, MDFS status and attenuation. Both the MDFS2 and MDFS2-S offer a measurement range of 0 to 1400 W/m2 , operating temperatures of -20 o C to + 60 o C and warning, pairing instruction via digital outputs, whilst the MDFS2 offers a measurement error of +- 2.1% the MDFS2-S offers a +- 2.2% measurement error.
The Data Acquisition System (DAS) model METEODATA-4000 collects the solar radiation gathered by the lean Reference Cell and the Dirty Reference Cell and additional information regarding tasks performed at the field sensed by the Control Box. This is all utilised in the calculation of attenuation due to soiling. The data collected by the DAS is recorded in a SQL Server installed in a Data Collection Centre where it is accessible to be displayed and exported to Excel files. “The MDFS is a welcome addition to the Senseca product range of environmental monitoring instrumentation, which we believe will assist in ensuring that PV farms and large commercial solar panel installations are running optimally at all times“ said Grobler.
