Fluctuations in the output of a photovoltaics plant can occur for a range of reasons, and these are considered to be an inevitable phenomena. These fluctuations risk lost time and money for plant operators, while the underperformance of power plants may lead to the imposition of penalties.

Image Credit: OTT HydroMet - Solar Energy
Making an accurate comparison between a plant’s estimated power output and its actual performance requires the precise on-site measurement of all relevant meteorological parameters. Tools must be in place to measure current solar irradiance, actual temperature, humidity, wind speed and wind direction.
Key Factors
The case study presented here looks at work with Trimark Associates, Inc. - a global leader in the provision of metering, SCADA and energy storage technology solutions. The company outlined how its operatives were able to utilize data from on-site meteorological measurements to facilitate the remote operation of PV plants.
Data Scientist Matthew Kesselring considers the two most vital questions in terms of assessing the performance of a PV plant:
- How much energy is a site producing?
- How much should the site be producing?
Trimark shares energy and meteorological data from the Riverside plant in Southern California. This data clearly showcases the value of on-site measurement.
The company collected two sets of data in different weeks, highlighting that the energy produced differs from the estimated energy output between each week.
Data from the on-site measurement of microclimate parameters can then be used to explore and analyze these differences.
This allows the plant operator to assess the presence of technical issues which require technical support, soiled panels which require cleaning or whether these differences are as a result of shifting weather and environmental factors.
Kipp & Zonen have provided a series of case studies exploring these issues. These case studies highlight how reliable real-time data helps plant operators evaluate the cause of an unexpected drop in power output, such as whether this requires immediate action to minimize production losses or simply a temporary issue.
Acknowledgments
Produced from materials originally authored by Martin Maly from OTT HydroMet.

This information has been sourced, reviewed and adapted from materials provided by OTT HydroMet - Solar Energy.
For more information on this source, please visit OTT HydroMet - Solar Energy.