Each system is comprised of polycrystalline photovoltaic modules with a performance peak of approx. 200 Watts which can produce differing results depending on their mounting location and module strands The direct current produced by the modules is converted to network-standard alternating current using a solar inverter and fed into the EVN network.

Four different subsystems have been installed in the reactor building, which differ in terms of their power rating and direction relative to the sun in order to supply significant performance data for different photovoltaic plants.
In addition, two further photovoltaic systems were installed in the open ground around the reactor building which primarily consist of a fixed, elevated solar park, as well as two dual-axle solar sails. These two subsystems can research and document the behaviour of optimally-positioned PV systems. Just as in the reactor building, the direct current generated here is converted into network-standard alternating current and fed into the 20kV EVN network.

Rudolf Berthold Ges.m.b.H supplies the required data collection system:
The aim of this project is to collect, save, present and transfer a large range of measured data from the plant and its differing configurations to produce continuative analysis and research of the behaviour of such systems. The following measurements and data are collected by the system. The system can be controlled directly on site in Zwentendorf using a research control panel and also via a comprehensive web-based internet control and monitoring system. All of the data saved from the inverter and the weather station, as well as the permanently-installed oscilloscopes with transient recorders can be accessed, exported and loaded via the web.

Weather data

The Davis Instruments, Vantage Pro II weather station is located in the open ground of the site. The weather station collects all relevant weather data for the operation of the photovoltaic plant such as temperature, humidity, wind speed, wind direction, solar irradiation, precipitation, etc.
The data is read by our software system via a network connection to the VantagePro station and transferred in cycles to a central SQL database for subsequent display and analysis.

Performance data from inverters

All inverters in the system require a serial connection which the systems can use to both communicate with each other and transmit data using an interface box supplied by the manufacturer.

This interface box is connected to the measurement data collection system using an integrated RS232 interface. The reprogrammable collection software is then able to collect all of the performance measurement data from each individual inverter and save it to the SQL database in the required form for further processing and display.

Performance measurement from direct measurements
In order to provide comparisons of results on the one hand, and also analysis of reactive current and performance on the other hand, all subsystems and inverters for direct current on the input side and all performance measurements (effective power, reactive power, apparent power) are determined additionally using measuring instruments.
These measurement values can then be compared to the other, non-measured, inverter values of similar plant types at any time.

Surface temperature measurement

In addition to weather data, the surface temperature of a number of selected solar panels is also measured. In order to achieve this, Pt100 heat sensors are integrated into the panels an connected to the analogue input components in the measurement data collection system by means of three-wire input.

Energy counter

Counter inputs are used at all supply points to measure the impulses per KWh that are fed into the electricity network.
The visualisation system displays the reading results as an overall counter for each subsystem and as an overall counter for the entire plant.
The measurement data collection system collects a total of more than 555,000 measurement values per hour, visualises them and makes them available in compressed form for further analysis.

If you have any questions concerning measurement data collection for photovoltaic plants, please feel free to contact us: Contact