'''Abstract'''

The aim of this paper is to introduce a system developed for monitoring PV solar plants using a novel procedure based on virtual instrumentation. The measurements and processing of the data are made using high precision I/O modular field point (FP) devices as hardware, a data acquisition card as software and the package of graphic programming, LabVIEW. The system is able to store and display both the collected data of the environmental variables and the PV plant electrical output parameters, including the plant I–V curve. A relevant aspect of this work is the development of a unit that allows automatic measuring of the solar plant I–V curve using a car battery as power supply. The system has been in operation during the last two years and all its units have functioned well.

'''Abstract'''

In order to analyze the performance of photovoltaic systems, we develop a real time expert system based on central microcomputer used as microserver and easily consultable with different automatic stations. So, we present in this communication the principles and specificities of the measurement systems and specially of the automatic data measuring device and its sensors and also some aspects of the database and expert system developed for this application.

'''Abstract:'''

In this paper, a solar photovoltaic (PV) performance monitoring system is introduced by utilizing a wireless Zigbee microcontroller. The proposed system can be used to monitor the performance of an array of PV panels to detect non-ideal operating conditions. Various studies have shown that significant reductions in power output and degradation of the performance of Maximum Power Point Trackers (MPPT) are possible under non-ideal conditions. Hence, monitoring and detection of non-ideal conditions is a critical issue in PV modules. In this paper we present the development of a low-cost small form factor electronic hardware consisting of a wireless Zigbee-enabled microcontroller. The system consists of a back end embedded program and a front end graphical user interface (GUI) that can provide remote monitoring of voltage, current, and power for an array of PV modules. The results of implementation on a proof-of-concept testbed consisting of two embedded controllers installed on two PV modules are presented. The experimental results indicate that the proposed system can provide a low-cost and reliable performance monitoring system for small and large scale PV power plants.

'''Abstract:'''

Data-acquisition systems are widely used in renewable energy source (RES) applications in order to collect data regarding the installed system performance, for evaluation purposes. In this paper, the development of a computer-based system for RES systems monitoring is described. The proposed system consists of a set of sensors for measuring both meteorological (e.g. temperature, humidity etc.) and electrical parameters (photovoltaics voltage and current etc.). The collected data are first conditioned using precision electronic circuits and then interfaced to a PC using a data-acquisition card. The LABVIEW program is used to further process, display and store the collected data in the PC disk. The proposed architecture permits the rapid system development and has the advantage of flexibility in the case of changes, while it can be easily extended for controlling the RES system operation.

'''Abstract:'''

The Guidelines for the Assessment of Photovoltaic Plants provided by the Joint Research Centre (JRC) and the International Standard IEC 61724 recommend procedures for the analysis of monitored data to asses the overall performance of photovoltaic (PV) systems. However, the latter do not provide a well adapted method for the analysis of stand-alone photovoltaic systems (SAPV) with charge regulators without maximum power point tracker (MPPT). In this way, the IDEA Research Group has developed a new method that improves the analysis performance of these kinds of systems. Moreover, it has been validated an expression that compromises simplicity and accuracy when estimating the array potential in this kind of systems. SAPV system monitoring and performance analysis from monitored data are of great interest to engineers both for detecting a system malfunction and for optimizing the design of future SAPV system. In this way, this paper introduces an online monitoring system in real time for SAPV applications where the monitored data are processed in order to provide an analysis of system performance. The latter, together with the monitored data, are displayed on a graphical user interface using a virtual instrument (VI) developed in LABVIEW ®. Furthermore, the collected and monitored data can be shown in a website where an external user can see the daily evolution of all monitored and derived parameters. At present, three different SAPV systems, installed in the Polytechnic School of University of Jaén, are being monitorized and the collected data are being published online in real time. Moreover, a performance analysis of these stand-alone photovoltaic systems considering both IEC 61724 and the IDEA Method is also offered. These three systems use the charge regulators more widespread in the market. Systems #1 and #2 use pulse width modulation (PWM) charge regulators, (a series and a shunt regulator, respectively), meanwhile System #3 has a charge regulator with MPPT. This website provides a tool that can be used not only for educational purposes in order to illustrate the operation of this kind of systems but it can also show the scientific and engineering community the main features of the system performance analysis methods mentioned above. Furthermore, it allows an external user to download the monitored and analysis data to make its own offline analysis. These files comply with the format proposed in the standard IEC 61724. The SAPV system monitoring website is now available for public viewing on the University of Jaén. (http://voltio.ujaen.es/sfa/index.html).

'''Abstract:'''

An inductive current measuring sensor is provided comprising several coils connected electrically in series and disposed in a polygonal contour, so as to surround the conductor on which it is desired to measure the current. Each coil comprises windings disposed on an insulating bobbin and connection elements. The bobbins are disposed on the face of a printed circuit having a central recess through which the conductor may pass. The printed circuit carries conducting tracks interconnecting the fixing points of the connection elements together and to external connection members.

'''Abstract:'''

Many homeowners and occupants are interested in energy conservation for economical and/or ecological reasons. A number of commercial energy conservation solutions exist on the market today. However, these products contain closed systems and do not provide easy access to much of the raw data needed for more sophisticated analysis. An open source solution would be a great benefit for homeowners and occupants, allowing access to (and custom analysis of) raw power readings. We present a complete open source solution that monitors power, stores raw power readings, and makes provision for an in-home display, that informs stakeholders about energy consumption through a real-time ambient feedback effectively becoming an eco-feedback device.