V. Di Dio

A mathematical model to determine the electrical energy production in photovoltaic fields under mismatch effect

Among the electrical energy production systems from renewable sources, the photovoltaic one represents today one of the most efficient and technically tested choice. In this paper the Authors present a mathematical model that allows the maximization of the generated power of photovoltaic (PV) plants under unequally radiation conditions.

Reconfiguration Techniques of Partial Shaded PV Systems for the Maximization of Electrical Energy Production

In this paper, the research of the optimal layout of photovoltaic (PV) modules in a PV array giving the maximum output power under different shaded working conditions is carried out. The particular condition of non uniform solar exposition of the modules is analyzed. The study of the different configurations has been carried out starting from a circuital model used for the design of PV cells and for the simulation of the working behavior of PV arrays. The attained results appear to be interesting although the complexity of the problem in mathematical terms is huge when the number of panels is high. Moreover, the results confirm that this approach often allows to attain a higher electrical energy production compared to that attainable with PV arrays with a static layout.

Energy and Economic Comparison of Different Conditioning System among Traditional and Eco-Sustainable Building

The use of bioclimatic principles can reduce energy demands and CO2 emissions in the building sector [1-. Costs are one of the most important barriers to a widespread adoption of the green architecture technologies [4-. The aim of this study is to compare the energy and economic performances of two buildings: a real residential bioclimatic building located in Cinisi (a small town near Palermo, Sicily) and an imaginary residential building supposed having the same geographical location, cubature, shape and orientation as the bioclimatic building but built by conventional building materials. The tools used for this study were TRNSYS and HOMER

Economical Incentives and Systems of Certification for the Production of Electrical Energy from Renewable Energy Resources

In order to succeed in observing the international agreements undertaken in the Kyoto agreement protocol, today it is necessary to increase the electrical energy production from renewables energy resources (RERs). In this paper a complete description of the Italian incentive systems for the production of electrical energy from photovoltaic (PV) and other RERs is done. Moreover, some considerations about the effects of the incentive actions on the wide spread of RERs to produce electrical energy are reported; particular attention is paid in the economical analysis related to PY and wind systems.

Economic analysis on dynamic photovoltaic systems in new Italian “feed in tariffs” context

Dynamic photovoltaic generators, based on the application of solar-trackers, are able to give an increment to the electric energy production from solar source. Their realization and maintenance costs are certainly higher than those of fixed ones. In this paper the Authors propose a method to estimate the increment of electrical energy generation that must be guaranteed by a dynamic photovoltaic generator, so as its realization could be more favorable with respect to that of a fixed generator one with the same rated power. This method, developed by means of classical economic indexes like the Pay-Back-Period and the Net Present Value, takes in to account the economic incentives for the PV systems. The method has been here performed on several numerical applications by considering different size of PV systems and of biaxial solar-trackers. Results report the possible advantages of the two PV plants type.

Integrated mathematical model of proton exchange membrane fuel cell stack (PEMFC) with automotive synchronous electrical power drive

In this work, the mathematical dynamical model of a PEMFC stack has been developed and implemented in Matlab environment. Lots of simulations have been executed in two different load conditions. Firstly with a resistive load and finally with a synchronous electrical power drive in automotive load conditions. The innovation in this field consists in the integration in PEMFC stack mathematical dynamic model of a synchronous electrical power drive one for automotive purposes. As regards the simulations with a synchronous electrical power drive, the complete mathematical model allows to evaluate the PEMFC stack performances and electrochemical efficiency. This represents a useful design tool.

Active power maximizing for Wind Electrical Energy Generating Systems moved by a Modular Multiple Blade Fixed Pitch Wind Turbine

This paper proposes a new solution for wind electrical energy generating system (WEEGS). The system here taken into account is moved by a modular multiple blade fixed pitch wind turbine (MMBFPWT) and foresees a new MPPT algorithm whose main characteristics are low cost, low noise, buildings simplicity and modularity. The mathematical model of the entire WEEGS has been here developed taking into account all the components starting from the wind turbine and ending with the electrical grid. The WEEGS mathematical model has been implemented in Matlab-Simulink in order to carry out the simulations needed to test the effectiveness of the proposed WEEGS. The simulations results show the effectiveness of both the designed MMBFPWT and the conceived MPPT algorithm.

A PV plant simulator for testing MPPT techniques

This paper introduces a versatile and reliable photovoltaic systems simulator. It includes the main components of a photovoltaic plant: a PV string and a PWM controlled boost chooper. The key feature of this simulator is the ability to consider different and non-uniform irradiation and temperature conditions (partial shading and partial heating of the strings). All the different I-V and P-V or P-I characteristics can then be determined in such non-uniform irradiation and temperature conditions, with the aim to try different MPPT algorithms. The simulator also allows to verify an enhanced version of the Incremental Conductance algorithm (IncCond) where, in order to reach the real absolute maximum power condition, the reference control current of the boost chopper are periodically reset to a given percentage of the short circuit current at standard conditions. After this perturbation, the steady state power values are registered and compared to establish the final value of reference current that allows the IncCond algorithm to reach a steady state at the real abolute maximum power transfer.

An electrochemical route towards the fabrication of nanostructured semiconductor solar cells

This work presents our preliminary results regarding an electrochemical process which allows the growth of nanostructured materials by means of nanopore templates. Also we analyze possible applications of this process to fabricate nanostructured semiconductors, such as CIGS, suitable for photovoltaic devices, and we consider the implications from the perspective of characterization techniques and device modelling when using such a technology.

A device for PV modules I-V characteristic detection

In this paper an electronic load suitable for the PV module I-V characteristic curve fast detection is presented. This device is designed in agreement with the IEC 82 Techinical Committee Standard since it allows the detection of the characteristic starting from voltage values even lower than 3% of the PV module open circuit voltage. The device main features are short time characteristc detection (2 s), limited ripple of the detected characteristic and low cost. Its validation is carried out by comparing measured data with data from simulations. Simulations are carried out considering two different commercial PV modules and by implementing in Matlab-Simulink environment the four lumped parameters PV cell mathematical model. This comparison sets the device is very reliable. Thanks to the device properties, the device allows the execution of experimental surveys directly on the premises, before the plant installation, optimizing the plants efficiency.