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33rd European Photovoltaic Solar Energy Conference and Exhibition; 2164-2170, The integration of high shares of variable renewable energy sources is becoming more and more challenging. The main options to achieve this task are the enlargement and reinforcement of the grid, the use of storage devices, and demand-side management. In this work, a multi-nodes modelling approach has been implemented to study the current situation of the Italian electric system. After evaluating the potentialities of variable renewable energy sources such as photovoltaic and wind power in terms of new installation and overall installed power, different scenarios have been developed. The final aim is to compare the single-node to the multi-nodes approach and to study the role of pumped hydro storage system as existing storage solution in Italy. At the increasing of the renewables generation, the results show the benefits in using the multi-nodes more complex methodology compared to the singlenode one. Considering the overall potential of Italian variable renewable generation within the system, the single-node model presents an under-estimation of the curtailments of about 7% and thus an over-estimation of the percentage of renewables in the system equal to 6.6%. The already installed power of pumped hydro storage allows for a better integration of renewables and highlight its central role in increasing the percentage of renewable electricity consumption.

31st European Photovoltaic Solar Energy Conference and Exhibition; 2784-2788, This paper analyzes the energy supply system of the municipality of Bressanone, province of Bolzano, studying renewable energy sources (RES) high penetration scenarios. Particularly, the benefits from the increase of photovoltaic installed power and high and low efficiency storage devices were evaluated. Firstly, the reference scenario was built using energyPLAN, system analysis tool based on energy consumption and production data for the year 2010. Three different scenarios were then produced and compared, with the reference system, on few parameters: renewable energy integration, carbon dioxide emissions and economic costs. The results show that an increase of photovoltaic capacity up to 20 MW (approximately 1 kW/person) produces an improvement of all the evaluating parameters: increases RES integration, reduces CO2 emissions and slightly decreases annual economic costs. The threshold of 50 MW of photovoltaic rooftop potential capacity in Bressanone – filtered for insolation level and historical city center - could be reached with an increase of annual economic costs. In order to further improve renewable energy integration and CO2 emissions, scenarios with different installed capacity of storage and different round-trip efficiency were thus investigated.

26th European Photovoltaic Solar Energy Conference and Exhibition; 3991-3999, The building envelope could be conceived not only as a passive solution, but also as an active system able to contribute to satisfy electricity demand if a PV system is integrated in it. Anyway, costs represent still a barrier for the use of PV as a common building material [1]. The prefabrication of an envelope component that integrates PV system could reduce the costs and, at the same time, enhance the overall quality and the energy performance. In this context a concept of an innovative prefabricated wooden façade component with integrated PV, has been conceived and developed. It is a multifunctional component constituted by three main layers: a structural part of framed wood panel with thermal insulation, an air gap for the natural ventilation and the PV system. The optimization of its energy performance was the objective of this research activity, which considered both the PV production and the impact of the component on the building energy balance. The methodology used to optimize the configuration of the prototype was a parametric analysis considering the following parameters as independent variables: the PV technology, the ventilation as well as the thickness of the air gap, the heat exchange features and the materials applied. The analysis considered as dependent variables the PV efficiency, i.e. the module’s temperature, which was evaluated through thermal energy simulations and the value of the thermal transmittance, which was assessed both through calculation and experimental campaign. The component prototype was tested in a calorimeter, part of Eurac indoor test facilities, to measure its steady-state thermal transmission properties. Then it will be installed in a prototypical building for an elementary school, which is entirely realized with prefabricated wood framed panels. This will allow to monitor the energy performance of the prototype working under real conditions and also to monitor its energy impact on the building fabric, providing a deeper understanding on the energy interaction between integrated PV and the building envelope.

26th European Photovoltaic Solar Energy Conference and Exhibition; 4265-4268, This paper presents monitoring results over a 8-month period of time for different thin-film photovoltaic (PV) technologies installed at the multi-technology rack-mounted PV test field at the Airport of Bolzano Dolomiti (ABD) in the Italian Alps. In the evaluation, different technologies were cross-compared: amorphous silicon (a-Si), copper indium gallium diselenide (CIS/CIGS) and micromorph silicon (a-Si/μ-Si). The various thin-film technologies were compared according to their performance ratio. Additionally the modules behavior were compared with those of the best crystalline Si (c-Si) in the field. The presented results refers to DC values. The PV modules were evaluated in relation to meteorological data registered on-site.

25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 4344-4349, This paper describes the details of the new multi-technology ground-mounted photovoltaic (PV) field installed at the Airport of Bolzano Dolomiti (ABD) in the Italian Alps. The plant, owned by ABD and developed with a co-financing of the European Regional Development Fund (ERDF), is divided into two main parts: a 662 kW commercial installation, mounting 8538 CdTe modules First Solar 277, and a 62 kW experimental installation, mounting 24 different types of modules, divided into 39 groups ranging between 1 and 2 kW each. In this experimental installation the modules are mounted on fixed racks, as well as on mono-axial and bi-axial active trackers. EURAC Research is the scientific responsible of this test facility and follows the monitoring and test activities to evaluate the performance and the lifetime degradation of the modules. The aim of the monitoring activity is to allow a better understanding of module loss mechanisms for each technology and evaluating the performance in the alpine climatic conditions. The PV modules are evaluated in relationship to meteo data from an on-site station, counting a sensor for ambient temperature, an anemometer, a pyrheliometer, three pyranometers, an albedometer and also a sun photometer which allows evaluating the influence given by aerosols, ozone and vapors in the atmosphere to the irradiance. PV reference cells are also used, mounted horizontally, on the module plane, and on the two trackers. The PV plant has been connected to the MV network on August 10, 2010, and it is presently in course of approval by GSE (Gestore Servizi Energetici) for the incentive scheme in force. Monitoring results can be presently shown only for a couple of days for a limited number of groups.

25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 5131-5134, This paper presents the monitoring results of a PV system integrated into the façade of an office building situated in the city center of Bolzano (Italy). Data regarding PV production, climatic characteristics and module temperature have been collected for a six months period. The temperature reached by the modules is, as expected and confirmed by monitored data that registered a peak of 57.4°C, one critical aspect of this BIPV system since it is integrated into the façade without ventilation. Simulations show that, considering one single day, ventilation of the modules could enhance the power production of 3.5%. In order to verify the correspondence between simulations and monitored values, a comparison considering one single day was carried out: the mathematical model used by the software for simulations, manages to predict the PV array irradiation and the average temperature of the modules with good accuracy (respectively -2% and +0.2%), while the power production is strongly underestimated (-20%).This could be due to several reasons that are discussed in the paper.

24th European Photovoltaic Solar Energy Conference, 21-25 September 2009, Hamburg, Germany; 4256-4258, A typical problem of retrofit BIPV systems is the power loss due to the temperature increase because the modules are often installed next to another surface. A way to decrease the temperature value of the module and thus of the cell is to allow natural convection underneath the modules, leaving a gap between the PV system and the other surface. The case study of a retrofit PV roof integration was analyzed and monitored. In order to understand the influence of modules arrangement on temperature distribution, several simulations were carried out. The results show that the distance between module arrays do not affect the temperature values in any significant way.

23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 3126-3128, This paper presents monitoring data and performance results of 12 photovoltaic systems installed in South Tyrol, which are based on different technologies, mainly crystalline and CdTe modules, and various dimension, from few kWp to more than 800 kWp. The target of the monitoring is an evaluation of performance ratio of the different systems, under the real regional climatic condition, for the benefit of installers and final users, and the collection of data to allow a better understanding of loss mechanisms. This paper summarizes 18 months of monitoring results. The monitored data include current from the PV array, array voltage, AC power delivered, global horizontal irradiance and ambient temperature, obtained from 26 weather station scattered on the region, and array temperature. The purpose of this work is to compare and to present operational performance results of grid-connected PV systems, as collected and elaborated for the project CoPES; a cooperation project between applied research institutions and several SMEs. The obtained results were used mainly as a feedback for the industry concerned with installation; besides that, selected results were used as a reference parameter for the validation of a new code for the efficiency prediction modeling of a PV module operating in outdoor conditions.

23rd European Photovoltaic Solar Energy Conference and Exhibition, 1-5 September 2008, Valencia, Spain; 3170-3173, This paper will present measurement results of small shadows on photovoltaic modules by different technology, using a test field installed on a roof. The three photovoltaic systems, which compose the test field, have the same peak power of 1 kWp and identical horizontal inclination and sun orientation, but are based on different technologies. In fact one is based on polycrystalline silicon modules, one is based on CdTe modules and one is based on hetero-junction with intrinsic thin layer solar modules. The measurement’s principle is to cast artificial shadow on the solar system during its functioning, in order to simulate the influence of shading objects. By same solar irradiation and shade area on solar system the measurement data will includes array voltage, array current and AC delivered power and will be repeated for each small system by different area. In addition to the results from this test center, some monitoring data from a commercial PV plant will be used. The roof, where the plant was installed, presents some problems caused by shading elements near the solar system. The purpose of this project is to allow a better understanding of small shadow effects on the performance ratio of PV systems. The obtained results will be a valuable aid to the PV installer of photovoltaic systems to understand the real effect of shadowing element on existing plants, which do not have optimal sun exposure conditions and to predict the consequence of shading on the electrical production by solar systems in planning.