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A new concept of a system for Combined Heat and Power generation is presented. The concept is based on hybrid use of two renewable energy sources, direct solar (thermodynamic solar) and biomass (indirect solar energy). Biomass combustion is conducted using a fluidized bed combustor. A second source of energy, given by the direct irradiation of the bed with a concentrated solar radiation, is integrated in the same system, using the fluidized bed as solar receiver. A Stirling engine converts heat into mechanical power. A Scheffler type mirror is adopted to allow irradiation of the system in a fixed focal point. Advantages of the proposed solution are illustrated and some preliminary results on the performance of the system, obtained with a simple model, are presented. The principal improvements with respect to existing systems of similar size and primary energy source are illustrated. The most important are the enhanced heat transfer processes that are realized with the help of the fluidized bed, and the possibility of continuous cogeneration during the day. Different working conditions are considered to estimate the contribution given by the burning of fuel, in presence as well as in absence of sun irradiation (as during the night). The distribution of energy shares among the different flux contributes is reported versus the amount of biomass burned per unit time. The results clearly demonstrate the advantage of coupling, in the same system, two sources for heat generation, thus maintaining the option of producing electricity without the supply of biomass fuel.

In this paper we argue for the need to apply a cognitive approach to understand deep dynamics and determinants of technological evolutions. After examining main contributions from innovation studies to the conceptualization of innovation and change in complex socio-technical environments, we highlight the contribution coming from the application of the cognitive approach to evolutionary studies on technologies and we introduce the concept of technological memory as an interpretative tool to understand those changes. We discuss our hypothesis with reference to several observations carried out in different local contexts – Mexico, India and Italy – in relation to technological change in the water sector. In those cases deliberate attempts to substitute traditional technologies with modern ones led to interesting trajectories of change ranging from the collapse of old technologies to the development of multifaceted hybridization patterns. Tema. Journal of Land Use, Mobility and Environment, 2014: INPUT 2014 - Smart City: planning for energy, transportation and sustainability of the urban system

This work deals with an integrated solar PV/T hybrid air collector suitable for applications such as heating and drying of hay and industrial products. The main purpose of this study is to evaluate and optimize the thermal and electrical performances of this PV component and its integration system. A 2D mathematical model describing the thermal behaviour of the component is presented. The simulation values are compared to the measured data obtained under steady conditions on a solar PV/T air collector. Then, a description is provided regarding the in situ experimental studies which are carried out on three various models of the same component, in order to validate the thermal model previously developed. As further steps, various simulations will be performed on a drying system under a full building integration setup. 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 5150-5152

To take capillary effect into account, a series of primary drainage experiments of water by a sample oil fluid have been studied. The experiments performed under different low flow rates on a horizontal high pressure glass type micromodel as a model of porous media. Based on conventional macroscopic flow equations,the relative permeabilities and capillary pressure are determined by parameter estimation technique from history matching of saturation and pressure data of unsteady state immiscible displacements. The Coery type of relative permeability and capillary pressure functions are used. The results show that the end point relative permeability of oil phase and the dynamic term of capillary pressure function increase with flow rate, but the saturation exponent of relative permeability functions are decreasing with flow rate. Also the results show that the capillary pressure and relative permeability curves are rate dependent and the relative permeability curves are increasing with flow rate. Key Words: Rate Dependent,Relative Permeability,Capillary Pressure,Unsteady State, History Matching,Micromodel

MILD combustion is a very attractive technology in energy production from diluted gas deriving from bio or thermochemical degradation of biomass for its intrinsic features. An effective use of such a technology for diluted fuel needs a thorough analysis of ignition and oxidation behavior to highlight the potential effects of the different fuel components on the basis of temperature and diluent/oxygen/fuel mixture composition. In this work ignition and oxidation of a model gas surrogating the gaseous fraction of biomass pyrolysis products containing C1-C2 species, CO and CO2 were experimentally and numerically studied in a wide range of temperature and overall composition in presence of large amount of CO2 or H2O. Experimental results showed that such species significantly alter the evolution of the ignition process in dependence on temperature range and mixture composition. Several kinetic models were tested to simulate experimental results. Significant discrepancies occur especially in case of steam dilution. Numerical analyses suggest that such diluents mainly act as third body species at low temperatures, conditioning both radicals production pathways and the relative weight of C1 oxidation/recombination routes, while strongly interact with the H2/O2 high temperature branching mechanisms at high temperatures. Further analyses are mandatory to improve the model ability to reduce the discrepancy between numerical and experimental data obtained in non standard conditions.

This study focuses on the mapping of oxygen-related defects in industrial monocrystalline silicon wafers. All mappings were obtained solely from resistivity measurements and specific furnace anneals. An emphasis is given on the boron-oxygen complex responsible for the light-induced degradation (LID) of the carrier lifetime in boron-doped wafers. It is shown that the predicted values for the lifetime limited by the boron-oxygen complexes after complete degradation are in very good agreement with the experimental observations. It is also shown that the present technique is a valuable tool to predict the cell LID from measurements on as-received wafers, which is of paramount interest for wafer/cell manufacturers. 28th European Photovoltaic Solar Energy Conference and Exhibition; 902-906

Laser Grooved Buried Contact (LGBC) solar cell technology is an attractive way for the production of solar cells designed to operate at one sun. Although LGBC cells can have higher efficiency when compared to standard screen-printed solar cells, a more complex manufacturing process is required, increasing their relative costs. In the FP6 EU funded project “Lab2Line,” screen print and LGBC solar cell processing techniques are hybridized in order to produce lower cost high efficiency solar cells processed on large area mono-crystalline wafers, using techniques scalable to industry. Two hybrid approaches have been considered: in the first, screen-print (SP) is applied for both rear and front contacts; in the second process SP is applied only to the rear and then electroless plating is used to form the front contacts. Both Lab2Line hybrid approaches offer high average efficiencies with a small performance distribution, while simultaneously presenting a more compact, cost effective option to production. The combination of SP techniques with LGBC processes and electroless plating has led to a maximum efficiency of 17.34% for the first process and 18% (17.44% average on 171 wafers) for the latter. Modules having such cells result in FF of 79.0% and efficiency of 17.0%. 25th European Photovoltaic Solar Energy Conference and Exhibition / 5th World Conference on Photovoltaic Energy Conversion, 6-10 September 2010, Valencia, Spain; 1660-1664

The solar radiation is a critical input parameter when working with solar energy and radiation dependent surface processes. In this study, we present preliminary results from an inter-comparison between hourly values from a pyranometer, MSG-SEVIRI sensor and two meso-scale models, WRF and RAMS, in clear and cloudy sky conditions. Cloudy sky condition is the most important because the attenuation of solar radiation in the atmosphere is strongly dependent on the cloud variability. Bias and RMSE errors are evaluated at a coastal site in the Mediterranean area. These statistics show the tendency of both models to overestimate short-wave radiation.