Energy performance of concentrator and flat plate photovoltaics in the mediterranean area
A comparative analysis of the energy production of a High Concentrator Photovoltaic (CPV) and a flat plate amorphous photovoltaic (PV) plants, installed in the same place in the southern Italy, is presented. This analysis aims at providing reliable production values of CPV based on a long term monitoring with reference to this specific geographic zone. The daily normalized power production in different weather conditions is presented and the correlation between energy production and daily solar irradiance is discussed. Further, a statistical analysis on the normalized energy production is developed for both plants, referring to the measured historical data. Finally, economic aspects and the evaluation of levelized cost of energy for CPV based on in-field data are reported. On the basis of these considerations, the feasibility of CPV systems in southern Europe are discussed.
Parametric optimization and performances analysis of four secondary optical elements for concentrator photovoltaic systems
t he study concerns a general, parametric and performances analysis of four secondary optical elements (SOE) to use for Concentrator Photovoltaic Systems (CPV) using the same primary optic element: the Fresnel lens (FL). It concerns the Compound Parabolic Concentrator (CPC), the Crossed Compound Parabolic Concentrator (CCPC), the Cone and Pyramid. The study starts from optical modeling and considers several classical materials, with various refractive indexes in order to get a clear idea about their influences on the efficiencies, the sizes and the geometrical needs of the SOEs. The performances of the whole concentrator systems are compared in term of achieved effective concentrations, acceptance angles, output light power distribution and tolerances in the placement of the secondary element regarding the FL. Based on the etendue law, the geometrical considerations reveal that the length and the input aperture size of the whole SOEs increase with the increase of the refractive index of the considered material. Results show that the pyramid-based concentrator gives the more uniform irradiance distribution and the high optical efficiency whatever the used material, and the largest tolerance angle never reported. At the end, to easiest the comparison of the four elements, a merit graph is developed and proposed
Impacts of climate and land use changes on flood risk management for the Schijn River, Belgium
Abstract Flooding is the most common natural disaster in Europe. Modern flood risk management relies not only infrastructure development but also on governmental and non-governmental actors applying legal, economic and communicative water management instruments. Within the European Union (EU), flood management closely relies on policy set at the EU and national levels. It is now recognized that a sound understanding of climate change is required in addition to current management by taking into account land use change and socio-political context, as climate and land use changes have major impacts on hydrological responses. This paper investigates the hydrological behavior due to urbanization under current and future climate scenarios of high summer and high winter rainfall for 20 sub-catchments of the Schijn River, located in the Flanders region near Antwerp, Belgium. As urbanization increases and existing rainfall-runoff models neglecting the specific behavior of urban runoff, a hydrological model was developed based on a basic reservoir concept and applied to the existing rainfall-runoff model (PDM) flow to examine the specific urban contribution. Results revealed that peak flow for urban runoff and the total peak flow (i.e. rural and urban runoff) were significantly higher (i.e. ranges from 200% to 500%) than the existing rainfall-runoff model (PDM) flows, because of faster and more peaked urban runoff response. The impact of climate change on current and future conditions was also assessed by estimating peak flows with respect to return periods from the flood frequency curve. The predicted peak flow of high summer future climate scenario was significantly higher (i.e. ranges from 200% to 250%) than that of the current climatic condition for this region. Furthermore, hourly peak flow and daily volume ratios of 100-year return period for the highest, lowest and average impervious area were projected for the time horizon of the year 2100. It is concluded that climate change impacts contribute the most in producing peak flow in coming years, while increased urbanization takes the second place for both hourly and daily values. Results on urbanization effect and climate change impact assessment are useful to the water managers for spatial planning, emergency planning and insurance industry.