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Concentrated Solar Power (CSP) and geothermal energy systems are outlined as two of the most promising technologies for sustainable and reliable electricity generation. Several studies in the technical literature have pointed out that the hybridization of solar and geothermal energy sources could lead to a reduction of the levelized cost of energy (LCOE) of geothermal systems, as well as improving the capacity factor of CSP systems. However, the technical literature shows that the integration of solar thermal collectors does not present a positive impact in all scenarios analyzed. The present study aims to further analyze the competitiveness of the hybridization of solar and geothermal systems under high irradiation conditions such as those observed in the Andean region in northern Chile. The evaluation was carried out by coupling a thermodynamic model in Engineering Equation Solver (EES) with a solar thermal model in the System Advisor Model (SAM). The assessment considers the configuration of an existing geothermal plant, considering the design constraints associated with the actual operating conditions of the plant. The analysis is based on an energy and exergy assessment, allowing us to identify the efficiency of the subsystems introduced for the hybridization and assess the competitiveness of the hybrid schemes by an economic assessment in terms of the LCOE. The results show that the hybrid schemes allow a reduction of the LCOE of a geothermal stand-alone plant by about 10 USD / MWh , increasing the competitiveness of the geothermal system. However, a large variation on such a reduction is observed depending on the size of the solar field and the storage tank of the solar system. [ABSTRACT FROM AUTHOR]

A simplified mathematical model of parabolic-trough solar thermal power plants, which allow one to carry out an energetic characterization of the main thermal parameters that influence the solar field performance, was evaluated through a comparison of simulation results. Two geographical locations were selected to evaluate the mathematical model proposed in this work—one in each hemisphere—and design considerations according with the practical/operational experience were taken. Furthermore, independent simulations were performed using the System Advisor Model (SAM) software, their results were compared with those obtained by the simplified model. According with the above, the mathematical model allows one to carry out simulations with a high degree of flexibility and adaptability, in which the equations that allow the plant to be energetically characterized are composed of a series of logical conditions that help identify boundary conditions between dawn and sunset, direct normal irradiance transients, and when the thermal energy storage system must compensate the solar field energy deficits to maintain the full load operation of the plant. Due to the above, the developed model allows one to obtain satisfactory simulation results; referring to the net electric power production, this model provides results in both hemispheres with a relative percentage error in the range of [0.28–8.38%] compared with the results obtained with the SAM, with mean square values of 4.57% and 4.21% for sites 1 and 2, respectively. [ABSTRACT FROM AUTHOR]

Multi-junction solar cells in concentrator photovoltaic systems (CPV) offer the potential for highly efficient, low-cost electricity generation. However, these systems are typically designed and rated against reference spectra or for standard atmospheric conditions which are often not representative of the real deployment environments. Indeed, it has been shown that the use of unrealistic spectra can impact annual energy yield estimations by up to 75%. Hence there is a need to routinely generate spectrally resolved direct normal irradiance (DNI) estimates that are based on real observations so that CPV systems can be optimised appropriately for different locations.Here we will first present an automated scheme to estimate spectrally resolved DNI based on the integrated use of a radiative transfer model, AERONET ground-based observations and analyses from the European Centre for Medium Range Weather Forecasting Copernicus Atmospheric Monitoring Service (ECMWF CAMS). Our approach takes particular care to account for aerosol effects, circumsolar irradiance and other relevant atmospheric parameters. The results are tested against ground-based observations from Santiago, Chile, and has shown that broadband DNI can be simulated with an average bias of less than 2%. We will then present our preliminary work on integrating the above spectrally resolved DNI estimation scheme with satellite retrieved aerosol optical depths from the Oxford-RAL Aerosol and Cloud (ORAC) retrieval scheme using (A)ATSR / SLSTR observations, and Solcore, a semiconductor solver for CPV power output estimations. This will enable a global, long-term assessment of CPV solar energy generation, and even the possibility of near-real-time power estimates. [ABSTRACT FROM AUTHOR]