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Process heating is the activity with the most energy consumption in the industrial sector. Solar heating (SH) systems are a promising alternative to provide renewable thermal energy to industrial processes. However, factors such as high investment costs and area limitations in industrial facilities hinder their utilization; therefore, hybrid systems that combine two different solar thermal or photovoltaic technologies where each technology operates under conditions that allow a higher overall performance than conventional configurations have been proposed. In this review, we discuss the limitations of conventional SH systems and the potential of hybrid configurations to overcome them. First, the current literature about conventional and hybrid systems is presented. Then, the application of common performance indicators to evaluate hybrid configurations is analyzed. Finally, the limitation, advantages, and potential applications of conventional and hybrid systems are discussed. This work shows that conventional systems are the most promising alternatives in low and high-temperature industrial applications. At the same time, in medium and processes, hybrid configurations have great potential to increase the performance of SH systems and help to boost their adoption in the industrial sector. There are few studies about hybrid systems in industrial applications, and further research is required to determine their potential. [ABSTRACT FROM AUTHOR]

Exergy is a thermodynamic property that represents the quantification of the maximum useful work that can be extracted from a system interacting with the environment. Regarding solar radiation, radiative exergy has been a matter of study over the last 60 years where the main models applied describe the radiation as undiluted and diluted. The exergy of solar radiation is useful in the preliminary assessment of the performance of solar technologies, since the efficiency of the system depends directly on this value. The present paper describes a review of the main models reported in the literature considering these two approaches, analysing the main differences between the models and the main assumptions applied. A comparative analysis is carried out for the models of diluted and undiluted radiation, where the behaviour of every expression is discussed in detail. For the undiluted expressions, the behaviour of every model within a temperature range is analysed. For black-body radiation at a source temperature of 6000 K, the model proposed by Jeter determines an exergy factor of 0.96, while Spanner, Petela, Press and Badescu calculate a value of 0.93. Parrott's model obtains a value of 0.99, which is above the value for Carnot efficiency. The diluted exergy expressions were evaluated according to wavelength and temperature range, where the trend in each comparison was that the exergy calculated from Karlsson, Candau and Petela was always the lowest. This result is attributed to the fact that these expressions consider the spectral entropy of the medium the radiation passes through. Finally, some new approaches are analysed which consider empirical correlations based on meteorological variables to model the exergy of solar radiation. [ABSTRACT FROM AUTHOR]

The trend to reduce CO2 emissions in cooling processes has made it possible to increase the alternatives for integrating solar energy with thermal equipment whose viability depends on its adaptation to polygeneration schemes. Despite the enormous potential offered by the industry for cooling and heating processes, solar cooling technologies (SCT) have been explored in a limited way in the industrial sector. This work discusses the potential applications of industrial SCTs and classifies hybrid polygeneration schemes based on supplying cold, heat, electricity, and desalination of water; summarizes the leading SCTs, and details the main indicators of polygeneration configurations in terms of reductions on primary energy consumption and payback times. To achieve an energy transition in refrigeration processes, the scenarios with the most significant potential are: the food manufacturing industry (water immersion and crystallization processes), the beverage industry (fermentation and storage processes), and the mining industry (underground air conditioning). [ABSTRACT FROM AUTHOR]

• Analysis of solar technologies for supply heat in mining industry in Chile. • TRNSYS simulations for non-concentrating and concentrating collectors. • Performing sensitivity analysis when fuel price, OPEX and collector cost vary. • In terms of cost FPC is the most appropriated technology. • A substantial reduction in CO 2 emissions can be achieved. Copper mining is the largest industry and energy consumer in Chile, utilizing heat from imported fossil fuels of which Chile is not a producer. The goals for decarbonization present opportunities to analyze how the Chilean industry can become sustainable with significant shares of renewable energy including solar heat. The present study analyzes the integration of solar heating to the copper refining process in order to gain insights on the technical, economical, and emissions performance of solar heating systems for the largest copper mining operations in Chile. The solar technologies considered in the analysis are flat plate, evacuated tube, and parabolic trough collectors. The results are validated by comparing with publicly available data from existing solar heating plants in copper mining facilities showing that solar plants are able to supply partially the thermal energy demand, although at different costs in terms of capital and operation and maintenance requirements. The economic analysis indicates that with current fossil fuel prices, solar heating technologies are a valid alternative for cost and emissions reduction in copper mining. Flat plate collectors show the lowest cost for solar heat when compared to evacuated tube and parabolic trough systems considering identical sets of technical and financial parameters. The parametric and sensitivity analysis indicate that the conditions under which solar heating is competitive with traditional fossil-fired heaters. which might still be required as backup systems in order to provide heat in a 24/7 regime, and in all the cases analyzed, a substantial reduction in CO 2 emissions can be achieved. [ABSTRACT FROM AUTHOR]

Knowledge of the solar spectrum is essential for the design and study of numerous technologies. Due to the area considered, the harsh conditions and the difficulty for accessing to some zones, information and measurement on local parameters and spectral resource are scarce. This fact, along with the special atmospheric conditions prevailing in Atacama Desert, has led to increasing interest on the part of the solar industry to ascertain the spectral variation respect to that of other places around the world. Considering the standard spectrum for a typical air mass as 1.5, the evaluation of PV module behaviour or device calibration under real conditions can generate a source of uncertainty where spectra may differ. This preliminary paper aims to study the influence of using the standard or local spectra in photovoltaic technologies in Atacama Desert, in order to highlight the necessity for a long-term ground-based measurement campaign. For that purpose, a first approach to the spatio-temporal average of solar spectrum in the Atacama Desert from satellite databases is estimated. Then, local spectra are compared against the Reference Spectra in order to show the differences in studies on solar energy applications. Long-term satellite database information is used to average the atmospheric parameters, such as Aerosol Optical Depth, Ozone, Precipitable Water Vapour, Albedo and Relative Humidity, for the entire Atacama Desert area and is then used to obtain the mean Global tilted Irradiance and Direct plus Circumsolar Irradiance solar spectrum. Finally, to study the influence that the shape of the local spectrum has on the performance of the different solar technologies, the photo-current density of two different solar cell types were studied under Atacama and standard conditions. The results indicate that there are considerable differences with the ASTM G173-03 reference spectra for short wavelengths, especially in the UV spectral range, which is 55% points higher than the reference, which influences in the performance of the solar technologies. [ABSTRACT FROM AUTHOR]

The primary goal of this work is to provide an understanding of the state of the art and future prospects for solar PV technology in Chile. Chile is leading the incorporation of this type of energy in Latin America, with a solar PV market that has experienced a dramatic growth in the last years, mainly due to the high solar resource and the favorable conditions of the market to new investors. Main findings of this study are based on the influence of geographical and climate conditions on the Chilean solar resource, the current status of solar PV industry, electric market and further insights to future deployment of PV technology in this country. A literature review about the effect of desert conditions on the performance of PV systems is also presented, including main results of different studies carried out in the Middle East, Africa, Asia, Australia, the United States and Chile, as they represent areas where emerging markets of solar PV are growing. Based on the literature review, this work provides some directions to future research in Chile highlighting the main scientific areas which need more extensive R&D efforts to analyze and improve the reliability of PV installations in Chile. [ABSTRACT FROM AUTHOR]