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The addition of lithium nitrate is assumed to improve the performance of molten salts, extending the work temperature range. This paper presents an evaluation of the influence of different degrees of purity of LiNO3, in a ternary mixture with composition 30 wt%LiNO3 + 13 wt%NaNO3 + 57 wt% KNO3 including a Chilean mixture obtained from the Atacama Desert brines. In addition, the use of synthetic lithium nitrate obtained from the chemical synthesis using Li2CO3 and HNO3, was incorporated in the comparison. The melting point results of the 30 wt% LiNO3 + 13 wt% NaNO3 + 57 wt% KNO3 mixture for different purities (128 °C, 124 °C), show a reduction of 92–96 °C with respect to the 223 °C of the solar salt and thermal stability results show maximum temperature are around 594 and 596 °C, which means that this mixture could work at maximum operating temperatures similar to those of solar salt. Finally, it was also determined that for the use of the proposed ternary mixture would mean a reduction of 35% in the volume of inventory with respect to solar salt since the proposed ternary salt presents an improvement about 14–21% in the heat capacity.

The copper mineral processing industry faces complex scenarios with increased demand, highly variable energy prices, falling ore grades that increase energy consumption, and increasing concern about the industry's carbon footprint. To reduce the risk imposed by these scenarios, the industry is looking at the use of renewable energy sources. Considering that the most important copper mines in Chile are situated in regions with high radiation levels, solar energy has the potential to be an attractive and sustainable source of energy. This paper provides an overview of the current solar technologies and how they have been applied to address some of the challenges faced by the copper mining industry today. It describes the use of solar thermal and solar photovoltaic technologies to produce power and heat for the copper mining processes. Indeed, solar photovoltaic technologies can be used to produce electricity for the comminution machines, electro-refineries and water pumping while solar thermal technologies are useful for electricity generation, heat production, thermal leaching and drying of copper concentrate. The review also analyzes, from a broader perspective, the potential of these technologies in the operation and design of new solar copper mineral processes. It is concluded that there several feasible options to integrate solar energy into the copper mining processes.

Soiling is an issue that impacts the performance of photovoltaic (PV) technologies as it attenuates the amount of solar resource reaching the solar cells. The chemical composition of the soil is essential to define cleaning strategies of photovoltaic companies. This paper reports the characterization of the chemical and physical properties of the soiling deposited on photovoltaic modules located in the Atacama Desert. The particle size, shape and chemical composition of dust were studied at 4 different locations (denoted as L1 to L4) with samples taken from the ground and the module surface. It was found that, most deposited material exhibits a diameter between 1 µm and 60 µm. The determination of the particle shape factor shows that smaller particles tend to have a circular appearance, while larger particles exhibit a prismatic form. These small particles show a shape factor close to 1 and occur at the 4 locations with the greatest frequency, 40–70%. The mineral species in both the deposited and ground dust, which were identified by means of X-ray diffraction, were albite, anorthite, calcite, cristobalite, gypsum, halite, quartz, muscovite and orthoclase. The compounds occurring with the highest frequency in both the module and ground dust at all locations were quartz and anorthite. Differences between the locations were found. Calcite was found only at L3. Gypsum was not detected at L1 and L3 but was present in L2 and L4. Similarly, cristobalite was found only at L1 and L3, halite was found at L2 and L3, and muscovite was found at L1 and L2.

Direct normal solar irradiation is a crucial parameter for site selection and design of solar power tower plants. It also has a high impact on economic studies, such as the levelized cost of electricity (LCOE). However, direct solar irradiation can be partially extinguished in its path between heliostats and receivers. Therefore, considering only direct normal solar irradiation in the solar resource assessment for tower plant projects is insufficient and leads to errors. This paper presents an improved methodology to estimate the extinction of radiation in the first 150 m of the lower atmosphere, where solar power tower plants are located. This work also shows the first atmospheric extinction maps, which in this case are elaborated for Chilean territory, and the intercomparison of extinction values with other places of interest in the sunbelt. Chile stands out for having the lowest annual atmospheric extinction values, below 4% for 1 km of slant range, while elsewhere annual losses can reach up to 17%. These values limit the amount of local useful solar resource available directly impacting on the LCOE values calculated for solar tower power plants. A new equation for the calculation of the LCOE considering atmospheric extinction is proposed in this paper.

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.

The estimation of daily solar radiation is needed in many studies related to solar power plant placements. To optimize photovoltaic (PV) systems, their placement must be as efficient as possible in terms of the prevailing meteorological conditions. There are situations where radiation data are not available, as in the case of desert areas, suitable for the operation of PV systems. In this work, daily global solar radiation has been estimated in desert areas using Artificial Neural Networks (ANN), where the inputs used are daily minimum and maximum temperatures and extraterrestrial radiation. The ANN model is validated with data from deserts in Chile, Israel, Saudi Arabia, South Africa and Australia. The results show that the average Relative Root-Mean-Square Deviation (RRMSD) value is 13%, the average Relative Mean Bias Difference (RMBE) value is less than 4% and the average correlation coefficient (r) value is about 0.8.

In the context of Concentrated Solar Power (CSP), the metallic materials employed to build the critical components of the plant are exposed to severe conditions, Carbon and stainless steel have been used for this application. However, the technology CSP will evolve, so these materials will probably be replaced by superior performing and economically competitive ones. Likewise, the investigation of molten salts with better thermophysical properties but no more corrosive than the actual benchmark has become a complex challenge. Thus, the research motivation was to study the performance of a martensitic steel exposed to a promising ternary molten salt with lithium nitrate at 550 °C by its corrosion behavior and mechanical properties. The corrosion process was monitored through electrochemical impedance spectroscopy (EIS). The mechanical properties in molten salt at high temperature were determined by slow strain rate testing (SSRT), complementing with the characterization of corrosion products to propose the corrosion mechanism in one scheme. The results showed that the steel is less robust but more ductile in the presence of molten salts at high temperatures; besides the material develop a multi-layer non-porous corrosion product that, despite deteriorating, confers corrosion rates within the recommended ranges for the application.

The understanding of soiling processes on photovoltaic modules is a necessary step for the development of cost-effective mitigation methods for the solar industry. This paper analyzes the soiling process for photovoltaic modules installed at the Atacama Desert. For this purpose, the dust deposited on photovoltaic modules and glasses (for one year) was characterized and the location's atmospheric parameters were monitored continuously. The dust samples were separated according to difference in solubility, obtaining three samples: soluble (recrystallized), insoluble (filtered), and original. Through x-ray diffraction measurements it was detected that the soluble part corresponds to gypsum and the other dust components are insoluble or low-solubility salts such as albite, anhydrite, calcite, quartz, and orthoclase. Scanning electron microscopy and energy dispersive x-ray spectroscopy of the dust on photovoltaic glasses show the presence of gypsum with a monoclinic prismatic structure covered with smaller dust particles. These prismatic crystals are also observed after recrystallization of the soluble sample suggesting that gypsum, as a soluble hygroscopic material, has a key role in the cementation process. Atmospheric parameters of each season were characterized through wind velocity, temperature, and relative humidity. All these parameters show large daily oscillation, which trigger a cementation process in which gypsum crystallization, after being completely or partially solubilized, causes the encapsulation of insoluble material.

When the availability of solar radiation is not enough to develop experimental investigation in the field of concentrating solar energy, solar simulators are a widely employed solution. They represent a source of artificial light, which can be comparable with concentrated sunlight. Besides, they provide advantages such as better parametric control of the process under study. In this work, it is presented an extensive review of the high flux solar simulators that are available in the different solar energy research centers around the world. Many of them are similarly designed and have common elements. Others are based on different concepts and their particular features are also pointed out. The main applications of solar simulators reported in literature are discussed along the work and remarked then in a specific section. The authors acknowledge the financial support provided by the FONDECYT project number 3150026 of CONICYT (Chile), the Education Ministry of Chile Grant PMI ANT 1201, as well as CONICYT/FONDAP/15110019 "Solar Energy Research Center" SERC-Chile. In addition, the first author wish to thank the University of Almeria and the Plataforma Solar de Almería for the collaboration and assistance devoted to the development of his Ph.D research.

Solar reactors designed and constructed for thermochemical applications present different configurations and general performance. The selection of a solar reactor that optimizes a particular process is always a difficult challenge. This work studies two types of reactor configuration by means of a comparative experimental analysis. It was employed a solar device, which is able to operate as fixed reactor with packed bed samples and as rotary kiln. The reduction of CuO into Cu2O was tested under both operation modes, due to its proved potential and interest as thermochemical storage material. It was found that heat transfer was hindered in static experiments limiting the fraction of reactive sample. Thermal gradients of about 200 °C were found in the packed bed through thermocouple and IR camera measurement. Heating rates and total fed energy must be restricted at the risk of front of the sample to melt, resulting in several operation drawbacks. In contrast, mixing conditions in rotary kilns allowed for higher heating rates and led to homogenous sample temperature. Maximum reaction yields in stationary mode did not overpass 14% while it was achieved more than 80% in rotary mode at temperatures about 860 °C. Thermal efficiencies were very limited in both operation modes due to the high thermal inertia of the solar reactor. Because rotary mode admitted much more energy, its thermal efficiency was even lower than static. A solution to increase rotary kilns thermal efficiency is working in continuous mode.

Rotary kilns have a long history of use in classical industries. They are able to achieve high temperatures with higher thermal efficiencies than other reactor types. Their performance has been widely studied and classified according to different parameters. Since it is a well-known technology, rotary kilns have been selected for high temperature solar processes. This article initially presents a brief review of the rotary kiln technology and it focuses on the employment of these devices for thermal and thermochemical processes conducted by concentrating solar energy. Among the solar devices, a novel rotary kiln prototype for thermochemical processes is presented and compared with a static solar reactor. Finally, some practical conclusions on the design and operation of solar rotary kilns are remarked and an analysis of their main limitations is presented. The authors acknowledge the financial support provided by the FONDECYT project number 3150026 of CONICYT (Chile), the Education Ministry of Chile Grant PMI ANT 1201, as well as CONICYT/FONDAP/ 15110019 ‘‘Solar Energy Research Center” SERC-Chile. Also, the second author wish to thank to the Plataforma Solar de Almería and the University of Almería for the collaboration and assistance devoted to the development of his Ph.D research.

Rotary kilns are worldwide used for industrial processes that involve thermal treatments of particulate materials. However, a great amount of fossil fuels is employed in such processes. As alternative, solar rotary kilns are considered for this application due to their versatility and potential to substitute traditional fossil-fuel driven devices. In order to boost the development of this technology, efforts have to be focused on the control of the particle temperature during the treatment. In this context, a lab-scale rotary kiln was built and tested using a 7- kWe high-flux solar simulator at University of Antofagasta. It was conceived to treat particulate materials of different nature and it is able to reach temperatures higher than 800 °C under different operation strategies. Silicon carbide was selected for initial tests because it is inert, endures high temperatures (up to 1600 °C) and it has been proposed as thermal storage vector in several researches on concentrated solar power. In a first stage, the empty kiln was preheated up to about 800 °C, reaching a steady state in less than three hours and with a power of approximately 370 W entering the kiln cavity. Afterwards, 43 g of silicon carbide were introduced in the furnace and the system was heated again up to a second steady state above 800 °C. In this stage, particles showed a fast increment of their temperature and exceeded 700 °C in less than three minutes after loading. A one-dimensional transient numerical model was also developed to perform the thermal analysis of the kiln and the estimation of both the particle temperature and the system efficiency. Numerical results showed good agreement with experimental data and thermal losses could be quantified in detail. Therefore, the model was also used to predict the thermal behavior of a solar rotary kiln working in batch mode. The authors acknowledge the financial support provided by the FONDECYT project number 3150026 of CONICYT (Chile), the Education Ministry of Chile Grant PMI ANT 1201, as well as CONICYT/ FONDAP/15110019 “Solar Energy Research Center” SERC-Chile. The authors also gratefully acknowledge the financial support received from the Sectorial Fund CONACYT-SENER-Energy Sustainability, through grant 207450, Mexican Center for Innovation in Solar Energy (CeMIE-Sol), whithin strategic project P-10 “Solar Fuels and Industrial Processes” (COSOLpi). Special thanks go to the students Lou Cardinale, Rodrigo Méndez, and Daniel Vidal who gave a precious contribution during the experimental trials at LaCoSA of University of Antofagasta.

A method to achieve a uniform flux distribution with a multi-faceted point focus concentrator for laboratory tests is proposed in this work. The method can be applied to different types of receiver - thermal or photovoltaic - and no additional device is required to homogenize the flux. The technique consists in moving the receiver from the focal plane and enlarging the solar spot impinging on it. At the same time, each mirror aim-point is adjusted in order to superimpose the images that have been generated by every facet. To evaluate the method, a real multi-faceted concentrator composed of eighteen spherical mirrors was modeled in a ray-tracing software. The procedure was validated through the comparison of an image of the real solar spot on the receiver generated by three mirrors, and the simulated flux obtained the same way. This way a mean concentrator global optical error of 2.8 mrad was estimated. This value was used then for further analyses. Results show that the concentration factor can be varied in a range of 150–900 suns over a receiver diameter of up to 7 cm. Hence, according to the receiver requirements, it is possible to expand the distribution and to alter the intensity of the flux. Finally, optical parametrical analyses were carried out, from which it is inferred that good quality optics give rise to a more homogeneous solar flux on the receiver.

Chile is committed to the development of non-conventional renewable energies, so to create the necessary incentives, several laws has been issued. One of the most recent actions was the Net billing law, which seeks to promote the integration of renewable technologies in the distribution segment. Because Chile has chosen not to use subsidies, only cost-efficient technologies are incorporated in the market. The net billing law has not shown much impact so far, therefore further incentive mechanisms are under discussion. This paper reports on the integration scheme for residential photovoltaic generation within net billing and net metering context. Different options of photovoltaic plants are analyzed: a) self-consumption, b) self-consumption and feeding into the grid, c) self-consumption and storage. Discrimination of the best options has been determined based on the economic benefits of each alternative, which are determined by performing calculation of Net Actual Value (VAN). Growth rates for each of sizing options have been also determined and compared with the price of energy for the residential segment (BT1) in order to find the optimal choice. The results obtained show that for the existing market conditions in Chile and the net billing scheme the size of the photovoltaic plant in northern Chile should be about 1 kW. Furthermore, the option of using storage is not yet economically feasible.

The solar conditions in northern Chile, in particular the Atacama Desert, which presents an annual global radiation value of 2500 kW h/m 2 and an index of direct normal irradiance (DNI) of 3500 kW h/m 2 , are among the best worldwide for capturing and storing solar energy. These features are of major importance when considering the saline deposits that are concentrated in this area. There are several factors that make CSP technology an ideal resource for a successful development in northern Chile, highlighting the excellent solar resource and their combination with storage could supply energy to mining industry, which requires energy 24 h per day. The focus of this paper is to develop an economic analysis for computing a projection of LCOE between 2014 and 2050 from a 50 MW CSP plant with five different composition of salts for it TES. Two different scenarios are considered for this study: IEA BLUE Map Scenario and Roadmap Scenario. Additionally, a comparison between the LCOE in the north of Chile and the most influential countries in solar energy (Spain and USA) is made. The research basis lay on contribution of recent Chilean plans together with international researches in order to support the great potential of the implementation of CSP plant in the north of Chile. The results show that new proposed molten salts reduce considerably the storage cost. Thus, it can contribute to a promising future of the growth of CSP in the Plataforma Solar del Desierto de Atacama (PSDA) at north of Chile.

With an elevation of 1000 m above sea level, once the coastal mountain range is crossed, the Atacama Desert receives the highest levels of solar radiation in the world. Global horizontal irradiations over 2500 kWh/(m2 year) and a cloudiness index below 3% were determined. However, this index rises to 45% in the coastal area, where the influence of the Pacific Ocean exists with a large presence of marine aerosols. It is on the coastal area that residential photovoltaic (PV) applications are concentrated. This work presents a study of the soiling impact on PV modules at the coastline of Atacama Desert. The current–voltage characteristics of two multicrystalline PV modules exposed to outdoor conditions were compared, while one of them was cleaned daily. Asymptotic behavior was observed in the accumulated surface dust density, over 6 months. This behavior was explained by the fact that as the glass became soiled, the probability of glass-to-particle interaction decreased in favor of a more likely particle-to-particle interaction. The surface dust density was at most 0.17 mg·cm−2 per month. Dust on the module led to current losses in the range of 19% after four months, which in turn produced a reduction of 13.5%rel in efficiency.

Soiling is currently one of the major issues for decreasing power production of PV plants in Chile. In order to prevent significant power losses cleaning frequencies of more than one time per month are scheduled. In the present study, we investigate the impact of soiling on energy yield (YA) of bifacial solar modules with different material combinations. We fabricated half-size and full-size one cell modules employing different glass thicknesses, encapsulants, transparent backsheets and glass-glass module configurations. Based on indoor current-voltage (IV) measurements which were carried out on front and rear side of each bifacial module type at different irradiance levels, a mathematical YA model was applied. Front and rear measurements were taken separately and simultaneously assuming the same bifaciality factor at a given irradiation. YA estimations show that module groups with half-cell design achieve the highest YA values compared to full-cell design. In addition, vertically mounted bifacial modules (VMBM) produce higher YA than tilted mounted bifacial modules (TMBM) if the power loss rate due to soiling is higher than 0.10% per day. To validate the YA model, real outdoor measurements were carried out in the Atacama Desert in Chile for TMBM and for VMBM.

The corrosive effects of a molten nitrate mixture of 48% Ca(NO 3 ) 2 +7% NaNO 3 +45% KNO 3 were appraised at 390 °C on two different types of stainless steels (AISI 304, 430), a low-Cr alloy steel (T22) and a carbon steel (A1). The corrosion rates were determined using gravimetric tests, which measured the weight gain during 2000 h to identify the corrosion products with scanning electron microscopy (SEM) and X-ray diffraction (XRD). Studies on stainless steel revealed a better behaviour in corrosive environment, which mainly identifies the formation of (K,Na)CrO 4 protective spinel. Fe 2 O 3 and Fe 3 O 4 were the other important products that were found in the tests performed at 390 °C; the formation of some stable compounds with salt impurities, such as carbonates and sulphates, was also observed.

The enhancements in the storage systems developed by solar thermal power plants have provided to renewable energy a considerable increase in efficiency. Thermal Energy Storage (TES) using HITEC mixture could be used as Heat Transfer Fluid (HTF) in concentrated solar linear technology. In this research, the corrosive effects of HITEC mixture composed by 40 wt% NaNO2 þ 7w t % NaNO3 þ 53 wt% KNO3 were assessed at 390 � C on a carbon steel (A516) and on low-Cr alloy steels (T11 and T22). The corrosion rates were determined by gravimetric tests, measuring the weight gain during 2000 h, identifying the corrosion products via scanning electron microscopy and X-ray diffraction. T22 steel shows a corrosion layer of 6.05 microns, with a protective layer formed in the inner zone to the material, identified through DRX as the K2CrO4 protective spinel. Fe2O3 and MgO were the others important products found on the tests performed at 390 � C, being observed also the formation of some stable compounds with the impurities of the salt, as carbonates. The use of the HITEC mixture in solar technology would provide a less aggressive behaviour for materials in contact with it, providing an increase in operational life cycles in current solar technology.

Crystalline silicon solar cells are currently the leading technology in the photovoltaic market with no great expectable change in the shares. The scientific community works on the further development and improvements of state-of-the-art as well as new solar cell materials. This paper reports on a chemical methodology for selective etching to study the metallization step in monocrystalline silicon solar cells. The object of study is a complete processed silicon solar cell which was cleaved via laser beam on the back side and broken per hand to obtain stripes of the size 15.6×1 cm². In the following a sequence of etching chemical solutions to selectively remove the components of the front side silver contact was applied. Scanning electron microscopy was used to investigate contact interface after each etching step. The silver finger, the glass and the silver crystallites grown in silicon could be removed. It came out that the silver crystallites preferably grow at the pyramid tips and edges of the textured wafer. A characterization with Energy Dispersive X-Ray Spectrometry was performed to quantify the components of the silver contact after each chemical etching step. While the weight percentage of silver reduced by more than 90% after an aqua regia treatment, it increased by 13% after hydrofluoric acid. Silver was practically eliminated after a second aqua regia bath. Similarly, the content of glass was also determined. The approach serves for interface investigations in semiconductor technology where screen printing approaches are used for the metallization.

In Northern Chile, the demand for electricity is expected to grow at a 5% annual rate over the coming years. The primary electricity consumers in the region are mining companies which, due to the characteristics of their activities, have a flat (constant) demand profile. The main energy consumers usually agree(Power Purchase Agreements, PPA) on long-term supply commitments at a fixed price, consistent with stable demand needs. Certain Non-Conventional Renewable Energies (ERNC), such as wind and solar, are or will be competitive to the in Northern Chile, but they do not adapt well to constant demand. CSP technology with thermal energy storage adapts better to the demand profile for Northern Chile but, currently,it isnoncompetitive when compare with a conventional PPA. Financial support, such as soft financing and direct grants, will help narrowing the gap for the first CSP projects in Northern Chile.

The current study has conducted a wide-ranging characterization, under high-temperature conditions, of a new ternary and quaternary heat transfer fluid, with the addition of Ca(NO3)2 and LiNO3, two of the solar salt additives with a greater potential for being included in these new formulations proposed for the new generation of concentrated solar power (CSP) plants. In this direction, the present research is focused on viscosity and thermal stability since these salts try to increase the work temperature range in CSP plants. Viscosity tests were analyzed each 10 °C from 130 to 300 °C in order to check the variation in this parameter close to their melting points. Isothermal analysis at 450 and 500 °C was also performed through thermal gravimetric (TG) analysis, measuring any resulting loss of mass in the sample at these temperatures. Results were compared with the behavior in binary solar salt. These tests showed a progressive thermal degradation of salts over the time and the maximum temperature for operation in CSP has been corrected regarding the use of ternary and quaternary molten salts.

Thermochemical storage of solar energy consists in reversible chemical reactions that absorb the solar heat during an endothermic step and release it by means of an exothermic reaction. CuO/Cu2O and Co3O4/CoO redox pairs have a high potential as materials to store solar energy at high temperature. Cobalt oxides have been so far studied by several authors and works while copper oxides suitability has been recently proved. However, in both cases, operation parameters need to be optimized. A theoretical study of the effect of total pressure, gas/solid molar rate and composition of working atmosphere on the systems equilibrium is presented. The equilibrium displacement caused by these parameters is calculated and discussed. Finally, some ideas for tentative implementations of these systems are commented.

In recent years, lithium containing salts have been studied for thermal energy storage (TES) systems applications, because of their optimal thermophysical properties. In solar power plants, lithium is seen as a way to improve the properties of molten salts used today. Lithium nitrate is a good candidate for sensible heat storage, due to its ability to increase the salt mixture’s working temperature range. In the present research, thermophysical properties characterization of lithium nitrate containing salts, produced in Chile, have been carried out. Corrosion evaluations of carbon and low chromium steels were performed at 390°C for 1000 hours. Thermophysical properties of the salt mixtures, such as thermal stability and heat capacity, were measured before and after corrosion tests. Chemical composition of the salts was also determined and an estimation of Chilean production costs is reported. Results showed that purity, thermal stability and heat capacity of the salts were reduced, caused by partial thermal decomposition and incorporation of corrosion products from the steel.

Energy policy of Chile establishes that by 2025, at least 20% of the annually generated energy must come from renewable energy sources. In this context, many projects of solar and wind farms have been presented for connection in ten Chilean electrical systems. The aim of this study is to evaluate the transient behavior of the Northern Interconnected System (SING) regarding the high levels of integration of wind generation. The behavior of the most important wind farms under construction and / or approved for construction is analyzed. A comparative study of the technologies of fixed speed, doubly fed and full converter is carried out in two points of the system employing software for electrical system analysis, DigSILENT. The main results show that technologies of fixed speed and doubly fed have a better response in the voltage and reactive power variables, meanwhile the angle and reactive power performs better in a full converter technology.

Thermochemical redox processes are currently considered one of the most promising methods for thermal storage of solar energy. Among the different types of materials available for this purpose, metal oxides allow higher operation temperatures in CSP systems. This is in agreement with the new R&D trends that focus on increasing the temperature to augment the efficiency. Copper oxide was previously proposed as a valid metal oxide for thermochemical storage. However, no demonstrative experiments had been carried out so far under solar radiation. In this work, the suitability of copper oxide was proved in a solar furnace. The employed solar reactor was a rotary kiln device with direct radiation absorption on reactive particles, which is a configuration that guarantees higher operation temperatures than other types of solar reactors. Given results include the performance of the CuO reduction in the rotary kiln under argon atmosphere and the cyclability of the pair CuO/Cu2O in air.

This paper reports on the performance of photovoltaic systems in the coastal zone of Antofagasta, northern Chile. This region is one of the most suitable places in the world for the use of solar energy due to the high solar radiation levels. However, this location is influenced by a coastal desert climate where the environmental effects on solar technologies are not well known. Therefore, we study the performance ratio of photovoltaic systems in a period of 16 months, in which solar radiation and ambient temperature were quantified. The technologies were modules based on amorphous/microcrystalline silicon tandem thin films and mono crystalline silicon solar cells. The global tilted solar irradiation reached mean values of 8.5 kW h/m 2 day in summer and 6 kW h/m 2 day in winter demonstrating the high radiation available here. We analyzed how the performance ratio is influenced by the dust accumulation and the ambient temperature associated to this place. It came out that the difference of energy yield between the technologies became larger for summer and smaller for winter, and that the performance ratio decreased due to the dust accumulation between −0.04%/day up to −0.13%/day for positive ambient temperature gradient, and between −0.13%/day up to −0.18%/day for negative ambient temperature gradient.

The enhancement in the storage systems developed by solar thermoelectric centrals brings to this renewable energy a considerable efficiency increase. This improvement propitiates the design of storage fluids with lower melting point and higher thermal stability such as molten salt mixtures. This research has broadly studied the HITEC mixture composed by 53 mass% KNO3 + 40 mass% NaNO2 + 7 mass% NaNO3, with the aim to improve the existing solar salt used as energy storage fluid in CSP plants and focus the thermal properties obtained for application in solar linear concentrated technology. HITEC molten salt shows better physicochemical properties than the binary solar salt (60 % NaNO3 + 40 % KNO3), due to its lower melting point which can improve the work temperature range in commercial solar plants. The tested properties studied by differential scanning calorimeter and thermogravimetric analyser were melting points, heat capacities and thermal stability, mainly. This proposed mixture could be used as heat transfer fluid in solar linear concentrated technology extending the work range temperature between 130 and 550 °C. Results conclude that the main challenge in nitrite salts lies in the need to protect the sample above 350 °C with inert gas, to prevent oxidation of nitrite by oxygen.

This paper presents a converter that allows the operation as rectifier or inverter, with high power factor, which the voltage output can be lower, equal or greater than the peak of the input voltage, besides that working with only a cell of conventional switching. The operation stages, equations, control strategy and design of the converter are presented. Finally, simulation results are shown for operation as rectifier and inverter.