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I. Lillo-Bravo
Department of Energy Engineering (ETSI), University of Seville, 41092 Seville, Spain

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Journal article
Published: 01 May 2021 in Materials
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The world population is growing by 1 billion people every 10 years. There will come a time when there will be more people to feed but less land to grow food. Greenhouses can be the solution to this problem because they provide the highest production yield per m2 and also use less water, provide food safety, and offer high quality. Photosynthetic active radiation (PAR) favors vegetable growth with a specific blue and red light ratio. Thus, increasing the amount of red light improves chlorophyll absorption and photosynthetic efficiency. In this article, we present a hybrid system that combines luminescent materials and photonic crystals for better management of the light reaching the greenhouse. The luminescent dyes considered herein are combined ensuring a Förster resonance energy transfer (FRET) nonradiative mechanism to enhance the absorption range. The designed photonic crystal maximizes reflections in the Near-Infrared (NIR) range, and therefore, thermal losses are minimized. Thus, by converting harmful or ineffective radiation for plant growth to the PAR region, we aim to demonstrate growth-condition enhancement for the different vegetables that have been used as a model.

ACS Style

M. Sánchez-Lanuza; Amador Menéndez-Velázquez; Antonio Peñas-Sanjuan; Francisco Navas-Martos; Isidoro Lillo-Bravo; José-María Delgado-Sánchez. Advanced Photonic Thin Films for Solar Irradiation Tuneability Oriented to Greenhouse Applications. Materials 2021, 14, 2357 .

AMA Style

M. Sánchez-Lanuza, Amador Menéndez-Velázquez, Antonio Peñas-Sanjuan, Francisco Navas-Martos, Isidoro Lillo-Bravo, José-María Delgado-Sánchez. Advanced Photonic Thin Films for Solar Irradiation Tuneability Oriented to Greenhouse Applications. Materials. 2021; 14 (9):2357.

Chicago/Turabian Style

M. Sánchez-Lanuza; Amador Menéndez-Velázquez; Antonio Peñas-Sanjuan; Francisco Navas-Martos; Isidoro Lillo-Bravo; José-María Delgado-Sánchez. 2021. "Advanced Photonic Thin Films for Solar Irradiation Tuneability Oriented to Greenhouse Applications." Materials 14, no. 9: 2357.

Journal article
Published: 15 April 2021 in Sustainability
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Concentrated solar power (CSP) and photovoltaic (PV) solar systems can be hybridized, creating synergies: on one hand procuring dispatchability by storing thermal energy, and on the other hand generating electricity at a highly competitive prize. In this paper, we present an approach to the operation strategies and modes for integrated hybrid CSP + PV systems. We focus on parabolic trough (PT) solar plants, especially those operating in the south of Spain. Our study consists in the definition of suitable states for each of the subsystems that constitute a hybrid solar plant. We then propose modes from the combination of suitable states and establish the conditions for the transition between modes depending on the operation strategy. We propose two operation strategies: demand coverage and base load production. The results of this paper can be used in decision making for hybrid solar system simulation programs.

ACS Style

José López-Álvarez; Miguel Larrañeta; Elena Pérez-Aparicio; Manuel Silva-Pérez; Isidoro Lillo-Bravo. An Approach to the Operation Modes and Strategies for Integrated Hybrid Parabolic Trough and Photovoltaic Solar Systems. Sustainability 2021, 13, 4402 .

AMA Style

José López-Álvarez, Miguel Larrañeta, Elena Pérez-Aparicio, Manuel Silva-Pérez, Isidoro Lillo-Bravo. An Approach to the Operation Modes and Strategies for Integrated Hybrid Parabolic Trough and Photovoltaic Solar Systems. Sustainability. 2021; 13 (8):4402.

Chicago/Turabian Style

José López-Álvarez; Miguel Larrañeta; Elena Pérez-Aparicio; Manuel Silva-Pérez; Isidoro Lillo-Bravo. 2021. "An Approach to the Operation Modes and Strategies for Integrated Hybrid Parabolic Trough and Photovoltaic Solar Systems." Sustainability 13, no. 8: 4402.

Journal article
Published: 06 August 2020 in Energies
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Most technoeconomic feasibility studies of photovoltaic (PV) systems with batteries are mainly focused on the load demand, PV system profiles, total system costs, electricity price, and the remuneration rate. Nevertheless, most do not emphasise the influence degradation process such as corrosion, sulphation, stratification, active material seeding, and gassing on battery lifetime, efficiency, and capacity. In this paper, it is analysed the influence of the degradation processes in lead–acid batteries on the technoeconomic analysis of PV systems with and without battery. Results show that Net Present Value (NPV), Payback Period (PBP), and Discounted PayBack Period (DPBP) have a heavy dependence on the assumptions about the value of the battery performance parameters according to its degradation processes. Results show NPV differences in the range from −307% to 740%, PBP differences in the range from 9% to 188%, and DPBP differences in the range from 0% to 211%.

ACS Style

Jose-Maria Delgado-Sanchez; Isidoro Lillo-Bravo. Influence of Degradation Processes in Lead–Acid Batteries on the Technoeconomic Analysis of Photovoltaic Systems. Energies 2020, 13, 4075 .

AMA Style

Jose-Maria Delgado-Sanchez, Isidoro Lillo-Bravo. Influence of Degradation Processes in Lead–Acid Batteries on the Technoeconomic Analysis of Photovoltaic Systems. Energies. 2020; 13 (16):4075.

Chicago/Turabian Style

Jose-Maria Delgado-Sanchez; Isidoro Lillo-Bravo. 2020. "Influence of Degradation Processes in Lead–Acid Batteries on the Technoeconomic Analysis of Photovoltaic Systems." Energies 13, no. 16: 4075.

Journal article
Published: 25 March 2020 in Renewable Energy
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Stand-alone photovoltaic systems usually use batteries to adjust energy yield to energy demand. An alternative energy storage system for stand-alone photovoltaic installations is proposed for three cooling applications: air conditioning, food preservation and freezing. A thermally insulated storage tank with ammonia in saturated mixture phase is integrated into the vapour-compression cooling cycle. A thermodynamic model and an economic assessment based on typical costs and cost sensitivity are included to assess the proposed system performance in comparison with a conventional stand-alone photovoltaic system with a vapour-compression cycle. Results show that the proposed storage strategy is an affordable option, especially in hot climates and for food preservation and freezing applications.

ACS Style

I. Lillo-Bravo; M.A. Bobadilla; S. Moreno-Tejera; M. Silva-Pérez. A novel storage system for cooling stand-alone photovoltaic installations. Renewable Energy 2020, 155, 23 -37.

AMA Style

I. Lillo-Bravo, M.A. Bobadilla, S. Moreno-Tejera, M. Silva-Pérez. A novel storage system for cooling stand-alone photovoltaic installations. Renewable Energy. 2020; 155 ():23-37.

Chicago/Turabian Style

I. Lillo-Bravo; M.A. Bobadilla; S. Moreno-Tejera; M. Silva-Pérez. 2020. "A novel storage system for cooling stand-alone photovoltaic installations." Renewable Energy 155, no. : 23-37.

Journal article
Published: 25 February 2020 in Applied Sciences
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Photonic crystals have the advantage of minimizing thermal losses from solar cells, reflecting the solar radiation that is not absorbed by the photovoltaic device. To optimize this optical response, photonic crystals are designed considering the relative position of the Bragg peak and the bandgap of the solar cell, under normal incident irradiation conditions. The aim of this research article was to determine experimentally the optical limits of a solar cell coupled to a photonic crystal acting as beam splitter. For that purpose, the photovoltaic system was characterized under indoor and outdoor conditions; angular dependence of the irradiation source was determined in each case, and both results were compared with good agreement. Moreover, other parameters such as irradiation spectrum and polarization of the light were investigated. The main conclusion is that photovoltaic performance is highly affected by the Bragg peak shifting and the profile is distorted, due to the angular dependence with the sun. These experimental limits must be considered at the early design stage to avoid performance losses.

ACS Style

J. M. Delgado-Sanchez; I. Lillo-Bravo. Angular Dependence of Photonic Crystal Coupled to Photovoltaic Solar Cell. Applied Sciences 2020, 10, 1574 .

AMA Style

J. M. Delgado-Sanchez, I. Lillo-Bravo. Angular Dependence of Photonic Crystal Coupled to Photovoltaic Solar Cell. Applied Sciences. 2020; 10 (5):1574.

Chicago/Turabian Style

J. M. Delgado-Sanchez; I. Lillo-Bravo. 2020. "Angular Dependence of Photonic Crystal Coupled to Photovoltaic Solar Cell." Applied Sciences 10, no. 5: 1574.

Journal article
Published: 13 July 2019 in Renewable Energy
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This article presents and evaluates the performance of a simplified model to generate 10-min global horizontal synthetic solar radiation data that would correspond to the measurements of a calibrated photovoltaic monocrystalline cell. The model, which only requires global horizontal solar radiation data measured with a thermopile pyranometer as input, is based on the characterization of the relation between the data measured with a thermopile pyranometer and a calibrated cell as a function of the sky condition and the solar elevation. We have used an extensive solar radiation database for the location of Seville (Spain) for the training of the model that has been tested in Seville and Lancaster (USA), showing satisfactory results and suggesting a global applicability with no local adaptation or calibration requirement. The model shows the best results for high levels of solar radiation and solar elevations and decreases its performance on days with high levels of diffuse irradiation and for very low solar elevation angles. We obtain a daily RMSD between measured and synthetic data of 1.9% in Seville and 5.2% in Lancaster. The frequency distribution of the synthetic datasets shows a KSI of 3.7 W/m2 in Seville and 8.6 W/m2 in Lancaster. We also evaluate the ramp rates of measured and synthetic sets through the KSI of the measured and synthetic ramp rates sets, obtaining 0.11 W/m2۰min in Seville and 0.20 W/m2۰min in Lancaster.

ACS Style

I. Lillo-Bravo; M. Larrañeta; E. Núñez-Ortega; R. González-Galván; Larrañeta M. Simplified model to correct thermopile pyranometer solar radiation measurements for photovoltaic module yield estimation. Renewable Energy 2019, 146, 1486 -1497.

AMA Style

I. Lillo-Bravo, M. Larrañeta, E. Núñez-Ortega, R. González-Galván, Larrañeta M. Simplified model to correct thermopile pyranometer solar radiation measurements for photovoltaic module yield estimation. Renewable Energy. 2019; 146 ():1486-1497.

Chicago/Turabian Style

I. Lillo-Bravo; M. Larrañeta; E. Núñez-Ortega; R. González-Galván; Larrañeta M. 2019. "Simplified model to correct thermopile pyranometer solar radiation measurements for photovoltaic module yield estimation." Renewable Energy 146, no. : 1486-1497.

Journal article
Published: 29 October 2018 in Energies
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This paper analyses the possible applications of medium temperature solar concentration technologies, Compound Parabolic Collector, Linear Fresnel Collector and Parabolic Trough Collector in the Spanish industrial sector. Results of this study allow evaluating whether or not solar technologies are an alternative to conventional sources. This possibility is analyzed energetically, economically and environmentally. Results show that the percentage of solar use is decisive in determining the true thermal energy generation cost. The other essential parameter is the solar field area due to produce economy of scale that reduces investment costs. Fluid temperature has significant influence mainly in Compound Parabolic Collector technology. Results obtained in this paper collect multiple alternatives and allow comparing for different scenarios the suitability to replace conventional energy sources by thermal energy obtained from medium temperature solar concentration technologies from an economic perspective. For instance, for percentage of solar use equal to 100%, the lowest thermal energy generation costs for each technology are 1.3 c€/kWh for Compound Parabolic Collector technology, fluid temperature of 100 °C and industrial process located in Seville, 2.4 c€/kWh for Linear Fresnel Collector technology, fluid temperature of 170 °C and industrial process located in Jaen, 3.3 c€/kWh for technology, fluid temperature of 350 °C and industrial process located in Jaen. These costs are lower than conventional energy sources costs.

ACS Style

Isidoro Lillo-Bravo; Elena Pérez-Aparicio; Natividad Sancho-Caparrini; Manuel Antonio Silva-Pérez. Benefits of Medium Temperature Solar Concentration Technologies as Thermal Energy Source of Industrial Processes in Spain. Energies 2018, 11, 2950 .

AMA Style

Isidoro Lillo-Bravo, Elena Pérez-Aparicio, Natividad Sancho-Caparrini, Manuel Antonio Silva-Pérez. Benefits of Medium Temperature Solar Concentration Technologies as Thermal Energy Source of Industrial Processes in Spain. Energies. 2018; 11 (11):2950.

Chicago/Turabian Style

Isidoro Lillo-Bravo; Elena Pérez-Aparicio; Natividad Sancho-Caparrini; Manuel Antonio Silva-Pérez. 2018. "Benefits of Medium Temperature Solar Concentration Technologies as Thermal Energy Source of Industrial Processes in Spain." Energies 11, no. 11: 2950.

Journal article
Published: 01 June 2018 in Renewable Energy
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ACS Style

S. Moreno-Tejera; M.A. Silva-Pérez; L. Ramírez-Santigosa; I. Lillo-Bravo. Evaluation of classification methods according to solar radiation features from the viewpoint of the production of parabolic trough CSP plants. Renewable Energy 2018, 121, 429 -440.

AMA Style

S. Moreno-Tejera, M.A. Silva-Pérez, L. Ramírez-Santigosa, I. Lillo-Bravo. Evaluation of classification methods according to solar radiation features from the viewpoint of the production of parabolic trough CSP plants. Renewable Energy. 2018; 121 ():429-440.

Chicago/Turabian Style

S. Moreno-Tejera; M.A. Silva-Pérez; L. Ramírez-Santigosa; I. Lillo-Bravo. 2018. "Evaluation of classification methods according to solar radiation features from the viewpoint of the production of parabolic trough CSP plants." Renewable Energy 121, no. : 429-440.

Journal article
Published: 01 May 2018 in Applied Thermal Engineering
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The freeze protection is essential in the majority of solar thermal installations to prevent breakage of solar thermal collectors. Therefore, there are different methods of protection against freezing of flat plate solar thermal collectors, all of them with certain limitations. This paper shows a novel freeze protection mechanism in the solar thermal collector by using flexible silicone peroxide tubes inside the absorber of the solar collector. We demonstrate, in a theoretical and experimental way, that the increase of volume and pressure produced inside a solar collector during freezing process can be absorbed using a flexible silicone peroxide tubes under all exposure conditions. The parameters that optimize the geometric configuration of the solution proposed have been calculated. A collector prototype with silicones peroxide has experimentally complied with the Standard ISO 9806:20 13, including freeze resistance test, without any significantly influence on its efficiency or pressure drop. Therefore, the solution proposed presents an inexpensive, effective, reliable and maintenance-free freeze protection system for flat plate solar collectors.

ACS Style

J. Vera-Medina; Isidoro Lillo Bravo; J. Hernández; Miguel Larrañeta. Experimental and numerical study on a freeze protection system for flat-plate solar collectors with silicone peroxide tubes. Applied Thermal Engineering 2018, 135, 446 -453.

AMA Style

J. Vera-Medina, Isidoro Lillo Bravo, J. Hernández, Miguel Larrañeta. Experimental and numerical study on a freeze protection system for flat-plate solar collectors with silicone peroxide tubes. Applied Thermal Engineering. 2018; 135 ():446-453.

Chicago/Turabian Style

J. Vera-Medina; Isidoro Lillo Bravo; J. Hernández; Miguel Larrañeta. 2018. "Experimental and numerical study on a freeze protection system for flat-plate solar collectors with silicone peroxide tubes." Applied Thermal Engineering 135, no. : 446-453.

Journal article
Published: 01 March 2018 in Solar Energy
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ACS Style

M. Larrañeta; C. Fernandez-Peruchena; M.A. Silva-Pérez; I. Lillo-Bravo. Methodology to synthetically downscale DNI time series from 1-h to 1-min temporal resolution with geographic flexibility. Solar Energy 2018, 162, 573 -584.

AMA Style

M. Larrañeta, C. Fernandez-Peruchena, M.A. Silva-Pérez, I. Lillo-Bravo. Methodology to synthetically downscale DNI time series from 1-h to 1-min temporal resolution with geographic flexibility. Solar Energy. 2018; 162 ():573-584.

Chicago/Turabian Style

M. Larrañeta; C. Fernandez-Peruchena; M.A. Silva-Pérez; I. Lillo-Bravo. 2018. "Methodology to synthetically downscale DNI time series from 1-h to 1-min temporal resolution with geographic flexibility." Solar Energy 162, no. : 573-584.

Journal article
Published: 03 February 2018 in Energies
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Photovoltaic (PV) plant failures have a significant influence on PV plant security, reliability, and energy balance. Energy losses produced by a PV plant are due to two large causes: failures and inefficiencies. Knowing the relative influence of energy losses due to failures and energy losses due to inefficiencies on the PV plant energy balance contribute to the optimization of its design, commissioning, and maintenance tasks. This paper estimates the failure rates, grouped by components, and the relative impact of the failures on the PV plant energy balance through real operation and maintenance follow-up data of 15 PV plants in Spain and Italy for 15 months. Results show that the influence of failures in energy losses of all analysed PV plants is low, reaching a maximum value of 0.96% of the net energy yield. Solar field energy losses only represent 4.26% of all failure energy losses. On the other hand, energy losses due to inefficiencies have represented between 22.34% and 27.58% of the net energy yield.

ACS Style

Isidoro Lillo-Bravo; Pablo González-Martínez; Miguel Larrañeta; José Guasumba-Codena. Impact of Energy Losses Due to Failures on Photovoltaic Plant Energy Balance. Energies 2018, 11, 363 .

AMA Style

Isidoro Lillo-Bravo, Pablo González-Martínez, Miguel Larrañeta, José Guasumba-Codena. Impact of Energy Losses Due to Failures on Photovoltaic Plant Energy Balance. Energies. 2018; 11 (2):363.

Chicago/Turabian Style

Isidoro Lillo-Bravo; Pablo González-Martínez; Miguel Larrañeta; José Guasumba-Codena. 2018. "Impact of Energy Losses Due to Failures on Photovoltaic Plant Energy Balance." Energies 11, no. 2: 363.

Journal article
Published: 01 December 2017 in Renewable Energy
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ACS Style

M. Larrañeta; M.J. Reno; I. Lillo-Bravo; M.A. Silva-Pérez. Identifying periods of clear sky direct normal irradiance. Renewable Energy 2017, 113, 756 -763.

AMA Style

M. Larrañeta, M.J. Reno, I. Lillo-Bravo, M.A. Silva-Pérez. Identifying periods of clear sky direct normal irradiance. Renewable Energy. 2017; 113 ():756-763.

Chicago/Turabian Style

M. Larrañeta; M.J. Reno; I. Lillo-Bravo; M.A. Silva-Pérez. 2017. "Identifying periods of clear sky direct normal irradiance." Renewable Energy 113, no. : 756-763.

Journal article
Published: 03 June 2017 in Theoretical and Applied Climatology
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ACS Style

M. Larrañeta; Sara Moreno; Isidoro Lillo Bravo; Manuel Silva-Pérez. A methodology for the stochastic generation of hourly synthetic direct normal irradiation time series. Theoretical and Applied Climatology 2017, 131, 1517 -1527.

AMA Style

M. Larrañeta, Sara Moreno, Isidoro Lillo Bravo, Manuel Silva-Pérez. A methodology for the stochastic generation of hourly synthetic direct normal irradiation time series. Theoretical and Applied Climatology. 2017; 131 (3-4):1517-1527.

Chicago/Turabian Style

M. Larrañeta; Sara Moreno; Isidoro Lillo Bravo; Manuel Silva-Pérez. 2017. "A methodology for the stochastic generation of hourly synthetic direct normal irradiation time series." Theoretical and Applied Climatology 131, no. 3-4: 1517-1527.

Journal article
Published: 01 April 2017 in Solar Energy
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A methodology to classify days as a function of the state of the sky for Concentrated Solar Power (CSP) plant operation is proposed. For this purpose, three indexes are used to characterize the energy, variability and time distribution of the DNI and to define the type of days by means of clustering techniques. Two sets of indexes are tested and compared. The energy of days is represented by the transmittance index, kb. Two indexes are used to characterize the variability of the DNI: persistence index of the instantaneous kb values (POPD) and Variability Index (VI). Equivalent indexes have been previously used to classify the types of days using Global Horizontal Irradiation (GHI). A novel index to define the time distribution of the DNI daily energy is introduced. Clustering analysis is applied to thirteen years (2000–2012) of 10-min DNI measurements recorded in Seville (37.40°N, 6.01°W) by the Group of Thermodynamics and Renewable Energy (GTER) at the University of Seville. The k-medoids algorithm is used for cluster analysis. Through the use of well-known internal validity indexes and with the help of the L-method, the optimum number of clusters (types of days) is found to be 10. The results are compared with the assessment carried out by five experts on a reference set composed of DNI daily curves from two years (2010 and 2011). This comparison reveals a better coincidence when the clustering is performed using VI.

ACS Style

Sara Moreno; Manuel Silva-Pérez; L. Ramírez-Santigosa; Isidoro Lillo Bravo. Classification of days according to DNI profiles using clustering techniques. Solar Energy 2017, 146, 319 -333.

AMA Style

Sara Moreno, Manuel Silva-Pérez, L. Ramírez-Santigosa, Isidoro Lillo Bravo. Classification of days according to DNI profiles using clustering techniques. Solar Energy. 2017; 146 ():319-333.

Chicago/Turabian Style

Sara Moreno; Manuel Silva-Pérez; L. Ramírez-Santigosa; Isidoro Lillo Bravo. 2017. "Classification of days according to DNI profiles using clustering techniques." Solar Energy 146, no. : 319-333.

Conference paper
Published: 01 January 2017 in SOLARPACES 2016: International Conference on Concentrating Solar Power and Chemical Energy Systems
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ACS Style

Elena Pérez-Aparicio; Isidoro Lillo-Bravo; Sara Moreno-Tejera; Manuel Silva-Pérez. Economical and environmental analysis of thermal and photovoltaic solar energy as source of heat for industrial processes. SOLARPACES 2016: International Conference on Concentrating Solar Power and Chemical Energy Systems 2017, 1850, 180005 .

AMA Style

Elena Pérez-Aparicio, Isidoro Lillo-Bravo, Sara Moreno-Tejera, Manuel Silva-Pérez. Economical and environmental analysis of thermal and photovoltaic solar energy as source of heat for industrial processes. SOLARPACES 2016: International Conference on Concentrating Solar Power and Chemical Energy Systems. 2017; 1850 ():180005.

Chicago/Turabian Style

Elena Pérez-Aparicio; Isidoro Lillo-Bravo; Sara Moreno-Tejera; Manuel Silva-Pérez. 2017. "Economical and environmental analysis of thermal and photovoltaic solar energy as source of heat for industrial processes." SOLARPACES 2016: International Conference on Concentrating Solar Power and Chemical Energy Systems 1850, no. : 180005.

Conference paper
Published: 01 January 2017 in SOLARPACES 2016: International Conference on Concentrating Solar Power and Chemical Energy Systems
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ACS Style

Miguel Larrañeta; Sara Moreno-Tejera; Isidoro Lillo-Bravo; Manuel A. Silva-Pérez. Cloud transient characterization in different time steps. SOLARPACES 2016: International Conference on Concentrating Solar Power and Chemical Energy Systems 2017, 1850, 140016 .

AMA Style

Miguel Larrañeta, Sara Moreno-Tejera, Isidoro Lillo-Bravo, Manuel A. Silva-Pérez. Cloud transient characterization in different time steps. SOLARPACES 2016: International Conference on Concentrating Solar Power and Chemical Energy Systems. 2017; 1850 ():140016.

Chicago/Turabian Style

Miguel Larrañeta; Sara Moreno-Tejera; Isidoro Lillo-Bravo; Manuel A. Silva-Pérez. 2017. "Cloud transient characterization in different time steps." SOLARPACES 2016: International Conference on Concentrating Solar Power and Chemical Energy Systems 1850, no. : 140016.

Journal article
Published: 01 July 2016 in Solar Energy
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The characterisation of the solar resource of a site is essential for different phases of solar energy projects. While only rough estimates of yearly levels of solar irradiation (global or direct, depending on the technology) are needed in their very early stages, the required depth of the assessment increases as the project advances, including long-term estimates that can only be obtained through a statistical analysis of a continuous and long-term database of solar radiation measurements. This paper provides the results of a statistical analysis of thirteen years of Global Horizontal Insolation (GHI) measurements and Direct Normal Insolation (DNI) measurements from Seville, Spain (37.4°N, 6.05°W) at different time resolutions, i.e. from annual to nearly instantaneous (5-s). In addition, a new methodology for gap-filling is proposed which keeps the frequency distribution of the original dataset and reduces the uncertainty of the aggregated values (hourly, daily, monthly, yearly) due to the gaps. Some relevant results of this analysis are: (a) the instantaneous values of GHI and DNI have bimodal distributions, although of different characteristics, in agreement with the results of some works developed in similar climate locations; (b) the frequency distributions of the instantaneous and 10-min clearness index (kt) and beam fraction index (kb) are almost identical, suggesting 10 min as a good time resolution for the simulation of Concentrated Solar Power (CSP) systems oriented to feasibility analyses; (c) the distributions of hourly kt and kb values, show significant differences with respect to the instantaneous ones; (d) the difference between the percentile 99 (P99) of the instantaneous GHI and its maximum value is very high, because of the enhancement effect due to the cloud reflection, while for the DNI the corresponding values are much closer. The comparison with the results of other locations of similar climates suggest that these results can be extrapolated, at least, to other locations of similar climates. Other, more site-specific, results are: (a) the number of typical overcast days in summer is extremely low, while it takes its maximum value in December, suggesting this month as the best for maintenance operations that require halting the operation of CSP plants; (b) the annual mean daily values are 4.98 kW h m−2 for GHI and 5.68 kW h m−2 for DNI, with a low inter-annual variability and a greater monthly variability which depends on the season. The monthly and yearly average values from Seville have been compared with three long-term databases derived from satellite images. The best concordance in GHI values is found with NASA’s Surface Meteorology and Solar Energy (NASA SSE), but NASA SSE provides significantly higher DNI values compared to the Seville database. A comparison of one year of DNI and GHI measurements recorded at two locations, Durban (South Africa) and Abu Dhabi (United Arab Emirates), with high solar potential is also addressed.

ACS Style

S. Moreno-Tejera; M.A. Silva-Pérez; Isidoro Lillo Bravo; L. Ramírez-Santigosa. Solar resource assessment in Seville, Spain. Statistical characterisation of solar radiation at different time resolutions. Solar Energy 2016, 132, 430 -441.

AMA Style

S. Moreno-Tejera, M.A. Silva-Pérez, Isidoro Lillo Bravo, L. Ramírez-Santigosa. Solar resource assessment in Seville, Spain. Statistical characterisation of solar radiation at different time resolutions. Solar Energy. 2016; 132 ():430-441.

Chicago/Turabian Style

S. Moreno-Tejera; M.A. Silva-Pérez; Isidoro Lillo Bravo; L. Ramírez-Santigosa. 2016. "Solar resource assessment in Seville, Spain. Statistical characterisation of solar radiation at different time resolutions." Solar Energy 132, no. : 430-441.

Conference paper
Published: 01 January 2016 in Proceedings of EuroSun2016
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Jonathan Vera Medina; Isidoro Lillo Bravo; Laima Reina Piñero; Sara Moreno Tejera; Víctor Martínez; José González. Influence of the Input Parameters Accuracy Defined in the Standard Iso 9459-5 for a Domestic Water Heating Thermosiphon. Proceedings of EuroSun2016 2016, 1 .

AMA Style

Jonathan Vera Medina, Isidoro Lillo Bravo, Laima Reina Piñero, Sara Moreno Tejera, Víctor Martínez, José González. Influence of the Input Parameters Accuracy Defined in the Standard Iso 9459-5 for a Domestic Water Heating Thermosiphon. Proceedings of EuroSun2016. 2016; ():1.

Chicago/Turabian Style

Jonathan Vera Medina; Isidoro Lillo Bravo; Laima Reina Piñero; Sara Moreno Tejera; Víctor Martínez; José González. 2016. "Influence of the Input Parameters Accuracy Defined in the Standard Iso 9459-5 for a Domestic Water Heating Thermosiphon." Proceedings of EuroSun2016 , no. : 1.

Journal article
Published: 01 December 2015 in Solar Energy
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Several studies have confirmed the relevant impact of the resolution and frequency distribution of solar radiation data on the results of detailed production models. Many of the available direct normal irradiance (DNI) databases generated from the satellite images have an hourly resolution. In the present work, we have proposed improvements to an existing model for the generation of 10-min synthetic DNI data from the hourly average DNI values. In the original model, the irradiance is divided into a deterministic and a stochastic component, i.e., the contribution from the hourly mean and stochastic fluctuation obtained from the mean depending on the sky condition, respectively. We have implemented several improvements, and the most relevant is the consistency of the synthetic data with the state of the sky. The adaptation and application of the model to the location of Seville show significant improvements over its predecessor as it achieved 7% rRMSD in hourly values and 1% rRMSD in daily values and presented a realistic frequency distribution in the 10-min resolution. In comparison with the original model, the application of the improved model showed significant performance improvements without any further adaptations to other locations with different climatological characteristics than Seville.

ACS Style

M. Larrañeta; Sara Moreno; Manuel Silva-Pérez; Isidoro Lillo Bravo. An improved model for the synthetic generation of high temporal resolution direct normal irradiation time series. Solar Energy 2015, 122, 517 -528.

AMA Style

M. Larrañeta, Sara Moreno, Manuel Silva-Pérez, Isidoro Lillo Bravo. An improved model for the synthetic generation of high temporal resolution direct normal irradiation time series. Solar Energy. 2015; 122 ():517-528.

Chicago/Turabian Style

M. Larrañeta; Sara Moreno; Manuel Silva-Pérez; Isidoro Lillo Bravo. 2015. "An improved model for the synthetic generation of high temporal resolution direct normal irradiation time series." Solar Energy 122, no. : 517-528.

Journal article
Published: 01 January 2014 in Energy Procedia
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ACS Style

S. Moreno-Tejera; E. Pérez-Aparicio; J.M. Barea-García; Isidoro Lillo Bravo; M.A. Silva-Pérez; Sara Moreno; Manuel Silva-Pérez. Assessment of a Global-to-Direct Empirical Model for the Long-term Characterization of Direct Normal Insolation. Energy Procedia 2014, 49, 2377 -2386.

AMA Style

S. Moreno-Tejera, E. Pérez-Aparicio, J.M. Barea-García, Isidoro Lillo Bravo, M.A. Silva-Pérez, Sara Moreno, Manuel Silva-Pérez. Assessment of a Global-to-Direct Empirical Model for the Long-term Characterization of Direct Normal Insolation. Energy Procedia. 2014; 49 ():2377-2386.

Chicago/Turabian Style

S. Moreno-Tejera; E. Pérez-Aparicio; J.M. Barea-García; Isidoro Lillo Bravo; M.A. Silva-Pérez; Sara Moreno; Manuel Silva-Pérez. 2014. "Assessment of a Global-to-Direct Empirical Model for the Long-term Characterization of Direct Normal Insolation." Energy Procedia 49, no. : 2377-2386.