Diez-Mediavilla Montserrat

Universidad de Burgos | UBU · Department of Electromechanical Engineering

In the present study, different models constructed with meteorological variables are proposed for the determination of horizontal ultraviolet irradiance (IUV), on the basis of data collected at Burgos (Spain) during an experimental campaign between March 2020 and May 2022. The aim is to explore the effectiveness of a range of variables for modellin...

Digital sky images are studied for the definition of sky conditions in accordance with the CIE Standard General Sky Guide. Likewise, adequate image-processing methods are analyzed that highlight key image information, prior to the application of Artificial Neural Network classification algorithms. Twenty-two image-processing methods are reviewed an...

In this study, ten-minute meteorological data-sets recorded at Burgos, Spain, are used to develop models of Photosynthetic Active Radiation (PAR) following two different procedures: multilinear regression and Artificial Neural Networks. Ten Meteorological Indices (MIs) are chosen as inputs to the models: clearness index (kt), diffuse fraction (kd),...

Plant growth is directly related to levels of photosynthetic photon flux density, Qp. The improvement of plant-growth models therefore requires accurate estimations of the Qp parameter that is often indirectly calculated on the basis of its relationship with solar irradiation, RS, due to the scarcity of ground measurements of photosynthetic photon...

The new European directives focused to achieve public Net-Zero Energy Buildings require for their application the knowledge of the potential of photovoltaics (PV) generation of these buildings. The available building surfaces (façades and roofs) for PV integration depend on the building's location and orientation, and relative position of the nearb...

Daylight availability knowledge is the first step for an energetic and visually efficient building and city design. It can be estimated with the Vertical Sky Component (VSC), which is defined as the ratio of the vertical diffuse illuminance over the unobstructed horizontal diffuse illuminance, simultaneously measured at the same point. These illumi...

A new design for the use of photovoltaic and thermal (PV/T) technology with thermal storage is reported in this work. In the new design, a phase change material (PCM) tank is added to the backside of the photovoltaic panel. The advantages of this design are the storage of thermal energy and the efficiency improvement of the photovoltaic (PV) panel...

Spain is among the European countries with the greatest photovoltaic potential. During the first decade of the 2000s, Spain was a European leader in installed photovoltaic power and job creation in the renewable energy sector, strongly influenced by a very favorable regulatory framework and public subsidies at a time of economic growth. That situat...

Spain is a country with a high dependence on fossil fuels. For this reason, in 2007, it implemented a bonus system that aimed to encourage the production of renewable energies, particularly photovoltaic solar energy. These production bonuses, guaranteed by the Spanish government, led to an exponential increase in the number of companies in the mark...

Sky classification is a complex problem, due in part to such abstract conceptual definitions as clear, intermediate, and overcast, as well as other intermediate ranges. The CIE (Commission Internationale de L’Éclairage) Standard classification offers a solution to this problem, although its application requires data on the luminance distribution of...

Composite materials have great potential for growth due to their excellent properties and their multiple applications. The study of the thermal properties of the new composites resulting from the combination of epoxy resin and phase change materials (PCM), as well as thickening agents and thermally conductive compounds, was the objective of this wo...

The determination of optimal illumination conditions in buildings is of great interest both for reducing energy consumption and for exploiting solar resources with greater efficiency and sustainability. The most commonplace method of estimating daylight is the luminous efficacy approach, using the more widely measured solar irradiance. In this pres...

Computational Fluid Dynamic (CFD) software is a really useful tool for both engineering and researching. With the only use of a computer it is possible to compare different geometries, material, contour parameters… Moreover, the software can show all parameter for each cell of the geometry, so the capacity to know the behaviour of the system in eve...

An experiment to characterize the behaviour of heat pipes is presented. Measurements allow carrying on parametric studies of the effect of the length, diameter, wick type and working fluid on the thermal resistance of different heat pipes. Furthermore, the design allows us to consider the effect of the tilt angle and of the relative height between...

Potential photovoltaic (PV) production from vertical façades facing the four cardinal points of the compass are calculated from daily average vertical global insolation readings measured in Burgos, Spain. Ten-minute data sets are collected over forty-five months, from January 2014 to September 2017, in the experimental campaign to produce estimates...

Daily data of Global, Diffuse and Beam Horizontal Insolation and Global Vertical (North, South, East and West orientations) insolation recorded in Burgos, Spain, are presented in this paper. Ten-minute irradiance data sets are collected over forty-five months in the experimental campaign to produce estimates of daily insolation levels. This data wa...

Daylighting is recognized as an important and useful strategy in the design of energy efficient buildings. Daylight is still the best source of light for good colour rendering and visual comfort. In this study, a new model of global luminous efficacy over a horizontal surface is proposed. A comparative study of eighteen classic models is presented,...

This paper presents a methodology to design and to predict the behaviour of electronic circuits, which combines artificial neural networks and design of experiments. This methodology can be used to model output variables in electronic circuits either with similar features to the circuit configuration that is analysed in this study or with more comp...

Outdoor daylight conditions in Burgos, Spain, are studied throughout a full year. The CIE standard sky type is selected in accordance with the lowest RMSD (Root Mean Square Deviation) following the comparison of both the theoretical and the experimental luminance distributions in the sky hemisphere. The selection is based on luminance distribution...

An exhaustive evaluation of the performance of decomposition models to estimate direct and diffuse components from the global horizontal solar irradiance has been carried out in this work. The main objective of this work has been to compare the model performance for two different time bases, hourly and monthly average hourly bases. An extensive dat...

Renewable energies, including photovoltaic energy, are attracting widespread international attention, in reaction to worsening environmental problems and the diminishing long-term sustainability of fossil fuel energies. In this work, the potential benefits of installing photovoltaic panels on several buildings at the Spanish Naval Military School (...

Four spatial interpolation methods (Inverse Distance Weighted, Spline, Kriging and Natural Neighbor) and their different variations are employed to map Global Horizontal Irradiation (GHI) in Castilla-León, Spain. The work has been performed using the software ArcGis, widely used in geostatistical applications, showing the versatility of the system...

Solar energy potential analysis on oriented and tilted surfaces, such as building façades, is of capital importance to estimate the energy production potential in integrated systems, such as BIPVs. The spatial distribution of solar diffuse energy outstands as one of the most critical factors in order to improve performance simulations. Nevertheless...

Direct solar irradiance has to be determined for the design of many energy applications such as photovoltaic systems and concentration systems, and the generation of solar potential maps for energy use. Knowledge of the accurate values of radiation components in a local area will allow optimal sizing of solar energy conversion systems. The estimate...

Grid connected PV systems, or GCPVS, produce clean and renewable energy through the photovoltaic effect in the operation stage of the power plant. However, this is the penultimate stage of the facilities before its dismantlement. Before starting generating electricity with zero CO2 emissions, a negative energy balance exists mainly because of the e...

Among the various methods of measuring diffuse solar irradiance, shadowing devices are ones of the most commonly used in solar research all over the world. These instruments work with a basic pyranometer, properly calibrated for the measurement of solar irradiance, with a shadowing element, which can be a disk or a band (Drummond’s shadow-band), th...

Dispositivo de medida de radiación difusa que comprende un marco y al menos dos sensores de radiación fijados a dicho marco, además comprende un anillo lobular fijado al marco, con un lóbulo por cada sensor de manera que cada lóbulo proyecta una sombra a un sensor diferente, proporcionando el anillo lobular sombra de manera simultánea a todos los s...

The variable nature of solar energy required for its efficient use the complement of energy storage to adapt adequately the generation and production curves. As PV/T technology produces both electricity and heat energy, two storage devices should be necessary. Batteries are the most common method for storing electricity. Nevertheless, different tec...

Four empirical mathematical models have been used to characterise the global vertical solar irradiation in the city of Burgos, Spain. The cardinal orientations (North, South, East and West) have been studied in order to determine the solar energy available on vertical surfaces in any orientation. The four models chosen from the literature cover all...

Four spatial interpolation methods (Inverse Distance Weighting, Spline, Kriging and Natural Neighbor) and their different variations have been employed to map Solar Global Horizontal Irradiation (GHI) in Castilla- Leon, Spain. The interpolation network consists of 71 ground meteorological stations and seven complete years of half hourly data have b...

In order to model and simulate solar energy plants (photovoltaic, thermal or hybrid) it results mandatory to characterize the site's solar potential. Moreover, for the complete integration of those systems in buildings and other urban structures, horizontal irradiance measurements are not enough and the value of all its components on any tilted and...

A device is proposed for the measurement of diffuse solar irradiance on tilted surfaces pointing-to as well as fixed on the equatorial direction. Most commercial devices are not designed for this purpose. Here, we present a specific design for a system based on a single multi-lobe shadow-ring that allows us to measure diffuse irradiance with severa...

En la presente comunicación se expone el diseño, configuración, calibración, particularidades y puesta en marcha de una micro-red de estaciones radiométricas situada en el centro de Castilla y León con objeto de mejorar la información climática disponible y la caracterización del recurso solar en la zona. En la actualidad, la micro-red está compues...

Hasta hace pocos años existían solo dos tipos de tecnologías para aprovechar la energía solar: producción de electricidad mediante paneles fotovoltaicos o la producción de calor mediante los paneles solares térmicos. Sin embargo, la tecnología fotovoltaica presenta una baja eficiencia, es decir se precisan grandes superficies para cubrir pequeñas d...

La tecnología solar híbridatérmica y fotovoltaica consigue la producción simultánea de calor y energía térmica a partir de la Radiación solar. Además de conseguir una eficiencia energética superior al sumar la de los dos equipos, la ventaja fundamental del sistema frente a la producción energética mediante sistemas fotovoltaicos y térmicos separado...

En este trabajo se estudia el acoplamiento de células termo- generadoras (celdas Seebeck) a la parte posterior de paneles fotovoltaicos, aprovechando el calor residual para producir energía. Además este acoplamiento reduce la temperatura de trabajo del panel fotovoltaico, mejorando tanto su rendimiento eléctrico como su vida útil a largo plazo. Se...

El presente trabajo se centra en la medida y estimación de la radiación solar difusa sobre superficies inclinadas tales como fachadas de edificaciones o paramentos entre otros. La mayor parte de los dispositivos comerciales existentes hasta la fecha no están preparados para este propósito. Es por ello que se presenta un nuevo dispositivo diseñado p...

Two complete years of operation of two grid-tied PV facilities is presented. Energetic and economic performance of both installations has been compared. Located in the same place, the installation of these facilities followed the same construction criteria - PV panels, panel support system and wiring - and the facilities are exposed to the same atm...

This paper is focused in the diffuse solar radiation measurement and estimation on inclined surfaces such as façades. Most commercial devices are not prepared for this purpose. Thus, we present an especially designed device. The proposed system is based on a single multi-lobes shadow ring and allows us measure diffuse radiation with several pyranom...

Distributed generation and auto-consumption contributes to sustainable energy system opening a new scenario of employment and financial welfare and further liberalization of the electricity market. Net Energy Metering (NEM) can help, in a decisive way, to the feasibility of it. The emergence in recent years of new concepts, developments and systems...

Distributed generation and auto-consumption contributes to sustainable energy system opening a new scenario of employment and financial welfare and further liberalization of the electricity market. Net Energy Metering (NEM) can help, in a decisive way, to the feasibility of it. The emergence in recent years of new concepts, developments and systems...

Current PV cells technology takes advantage mainly from beam radiation. In this context the sun- trackers are such devices for efficiency improvement. On the other hand, projected shadows be- tween devices make mandatory to increase the distances between mounting systems. Thus, the land’s capacity for mounting PV panels can be dramatically decrease...

The principal objective of this study is to analyze the performance of sun-trackers devices compared with fixed flat plate systems using data from a widely used irradiation prediction software (PVGIS). We analyze typical parameters as daily and monthly sum of global irradiation (Hd and Hm) or average daily and monthly estimated electricity producti...

The feasibility of exploiting solar energy in Castilla y León, Spain, is investigated in this study. The temporal and the geographical solar resources in the region and their trends were studied over a seven year period. Maximum, minimum, and average values of monthly and annual global horizontal radiation and the clearness index were calculated fr...

The durability of PV modules is a topic of great importance to the PV community. The rapid expansion of PV capacity in Spain has resulted in a greater need to monitor those PV modules that have been in operation over long periods. For instance, the potential degradation of PV modules is a topic of great interest to manufacturers, plant managers and...

A new procedure is presented to analyse the performance of grid-tied PV facilities. It needs limited amounts of data that are easily sourced and is based on knowledge of the analysed system and its mode of operation. The procedure is applied, in a case study, to compare real PV production at two 100 kWp grid-connected PV installations. Located in t...

In this paper, main configurations and technical regulations in Spain about Net Energy Balance Systems and Smart Grids are presented. This short of installations is quite interesting for the future developments of Green Energy Sources, especially photovoltaic ones. The main benefits are the reduction of power losses in the distribution system, opti...

The average hourly value of DNI (Direct Normal Irradiation) is estimated, in terms of the clearness index and the diffuse fraction, using the average hourly and monthly data on global and diffuse radiation recorded at five Spanish cities with different latitudes. The data sets were recorded by AEMET (National Meteorological Agency) over more than t...

This comparative study of two PV grid-connected systems discusses their operation, and their production and generation costs, using a new procedure that requires only a small number of easily obtained parameters. The procedure compares the real PV production of the two installations at the same location. Their construction shares the same design cr...

The main aim of this research work is to analyse the importance of modelling solar data. Should engineers and scientists spend time modelling solar data from other variables or it is a simply waste of time? Which applications truly need a precise forecast of the solar variables? Which spatial and time resolution is needed? In this work we have prop...

In this paper, an efficient method is presented for kinematic analysis of a designed parallel kinematics sun tracker. This design improves the distribution of the forces and so, makes this device more adaptable for roof-top installations. Future developing work related with this prototype makes a kinematic analysis mandatory. This analysis describe...

The accurate prediction of energy production is crucial to the design and installation of PV plants. Several commercial and freeware tools exist to predict energy production. Four software modeling tools have been evaluated in this study: RETScreen, Solar Advisor Model (SAM), PVGIS and PVSyst. This evaluation compared the predicted data on a monthl...

Real PV production is compared between two 100 kWp grid-connected PV installations. The facilities are located in the same area, are subject to the same ambient temperature and radiation, and applied the same construction criteria: PV panels, panel support system and wiring. Their main difference is found in the inverter technology that each one us...

A detailed description is made of a software application that is designed to optimize a sun-tracker mechanism. It takes the main characteristics of any given installation site into account: geographical coordinates, inclination and orientation of the assembly platform. The desired result is a low-cost mechanism, which will have minimum-length const...

In this paper, an efficient method is presented for kinematic analysis of a designed parallel kinematics sun tracker. This design improves the distribution of the forces and so, makes this device more adaptable for roof-top installations. Future developing work related with this prototype makes a kinematic analysis mandatory. This analysis describe...

The accurate prediction of energy production is crucial to the design and installation of PV plants. Several commercial and freeware tools exist to predict energy production. Four software modeling tools have been evaluated in this study: RETScreen, Solar Advisor Model (SAM), PVGIS and PVSyst. This evaluation compared the predicted data on a monthl...

A small hydropower plant in Spain is studied from an energetic and economic perspective. The viability of the facility is examined using the freeware software RETScreen. Calculated and standard operational data are compared, thereby demonstrating the feasibility of the project from all points of view. The study highlights the growing interest in re...

ABSTRACT: A study is conducted of real PV production from two 100 kWp grid-connected installations located in the same area, both of which experience the same fluctuations in temperature and radiation. Data sets on production were collected over an entire year and both installations were compared under various levels of radiation. The installations...