UN METODO EMPIRICO PARA LA PREDICCION DE LA RADIACION SOLAR GLOBAL DIARIA MEDIA MENSUAL,SOBRE UNA SUPERFICIEHORIZONTAL, EN COSTA RICA

Lo que se pretende con este trabajo es probar el método de Swartman y Ogunlade (1966), en las aéreas geográficas de Limón, Buenos Aires, Fabio Baudrit (Alajuela), Nicoya y Puntarenas, donde existen datos de brillo solar, humedad relativa y radiación solar global diaria media mensual. Se prueba la validez de este método para estas estaciones en estudio, con un valor aceptable de ± 10% de error en la mayoría de los casos. En ausencia de aparatos que miden directamente la radiación solar global, se recomienda utilizar este método, pues únicamente requiere datos de humedad relativa y brillo solar, que se miden directamente en casi todas las estaciones meteorológicas del país.   SUMMARY This article attempts to verify the method used by Swartman and Ogunlade (1966) in the areas of Limón, Buenos Aires, Fabio Baudrit (Alajuela), Nicoya and Puntarenas, where data exist concerning solar brilliance, relative humidity and daily global solar radiation based on monthly averages. The validity of this method is proved in reference to the above mentioned study sites, with an acceptable error factor of ± 10% in the majority of the cases. The usage of this method is recommended in the absence of apparatus that measure directly the global solar radiation, because you only need data concerning relative humidity and solar brilliance; data that is directly collected in all of the meteorogical stations located in Costa Rica.   RESUME Le but de ce travail est la probation de la méthode de Swartman et Ogunlade (1966), en l’appliquant dans des aires géographiques tant diverses comme Limón, Buenos Aires, Fabio Baudrit (Alajuela), Nicoya et Puntarenas ; c'est-à-dire là où existe des mesures de la durée de l’ensoleillement, de l’humidité relative et de la moyenne mensuelle de la radiation solaire globale quotidienne. Le test de cette méthode, para ces stations donne une erreur relative de 10% dans la plupart de cas. Quand on manque d’appareils pour la mesure de la radiation solaire globale, on recommande l’usage de cette méthode, puisqu’elle se base Our les registres d’humidité relative et d’heures d’ensoleillement mesurées que toutes les stations météoritiques du pays.  

Medición y predicción de la radiación solar global ultravioleta (0.295-0.385 μm) en condiciones de cielos claros y sin nubes (ING)

Values of ultraviolet global solar radiation were measured with an ultraviolet radiometer and also predicted with an atmospheric spectral model. The values obtained with the atmospheric spectral model, which is physically based, were analyzed and compared with the experimental values measured in situ. The measurements were performed for different zenith angles under clear skies conditions in Heredia, Costa Rica. The necessary input data include latitude, altitude, surface albedo, Earth-Sun distance, as well as atmospheric characteristics: atmospheric turbidity, precipitable water and atmospheric ozone. The comparisons between the measured and predicted values gave satisfactory results.

Cálculo espectral de la irradiación solar directa, difusa y global en Heredia, Costa Rica (ING)

A clear sky solar spectral model which describes the irradiation flux has been tested experimentally in Heredia, Costa Rica. A description of the model and comparisons with radiation data are presented. The model computes spectral fluxes of direct, diffuse and global solar irradiation incident on a horizontal surface. Necessary inputs include latitude, altitude, and surface albedo as characteristics of a location as well as the atmospheric characteristics: turbidity, precipitable water vapor, and total ozone content. The results evidence a satisfactory agreement.

Cálculo y mapeo de la radiación solar directa y difusa en Costa Rica (ING)

Knowledge of direct and diffuse solar radiation in the area is vital importance for the use of solar energy, since it is a prerequesite information for the assessment and design of solar energy system. The work presented here focus on calculation and plotting of contours values of direct and diffuse solar radiation maps based on sixty two scattered radiometric stations nation wide. In the plotting of these contours experimental and predicted values are used, these are compared with the period of dry and rainy season into the six main climate regions of Costa Rica: Central Valley, North Pacific, Central Pacific, South Pacific, North Zone and Caribbean Region. The observed daily mean levels of direct solar radiation oscillate between 6.1 and 10.1 MJ/m2 with higher values in the North Pacific, western part of the Central Valley and in the tops of the highest mountains. The lowest values agree with the North Zone and the Caribbean Region. The highest values of diffuse solar radiation agree with the North Zone and the South Pacific. It is observed an increase of 40% of the direct radiation during dry season months.