Should solar irradiance be included in inverse modeling

Comparative Study of Solar Radiation Models for the Estimation of Solar Radiation Using Short-Term Meteorological Data in Lawra, Ghana, 2022

Monthly average daily global solar radiation data are essential for the design and study of solar energy systems. The performance and accuracy of eleven models for the estimation of monthly average global solar radiation were compared in this study. Nineteen months (Nov 2020 – May 2022) ground measurement data consisting of monthly mean daily sunshine duration, relative humidity, minimum and maximum temperatures, and global solar radiation collected from the Lawra Solar Plant were used. The models were compared using statistical indices. According to the indices, most of the models were in reasonably good agreement with the measured data. Two model equations, however, were found to have the highest accuracy and can thus be used to estimate monthly average global solar radiation in Lawra and other places with similar climatic conditions where radiation data is unavailable.

Energy Procedia

District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasing the greenhouse gas emissions from the building sector. These systems require high investments which are returned through the heat sales. Due to the changed climate conditions and building renovation policies, heat demand in the future could decrease, prolonging the investment return period. The main scope of this paper is to assess the feasibility of using the heat demand-outdoor temperature function for heat demand forecast. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665 buildings that vary in both construction period and typology. Three weather scenarios (low, medium, high) and three district renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were compared with results from a dynamic heat demand model, previously developed and validated by the authors. The results showed that when only weather change is considered, the margin of error could be acceptable for some applications (the error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and improve the accuracy of heat demand estimations.

2013

It is very unusual to have global irradiance data for a tilted surface and even more for a surface with a perfect sun tracking. The most common available data is the global horizontal irradiance, thus it is necessary to convert the available data into the desirable inclination. The purpose of this paper is to analyse the different response of the radiation models that are used to calculate the global irradiance in static surfaces and in surfaces with a perfect sun tracking (two axis). For that end 10 years of measured data has been utilized. The combination of methods that better approaches to the experimental values is the one formed by Orgill Hollands and Perez for stationary surfaces and modeTemps-Coulson for two-axis tracking.

A new set of climatic data for different kinds of calculations has been compiled for various Swiss localities. This includes the generation of new design reference year data sets with hourly values for e.g. building simulations. The procedure conforms to a set of new European standards describing the algo- rithms. One key element in this is the processing of solar radiation information, especially for the separation into direct and diffuse components. The most advanced methodology was used. Simulation examples for testing the data showed surprisingly high differences in the energy consumption results compared to the old data sets. Differences as high as +34% in cooling energy resulted for a realistic case. Analysis showed the main reason being the radiation data and especially the direct/diffuse split. This puts into perspective some controversies concerning model details.

International Journal of Sustainable Built Environment, 2014

This research work proposed a new model used to predict the direct, diffuse and global solar flues for clear skies, by making the comparison between the numerical simulation of this model and the climatology measured data of Energetic Laboratory station the Faculty of science of Tetouan city (35.57361 latitude, À5.37528 longitude) in Northern Morocco.

2016

Abstract- The estimation of hourly and daily solar radiation values on inclined surfaces starts with the determination of the corresponding hourly values on the horizontal plane. To serve the latter purpose the Meteorological Radiation Model was developed. The goal of the model is to estimate solar radiation at places where there are not available measurements. This work presents a theoretical description of the code and gives comparison between meas urements and estimated values for Athens, Lisbon and a Japanese location.

Energy Conversion and Management, 2006

In a lot of sites, at best, only global irradiations on horizontal planes are available. As most systems using solar energy are tilted, it is obvious that these data are not sufficient. The purpose of our work consists in predicting the solar irradiation on inclined surfaces based on horizontal measurements. To reach this goal, two previous studies were performed. They consisted in quantifying the accuracy of various well-known models of the literature: the first type of models (seven correlations) calculated diffuse horizontal irradiations from global ones and the second type (fifteen models) computed global irradiations on inclined planes from diffuse and global components on a horizontal surface. This study combines the two classes of models and calculates the adequacy of each association for experimental hourly data collected on the French Mediterranean site of Ajaccio. We compared these combinations with the Olmo model, transforming global irradiations directly onto tilted planes from horizontal ones.

Proceedings of the 9th International MODELICA Conference, September 3-5, 2012, Munich, Germany, 2012

This paper presents a model to estimate the solar radiation under clear sky conditions over stationary, moving as well as flying objects. For the latter it is important to predict the peak solar irradiance under clear sky condition to calculate maximum possible solar thermal loading. In this paper results of irradiation over surface on ground and over aircraft windows and windshields at cruise altitude are presented. Another model implemented, calculates the view factor between two or more surfaces. Determination of the long-wave radiant heat exchange between two or more surfaces or heat exchange with a surface itself requires a view factor matrix. There are several analytical solutions available to calculate view factors for simple and known configurations. Many building simulation programs estimate the view factors in a simplified way, especially when complex geometries are involved. The simplified approach may result in high errors of surface temperatures, which can further cause error in energy balance and estimation of comfort level. The purpose of creating this model is to calculate view factors between complex geometries. The view factor matrices of an enclosed space and of a geometry with openings on its surfaces are presented in this paper. A sensitivity analysis of a view factor matrix is also presented.

Applied Sciences

The achievement of the targets for reducing greenhouse gas emissions set by the Paris Agreements and the Swiss federal law on the reduction of greenhouse gas emissions (CO2 law) requires massive use of renewable energies, which cannot be achieved without their adoption by the general public. The solar cadaster developed as part of the INTERREG G2 Solar project is intended to assess the solar potential of buildings at the scale of Greater Geneva—for both industrial buildings and for individual residential buildings—at a resolution of 1 m. The new version of the solar cadaster is intended to assess the solar potential of roofs, as well as that of vertical facades. The study presented here aims to validate this new version through a comparison with results obtained with two other simulation tools that are widely used and validated by the scientific community. The good accordance with the results obtained with ENVI-met and DIVA-for-Rhino demonstrates the capability of the radiative mode...

Building energy balance is strictly connected with incident solar irradiation, whose reliable estimation on envelope surfaces is essential for the evaluation of building solar gains. While diffuse and beam solar components on tilted surfaces are required, meteorological stations usually measure only global radiation on horizontal plane. In the literature, several diffuse irradiance and tilted surface irradiance models are reported, nevertheless, none is suitable for any locality. In this work, we assess the extent to which the choice of solar radiation models affects the predicted energy performance of a set of simplified reference buildings. By means of a full factorial plan, a set of 72 simplified residential buildings is defined by changing the main building features. A full combination of 22 horizontal diffuse irradiance models coupled with 12 irradiance models for tilted surfaces is implemented and used as a preprocessor of solar data used in TRNSYS. The results highlight that ...