20 documents found, page 1 of 2
Solar Irradiation Data Processing using estimator MatriceS (SIMS) validated for...
Silva, Hugo G.; Abreu, Edgar F.M.; Lopes, Francisco; Cavaco, Afonso; Canhoto, Paulo; Neto, Jorge; Collares-Pereira, ManuelAccurate solar resource assessment is essential in all the different phases of solar energy systems design and implementation. On a local scale, the solar resource is best assessed from ground measurements and, if available, with the existence of complete time-series of hourly values for the long-term resource estimation. However, these usually suffer from the occurrence of data gaps that can be as large as sev...
Solar Irradiation Data Processing using estimator MatriceS (SIMS) validated for...
Silva, Hugo G.; Abreu, Edgar F.M.; Lopes, Francisco; Cavaco, Afonso; Canhoto, Paulo; Neto, Jorge; Collares-Pereira, ManuelAccurate solar resource assessment is essential in all the different phases of solar energy systems design and implementation. On a local scale, the solar resource is best assessed from ground measurements and, if available, with the existence of complete time-series of hourly values for the long-term resource estimation. However, these usually suffer from the occurrence of data gaps that can be as large as sev...
Improved method for solar resource assessment using simulations from the numeri...
Pereira, Sara; Abreu, Edgar F.M.; Iakunin, Maksim; Canhoto, Paulo; Salgado, RuiNumerical Weather Prediction (NWP) models tend to show significant errors to what solar radiation forecast is concerned, mainly due to difficulties with the correct parameterization of clouds, the usage of monthly-mean aerosol climatology, and the high computational effort associated to the detailed modeling of radiative transfer in the atmosphere. This is especially evident in the case of direct normal (DNI) a...
Prediction of circumsolar irradiance and its impact on CSP systems under clear ...
Abreu, Edgar F.M.; Canhoto, Paulo; Costa, Maria JoãoIn this work, a model to estimate circumsolar normal irradiance (CSNI) for several half-opening angles under clear skies was developed. This approach used a look-up table to determine the model parameters and estimate CSNI for half-opening angles between 0.5° and 5°. To develop and validate the proposed model, data from five locations worldwide were used. It was found that the proposed model performs better at ...
Method for solar resource assessment using numerical weather prediction and art...
Pereira, Sara; Abreu, Edgar F.M.; Iakunin, Maksim; Cavaco, Afonso; Salgado, Rui; Canhoto, PauloIn this work a method for regional solar resource assessment based on numerical weather prediction (NWP) and artificial neural network (ANN) models is presented. The method was developed using typical meteorological and solar radiation data and applied to the location of E ́vora, Portugal with the goal of assessing solar global horizontal (GHI) and direct normal (DNI) irradiations with 1.25 km of horizontal res...
Impact of a large artificial lake on regional climate: A typical meteorological...
Iakunin, Maksim; Abreu, Edgar F.M.; Canhoto, Paulo; Pereira, Sara; Salgado, RuiLarge artificial lakes and reservoirs affect the meteorological regime of the shore area and the local climate takes on a number of new features that were previously absent. This work focuses on the weather impact of the Alqueva reservoir, the largest artificial lake in Western Europe. An extensive set of numerical simulations using Meso-NH mesoscale atmospheric model coupled with FLake (Freshwater Lake) scheme...
Circumsolar irradiance modelling using libRadtran and AERONET data
Abreu, Edgar F.M.; Canhoto, Paulo; Costa, Maria JoãoThe aperture angle of pyrheliometers is greater than the limit angle of the solar disk, which leads to a contribution of circumsolar radiation to the measurements of direct normal irradiance (DNI). On the other hand, since Concentrating Solar Power (CSP) technologies have, generally, a lower aperture angle with respect to pyrheliometers, it is important to determine the fraction of circumsolar irradiance presen...
Modifying a pyrheliometer to measure direct normal and circumsolar irradiance
Abreu, Edgar F.M.; Canhoto, Paulo; Costa, Maria JoãoDirect normal irradiance (DNI) is key to concentrating solar power (CSP) systems energy generation. However, pyrheliometric measurements of DNI also include a circumsolar normal irradiance (CSNI) component because the aperture angle of the instrument is larger than the sun disk. CSNI is due to the scattering of the sun rays by molecules, aerosols and some cloud types such as cirrus clouds [1]. As a result, ener...
Comparison and assessment of circumsolar ratio models for Évora, Portugal
Abreu, Edgar F.M.; Canhoto, Paulo; Costa, Maria JoãoThe sun rays are scattered due to molecules, aerosols and some cloud types, such as cirrus clouds, and a region near to the vicinity of the sun disk, known as circumsolar region, with relatively high diffuse sky radiance is formed [1]. Consequently, this diffuse radiation is called circumsolar normal irradiance (CSNI). Modelling the CSNI is important because pyrheliometers (the instruments that are used to meas...
Atmospheric extinction levels of solar radiation using aerosol optical thicknes...
Carra, Elena; Marzo, Aitor; Ballestrín, Jesús; Polo, Jesús; Barbero, Javier; Alonso-Montesinos, Joaquín; Monterreal, Rafael; Abreu, Edgar F.M.In order to make the concentrating solar power (CSP) more competitive, an accurate prediction of the solar radiation incident on CSP tower plant receivers is necessary. The extinction in the heliostat-receiver pathway plays an important role in the optical loss of the solar field and therefore, in the performance of the plant. In order to correctly operate these kind of plants and to select new potential emplac...