Ground level solar radiation prediction model including cloud cover effects

Solar Energy ◽  
1984 ◽  
Vol 33 (6) ◽  
pp. 493-499 ◽  
Author(s):  
Russell Brinsfield ◽  
Melih Yaramanoglu ◽  
Fredrick Wheaton
2018 ◽  
Vol 140 (2) ◽  
Author(s):  
Jesús García ◽  
Iván Portnoy ◽  
Ricardo Vasquez Padilla ◽  
Marco E. Sanjuan

Variation in direct solar radiation is one of the main disturbances that any solar system must handle to maintain efficiency at acceptable levels. As known, solar radiation profiles change due to earth's movements. Even though this change is not manipulable, its behavior is predictable. However, at ground level, direct solar radiation mainly varies due to the effect of clouds, which is a complex phenomenon not easily predictable. In this paper, dynamic solar radiation time series in a two-dimensional (2D) spatial domain are obtained using a biomimetic cloud-shading model. The model is tuned and compared against available measurement time series. The procedure uses an objective function based on statistical indexes that allow extracting the most important characteristics of an actual set of curves. Then, a multi-objective optimization algorithm finds the tuning parameters of the model that better fit data. The results showed that it is possible to obtain responses similar to real direct solar radiation transients using the biomimetic model, which is useful for other studies such as testing control strategies in solar thermal plants.


1992 ◽  
Vol 11 (2) ◽  
pp. 37-41 ◽  
Author(s):  
Jinlai Xie ◽  
Xunren Yang ◽  
Qitai Li

Can solar eclipses generate AGWs? If so, how are they excited? This is still an open question and a long-standing dispute within academic circles. The annular solar eclipse which traversed the Chinese mainland on September 23rd 1987 afforded a rare and excellent opportunity to study this problem. Vast amounts of data of microbarometric pressure at ground level, radio-sondage, solar radiation and ionospheric probing were obtained from various observation stations. By making use of these abundant data synthetically, an important conclusion has been reached: there is an obvious accord between the period of the solar eclipse, AGW and the fluctuation period of solar direct radiation. All the solar eclipse AGWs in different places come from two different kinds of atmospheric oscillation, i.e., the forced oscillation generated directly by changes in direct solar radiation and the buoyancy oscillation in the local atmosphere above various spots. The former has a longer wave period and a larger amplitude, depending directly upon the radiation change during the solar eclipse; the latter has a shorter period and smaller amplitude, depending upon thermodynamic stability in the local atmosphere during the solar eclipse and the atmospheric moisture condition.


Climate ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 89 ◽  
Author(s):  
Andri Pyrgou ◽  
Mattheos Santamouris ◽  
Iro Livada

High daily temperatures in the Mediterranean and Europe have been documented in observation and modeling studies. Long-term temperature data, from 1988 to 2017, from a suburban station and an urban station in Nicosia, Cyprus have been analyzed, and the diurnal temperature range (DTR) trend was investigated. The seasonal Mann–Kendall test revealed a decreasing DTR trend of −0.24 °C/decade at the urban station and −0.36 °C/decade at the suburban station, which were attributed to an increase in the daily minimum temperature. Variations in precipitation, longwave radiation, ultraviolet-A (UVA), ultraviolet-B (UVB), cloud cover, water vapor, and urbanization were used to assess their possible relationship with regional DTR. The clustering of daytime and night-time data showed a strong relationship between the DTR and observed cloud cover, net longwave radiation, and precipitation. Clouds associated with smaller shortwave and net longwave radiation reduce the DTR by decreasing the surface solar radiation, while atmospheric absolute humidity denotes an increased daytime surface evaporative cooling and higher absorption of the short and longwave radiation. The intra-cluster variation could be reduced, and the inter-cluster variance increased by the addition of other meteorological parameters and anthropogenic sources that affect DTR in order to develop a quantitative basis for assessing DTR variations.


2021 ◽  
Author(s):  
Ines Sansa ◽  
Najiba Mrabet Bellaaj

Solar radiation is characterized by its fluctuation because it depends to different factors such as the day hour, the speed wind, the cloud cover and some other weather conditions. Certainly, this fluctuation can affect the PV power production and then its integration on the electrical micro grid. An accurate forecasting of solar radiation is so important to avoid these problems. In this chapter, the solar radiation is treated as time series and it is predicted using the Auto Regressive and Moving Average (ARMA) model. Based on the solar radiation forecasting results, the photovoltaic (PV) power is then forecasted. The choice of ARMA model has been carried out in order to exploit its own strength. This model is characterized by its flexibility and its ability to extract the useful statistical properties, for time series predictions, it is among the most used models. In this work, ARMA model is used to forecast the solar radiation one year in advance considering the weekly radiation averages. Simulation results have proven the effectiveness of ARMA model to forecast the small solar radiation fluctuations.


2016 ◽  
Vol 13 (4) ◽  
pp. 376-380 ◽  
Author(s):  
Abdelouahab Zaatri ◽  
Norelhouda Azzizi

Purpose Using modeling approaches, this paper aims to propose different mathematical models for estimating the different components of the solar radiation as well as the received solar energy by a collector. Design/methodology/approach In this article, the authors consider three mathematical models to estimate the solar radiation captured at ground level by a solar collector. These models are Capderou model, Liu & Jordan model and R.sun model. In the context of the design of experiments, we performed measurements of solar radiation received by a collector using a pyranometer. The obtained measurements were compared with the three mathematical models. Findings The comparison enabled the subsequent evaluation to determine the most appropriate model that best fit for our region. As a result, the Capderou model reveals to be the most suitable for our region. Originality/value Estimation of solar radiation at ground level (received by a collector) is of paramount importance for the design and optimization of solar energy systems. Nevertheless, many factors influence the amount of energy received by a collector situated at a ground, such as the longitude of the location, latitude, altitude, tilt collector orientation, temperature and humidity of the environment, wind speed, etc. Because of the complex influence of these parameters, the received solar radiation by the collector is a dynamical and a random process.


Sign in / Sign up

Export Citation Format

Share Document