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The global warming effect has been accelerating rapidly and poses a threat to human survival and health. The top priority to solve this problem is to provide reliable renewable energy. To achieve this goal, it is important to provide fast and accurate solar radiation predictions based on limited observation data. In this study, a fast and accurate solar radiation nowcasting method is proposed by combining FY-4A satellite data and the McClear clear sky model under the condition of only radiation observation. The results show that the random forest (RF) performed better than the support vector regression (SVR) model and the reference model (Clim-Pers), with the smallest normalized root mean square error (nRMSE) values (between 13.90% and 33.80%), smallest normalized mean absolute error (nMAE) values (between 7.50% and 24.77%), smallest normalized mean bias error (nMBE) values (between −1.17% and 0.7%) and highest R2 values (between 0.76 and 0.95) under different time horizons. In addition, it can be summarized that remote sensing data can significantly improve the radiation forecasting performance and can effectively guarantee the stability of radiation predictions when the time horizon exceeds 60 min. Furthermore, to obtain the optimal operation efficiency, the prediction results were interpreted by introducing the latest SHapley Additive exPlanation (SHAP) method. From the interpretation results, we selected the three key channels of an FY-4A and then made the model lightweight. Compared with the original input model, the new one predicted the results more rapidly. For instance, the lightweight parameter input model needed only 0.3084 s (compared to 0.5591 s for full parameter input) per single data point on average for the 10 min global solar radiation forecast in Yuzhong. Meanwhile, the prediction effect also remained stable and reliable. Overall, the new method showed its advantages in radiation prediction under the condition that only solar radiation observations were available. This is very important for radiation prediction in cities with scarce meteorological observation, and it can provide a reference for the location planning of photovoltaic power stations. [ABSTRACT FROM AUTHOR]

We used the data of observational site in photovoltaic power plant (PV site) and reference site in summer 2020 to compare the characteristics of surface energy flux of PV site and Gobi underlying surface. We defined the photovoltaic virtual flux and calculated the proportion of photovoltaic power generation in the net radiation by using daily power generation and generating hours. The results show that the net radiation of PV site was larger than that of reference site throughout the day. Compared with the reference site, the sensible heat flux and latent heat flux of PV site increased by 6.0% and 53.5%, respectively. Sensible heat flux, soil heat flux, latent heat flux, and photovoltaic virtual flux accounted for 43.2%, 14.5%, 8.6%, and 6.1% of the net radiation, respectively. The sensible heat accounted for the largest proportion; the energy balance closure increased from 0.60 to 0.67 in the daytime. [ABSTRACT FROM AUTHOR]

Solar energy plays an essential role in achieving carbon goals and mitigating climate change. Therefore, solar power plants are rapidly developing in the renewable energy sector. However, many reports of solar power plants are on land, and extremely limited observational research has been conducted on the impacts of fishery complementary photovoltaic power plants (FPVs) on near-surface meteorology and surface energy. This study selected two adjacent eddy covariance observational towers at the fishery complementary photovoltaic power plant (FPV) in Yangzhong, Jiangsu Province, China, to explore this topic. The results indicated that the percent frequency of east wind (<4 m s−1) at 2 m decreased by 25.3% in the FPV site compared with the reference site. The FPV array has not an obvious heating effect on the ambient environment. The average air temperature difference in the two sites at 2 m and 10 m was 0.3 K and 0.1 K, respectively, during the heating period. The net radiation increased by 47.8 W m−2 in the two sites. The sensible heat increased by 7.9 W m−2 due to the heating effect. The latent heat in the two sites is contrary to the sensible heat (−13.0 W m−2). The difference in the water storage heat is 32.18 W m−2, which implies that the water absorbs higher heat in the FPV site than in the reference site. This work illustrated the importance of observational experiments to animate process-based understanding combined with FPV systems and provides a scientific basis for establishing FPV energy balance models based on observations that may be used to reveal the impact of utility-scale FPV deployment on climatic effects. [ABSTRACT FROM AUTHOR]

Due to the rapid development of solar energy and photovoltaic industries in China, it is crucial to provide the reliable and accurate solar radiation predictions. In this work, three commonly used machine learning models for predicting global and diffuse solar radiation were assessed in eight Chinese cities, representing different geoclimatic and pollutant conditions. According to the results; regarding the nRMSE, nMAE, nMBE and R values, coastal locations (such as Shanghai, Guangzhou, etc.) obtained higher values than inland locations (such as Lanzhou and Wuhan). Moreover, the SVM (support vector machine) highly outperformed the other models in all locations, regardless of whether the study area was arid, semiarid, semihumid or humid, followed by GLMNET (generalized linear modeling) and RF (random forest). In addition, when assessing the SVM in different locations under different climatic and pollution conditions, it was indicated that the accuracy of solar radiation prediction was closely related to the weather and pollution condition levels. In general, the global solar radiation prediction error was in line with the weather condition levels. The prediction error increased as the weather level increased. However, the relationship between the pollution condition levels and the global solar radiation prediction showed a non-linear relationship. Moreover, for the prediction results of diffuse solar radiation, its variation law with different weather and pollution condition levels was almost different from that of global solar radiation. The maximum high error occurrence probability of global solar radiation and diffuse solar radiation appeared at pollution levels 5 and 1, respectively. Overall, the SVM model demonstrated its reliability in radiation prediction under slight pollution and stable weather conditions. This is crucial in locations with scarce meteorological data and can be used to optimize the selection of geographical locations for photovoltaic power station construction. [ABSTRACT FROM AUTHOR]

• Microclimate and soil characteristics under Gobi PV arrays were first observed. • South-facing PV panels reduced wind speed with the prevailing northerly wind below. • PV panels had buffer effects on microclimate and soil thermal regime change. • Annual net radiation reduction was up to 92.68% since the shading of PV. • The significant increase in relative humidity during winter was caused by snow cover. The high demand for low-carbon energy sources to mitigate climate change has prompted a rapid increase in ground-mounted solar parks. The implementation of photovoltaic (PV) significantly impacted the local climate and ecosystem, which are both poorly understood. To investigate the effects of a typical solar park on the Gobi ecological system, local microclimate and soil thermal regimes were measured year-round under and between PV arrays, at an applied solar park sited in Xinjiang, China. Our results demonstrated their seasonal and diurnal changes. Under solar PV arrays, the mean annual net radiation and wind speed decreased by 92.68 % and 50.53 % respectively. In contrast, PV panels caused an increase of the rear sides air by 10.12 % with 0.87 °C. South-facing PV panels reduced wind speed with the prevailing northerly wind below. In addition, the relative humidity rapidly decreased when snow covered the ground, but slightly increased from April to September. We found the soil under PV panels was cooler and tended to be a sink of energy during spring and summer whereas was more often a source during autumn and winter compared with the soil between PV panels. Observed data developed the understanding of the energy processes of solar parks in Gobi ecosystems and provided evidence to support the sustainable management of the solar park. [ABSTRACT FROM AUTHOR]