Analysis of Approaches to Determining Solar Radiation Intensity at Preset Geographical Point

Currently, photovoltaic energy converters are becoming increasingly popular for power supplying various objects, both connected to centralized power grids and operating offline. As a result, a large number of studies are carried out to justify, develop and create new technologies and equipment for the solar energy utilization, which could be effectively used by diverse consumers for different regions. Designing any photovoltaic installation, the selection of the actinometrical data source is the priority issue. There is a large number of approaches to determining the gross potential of solar energy, however, not all of them contain the full array of data that is necessary for designing, while some of them are not very accurate, while others are difficult to use and their accuracy is limited by the observation period. The article presents a methodology for the express assessment of the solar energy potential, designed by means of combining the calculated and experimental data, which allows determining with a high degree of reliability the hourly sums of all components of solar radiation on differently oriented receiving surfaces. Such combined application of various approaches introduced the following features of the method: the proposed approach is based on the data averaged over a period of 20 years, and their array is interpolated to the grid of 0.5x 0.5. Therefore, it is relevant to assess the applicability of the developed method of express assessment of solar energy potential for a preset geographical point, for which experimental studies were carried out. The reliability of the calculated total solar radiation intensity by the presented method is confirmed by deviation of 0.2–8 % for every day of the year. The deviation of 0.6– 8.2% is achieved for the months of the year in the range of calculated values comparing to the actinometrical values.