Abstract
Detailed data on incoming solar radiation are needed in the design of solar energy systems of any scale: from large PV plants to small off-grid systems. However, in most cases, obtaining data on measurements of solar radiation is connected with difficulties due to financial or technical restrictions. Often, ground-based measurements of solar radiation are either not carried out at all or only the value of the global horizontal intensity of solar radiation is measured. The aim of the present study is to review and to verify some existing empirical models of the global solar radiation and its components for the climatic conditions of Kyrgyzstan as well as to estimate the applicability of Meteonorm database model for the available solar radiation in the territory of Kyrgyzstan. The necessity to select the most suitable models of the solar radiation is called by the lack of similar studies on this direction for the conditions of the country.
TopBackground
The evaluation of solar resources is one of the first and, obviously, one of the most important stages in the development of projects for solar energy systems of any type. Indeed, only a reliable evaluation of the available resource allows you to make the right technical or economic decision. Currently, developers and researchers in the field of solar energy have become available databases containing the necessary information. These sources include such global databases as the World Radiation Data Center (WRDC) (WRDC, 2019), Swiss database Meteonorm (Meteonorm, 2019), USA database NASA POWER (NASA, 2019) and others. There are also regional databases, which is considered in this research, e.g. Handbook on the Climate of the USSR database (Handbook on the Climate of the USSR, 1989) .
Key Terms in this Chapter
Diffuse Solar Radiation: The total amount of solar energy received by a horizontal surface from all parts of the sky apart from the direct sun.
Mathematical Model: An abstract mathematical representation of a process, device, or concept; it uses a number of variables to represent inputs, outputs and internal states, and sets of equations and inequalities to describe their interaction.
Meteonorm: A widely used and accepted solar radiation data source in the solar energy industry. It has been around for 30+ years (first released in 1985), and became the standard meteorological database for solar energy simulations. It is also the default meteorological database of some popular PV design software, such as PVsyst or PVSOL.
Extraterrestrial Solar Radiation: Solar radiation received at the limit of the Earth’s atmosphere.
Direct Normal Radiation: Solar radiation arising from a narrow solid angle (5° aperture) centered around the sun's disk and impinging on a surface normal to the direction of the radiation.
Global Solar Radiation: Hemispherical solar radiation received by a horizontal plane.
Solar Radiation: Incident energy per unit area of a surface, found by integration of solar irradiance over a specified time interval, often an hour or a day.
Actinometric Station: A type of meteorological station which observes and measures solar radiation incidence on the Earth’s surface.
Sunshine Duration: The length of time that the ground surface is irradiated by direct solar radiation (i.e., sunlight reaching the Earth’s surface directly from the sun).