Isaac Moridi - Ph.D. Student in Climatology, Kharazmi University of Tehran, Tehran, Iran
Peyman Kanan - Director of Solar Energy Office, Renewable Energy Organization of Iran (SUNA), Tehran, Iran

Incoming solar radiation (insolation) is the main energy source of all chemical and biochemical processes that take place on the earth. Knowledge of the amount of solar irradiance reaching on earth surface is desirable for application in solar energy engineering, forestry, meteorology, environmental assessment, and ecological research. However, in the many parts of the world, irradiance data are not available or are measured in a few stations and must be estimated via mathematical models or interpolating methods. Simple interpolation and extrapolation of point-specific measurements are typically not feasible, because insolation can vary significantly within short distances due to topographic, heterogeneity and near ground features. While some geographical information systems (GIS) based solar radiation modeling capabilities have been developed, there is a need for expanded functionality, accuracy, and calculation speed. The Solar Analyst has been developed as an Arc View GIs extension, using C++, Avenue, and the Grid10 library. The Solar Analyst is a comprehensive geometric solar radiation-modeling tool. It calculates insolation maps using digital elevation models (DEMs) for input. Highly optimized algorithms account for the influences of the view shed, surface orientation, elevation, and atmospheric conditions. The Solar Analyst model was validated by comparing calculated temporal and spatial patterns of insolation in the vicinity of Rocky Mountain Biological Laboratory (RMBL) with detailed monitoring of insolation, weather, and vegetation. The Solar Analyst provides a convenient and effective tool for understanding spatial and temporal variation of insolation at landscape and local scales.

Solar Analyst, Solar Radiation, GIs, Solar Power Plant, Shiraz