Beam solar irradiation assessment for Sonora, Mexico

Located in north western Mexico, the State of Sonora has an excellent quality solar resource, with the highest solar irradiation levels in the country. In less than 1% of its vast arid territory, it receives enough solar power to satisfy the energy demand of the entire country. In spite of its huge solar potential, there has been little work on the measurement of solar radiation in this area. At a few locations, global solar radiation has been measured for some years. Also there have been some works reporting evaluation of solar irradiation based on empirical models or satellite images. Because of the very small amount of precipitation on most of its territory, Sonora is ideal for the implementation of concentrated solar power (CSP). Beam solar radiation data is necessary for the sizing and assessment of CSP plants. Unfortunately, very little information is available on this solar radiation component for Sonora. The present work reports on the results of recent measurements of beam and solar global radiation for the area of the city of Hermosillo, in the center of the state. The obtained results are compared with other available information obtained by indirect methods, such as satellite based or empirical climate data based models. The yearly available energy as well as the utilizable energy for certain irradiance levels is evaluated.