New Method for Energy Prediction of Solar Energy Collectors Systems in Yemen

Abstract

The design of any solar system will require the full understanding of the most influenced factors on its power generation and performance year round. Therefore, one has to consider the system components variables, namely collector types, tilts and collectors orientations to capture most of the incoming solar radiation. Direct measurements of global solar radiation do exist for a number of sites around the country for many years and can be used to derive a set of equations to predict the solar system design values and its output performance. But, the solar system power output, whether it�s electric or thermal energy can be very difficult to predict in the absence of measured data and variable load�s demand requirements. This paper examines the effects of solar radiation in each site on the systems power output of PV and thermal energy for different type of collectors. Using the existing data from meteorological stations to derive an accurate and simple equations with only one input variable, the monthly average clearness index to be used for the design of photovoltaic and solar thermal system power outputs for tilted flat plate, polar and two axis tracking collectors for a given site instead of existing lengthy methods of solar radiation components (direct, diffuse, and reflected radiation) for different types of collectors currently in use or computer simulations programs. The results of the new equations provide a valuable tool for solar collector designer and prediction method for the systems power outputs. Furthermore, the new equations indicate the possibility of universal applications with minimum adjustment for latitude.