Performance Evaluation of Solar Chimney Power Plants in Egypt

Abstract

Power generating technology based on renewable ener gy resources will definitely become a new trend of future energy util ization. The solar chimney power plant is a natural draft device which provides an upward momentum to the in-flowing air by firstly converting solar energy into thermal energy in the solar collector. Secondly the generated thermal energy is converted into kinetic energy in the chimney and ultimately into electric energy using a combination of a wind turbine and a generator. The purpose of this study is to evaluate the performance of sol ar chimney power plants in some locations in Egypt theoretically and to make an app roximation of the quantity of the generated electrical energy. A simple mathematical model based on the energy balance was developed to estimate the power output of solar chimneys as well as to observe the effect of various ambient conditions and structural dimensions on the power generation. It was found that, the wind speed inside chimney reach es more than 7 times of the value of free wind speed outside chimney. The solar chimney power plant with 500 m chimney height, 50 m chimney diameter and 3000 m collector diameter is capable of producing yearly between 1.6-1.7 ◊ 10 8 kW hr in the selected locations in Egypt. Therefor e the use of solar chimney power plants in many locations in Egypt will be attractive. It can cover a considerable section of the increasing demand to en ergy. It can save the use of conventional sources of energy like oil and natural gas and consequently reduces the emissions of harmful gases.