Floating Solar Chimney versus Concrete Solar Chimney Power Plants

Abstract

A solar chimney power plant has three major components: (1) A circular solar collector (Greenhouse) (2) A tall cylinder in the center of the solar collector ( Solar Chimney) (3) A set of air turbines geared to electric generators around the bottom of the solar chimney The air warms up inside the greenhouse by the solar irradiation and, due to its buoyancy, tends to escape through the Solar Chimney. This warm stream of air is leaving part of its thermodynamic energy to the air turbines placed in the path of the airflow. The solar chimney power stations were named Solar Aero-Electric Power Plants (SAEPPs) due to their similarity to Hydro Electric Power Plants. The efficiency of the SAEPPs is roughly proportional to the height of their solar chimneys. Solar Chimneys can be made as reinforced concrete structures (Concrete Solar Chimneys, CFCs), or as lighter than air inflated structures (Floating Solar Chimneys FSCs). These floating solar chimneys are made by successive balloon tubes, filled with a lighter than air gas. This permits to the FSCs to float in the air and thus to have heights 1.5divide3 Km giving to their SAEPPs higher efficiencies than Concrete Solar Chimney SAEPPs. Using ground thermal storage, or artificial thermal storage in the form of water in closed plastic tubes, it can be proved that the SAEPPs can operate 24 hours per day 365 days per year with a minimum guaranteed power production. This means that the SAEPPs, although renewable by nature, can have a similar operation to conventional power stations and thus can replace them. In the present paper a comparison for construction cost of SAEPPs with Floating Solar Chimneys and Concrete Solar Chimneys is given. It is shown that FSC Technology Power Plants is 5 to 6 times cheaper than CFC Technology Power Plants.