Thermodynamic Approach to the Optimization of Central Solar Energy Systems

Abstract

The sun is equivalent to a 5800 K thermal reservoir. If we should be capable to concentrate the sun light on the earth, close to the thermodynamic limit and to use its power almost without losses, we should obtain the most powerful thermal engine with a fantastic efficiency of more than 90%. Unfortunately this seems to be impossible and we must be content with much less. Only a minute process of optimization of all the system components that take the solar energy and transform it in a transportable energy form (i.e. electricity) will increase the actual (rather) low efficiency and will transform it in a competitive efficiency comparative with the non-renewable energy process efficiencies. The central solar energy systems seem to be unique qualified of efficiently producing of high temperatures capable to achieve high thermodynamic efficiencies and therefore the future looks to be more promising for the central receiver (or solar tower) concept. This work is dedicated to an attempt to optimize a central solar energy system from the thermodynamical and optical points of view.