Economic Evaluation of Towers for Central Receiver Systems

So far, the tower is probably the most under-investigated component of solar thermal power tower plants. While the capacity of these plants is constantly increasing, also the tower dimensions are rising, calling for higher towers that can bear receivers of bigger size and weight. It has been found that currently no consistent method to determine the most economical build of a solar tower can be identified. Therefore, five different tower designs for large towers with molten salt technology receivers were designed and modeled using finite element software. The designs were then compared regarding their load-bearing behavior, required construction masses and material costs. The choice of tower shape and material is subject to a high number of boundary conditions that must be considered while aiming at the optimum tower solution. Site conditions as well as receiver dimensions play a key role. It could be identified that for the conditions defined in the study concrete towers represent the most cost-effective design whereas steel truss towers will not lead to a cost competitive solution. In a holistic investigation, it was identified that erection time of the receiver on site must be minimized This can best be achieved by designing the tower in a way that the receiver can be assembled on the ground and be pulled up in one piece. The largest possible time savings can be achieved by developing an anticipatory tower design that provides for maximum ease of receiver and piping installation and thus the shortest possible construction time. The findings were used to design a tower that is currently projected for a site in South Italy.