Design and configuration of solar thermal multi-tower field layout

Abstract

In a multi-tower configuration, additional towers are introduced in the field veering away from the conventional setup of a single tower system. The heliostats in the field are placed in-between the towers hence providing an alternate aim point for those heliostats with lower optical efficiency values. The configuration is investigated to find the effect of alternate aim points on weaker heliostats and develop ways on how the possible increase in the Levelized Cost of Energy (LCOE) can be reduced. First, a model of a conventional power tower system plant using the radial staggered configuration is generated and the annual thermal energy generated is simulated and optimised. Subsequently, one additional tower was added and optimized for 50MWth. The results for the multi-tower field were evaluated and compared with the conventional field. A new method of field layout was developed. This new method involves removing the poorly performing heliostats in the field and moving them near the additional tower of the multi-tower setup. The results show a higher optical efficiency value in the multi-tower setup at the expense of a higher LCOE. The new method introduced is able to reduce the LCOE in the field, more so for bigger and larger fields.