Direct absorption receiver (DAR) systems assessment

The direct absorption receiver (DAR) represents a fairly significant departure from conventional salt-in-tube receiver technology and appears to offer substantial promise for future generations of receivers. The DAR concept involves absorbing the solar flux directly into a film of molten salt that flows in a thin film over a plate. Since the film absorbs most or all of the flux directly, the flux limits associated with tubular receivers can be relaxed substantially. This allows smaller and lighter receivers, which results in better thermal performance and lower capital costs. This report describes the results of an effort to analyze the effects of these factors on system performance and energy cost for both cavity type and external DAR configurations. The approach taken is to directly compare a central system with a DAR receiver and the same system with a salt-in-tube receiver. The results show about a 16% improvement in the thermal performance (annual energy delivered) of a cavity DAR system, while the cost estimate for the DAR indicates a reduction of over 50% in the cost of the receiver. These two effects combine to produce about an 18% reduction in the levelized cost of delivered energy when compared to a system withmore » a conventional salt-in-tube receiver.« less