Vipertex® developed the EHT series of solar surfaces that provide: an enhanced energy exchange surface; is lighter; and provides the same or greater structural rigidity as classic absorbers. The results were presented at SOLAR 2012.
The title of the paper was:
ENHANCED HEAT TRANSFER SURFACES FOR USE IN THE DEVELOPMENT OF HIGH PERFORMANCE SOLAR THERMAL SYSTEMS
The following is a link to the presented paper: http://ases.conference-services.net/resources/252/2859/pdf/SOLAR2012_0032_full%20paper.pdf