Mapping the development of various solar thermal technologies with hype cycle analysis

This paper focuses on the technological development of solar thermal technologies through the analysis of patent records and search traffic. First, various solar thermal technologies are reviewed and discussed. Then, the related published patents are analysed. To improve the accuracy of patents retrieval, a new framework is proposed and employed based on the combination of keywords and keycodes. In this new framework, the proposed methodology can enhance the retrieved patent pool resolution by eliminating the patent with the relevant title but irrelevant technology scopes. Furthermore, new technological features such as technology attractiveness and acceleration are introduced and applied to solar thermal technologies. These two introduced features help to recognize interested areas by industrial players in the technological field. The pace of technology being developed and becoming matured could be identified by how fast the industry invests in technology by protecting its intellectual properties. The logistic S-curve is employed for assessing the current state of solar technologies on the technology life cycle. The market diffusion of each solar thermal technology is assessed by developing adoption curves using search traffic. Finally, the hype cycle of solar thermal technologies is demonstrated by combining the two technological assessment graphs. Through the proposed methodology, 8740 related patents are retrieved and screened. The analysis shows that Photovoltaic-thermal has the highest share in published patents and the parabolic trough and evacuated tube collectors are in their maturity phase. The parabolic dish collector is identified as one of the highest accelerated technologies and also located near the maturity phase. Therefore, it can be predicted that the next technology reaching the maturity phase would be the parabolic dish collector. Overall, all solar-heat driver cycles are in their growth stage, but the Rankine cycle is more developed. Text analysis determines the main challenge with cycles is the operation and maintenance that should be overcome to meet the maturity phase.