Novel integration options of concentrating solar thermal technology with fossil-fuelled and CO2 capture processes

Abstract Concentrating solar thermal (CST) technology has been commercially proven in utility-scale power plants that have been in operation since the 1980’s. CST uses reflecting surfaces to focus solar energy onto collectors, generating extreme heat than can be used for a variety of purposes. The current focus of CST is large-scale electrical power generation. However, new applications, such as solar fuels, are quickly gaining momentum. One key shortcoming of CST technology is its sensitivity to disruptions in sunlight availability over time. CST systems require either thermal energy storage or backup systems to operate during heavy cloud periods or at night. On the other hand, fossil-based energy systems have high availability and reliability, but they generate substantial CO 2 emissions compared to equivalent CST processes. A novel solution would combine the benefits of CST technology and of fossil-fueled energy systems. Such a solar-fossil hybrid system would guarantee energy availability in the absence of sunlight or stored solar energy. The addition of carbon capture to these systems could reduce their carbon intensity to almost zero. This paper introduces three important solar-fossil hybrid energy systems: (1) Integrated Solar Combined Cycle (ISCC), (2) Solar-assisted post-combustion capture (SAPCAP), and (3) Solar gasification with CO 2 capture. These novel concepts have great potential to overcome the inherent limitations of their component technologies and to achieve superior greenhouse gas mitigation techno-economic performance in large-scale applications. The paper describes the features of the three solar-fossil hybrid systems described earlier, discusses its advantages and disadvantages, and provides examples of applications. The goal of this manuscript is to introduce experts in the CCS and CST fields to the opportunities of integration between these technologies and their potential benefits.