In the literature, the studies that investigate the use of CO\({}_{2}\) inside the solar collector and its direct incorporation in the power cycle are seldom. Practically, there is a group of studies [25; 26; 27; 28] that investigates the use of a simple transcritical Rankine cycle with evacuated tube collectors. More specifically, [PERSON] et al. [26] found experimentally that the system efficiency is up to 9.45%, while the solar collector efficiency is in the range of 65-70%. At this point, it is useful to refer to some important studies that examine the modeling of the supercritical CO\({}_{2}\) inside the solar concentrating collectors. [PERSON] et al. [29] investigated a supercritical CO\({}_{2}\)-based PTC with a developed model with non-constant heat flux in the absorber tube periphery. They developed a formula for the prediction of the collector thermal efficiency for two pressure levels which are the 90 bar and the 200 bar. They found that the PTC thermal efficiency can reach high values by up to 84%. In another work, [PERSON] and [PERSON] [30] studied a supercritical CO\({}_{2}\)-based PTC for various pressures and temperatures. They emphasized the thermal and exergy analysis of the solar collector. The global maximum exergy efficiency is found at 45.3% for inlet CO\({}_{2}\) temperature at 750 K. Moreover, [PERSON] et al. [31] found the experimental operating feasibility of a supercritical CO\({}_{2}\)-based PTC at 500 \({}^{\circ}\)C.  
The aforementioned investigations indicate that there is a huge interest in CO\({}_{2}\)-based units in the last years due to the high efficiency of these systems and because CO\({}_{2}\) is a very environmentally friendly fluid. In this direction, this analysis investigates a solar-driven power cycle that uses a parabolic trough collector and CO\({}_{2}\) in a transcritical Rankine cycle. The main innovation novelty of this investigation is based on the direct pass of the CO\({}_{2}\) through the PTC, something that increases the efficiency of the total system. More specifically, the direct heating of the CO\({}_{2}\) from the PTC makes possible the operation in high temperatures without the limitations of the maximum temperatures of an intermediate fluid (e.g., thermal oil operates up to 400 \({}^{\circ}\)C). Moreover, the systems with different fluids in the solar field and the power cycle lead to exergy destruction in the heat transfer process, something that does not exist in the present configuration. Therefore, the use of a supercritical fluid is able to achieve high-temperature levels, something beneficial for the thermodynamic efficiency and also not to have an intermediate fluid between solar field and cycle which creates exergy destruction issues due to the pinch points. The examined system is studied for different values of critical parameters such as the turbine inlet temperature, the turbine inlet pressure, the heat rejection temperature, the solar irradiation level and also the optimization of this configuration is presented. Furthermore, the default scenario is studied on a daily, monthly and yearly basis and a basic financial evaluation is conducted. Moreover, the system is compared with a basic solar-fed ORC in order to prove the superiority of the suggested configuration. The investigation is conducted with a detailed created mathematical model which is programmed in Engineering Equation Solver (EES) [32] that has been validated with data from the literature.