Research Article Towards High Solar Contribution in Hybrid CSP-Combined Cycle Gas Turbine Plants Antonio Rovira , 1 Rubén Barbero , 1 Guillermo Ortega , 2 Antonio Subires , 1 and Marta Muñoz 1 1 National University of Distance Education, UNED, Spain 2 School of Engineering, University of Huelva, UHU, Spain Correspondence should be addressed to Antonio Rovira; rovira@ind.uned.es Received 17 May 2023; Revised 3 August 2023; Accepted 18 August 2023; Published 2 September 2023 Academic Editor: Mahmoud Ahmed Copyright © 2023 Antonio Rovira et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. This paper proposes and analyses several configurations for hybridising concentrating solar power (CSP) plants with combined cycle gas turbines (CCGT). The objective is to increase the solar contribution to a large extent, much higher than those obtained in integrated solar combined cycles but maintaining synergies, which are usually lost when increasing the solar share. For that, two thermal energy management systems are introduced at different temperature levels. First, a configuration with only the low-temperature system is proposed. Then, an enhanced configuration with the low- and high-temperature systems is conceived. These configurations are compared to reference CSP and CCGT state-of-the-art plants. The analyses include different strategies of operation and two sizes for the thermal energy storage system. The results show that the first proposed configuration introduces some synergies but cannot improve the performance of the reference CSP and CCGT working separately, due to an issue with the solar dumping on days with high solar irradiation. The enhanced configuration overcomes this problem and maintains the synergies, leading to an improvement from both the thermodynamic and economic points of view, increasing the solar contribution and decreasing the levelized cost of energy over the reference plants. 1. Introduction CSP provides dispatchable electricity from a nondispatch- able renewable source, such as solar energy. This not only ensures sustainability but also enables CSP plants to work at both baseload or peak scenarios while stabilizing and increasing the reliability of the electricity grid, which is par- ticularly required when the penetration of renewable ener- gies is high ([1, 2]). CSP is usually deployed through standalone power plants, but it can be hybridized with other power plants and resources, such as gas-fired or biogas power plants. In this regard, integrated solar combined cycles (ISCC) stand as an interesting technology, integrating CSP into a com- bined cycle gas turbine (CCGT) plant [3]. The technical lit- erature shows that there is a wide consensus regarding of the synergies between CCGT and CSP [4–6]. The main reason to find synergies is that the production of conventional CCGT plants decreases on the days of high solar radiation due to the high ambient temperature, which is when the solar field of the CSP performs best. Nevertheless, they go beyond. Indeed, there are multiple points where the solar energy can be supplied [7–10] and many available CSP tech- nologies that open a wide optimisation window [11, 12] to make the integrated plant more efficient than the CCGT and CSP plants working separately. However, ISCCs have two main weaknesses. On the one hand, to reach good synergies, the nominal solar contribu- tion over the total nominal production is small [6, 12, 13]. For example, Al-Abdaliya ISCC plant [14] includes 60 MW th in a 280 MW e CCGT; Khandelwal et al. [5] consider 15 MW th into a 320 MW e one; Duan et al. [15] consider Hindawi International Journal of Energy Research Volume 2023, Article ID 8289873, 16 pages https://doi.org/10.1155/2023/8289873