To avoid driving climate change on a dangerous path, a substantial reduction in greenhouse gases emissions is required. Hence, a high penetration of renewable energy technologies is essential, but most renewables are either affordable or dispatchable but not both.
Energy storage systems integrated into concentrating solar power (CSP) plants can enhance dispatchability and solar-to-electricity efficiency. Besides, the combination of dispatchable CSP plants with lower cost photovoltaic (PV) plants exploits synergies between the reliability of CSP with energy storage and cost of PV. However, this integration leads to complex interactions between the different technologies and requires sophisticated design guidelines to achieve low costs and high dispatchability simultaneously.
In this thesis, a two-stage multi-objective optimisation framework for the design and operation of hybrid CSP-PV plants with energy storage is developed. The two-stage optimisation simultaneously optimises the design and operation of a hybrid solar power plant with respect to competing technical and financial performances.
The multi-objective operational optimisation stage finds the best operational strategy of a hybrid power plant with energy storage systems. The model, written in Python, uses a typical meteorological year to optimise one-year hourly operation. The results demonstrate that the integration of an energy storage system in a concentrating solar power plant provides dispatchability and, when hybridised with photovoltaic, enhances its competitiveness with current electricity prices. The low mismatch between supply and demand, even when a fixed commitment is required throughout the year, together with high overall efficiency, indicates that the integration of energy storage in hybrid solar power plants is an opportunity to increase the penetration of solar energy in the power sector.
The design of reliable and cost-competitive hybrid solar power plants requires the careful balancing of trade-offs between financial and technical performance. Hence, the design optimisation stage optimises the capacities of the main components of the hybrid power plant and handles financial and technical objectives.
Different configurations are analysed as case studies throughout the thesis to analyse the impacts, interactions, and synergies of technology integration. Three locations are investigated, which present different solar resource profiles: Seville (Spain), Tonopah (USA), and the Atacama Desert (Chile).
The optimisation results are used to develop some guidelines for the optimal design of dispatchable hybrid solar power plants with energy storage based on the given solar resource and required dispatchability. These guidelines provide an initial design for affordable and dispatchable hybrid solar power plants and can enable their widespread deployment.
The model developed can be applied to other locations under different input parameters and demand profiles. Besides, the flexibility of the model allows it to be extended in order to evaluate different energy conversion and storage technologies to design hybrid power plants with energy storage under different configurations and requirements. Thus, the optimisation framework can provide valuable information for the integration of different technologies to support the affordable and sustainable transition to a clean energy system
