Global potential for the transformation of thermal power plants to thermal storage power plants

Abstract

With the trend of energy technology development and the continuous promotion of related renewable energy policies from governments, the share of renewable energy for power generation is constantly increasing, leading to the second phase of the energy transition, which is the problem of residual loads that arise as a result. Thermal storage power plants, also known as TSPP, can solve the problem of future residual loads. On one hand, they can provide a flexible power supply, and on the other hand, their built-in Carnot battery effectively addresses the issues of charging and discharging power from and to the electricity grid. In addition, the reduced use of fossil fuels by TSPP aligns with the current energy conservation and carbon emission reduction policies. More importantly, TSPP can be transformed from conventional thermal power plants. This kind of transformation can significantly reduce the installation costs compared to completely deconstructing the old power plant and building a new one. According to a reference scenario aiming at 100% renewable supply, Germany's residual load is projected to reach 213 TWh by 2040, which accounts for one-third of the total electricity generation at that time. To meet this demand, approximately 70 GW of TSPPs need to be transformed. The purpose of this dissertation is to investigate whether this TSPP transformation is feasible from a technical point of view. Using Germany as a case study, this dissertation assesses the feasibility of TSPP on a global scale to achieve the carbon reduction targets and the energy policies in different countries. This thesis develops research from three aspects. Firstly, an analysis of the photovoltaic potential in Germany is performed using a Geographic Information System (GIS) as auxiliary software. Potential geographical locations suitable for installing photovoltaic systems across Germany are identified, and it is determined that the total area of these locations is sufficient to meet the 105 GW photovoltaic demand required for TSPP transformation according to the reference scenario. Furthermore, a classification of all traditional thermal power plants in Germany is conducted to prioritize the most suitable plants for transformation. The second part analyzes the residual biomass potential in Germany. The total potential of the three main types of residual biomass is summarized, and an algorithm is developed to allocate the area for these biomass potentials as well as the area for photovoltaics in the transformed TSPPs. In addition, this thesis provides a detailed comparison of the electricity generation costs for various types of thermal power plants before and after the transformation by making an economic analysis. The result of this cost comparison demonstrates that TSPP can effectively mitigate the large price fluctuations of fossil energy sources, and at the same time, they substantially reduce the cost of additional electricity generation which is related to less CO2 emissions. In conclusion, the final goal of this thesis is to present the potential of transforming conventional power plants into TSPPs in Germany in the form of an atlas. This includes a macro-level analysis of the transformation plan for a total of 70 GW capacity in Germany, along with the corresponding installation locations for photovoltaics and biomass. It also includes a micro-level analysis, focusing on optimal transforming plans for specific thermal power plants.