Thermal power plants were originally developed to be operated with fossil fuels, but they can and are already being utilized with renewable energy sources such as geothermal heat and solar heat. Furthermore, they can be utilized in an efficient manner by burning sustainably produced e-fuels, which are derived from sustainable biomass or green hydrogen and captured CO2. In this chapter dedicated to an in-depth examination of thermal power plant technologies, including steam power plants, gas turbine cycles, combined cycles, and heat pumps, and their integration with renewable heat sources. Steam and gas turbines are constructed from a range of basic metals, including cast iron, various steel grades, aluminum, and copper. These materials are widely available in large quantities and can be fully recycled, thereby facilitating their integration into a circular economy. Additionally, heat pumps represent an efficient means of generating heat, even up to 180 °C, within an energy system based on electricity without combustion processes. Heat pumps have the potential to utilize low-value waste heat from a variety of industrial processes, including those associated with wastewater treatment plants. This can lead to enhanced energy efficiency in these processes and a reduction in heat pollution to water bodies.