In this paper, a new thermodynamic concept for improving the Single-Flash and the Double-Flash cycles in geothermal power plants is presented. This process, named Self-Superheating, uses a part of the heat contained in the geothermal fluid at the well-head to increase the temperature of the steam that enters the turbines. When optimal separator temperature is used, the results of this novel ... [Show full abstract] process are an increase of the specific output (approximately 5%) of the geothermal power plant and a reduction (approximately 20–40%) of the liquid content in the last stages of the turbines. The optimal separator temperature for the cycles using Self-Superheating is about 5 °C lower than the optimal separator temperature of the Single-Flash and Double-Flash cycles. The simple but fundamental process of Self-Superheating opens the route for more complex thermodynamic cycles in geothermal power plants.