Two major developments are currently reshaping the global stage. First, the divide between autocracy and democracy is widening as more states drift toward authoritarianism and even democracies increasingly exhibit autocratic tendencies. Second, energy has become one of the most critical resources of our time, shaping not just economic stability but also global influence, conflict and cooperation. While traditionally linked to hard power, energy also opens new avenues for soft power, particularly the global shift to renewables and the exertion of energy diplomacy. This thesis lies at the intersection of these two trends. It explores how democratic and authoritarian regimes engage in green energy diplomacy as a tool of soft power, and what this reveals about their relative effectiveness in shaping the global energy transition. In particular, it investigates how states like democratic Germany and authoritarian China use green energy diplomacy to extend their influence abroad and addresses the following question: How do China and Germany exert soft power through green energy diplomacy in South Africa and what role does regime type play in shaping their strategies? This analysis employs content and discourse analysis to assess normative and operational dimensions of green energy diplomacy, namely normative influence, institutional engagement and project performance. The results show that, as expected, Germany holds an advantage in normative influence and institutional engagement. However, no conclusive findings are identified for the dimension of project performance. In addition, the two regimes differ in their approaches to green energy diplomacy and soft power strategy: China leverages its economic strength, whereas Germany adopts a more multi-level approach. Thus, the findings contribute to a deeper understanding of energy diplomacy as a geopolitical instrument and underscore its strategic function as a form of soft power.