Given energy’s powerful role in achieving sustainable development (SD), the relevance of turning to sustainable energy (SE) – understood as renewable energy and energy efficiency – has been recognised as an essential instrument in the global SD agenda. In its Treaties, the European Union (EU) made a profound commitment to the SD principle, and to environmental sustainability, by enshrining it as an objective of the Union and vowing to promote it both domestically and abroad. With Manners’ introduction in 2002 of the ‘Normative Power Europe’ (NPE) conceptualisation of the EU, this commitment can be linked to the EU’s very identity (Manners 2002). The EU is to be a norm promoter in the world to which it can be held accountable. The objective of this thesis is to determine if the EU can legitimately be called a green normative power to the extent that it abides by its commitment to promote SD in the world. In order to test this proposition this research applies Manners’ NPE approach to the case study of the EU’s SE cooperation with China. With its fast paced rise as an economic powerhouse and main fossil fuel consumer, China currently poses one of the single greatest challenges to the achievement of effective SD for the planet. China is also one of the main countries with which the EU developed its SE cooperation. This work presents three main contributions. First, the thesis' main originality derives from the use of Manners’ tripartite analytical framework (Manners 2009b) in the context of EU-China relations in SE. This provides for a comprehensive assessment of the EU’s normative status, not only addressing the EU’s commitment to SD but also to promoting it in a normative way (Manners 2002) by looking at the whole policy process. In doing so, this research seeks firstly to enrich the currently very limited NPE literature on the EU’s status as green normative power by extending it to the field of SE. Secondly, the thesis also aims to add an originally researched case study on China to the NPE field of study. Finally, the thesis also contributes to expanding the application of Manners’ analytical framework by operationalizing it to the study of the SD norm as a concept.