Local to regional participatory planning processes in the field of renewable energy technologies are very important for energy democracy. Any planning and implementation process starts with the pros and cons of those directly affected facing the broad and rather unspecific costs and benefits of the general public. Therefore, all interested and affected parties should be involved in the exchange and negotiation process between different perspectives, views, and values. The chapter focuses on different functions of participation based on the division among normative, substantive, and instrumental rationales of participation. It connects to debate on environmental justice and energy democracy while stressing the reputation of fair and just decision-making processes. Considering this justice perspective, some recommendations on a distributional and procedural level are made. Finally, the chapter investigates the importance of managing participatory planning processes professionally and examines at the same time potential obstacles and limits of involving different parties and stakeholders.