This course introduces different waste to energy (WtE) solutions and innovations. It also discusses the critics towards WtE and summarizes the current state of WtE in Europe and in Finland. This Open Course Introduction: WastED – Waste Treatment as well as the related Premium Course WastED – Waste Treatment deal with waste treatment in a wide perspective. Different waste treatment methods are introduced and also new innovative future methods are included. Waste treatment courses concentrate on finding the best future solutions for waste treatment in the matter of economy, material efficiency and sustainable development.