Under the guidance of a number of inventors, the children of Primary School de Petteflet in Groningen are tasked with the challenge of coming up with an energy-generating playground device. In the ‘Playing Energy’ project, the children of grade 5 / 6 develop a playground device that generates energy and uses this generated energy to make playing more fun. Scale models are built in project groups and then the best design is to be executed and placed at the playground of the school.