This paper poses the question: ‘can energy innovation initiatives in Innovation Playgrounds foster a new ‘energy urbanity’ through active citizen participation in the energy transition?’ The concept of ‘Innovation Playgrounds’ and an accompanying Framework are described and linked to implementation evidence of the EU H2020 positive energy research and innovation project +CityxChange, related to emergent active citizen participation in two cities: Limerick, Ireland and Trondheim, Norway. The purpose of the study is to demonstrate that spatially clustered energy innovation initiatives in urban areas involving active citizen participation contribute to a new ‘energy urbanity’ for the energy transition. The research methods are based on a comparative case study approach and close observation of two case sites, with a focus on the ‘Innovation Playground’ area of each city. The article’s three main conclusions are: that a Framework approach to active citizen participation in energy innovation initiatives in urban areas facilitates new models of active citizen and community participation around energy innovation; emergent active citizen participation in energy innovation initiatives in urban areas suggests a new type of engagement that is information-rich, blended, action-led, citizen-focused, and spatial; and that a new paradigm of ‘energy urbanity’ for the energy transition can be proposed.