The Earnest App – a virtual community for sustainable mobility in Darmstadt

The case study explores how the regular use of a sustainability app can foster energy citizenship among members of a virtual community. The case study is conducted in Darmstadt – a city with 160.000 inhabitants located in the state of Hesse in Germany. In cooperation with students from the University for Applied Science in Darmstadt (h_da), the case study explores how a virtual energy community – connected by the shared experience of using an app – affects citizens’ awareness and behaviour in regard to their mobility and energy consumption choices in everyday life.

A mobile app that encourages behavioural changes through information on the systemic consequences of mobility and consumption choices

The case study participants use the Earnest App – a freely available digital app providing information and advice about energy and CO2 emissions. The Earnest App is an informative, interactive and game-like online tool that provides information, quizzes, and small challenges including push-up messages for its users to begin (or continue) to question their current energy and mobility behaviour. It aims to encourage reflections on energy behaviour and – based on a growing understanding of the systemic consequences of mobility and consumption choices – seeks to incite gradual behavioural change toward a more climate-friendly everyday life. Case study members exchange their experiences with the app regularly online – as part of a virtual community.

The app is designed with a system-wide approach for citizens to gain insights and actively engage in reduced energy consumption behaviour in their everyday life. One key aspect of the app includes information and behavioural nudges in the categories of mobility and travel, which is the focus of the case study. Engaging with the app may lead to broader sustainability views and to adopting conscious actions in other areas, such as energy efficiency (spillover effects). In addition, community members might influence others and act as role models – leading not only to a more active type of energy citizen but also to spreading the knowledge and starting to create a socially normative pro-environmental behaviour.

We will study how a virtual energy community can support awareness and engagement in the energy transition

The case study design applies a mixed-method approach allowing us to analyse not only if and when people change their behaviour but also why and how. Participants respond to a quantitative pre- and post-survey (before and after a phase of using the app) to monitor their behaviour and potential behavioural changes in regard to mobility and energy consumption activities. In addition, a qualitative discussion group assesses energy citizenship transition pathways studying more closely how and why participants do or do not change levels of energy citizenship engagement. The case study provides valuable insights for GRETA. It speaks to the role of an app and nudging approaches in supporting energy awareness enhancement and offers information on the effects of participating in digital communities for the development of energy citizenship. Furthermore, it highlights the role of a crucial demographic for a successful transition to a sustainable and just energy system now and in the future: young citizens.

The case study takes place in the summer of 2022 at the University of Applied Science in Darmstadt and is led by Fraunhofer Institute for Systems and Innovation Research.


Dr. Anne Kantel
Senior Scientist, Fraunhofer Institute for Systems and Innovation Research

Dr. Sabine Preuß
Senior Scientist, Fraunhofer Institute for Systems and Innovation Research

Maria Stadler
Researcher, Fraunhofer Institute for Systems and Innovation Research

Join the community

Are you taking part in GRETA’s case studies? Join the GRETA Community on Facebook! In the community, you can share your experiences and best energy-related practises, learn from other community members, participate in the co-design of GRETA’s processes and keep up to date on our project news.

GRETA community facebook group