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

The Earnest App case study investigated how using a sustainability app within a virtual community can promote energy citizenship. The study took place from March 2022 to February 2023 in Darmstadt, a city in Germany with 160,000 residents. 

A mobile app that encourages behavioral changes

One key aspect of the Earnest app includes information and behavioural nudges in the categories of mobility and travel, which is the focus of the case study. In collaboration with students from the University for Applied Science in Darmstadt (h_da), a Fraunhofer ISI research team examined how being part of a virtual energy community, united by their use of the app, influences citizens’ awareness and behavior regarding their daily mobility and energy consumption choices. 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.

The Earnest App case study had three main objectives:

1. To assess how a digital app can influence energy awareness and behavior related to sustainable mobility in people’s daily lives.

2. To explore the role of virtual communities in shaping energy citizenship.

3. To emphasize the importance of young citizens in achieving a sustainable and equitable energy system, both now and in the future.

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

The Earnest App case study aimed to understand the factors influencing changes in people’s energy consumption and mobility behaviors, focussing on the reasons behind these changes. The study used a mixed-method approach, combining qualitative and quantitative research methods to address the following research questions:

  • What motivates or hinders individuals to save energy in their daily lives?
  • How does the use of a mobile app contribute to the development of energy-conscious behavior?
  • What role does participation in a virtual community play in fostering energy-saving behavior?
  • In what ways do considerations of social justice impact the development of energy-conscious behavior and digital energy communities?
  • How can policy support the digital energy communities, and where should policy initiatives begin?

To gather data, the Fraunhofer ISI research team employed various methods:

  • Quantitative online pre- and post-surveys were administered to participants to track changes in behavior before and after using the app.
  • Participants engaged in ongoing discussions on an online board as part of a virtual community, sharing their experiences with the app (qualitative empirical data).
  • Three in-person workshops and an online discussion group provided deeper qualitative insights into the pathways of behavioral change and the reasons behind participants’ choices in energy citizenship.
  • Qualitative interviews were conducted with citizens, policymakers, businesses, and citizen initiatives/NGOs involved in sustainable mobility initiatives in Darmstadt and its surroundings.

By using these comprehensive methods, the study aimed to shed light on the dynamics of energy-conscious behavior change in everyday life and underscores the significance of young citizens in achieving a sustainable and just energy system. The sample comprised 50 participants, primarily female students under 30 years old, meeting our target demographic of younger citizens.

Our findings

The Earnest App case study aimed to test if using the app could increase users’ awareness of their mobility and energy consumption, their contributions to CO2 emissions, and promote sustainable behavior. While the observed changes in pre- and post-survey data were not statistically significant (but showed descriptively a trend in the expected direction), qualitative data suggests that the app can improve awareness of sustainable mobility and contribute to behavior change. 

Furthermore, it was hypothesized that engaging with the app and learning about mobility could lead to broader sustainability awareness and conscious actions in other areas, such as energy efficiency (spillover effects). Although most self-selected participants already engaged in sustainable mobility behaviours in their everyday lives, respondents reported increased sustainable behavior in sectors like household electricity and heating consumption when using the app. This could partly be attributed to situational context as the case study took place during the Russian invasion in the Ukraine. However, qualitative data indicates that the app did encourage participants to explore sustainability in previously unfamiliar areas.

It was also proposed that community members might influence and act as role models, fostering more active energy citizenship and normative pro-environmental behavior. The case study supports this idea, emphasizing the role of group dynamics in energy citizenship. Virtual communities offer opportunities for participation in the energy transition, particularly for highly mobile young people. Yet, it is essential to consider potential drawbacks like access, affordability, and commitment. Further research should explore optimal designs for virtual tools and digital communities in the context of energy transition. Overall, the use of the Earnest app led to an increase of awareness regarding energy citizenship.

Conclusions and recommendations

Among others, the Earnest App case study highlights four relevant barriers and derived potential recommendations of policy and society. 

1. The lack of integrating local and community knowledge into policymaking hinders energy citizenship. Findings from the case study suggest that digital platforms, appealing to young citizens, could help collect and integrate community knowledge. To achieve this, funding could be provided to third parties to create user-friendly digital platforms for knowledge exchange between citizens and policymakers, particularly targeting young people. 

2. Complex policy landscapes are a barrier for both policymakers and citizens. To address this, regular communication between policymakers across different levels and domains in national and regional transport policies should be mandated. This will clarify responsibilities and promote coordination and knowledge sharing among policymakers. Additionally, creating regional access points for information would help citizens navigate the transport policy landscape and identify responsible policy actors, facilitating their engagement in energy citizenship activities.

3. Despite citizens’ strong motivation for sustainable lifestyles, the significant time commitment required for communal activities poses a challenge. To encourage more citizen participation in energy transitions, incentives and compensation mechanisms should be established to recognize and monetarily value the time and engagement of energy citizens.

4. The case study focus on sustainable transportation options, underscores the importance of establishing good infrastructure as a foundation for sustainable mobility. Policymakers should prioritize timely, comprehensive, and affordable public transportation systems in both urban and rural areas – for a just and sustainable energy transition.

Read more about our finding and recommendations in the case study report


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

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