Participation in citizen energy cooperatives can strengthen community cohesion, support municipal partnerships, and spill over into other sustainable behaviors. But what needs to change locally, and which information actually motivates people to engage in citizen energy cooperatives? We test (a) how information framing affects intention to participate in citizen energy cooperatives for green hydrogen, (b) who prefers which information, and (c) which psychosocial predictors are associated with participation intention. A representative German sample (N = 1,800) is randomly assigned to one of four brief video conditions or a neutral control: financial risks, environmental benefits, combined risks and benefits, or a free-choice arm in which participants choose either the risk or the benefit video. The primary outcome is participation intention; attitudes are secondary and tested as a mediator. Moderators include environmental consciousness, subjective norm, perceived behavioral control, acceptance of local H₂ production, and income. Analyses rely on ANCOVA to examine main and moderating effects; information choice is modeled with logistic regression; sensitivity analyses apply latent change-score SEM to test mediation via attitude change and moderation by environmental consciousness (benefit framing) and income (risk framing). This study aims to inform evidence-based communication and participatory design for local H₂ projects by indicating which messages may engage which audiences, and under what conditions engagement is more likely. Put simply: if participation is the engine of a just energy transition, we explore what 'fuel' (information) it might need, for which 'drivers' (citizens), on which 'roads' (local contexts).