Public participation in decision making is considered an important factor that could enhance public acceptability of decision-making process and resulting decisions on renewable energy projects. Yet, little is known about when and how public participation can enhance public acceptability. In two experimental studies where no real decisions were taken, we compare the effect of shared influence versus full influence (either with or without expert support) on public acceptability of the decision-making process, the decisions to be taken, and the resulting energy projects. Results showed that having full influence over decision making (e.g., citizen control) did not lead to higher public acceptability of the decision-making process, final decision and resulting project, compared to having shared influence (e.g., partnership). Respondents perceived the public as not having sufficient expertise to develop energy projects and believed that full influence would lead to lower quality decisions, which may explain why full influence did not enhance public acceptability. Interestingly, the decision-making panel comprising both experts and citizens was evaluated as having more expertise and more capable to take high quality decisions, compared to a decision-making panel comprising only citizens and even when citizens could consult experts. The pattern of results was very consistent in the Netherlands and China.