For crowd investing platforms that focus on renewable energies, the challenge lies in building trust via their platform in order to attract potential investors and convince them to invest their money. After all, an investment always involves potential risks that must not be concealed. This is the first time that a technically sound study has examined and explained which trust criteria must be met in this context and how these are implemented and communicated by the platforms in practice. Supported by the consideration of various research perspectives, this empirical work provides an overview of the current state of trust research. In addition, the book contains a guide on how to gain the trust of potential investors in practice so that more ecological projects can be successfully financed in the future.