Climate change is threatening the well-being of both humans and nature, and new efficient strategies are needed to engage individuals in quickly adopting a more sustainable lifestyle. The present thesis addresses if Mental Accounting, as a central decision mechanism, can be used for designing behavioral interventions which are based on modifications of the choice architecture (“nudges”). Presenting evidence for such central mechanisms in the context of energy conservation, our findings reveal that individuals ascribe dissimilar environmental behaviors to different mental accounts, and are more likely to spend money labelled in a green context on pro-environmental purchases that is in accordance with the dedicated purpose of its account. We further indicate that mental accounts are dynamic and can be refined by a knowledge intervention which teaches the specific environmental impact of a series of energy-relevant behaviors. These mechanisms could be integrated into intervention strategies to increase energy conservation.