Abstract for: Tackling the Elephant in the Room of Energy Models: Simulating Behavior Change and Feedback Dynamics

The transition to decentralized renewable energy systems involves complex socio-technical dynamics, where individual investment decisions play a crucial role. Energy models often underrepresent behavioral factors shaping the energy transition. This study presents a theory-based approach to simulating residential energy investments by combining the Stage Model of Self-Regulated Behavior Change (SSBC) with the System Dynamics method. Our model extends the SSBC by operationalizing it in the energy context and enriching its linear stage structure with individual and systemic feedback dynamics. The novel approach enables a systematic representation of the implementation gap in renewable energy adoption and the discrepancies between intentions and actions across decision stages. The findings highlight that the main bottleneck in technology diffusion arises among individuals who intend to invest but fail to act. Social norms emerge as the strongest feedback loop, while individual characteristics – particularly responsibility and environmental awareness – strongly influence action. Overall, the simulation results show that techno-economic models ignoring behavioral dynamics may overestimate early-stage adoption while underestimating the influence of social contagion in later stages of technology diffusion. Developed in a generic form, the model is adaptable to a wide range of energy investment decisions. It advances theoretical understanding and offers policy-relevant insights to support the design and evaluation of strategies for accelerating the energy transition.