Evaluating the impact of regulation on the path of electrification in Citizen Energy Communities with prosumer investment.

The success of incentives for investments in sustainable residential energy technologies depends on individual households actively participating in the energy transition by investing in electrification and by becoming prosumers. This willingness is influenced by the return on investments in electrification and preferences towards environmental sustainability. Returns on investment can be supported by a preferential regulation of Citizen Energy Communities, i.e. a special form of a microgrid regulation. However, the exact effect of such regulation is debated and therefore analyzed in this study. We propose a multi-periodic community development model that determines household investment decisions over a long time horizon, with heterogeneous individual preferences in regards to sustainability and heterogeneous energy consumption profiles. We consider that investment decisions which increase individual utility might be delayed due to inertia in the decision process. Decisions are determined in our model based on individual preferences using a multi-objective evolutionary algorithm embedded in an energy system simulation. In a case study, we investigate the development of a neighborhood in Germany consisting of 30 households in regards to community costs and community emissions with and without Citizen Energy Community regulation as proposed by the European Union. We find that Citizen Energy Community regulation always reduces community costs and emissions, while heterogeneous distributions of economic and ecologic preferences within the community lead to higher gains. Furthermore, we find that decision inertia considerably slows down the transformation process. This shows that policymakers should carefully consider who to target with Citizen Energy Community regulation and that subsidies should be designed such that they counterbalance delayed private investment decisions. • We simulate private investment in Citizen Energy Communities (CECs) over time. • We differentiate between ecological and economical preferences of participants. • The impact of CEC regulation is largest for heterogeneous preferences. • CECs have a socially desirable influence on cost and emission in all analyzed cases. • Decision inertia slows down investment and should be considered by policymakers. [ABSTRACT FROM AUTHOR]