This paper evaluates the economic impact of Renewable Energy Communities (RECs) on the Italian wholesale power market. Combining a bottom-up engineering approach with a short-run economic impact assessment, the study begins by mapping existing and emerging RECs in Italy. We identify key characteristics of RECs, such as average installed capacity, institutional profiles of members, types of renewable systems used, and distribution across Italy's electricity market zones. This mapping yields representative REC configurations, which are employed within a bottom-up engineering model to generate energy injection and self-consumption profiles for different REC prosumer and producer categories (residential, public, small and medium enterprise, non-profit organization, and standalone installation), considering the different levels of solar irradiance in Italy based on latitude. These zonal results, aggregated on an hourly basis, inform the implementation of the synthetic counterfactual approach, which develops alternative scenarios (e.g., 5 GW target for REC-driven capacity set by Italian policy for 2027) to assess the impact of REC-driven injection and self-consumption on the Italian day-ahead power market. The findings suggest that REC deployment can increase equilibrium quantities during daylight in most of the time, while decreasing equilibrium quantities mostly during the cold months, as electrified heating drives greater self-consumption and offsets lower grid injections. Both positive and negative effects on equilibrium quantities suggest that REC deployment also has a potential to reduce wholesale electricity prices. Moreover, by reducing grid exchanges through higher self-consumption, REC proliferation can alleviate pressure on the distribution system.

翻译：本文评估了可再生能源社区（RECs）对意大利批发电力市场的经济影响。研究采用自下而上的工程学方法与短期经济影响评估相结合的方式，首先对意大利现有及新兴的RECs进行系统性梳理。我们识别了RECs的关键特征，包括平均装机容量、成员机构属性、采用的可再生能源系统类型以及在意大利电力市场分区中的分布情况。基于此映射结果，我们构建了具有代表性的REC配置方案，并将其应用于自下而上的工程模型中，针对不同REC产消者与生产者类别（居民、公共机构、中小企业、非营利组织及独立设施），结合意大利基于纬度的不同太阳辐照度水平，生成了电力注入与自消费的时序曲线。这些分区结果按小时聚合后，为实施合成反事实分析方法提供了数据基础。该方法通过构建替代情景（例如意大利政策为2027年设定的REC驱动容量5GW目标），评估REC驱动的电力注入与自消费对意大利日前电力市场的影响。研究结果表明：在多数时段，REC的部署能够增加日间市场均衡电量；而在寒冷月份，由于电气化供暖导致自消费增加并抵消电网注入的减少，均衡电量普遍下降。均衡电量所受的正负双向影响均表明，REC部署具有降低批发电价的潜力。此外，通过提升自消费水平减少电网交换量，REC的普及能够缓解配电系统的运行压力。