Based on the analysis of the reference case, models developed at the PVLAB-EPFL and IPESEEPFL have been valued and improved to assess the impact of distributed generation and ancillary services on REel demonstrator. The models are used to evaluate solutions capable to cope with the variability and uncertainty of renewable energy generation, avoiding curtailment and reliably supplying all the demanded energy to customers. The database compiled by the JA-RED partners [10], have been enhanced and converted into an essential tool to support communication and strategic decisions among the REel Demonstrator Community. This database contains for each building the typology, the actual energy agents, an estimation of the energy demand, the relation with the injection point of the energy distribution networks and the actual usage and potential of renewable energy such as the solar PV potential. In order to evaluate the energy flow in the grid with sufficient precision, skills have been developed in the allocation of stochastic load profiles from aggregated measurements. Moreover, the profiles for PV generation have been refined considering the optimal roof’s area and orienta tion. Methods to assess the power grid flexibility are based on both consumers behaviour and technical and operational flexibility. The assessment of the latest relies on a model recently developed for the generation optimal design and operation of energy technologies in buildings [17]. Finally, the limits imposed by the existing power supply infrastructure have been identified using a power flow algorithm to conduct grid stability assessment and detect the bo􀆩lenecks in the power grid. For this task, the stochastic nature of the proposed load profile allocation model is fundamental.