Evaluating Allocation Methods for Collective Selfconsumption in Nordic Multi-Dwelling Buildings

Abstract

This study evaluates four energy allocation methods for collective self-consumption (CSC) in Finnish multi-dwelling buildings (MDB) using photovoltaic (PV) systems. The methods are compared to the ideal Neighboring Credit (NC) system, which prioritizes surplus energy distribution to apartments with unmet needs. Two PV dimensioning scenarios-optimal and practicalare analyzed using consumption and simulated production data from two case properties. Under optimal PV dimensioning, the NC system achieved a self-consumption ratio (SCR) of 86.9 88.3 %, while fixed allocation methods resulted in reductions of 617 percentage points. Economically, the decrease in total electricity cost savings compared to the ideal NC system ranged from 2.3 to 9.1 € kWp. Under practical PV dimensioning, the NC system achieved a near 100 % SCR, reflecting efficient energy utilization. The results indicate that allocation methods significantly influence SCR and financial outcomes in the utilization of PV systems in MDBs.