Solar collective self-consumption: Economic analysis of a policy mix

Solar photovoltaic (PV) systems can play a key role in ecosystems by satisfying the energy needs of people and businesses, helping countries become energy independent and propelling nations towards a climate-neutral future. Within this context, collective self-consumption (CSC) represents a new challenge, anchored in a new conception of the prosumer. The present work aims at calculating the economic profitability of PV systems with respect to both household and non-household self-consumers. The methodology is based on the calculation of net present value (NPV), with break-even point (BEP) analysis applied to the percentage of self-consumed energy. As economic viability is dependent on the specific policy tool(s) available, the analysis is applied to the Italian context, considering both a tax deduction of 110% over 5 years and a CSC subsidy of 100 euro/MWh. The findings demonstrate economic profitability in multiple scenarios, strongly linked to the percentage of self-consumed energy. The mix of policy tools significantly influences the results and generates BEPs in the range of 8-13% (calculated in terms of the share of self-consumed energy) and NPVs ranging from 1035 to 3178 euro/kW for 30-60% self-consumption. Profit distribution scenarios among renewables self-consumers (RSCs) and policy recommendations are provided to foster RSC development, and thereby make residents responsible for their country's energy transition.