The impact of metering methods on collective self-consumption: Insights from multi-dwelling buildings in Finland

Globally, legislative reforms have significantly promoted the adoption of solar photovoltaic systems. In many European countries, updated legislation encourages the formation of energy communities and collective self-consumption in residential buildings. This study investigates the financial viability of solar photovoltaic systems in Finnish multi-dwelling buildings, focusing on the impact of recent legislative enhancements supporting collective self-consumption through virtual net-metering, known as the credit calculation model. By analyzing hourly consumption data from two properties in 2018 and 2020, and incorporating simulated photovoltaic production with electricity market prices, our findings highlight the advantages of virtual net-metering. Self-consumption ratios increased from 15% to 38 %, and annual revenue improved by 10 EUR/kWp to 29 EUR/kWp. Comparing the credit calculation model with behind-the-meter approaches using joint electricity subscriptions revealed self-consumption ratio differences of 5 % to 15 % for identical system sizes. Additionally, electricity purchasing cost savings of 16 % to 19 % were identified with behind-the-meter, increasing further compared to costs from other Finnish distribution system operators. This underscores the economic benefits of such arrangements and highlights potential savings across different regional pricing models. These insights demonstrate the financial benefits of collective self-consumption and joint electricity subscriptions in multi-dwelling contexts, signaling the need for extended research across diverse settings to validate these findings.