Techno-economic analysis of impact of net metering interval changes on residential solar PV systems

Abstract

Residential solar PV systems are increasingly popular among prosumers due to their potential to reduce electricity costs while mitigating environmental impacts associated with conventional energy generation. Net energy metering (NEM) enhances the financial viability of these systems by offsetting grid consumption with self-generated electricity. In the European Union (EU) countries, the shift from current 1-hour metering intervals to 15-minute intervals is underway, with the possibility of 5-minute intervals in the future. This transition raises concerns about its impact on energy flow and profitability for prosumers. This study evaluates the effects of shorter NEM intervals on energy flow and economic performance of residential solar PV systems in Finland, utilizing three years of measured data from two households. Key metrics analyzed include electricity imports, exports, self-consumption (SC), self-sufficiency (SS), and monetary value across different scaled capacities (1 kWp to 20kWp). Results indicate shorter intervals increase grid imports and exports, reduce self-consumption and self-sufficiency, and slightly lower value of solar PV, with larger systems showing greater resilience. Additionally, a recent VAT increase mitigates some negative economic impacts. These findings offer insights for policymakers and prosumers transitioning to shorter metering intervals.