Scenario-Based Dynamic Assessment of Rooftop Solar Photovoltaic and Heat Pump Systems for Low-Emission French Single-Family Houses

Achieving the European Union’s (EU) climate neutrality targets requires residential buildings to reduce operational carbon emissions, while increasing on-site renewable generation. However, the relative contributions of rooftop photovoltaic (PV) systems with battery storage and heat pump (HP) retrofits have not been comprehensively evaluated for representative French single-family house typologies. This study assesses two representative French detached-house typologies, Mozart (single-storey) and Puccini (two-storey), across four climatic zones (Paris, Lyon, Brest, and Nice) using a scenario-based dynamic simulation framework. Three retrofit scenarios were developed from prototype models of each building typology: (i) a baseline configuration with existing electric radiators, (ii) rooftop distributed PV systems combined with battery storage, and (iii) PV–battery systems combined with the replacement of the existing heating systems by water-to-air HPs. Performance was evaluated using energy, carbon, economic, and grid-dependency indicators, including the self-consumption ratio (SCR), self-sufficiency ratio (SSR), grid import dependency ratio (GIDR), operational carbon emissions (OC), levelized cost of energy (LCOE), and carbon emission reduction (CER). The results show that Scenario 2 (PV–battery systems) reduces OC relative to the baseline and achieves SSR values of approximately 36.21–50.62%, while grid-import dependency remains high because of the seasonal mismatch between PV generation and winter heating demand. Replacing the existing electric radiators with water-to-air HPs reduces heating electricity demand but does not uniformly reduce total annual electricity consumption. For Puccini, energy consumption in Scenario 3 is higher than in Scenario 2 in Paris, Lyon, and Nice because cooling and additional heat pump system loads—including fans, pumps, heat rejection, and supplemental electric heating—offset the heating savings. However, houses in the Mediterranean climate zone perform best overall, whereas those in oceanic climates require more careful system design. These findings emphasize the importance of retrofit strategies and financial support that are sensitive to both typology and climate, to support effective progress towards EU climate neutrality.