The increasing demand for energy-efficient and low-emission housing drivesthe adoption of renewable energy systems in residential buildings. This thesisexamines the performance of an off-grid hybrid system that integratesphotovoltaic panels, battery storage, and a NIBE F2050-6 kW air-to-waterheat pump for a typical single-family house of 85 m² in Markaryd, Sweden.The system configuration includes 5–20 kW of photovoltaic capacity and 50–150 kWh of battery storage, achieving a seasonal self-sufficiency ratio thatranges from approximately 60 % in winter to around 95 % in summer,depending on the system size and current climatic conditions. Realoperational data from the heat pump is analysed to identify heating and hotwaterdemand patterns, the coefficient of performance, and their relationshipwith outdoor temperature. MATLAB simulations complement the analysis byevaluating battery behaviour, PV generation, and the system’s selfsufficiencythroughout the year. The findings show that space-heatingdemand is strongly influenced by outdoor temperature, whereas domestic hotwaterdemand remains relatively stable. COP values rise with higher outdoortemperatures, varying from around 2.8 in winter to above 5 in summer, whichaligns with previous studies of residential heat-pump performance. Solarradiation and PV output follow clear seasonal cycles, producing ample energyduring summer and minimal generation in winter. The battery state of chargeremains high during warmer months but drops sharply in winter due toreduced solar input and greater heating requirements. The self-sufficiencyratio improves with larger PV and battery capacities but does not fullyovercome winter shortages, highlighting the need for optimal system sizing.This study demonstrates that the integrated PV–battery–AWHP configurationachieves high efficiency and near self-sufficiency during summer whileremaining constrained by seasonal imbalance in winter. The results highlightthe system’s potential to reduce grid dependency, operational costs, andenvironmental impact, making it a promising solution for eco-friendly andfuture-ready homes. This contributes valuable insights for designing flexibleand sustainable residential energy systems in Nordic climates.