This paper analyzes the time-dependent energy profile of deeply renovated buildings in various locations across Estonia, employing well-established key performance indicators (KPIs) such as self-consumption, self-sufficiency, and the newly introduced renewable energy use index. One of the key findings of this study is the strong correlation between the specific installed photovoltaic (PV) power and these KPIs. Furthermore, the study investigates the impact of time-dependent electrical measurements and environmental conditions on the accurate assessment of the power mismatch between on-site PV generation and the net building demand. While buildings equipped with exhaust air heat pumps generally outperformed those with heat recovery ventilation, with their KPIs peaking during the summer months, a few notable exceptions were observed. Overall, the insights presented herein aim to serve as a reference for design engineers who are looking for efficient design of on-site PV systems and improvements in the energy autonomy of zero-emission buildings.