Research on the heat storage characteristics of building envelope structures for heating with photovoltaic power

Amid the global energy transition, buildings as key electricity consumers support high-proportion PV integration via flexible grid interaction, effectively addressing PV power accommodation challenges from solar radiation instability through enhanced energy use flexibility. Based on the reaction coefficient method and room heat balance equations, this paper develops and experimentally validates a dynamic model for heated rooms. This study analyzed the effects of four wall types, three intermittent operation modes, convective and floor heating, and ventilation rates. In solar heating with reinforced concrete walls exhibits a temperature fluctuation of approximately 1 °C and the stored heat of about 3.81 kWh, while the foamed concrete walls shows 3 °C and 3.54 kWh. Compared to the baseline condition of 0 air changes per hour (ACH) (stored heat: 1.38 kWh), increasing the ACH to 0.1, 0.3, and 0.5 h−1 raises the heat storage per cycle by 17.02%, 53.61%, and 89.60%, respectively. In floor heating with hollow bricks and the heating duration is 6 h, the stored heat of the room is 10.41 kWh, which is higher than the 3.03 kWh of convective heating. The temperature drop at the moment of heating shutdown is 0.17 °C, significantly lower than the 0.93 °C of convective heating.