• • South-facing orientation yields the highest daily power enhancement efficiency at 34.6%, compared to 23.1% (southwest), 16.7% (west), 11.9% (southeast), and 6.7% (east). This 5.2-fold spread between south and east directly impacts building energy yield calculations and PV window placement strategies for net-zero buildings.
• • Inner surface cooling effect is highest for southeast (44.1%) and east (44.0%), exceeding west (41.7%), southwest (38.3%), and south (36.9%). Despite lower cooling percentages, south-facing windows achieve superior power gains due to higher cumulative irradiance, indicating that cooling percentage alone is a misleading performance metric.
• • The ratio of heat removed by water to cumulative solar radiation ranks south > southeast > west ≈ southwest ≈ east, confirming that south-facing windows transfer more thermal energy per unit radiation. This has direct implications for combined PV-thermal (PVT) system design and heat recovery efficiency.
• • Maximum power generation occurs at 13:10 for south, 16:00 for west, 14:45 for southwest, 09:20 for southeast, and 08:10 for east. The power variation characteristics are symmetric for south, ramp-up/steep-drop for west, and steep-rise/ramp-down for southeast and east, enabling predictive control of water flow scheduling.