## 8 Results and Discussion
### Impact of Seasonal Variations on Energy Management  
The impact of seasonal variations on the performance and efficiency of the HEMS in Liaoning Province, China, is substantial. The region's diverse climate, characterized by cold  
Figure 18: Daily Electrical Load Profiles with Varying Degrees of DR Participation.  
winters and warm summers, significantly influences energy generation and consumption patterns, making it crucial to understand these seasonal effects to optimize the system's operation throughout the year. During summer, the longer daylight hours and higher levels of solar irradiation lead to increased PV output. PV generation starts early, around 5:00 a.m., and peaks at midday, reaching up to 910 W. Conversely, in winter, shorter days and lower solar irradiation reduce PV generation, with PV output starting later, around 7:00 a.m., and peaking lower, typically around 750 W. Wind energy generation remains relatively consistent throughout the year, with peak wind speeds around 8.89 m/s, although winter months may see higher peaks due to increased wind speeds. Load demand also varies with the seasons. In summer, higher temperatures increase the use of cooling systems, resulting in higher peak loads in the afternoon and evening, with a notable peak of 1658 W at 9:00 p.m. Early morning demand starts at 916 W and decreases slightly to around 642.67 W by mid-morning. In winter, lower temperatures lead to increased heating demands, causing higher energy consumption in the early morning and evening. For instance, the load demand in winter may start at 1093.81 W at 1:00 a.m., dropping to 897.97 W by 2:00 a.m., and peaking again in the evening.  
The utilization of backup systems, such as batteries, FCs, and EVs, is crucial in meeting the fluctuating load demands caused by seasonal changes. In summer, these systems are heavily relied upon during late afternoon and evening peaks when cooling demands are high. For example, during peak hours at 9:00 p.m., the system relies on wind generation contributing up to 1044 W and battery discharge up to 1004.42 W. In winter, backup systems are essential during early morning and evening peaks when PV generation is minimal. Batteries discharge heavily in the early morning, with values like 527.70 W at 4:00 a.m., and peak battery discharge can reach up to 903.24 W in the evening. Wind generation supplements the energy supply throughout the day, helping to balance the system. Seasonal variations also impact the cumulative operational cost of the HEMS. Higher energy usage for cooling during the summer increases operating costs, especially during peak periods. In the baseline scenario (No DR), the cumulative cost reaches $767.067 by the end of the day. Similarly, increased heating demands in winter elevate costs, although higher wind generation can offset some expenses.  
Implementing DR programs can significantly reduce these costs by shifting energy usage to off-peak periods and enhancing the utilization of REs. For instance, with a 40% DR program, the cumulative operating cost drops to $749.09. The LPSP remains a critical metric, indicating the chance of not meeting the load requirements. Across all scenarios and seasons, the LPSP values stay within the acceptable range of 0 to 0.05, demonstrating the system's reliability. The highest LPSP value recorded was 0.0010 at 2:00 a.m. in winter, suggesting a robust system capable of meeting energy demands with minimal risk of power shortages. Seasonal variations in Liaoning Province significantly affect the performance and efficiency of the HEMS. By understanding and adapting to these changes, the HEMS can improve the use of PV and WTs generation, reduce reliance on backup systems, and minimize operating costs. The effective implementation of DR programs further enhances system efficiency, ensuring reliable and cost-effective energy management throughout the year.