Enhancing solar water heater efficiency: A study on heat transfer with phase change material

• Solar energy is abundant, affordable, and renewable, making it vital for domestic use. Its inconsistent availability requires effective storage solutions. • The study proposes using phase change materials (PCMs), specifically beeswax, to store solar energy. • Beeswax melts at 50–55 °C, storing latent heat during the day and releasing it to heat water. • This method maintains a consistent system temperature, thereby improving overall efficiency. • Energy efficiency improves by approximately 49.5 % when integrated PCM is used in solar water heating systems. • The approach reduces reliance on fossil fuels and cuts carbon emissions. • The study encourages further research in PCM-based solar energy storage. Solar energy, known for its abundance, affordability, and renewability, plays a crucial role in domestic applications. However, its intermittent nature demands efficient storage systems. This study proposes using beeswax, a low-melting-point phase change material (PCM), to store solar energy. During the day, solar radiation heats water and melts beeswax, which stores latent heat. As beeswax melts at 50–55 °C, it maintains a stable system temperature. This approach enhances energy efficiency by approximately 1.2 % compared to systems without PCM. This work explores the heat transfer characteristics of beeswax, evaluates its effectiveness in solar water heating, and suggests avenues for future research.