Is it better to install solar panels on the roof or ground in a hot climate?

Temperature Effects on Solar Panel Efficiency

Solar panels convert sunlight into electricity, but their efficiency is affected by temperature. In extreme heat, panel temperatures can rise above 120°F (49°C), reducing efficiency by 10-20% or more. This phenomenon is known as summer heat derating. Ground-installed systems can benefit from better airflow, which helps to dissipate heat more effectively than roof-mounted systems.

Ground vs Roof Installation Considerations

When comparing ground and roof installations, ground-mounted systems often have an advantage in hot climates. By placing panels on the ground, air can circulate beneath them, reducing heat absorption and improving system efficiency. Additionally, ground-mounted systems can be tilted at a slightly steeper angle (around 25°) to maximize energy production during the day. This angle also allows for easier cleaning and maintenance. Conversely, roof-mounted systems are often tilted at a shallower angle (around 20°), which may reduce energy production.

Derating Factors and Mitigation Strategies

Summer heat derating is a critical consideration in hot climates. To mitigate its effects, ground-installed systems can employ various strategies. These include using high-efficiency panels, installing a reflective coating on the panel surface, or incorporating a cooling system. By selecting the right equipment and installation approach, system owners can minimize the impact of summer heat derating and maximize their energy output. Ground-mounted systems, in particular, offer an advantage in this regard, allowing for better airflow and reduced heat absorption.