Does having thermal insulation under solar panels enhance performance?

Reducing Summer Heat Derating

Thermal insulation under solar panels is a simple yet effective technique to minimize the negative impact of summer heat on solar panel performance. When solar panels are exposed to high temperatures, their efficiency decreases. This phenomenon is known as summer heat derating, where the panel’s temperature coefficient causes a reduction in power output. According to the National Renewable Energy Laboratory (NREL), a 1°C increase in panel temperature results in a 0.4-0.5% decrease in efficiency. By installing thermal insulation, you can reduce the temperature of the panels, thereby minimizing the heat derating effect and increasing overall system efficiency.

Choosing the Right Insulation Material

When selecting a thermal insulation material for under solar panels, it’s essential to consider factors such as UV resistance, moisture resistance, and thickness. Some popular options include polyisocyanurate (PIR), polyurethane (PUR), and expanded polystyrene (EPS). A 1-inch (2.5 cm) thick insulation layer can reduce the panel temperature by up to 10°C, resulting in a 4-5% increase in efficiency. It’s also crucial to ensure that the insulation material is compatible with the solar panel frame and mounting system.

Installation Best Practices

Proper installation of thermal insulation under solar panels is critical to achieve optimal results. The insulation material should be cut to fit snugly under the panels, and any gaps should be sealed using a suitable sealant. It’s also essential to ensure that the insulation material is not compressed or damaged during installation. A recommended installation technique is to use a 1/4-inch (6 mm) gap between the insulation and the panel frame to allow for thermal expansion and contraction. By following these best practices, you can effectively reduce summer heat derating and maximize the performance of your solar panel system.