Can High Heat Affect Solar Panel Efficiency In Arizona?

High Heat Derating in Arizona

In Arizona’s scorching summers, temperatures often soar above 110°F (43.3°C), putting a strain on solar panels. To compensate for this, solar panels are typically derated by 20-30% at high temperatures. For example, if a 300-watt solar panel is rated at 25°C (77°F), its actual output might be reduced to 210-270 watts at 100°F (38°C) or 180-240 watts at 115°F (46.1°C). This means that solar panel efficiency decreases by approximately 30% at high temperatures.

Dust Impact on Solar Panels

Dust is another major factor affecting solar panel efficiency in Arizona. According to the National Renewable Energy Laboratory (NREL), a 1-millimeter layer of dust can reduce solar panel efficiency by up to 40%. To mitigate this, solar panel owners can use techniques such as cleaning the panels regularly, using self-cleaning coatings, or installing solar panels with built-in dust-repellent surfaces. In a study by the University of Arizona, a solar panel installation cleaned every 6 months showed a 2.5% greater energy output compared to one cleaned every 12 months.

Summer Overcapacity Planning

To ensure a stable energy supply during Arizona’s hot summers, solar panel owners need to plan for overcapacity. This means sizing their solar panel system to produce more energy than they need during peak summer months, so they can export excess energy to the grid and offset their energy bills. According to the U.S. Department of Energy, a 5-kilowatt (kW) solar panel system can produce up to 7,200 kilowatt-hours (kWh) of energy in Arizona’s hottest month. To account for high heat derating, owners should consider adding 20-30% to the system’s total capacity. For example, a 5-kW system might need to be sized at 6-7.5 kW to ensure adequate energy production during peak summer months.