hot weather, bad for solar panels, is that right?
Heat in the case of photovoltaic solar panels is a electrical resistance to the flow of electrons. During hot conditions, not only does a solar panel become less efficient but the voltage decreases thus meaning you will produce less kWh (kilowatt-hours) on days 75 degrees and above. You have to remember, the temperature on the roof is higher then inside your home. Airflow on all sides of solar panels is critical to the overall performance of your solar power system.
Some solar panels, such as the Sanyo Solar Panels are specifically designed to have a better temperature coefficient which perform better then standard solar panels in high heat conditions. So when comparing multiple solar panels you should always look into the temperature coefficient and make sure your panel will perform well when the weather gets hot.