This can vary depending on your north-south location, but it generally ranges from 30-45 degrees for homeowners in the continental United States. Factors such as roof pitch and time of year can affect the overall efficiency of your arrays.
Solar panels should be installed at angles that correspond to the roof pitch for the best energy efficiency. For a roof pitch of 20 degrees, optimal solar panel angles range from 30 to 35 degrees.
The minimum practical roof pitch for fixed solar panels is around 5° to 10°. At angles below this range: Water and debris may not easily run off. Energy generation can decline if snow or dirt accumulates.