This video is courtesy of Cooperative Energy. 

Not all solar panel washing is equal. In the southeast where the MS Solar 3 project is sited, pine tree pollen adheres and hardens on the panels. Given the use of chemicals will void solar panel warranties, removing hardened pollen required some creative problem solving. The Origis Services team researched and found a water heating solution to heat the water for washing and gently lift the solidified pollen from the panels. No chemicals, no voided warranties, no damage to the panels. 
 
For more information about MS Solar 3.