This is a 12-volt DC fan that can work with a solar panel from 40 watt to 100 watt. This is very good fan in all respects: Airflow, sound intensity, vibration and efficiency. Quite suitable for solar application. Works GREAT with 100W, (~)12V panel but will work with much smaller panels too. When wired - to black and + to blue the airflow is towards the wires, the screen, towards you as pictured. The good quality motor designed for a demanding environment. It can be used it in my greenhouse. Does the job nicely and will fulfill a multitude of diverse applications. This item is Recommend buy from most customers! The dimension of the fan is 12" x 12" x 3" design produces maximum air flow. The fan can be installed in an opening such as a gable vent. Kit come with 4 brackets to install the fan. Instructions Included. Full refund if the product is defective.