US Sunlight Solar SC12 Solar Attic Fan Controller and Remote Intelligently simple attic ventilation. Enables after dark operation of U.S. Sunlight Solar Powered Attic Fans and provides easy monitoring of fan operation and attic temperature and humidity conditions with the convenient hand-held remote The addition of the Solar Controller with Dual Mode Technology will enable your Solar Powered Attic Fan to run after sunset or when there is no light available from the sun When there is no sunlight available to power the fan and the Solar Controller has the optional house power connection enabled, the Solar Controller will cycle house electricity for 15 on, 15 minutes off every half-hour in order to power the fan. This will allow your attic temperature to continue to drop after sunset and help remove the hot, stagnant air that can build up on those warm summer evenings The Solar Controller allows you to power your fan with free, abundant solar power when you need it most while also giving you the option to run your fan after sunset using only a small amount of house electricity - all without the noise and operating expense of an outdated, traditional, electric attic fan The readout on the included remote control sends a radio signal through your walls and ceiling to give you a real-time status update on fan operation to let you know if your fan is running and if the power source is from the solar panel or the house electricity