This is our SOPRANO solar air conditioner - SmartCool series with a new features. we've had so many requests for solar air conditioning technology, requires no grid connection. It also needs no batteries, no inverter, no charge controller - just plug in the solar panels and start saving up to 100% on daytime cooling or heating costs. A grid connection can be added to automatically allow operation at night, as well as to provide higher daytime capacity & uninterrupted operation during cloudy or low sunlight conditions.