I'm not sure what I was expecting from the fan. It's not really noisy but you can hear it.  The volume of air it moves is very low and barely noticeable.  On solar only, you'll need a bright sunny day between 10:30am-1:30pm to generate enough sun light to power the fan.  The hat fits comfortabily but doesn't fit snuggly and will fall/blow off, likely due to the placement of the solar cell and fan.