Chill/No Chill: Really Slow Solar-Powered Planes

The Solar Impulse 2 landed in Phoenix Monday night, after a 16-hour flight from Silicon Valley—a jaunt that would have taken just over an hour on a commercial jet. To its credit, this gas-free plane aims to be the cleanest flight in the air and is the first plane of its kind.

The test pilots are on a mission to fly the first solar-powered airplane around the world. 

While the plane is clean and presumably cool for the environment, it only reaches speeds of about 45 mph and a maximum altitude of 22,000 feet. The average fuel-powered flight hits about 575 mph.

Are painfully slow solar-powered travel times for the sake of saving the environment chill?  Or is creeping at a snail's pace, even if it saves the planet for your kids, simply no chill?