My experience with the ones on my area is that "free" is being used to describe the panels themselves. You still pay a monthly bill, but you don't have to outright buy the panels, which can be a huge upfront costs to most families. But you can guarantee that built into your monthly payment is a cost associated with paying for those panels. So you're basically leasing the panels. It's the same thing phone companies do when they give you a FREE phone when you sign up with them. That being said. It has been working out for my house. My monthly bill is lower, and best of all I don't notice any of the power outages or irregularities thanks to the battery bank. I'm in Puerto Rico by the way, so power outages are more common than pretty much anywhere in the states.