Bright Saver, a San Francisco-based nonprofit, aims to bring the European balcony solar trend to U.S. homes with low-cost, plug-in systems that require no interconnection and no permits in some places

This is an innovative model. They are working with people on low incomes, renters and apartment dwellers. All people cut out of traditional rooftop solar. People will be paying $35 a month for two free-standing 7 by 4 feet panels. There doesn't seem to be any upfront cost, though a qualified electrician needs to install them.

If those two panels generate more than $35 worth of electricity a month, then this seems like a no brainer.