Plug-in solar has long been popular in Europe, but rising energy costs and a raft of new state laws are boosting its popularity in the U.S.

Often called "balcony solar," it offers a cheaper starting point than a traditional rooftop array.

Imagine powering your home with the sun, no rooftop installations, no complex wiring, and no need to call in a professional. With the rise of plug-and-play solar panels, this vision is no longer ...