"Balcony solar systems are particularly suited for renters, apartment dwellers, and homeowners who cannot or do not wish to install a conventional rooftop system. They are installed on balconies, terraces, flat rooftops, garden fences, and exterior walls."
"Balcony solar power" (Wikipedia)
"Where a residential rooftop solar system tends to be 5,000-10,000 watts, plug-in solar systems are smaller, typically around 200-1800 watts."
Senate Passes Senator Wiener’s Plug-in Solar Bill To Lower Energy Costs