This plug-and-play alternative to a rooftop system harnesses solar power via an "astronomical control system," moving horizontally and vertically to capture sunlight during the entire course of the day. One year of smartflower POP electricity will give you around 4.000 kWh, or, the "average complete annual consumption of a central European household." This is probably a tenth of an American household, but it's better than nothing.
The flower is also self-cleaning—ridding itself of dust and snow deposits by folding and unfolding itself—and self-cooling, meaning the most work you'll put into this system is in its initial set-up.
Find a dealer here.