From Fast Company:
Philipp Hutfless, an industrial designer from Germany, is trying to develop Vereos, an idea for coastal cities with limited space for growing food. It's a floating greenhouse that recycles freshwater and gets power from built-in solar panels.
The greenhouse is 42 square feet with shelves for growing vegetables inside. It has a reverse-osmosis plant onboard, which pushes saltwater at high pressure through a membrane to produce freshwater. Then there's a tank and pump, powered by electricity. The frame is aluminum and the covering is made of a hard-wearing plastic. Most importantly, the greenhouse uses hydroponics, which is less water-intensive than conventional growing (50 percent of the water is recycled) and less heavy, because there's no soil involved.
For more, visit the Fast Company website.