A Floating Urban Farm
The Science Barge is a prototype sustainable urban farm floating on the Hudson River. About an acre of food can grow on the barge without any pesticides, runoff, or carbon emissions. The energy needed to power the Barge comes from solar panels, wind turbines, and biofuels. Hydroponic and aeroponic growing methods are used in the greenhouse, using solely collected rainwater and purified river water. Thus, the Barge is completely off the grid.
Hydroponics is a method of growing plants in mineral nutrient solutions in water, usually without soil. Usually, a pump is needed to circulate the solutions, which can require a good deal of energy. The Barge had a number of different hydroponic systems, and it was interesting to see their different requirements and yields.
The pumpless window farm, modeled after the instructions from windowfarms.org (http://www.windowfarms.org/), did not have a pump at all. Though this used the least energy, Gwen, the greenhouse specialist, expressed that they have had some problems with this system.
Their most successful system was an energy-intensive gutter-like system that required constant pumping. Special solutions were prepared for different parts of a plant's life cycle. This was the most efficient on a large-scale, and when the required energy was available (and sustainable!). They also had an energy-intensive pumped viney-plant system.
They used an aeroponic system that was connected to a fish tank. The fish's waste provided the nutrients for the plants, and the plants filtered the water.
The VertiGrow system only needed to be pumped once a day and was more reliable than the Window Farm system. They suggested we explore this method in our pursuit of hydroponics. And we will.
The Barge has volunteer hours and visiting hours every weekend! For more information, go to http://www.groundworkhv.org/programs/environmental-education/science-barge/ .