An old meatpacking warehouse in Chicago is being turned into an urban aquaponics farm. Called “The Plant,” the facility is already operating as a fish hatchery, hydroponic garden, commercial kitchen and brewery for both beer and kombucha tea. The waste from one part of the farm serves as raw material for another, making it a net-zero system.
Fish feed on spent barley from the brewery, and plants feed on waste from the fish. Kombucha tea cultures feed off oxygen produced by plants, while plants feed off carbon dioxide produced by the kombucha cultures. In about a year, The Plant will have an anaerobic digester, which will convert waste to biogas that will be used to power turbines to create electricity. Once the anaerobic digester is installed, The Plant will be completely off the grid. (http://www.huffingtonpost.com/2012/05/07/the-plant-explained-chicago-urban-farm_n_1497832.html?ref=topbar#s=more224918 )