The vertical farm’s power would come from solar panels and wind spires on the roof. Its circular (cylindrical) design uses the space most efficiently, allowing maximum light into the center. The city’s wastewater would be filtered and sterilized, then used for irrigation, and rainwater would also be collected and used to clean pollutants off the building’s outside surface. An electronic crop picker would monitor fruits and vegetables, using color detection to check for ripeness, and an electronic feeder would direct programmed amounts of water and light to crops according to a set schedule. Crops could grow both up (like corn) and down (like hanging tomatoes), maximizing space.