Submission to the 2016 Land Art Generator Initiative design competition for Santa Monica
Team: Alexandru Predonu
Artist Location: Bucharest, Romania
Energy Technologies: photovoltaic panels, algae bioreactor
Water Harvesting Technology: solar powered osmotic desalination (with waste brine used to culture algae for livestock feed)
Annual Capacity: 440 MWh (100% goes to power desalination processes and rotate the Ring Garden)
60 million liters of drinking water (40 million liters goes to agricultural production)
18,000 Kg of aeroponic crop yield (conserves 331 million gallons of water)
5,000 Kg of spirulina biomass for livestock feed
Agriculture is the largest user of fresh water in California. Ring Garden demonstrates a solution by creating a highly efficient ecosystem including a desalination plant, a rotating aeroponics farm, and an algae bioreactor. It harvests seawater, CO2, and the sun’s energy to create food, biomass, and fresh water.
Seawater enters the desalination plant through special screens that protect fish and local wildlife. Solar panels power a high-pressure pump to pressurize seawater above the osmotic pressure and through a semi permeable membrane.
The plants in the rotating farm use 60% of the water produced. The remaining 30% is sent to the city grid. The brine water is fed through the bioreactor to produce cultures of spirulina that, once mature, are sent to an offsite plant to produce biomass.
The aeroponics system uses 98% less water than conventional farming and yields on average 30% more crops without the need for pesticides or fertilizers. Ring Garden demonstrates that the main elements a plant needs in order to grow—water, sun, nutrients, and CO2— are on site and don't need to be transported.
Assisted by the power of the sun, the desalination plant provides fresh water and nutrients filtered from the seawater. On a footprint of about 1,000 m2 the farm can produce vegetables that would otherwise take 26,000 m2 of land and 340 million gallons of fresh water per year. Ring Garden consumes only nine million gallons of water per year. It saves 331 million gallons that would simply evaporate, which is water that can be redirected to 2,300 households.
The farm rotation reflects the movement of the Pacific Ferris wheel on the pier, and ensures that each “spoke” of planted area receives the appropriate amount of sunlight. The plant supports have a swivel mechanism that uses gravity to keep the plants always facing upward.
The structure is oriented south for best sun exposure. Ring Garden is tilted approximately 8.5 degrees so that on Earth Day (April 22) the sun seen from the Santa Monica Pier will set through the middle of the wheel.