The aquaponics system at CEI produces enough lettuce to feed our community twice a day, seven days a week. The fish production is increasing in the next year, and provides one meal a week of fresh tilapia. Right now the system is good, but does have a few minor opportunities for improvement. One issue we are facing is an over-abundance of solid waste settling out at the bottom of our deep water hydroponic beds. One way to solve this “problem” is to install additional filters which would have to be purchased, shipped, installed, and run on electricity. The filters would use more fresh water to clean, and require more time and maintenance. This isn’t the ideal solution when we are trying to reduce imports, simplify operations, maintain affordability, and conserve water.
We instead looked for a permaculture way of solving the solid waste issue, and found one!Last Friday a shipment arrived at Governors Harbor Airport of three small boxes from a company in Florida called Miami-Aquaculture Inc. Inside the three boxes were approximately 2,000 post-larval giant freshwater prawns (Macrobrachium rosenbergii) which can grow to twelve inches in length in just one year. Continue reading →
In recent weeks, the CEI/IS biodigestion system has quietly been generating an unheralded form of renewable energy: biogas. Although biodigestion is the most recent addition to the renewable energy scheme on campus, the process of generating renewable energy through anaerobic digestion is arguably the cleanest form of energy production we have. By closing the loop between food production, energy production, and waste management, biodigestion represents a serious step forward in our efforts to become more self sustaining and generate models that can be replicated on a local level. What is biodigestion, though? In layman’s terms, biodigestion is simply the breakdown of organic material in an anaerobic setting. As naturally occurring bacteria consume organic wastes, they generate gas, mostly methane, which can be used as a fuel source. During the break down process,any potential pathogens or harmful bacteria are out-competed, leaving nutrient rich fertilizer as an end result. In short, biodigestion uses safe waste management techniques to generate renewable energy and nutrient dense fertilizer, which is capable of increasing plant yields significantly. Continue reading →