Net Zero Algae Food and Biofuels
by Dr. Mark Edwards
et zero food production has minimal or no negative impact on the environment. In May 2011, Except Integrated Sustainability announced the Polydome, a revolutionary approach to greenhouse agriculture that offers the possibility of commercial scale, net-zero-impact food production. The Polydome looks similar to a version upgrade of the Biosphere II in Oracle, Arizona. Biosphere II explores the complex web of interactions within life systems in a structure that included five areas based on natural biomes. The project includes an agricultural area and human living/working space to study the interactions between humans, farming and technology with the rest of nature.
The Polydome, from the Netherlands, focuses on sustainable agriculture and is a form of freedom microfarm or vertical farms that have been profiled in prior Algae 101 posts. The Polydome greenhouse interweaves a wide variety of crops and animals, taking advantage of every inch of the greenhouse while eliminating the need for synthetic fertilizers and pesticides. The Polydome creates high yields (60-90 kg per square meter), and diverse outputs. The plan covers over 50 crops, two mushroom varieties, chickens, eggs, fish, and honey. A small Polydome system can provide a richly varied food supply for a large population. Using Polydome, even a city as dense as New York could provide the majority of its own food supply using available roof space.
Polydome maximizes food production and variety by operating as a self-maintaining ecosystem rather than an industrial farm. Plants, mushrooms, livestock, and insects interweave to connect waste, water, and energy flows between species and capture the benefits of varied space and light conditions. Taller crops that soak up sun provide shade-loving plants shelter. Chicken and fish provide ready-made fertilizer, while beneficial insects act as natural substitutes for pesticides. Animals within the system range freely and live naturally, while the design of the crop layout limits the need for repetitive human labor.
Feeding our cities
Cities are dependent on outlying agricultural land to produce food. The Polydome system’s increased variety, efficient spatial arrangements, and reduced environmental footprint mean that a compact Polydome system could sustainably feed a large population locally. With its flexible cropping schedules, a Polydome system can respond quickly to local food demands and offer more economic resilience than standard single crop systems.
The innovation company Except, estimates that cities as densely populated as New York City could provide the majority of their own food supply using available roof space. A less dense city like Rotterdam could provide 80% of its food needs using only 3% of its surface area. For the first time in history, cities could become producers rather than just consumers. The Polydome system enables cities to provide for many of their needs from within; reducing the disconnect between urban life and agricultural production. Local food production creates a magnificent benefit set outline in a prior post on the SOAR project.
The Algae 101 post on the SOAR project, Save Our children’s Agricultural Resources, holds promise to yield over six times the energy derived from 9 billion gallons that the entire corn ethanol crop produces annually. SOAR can deliver 36 billion gallons of diesel without producing a drop of algae transportation fuel. SOAR creates this substantial energy savings by growing 50% of our food within 50 miles of consumers. The Polydome project leaders estimate we could grow 80% of our food locally, even in large cities.
SOAR offers a broad spectrum of additional health, social, economic and environmental benefits that total several times the value of the fuel delivered.
Polydome offers a range of environmental savings, highly efficient and localized production, attention to both human and animal welfare, and innovative energy and water management strategies. The Polydome systems could represent a step towards truly sustainable agriculture and serve as a vital building block of a resilient, sustainable society.
Except is a consultancy in the Netherlands that works with companies, governments, and NGOs to chart a path to a sustainable future and figure out the most effective way to get there. Funding for the Polydome project was provided by InnovatieNetwerk, an agency supported by the Dutch Ministry of Agriculture, and SIGN, the organization for innovation in the greenhouse sector in the Netherlands. The complete project report is available on Except’s website: http://www.except.nl
Net-zero algae food
Another production system, abundance, also creates a net-zero food supply. Of course, abundance growers can grow algae in combination with many other crops in a Polydome. Abundance microfarms, also called freedom microfarms in a prior Algae 101 post, give growers the freedom to produce good food nearly anywhere. Microfarmers mimic nature and use the oldest, simplest, yet most efficient growing system on Earth – photosynthetic microorganisms called algae. Growers practice abundant agriculture as they use no or minimal non-renewable inputs. Growers recycle energy and nutrients from farm, garden or municipal organic waste streams rather than using fossil inputs.
Microfarmers cultivate communities of algae and other microorganisms that they train to produce proteins, oils, carbohydrates and other valuable coproducts rapidly. Microfarms grow food, nutrients, feed, fodder, fertilizer, biofuels, nutraceuticals, medicines and advanced compounds in cultivated algae production systems, (CAPS) scaled to any size. A microfarm may serve a family or community and operate in a backyard, rooftop, balcony, vacant lot, barn, barren field or on other non-crop land.
Microfarms are geography and weather independent and grow colorful and tasty foods with superior nutritional profiles 70 times faster than modern agriculture. Growers experience little yield risk because they harvest half of the biomass each day. Culture growth slows or halts during cloudy or stormy days but begins again when the sun reappears. In geographies with little sun or long winters, grow lights can provide the photons for photosynthesis. Other growers may produce algae biomass in closed containers and feed the algae sugar instead of solar energy.
Microfarms are non-pollutive and can regenerate degraded air, water and soil. Algae use solar energy efficiently to transform wastewater, surplus CO2 and possibly some additional nutrients into a green biomass rich in lipids, sugars, proteins, carbohydrates and other valuable organic compounds. Algae convert inorganic substances such as carbon, nitrogen, phosphorus, sulfur, iron and trace elements into organic matter such as green, blue-green, red, brown or other color biomass.
Microfarms produce freedom foods that avoid most of the resource consumption, pollution, risk, and weather problems that plague fossil foods. Growing freedom foods can repair air and water pollution and regenerate soils. Therefore, freedom foods consumers leave a tiny ecological footprint.
Algae-based biofuels do not leave a net zero e-footprint but are significantly less consumptive than fossil fuels or crop-based biofuels. Algae biofuels could yield an e-footprint of 20/100 or lower if producers use waste or brine water for nutrients and waste CO2 for their carbon source. Growers could also avoid most fossil fuels by using renewable energy from wind, waves, geothermal or solar energy. The theoretically opportunity exists to grow algae biofuels in a Polydome using abundance methods to produce a high quality fuel with a minimal e-footprint.
Watch for DARPA to come up with this idea soon. A Polydome or Freedom Microfarm combination near a military based could produce food, fuel and freshwater for soldiers locally.
Adapted from: Edwards, Mark R. Freedom Foods: Superior Nutrition and Taste from low on the Food Chain for People, Producers and Our Planet, CreateSpace, 2011.