Grantee Research Project Results
Final Report: Sustainable Year-Round Food Production in Cold Climates
EPA Grant Number: SU834757Title: Sustainable Year-Round Food Production in Cold Climates
Investigators: Powers, Susan E. , Gonyer, Daegan A.J.
Institution: Clarkson University
EPA Project Officer: Page, Angela
Phase: II
Project Period: August 15, 2010 through August 14, 2012
Project Amount: $75,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2010) Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Sustainable and Healthy Communities , P3 Challenge Area - Air Quality , P3 Awards , Sustainable and Healthy Communities
Objective:
The primary goal of the project is to complete the design, feasibility, analysis, and impact assessment of a pilot Control Environment High Rise Farm (CEHRF) to provide year round food using sustainable water and energy approaches. The system uses electric lighting, climate control, and passive solar design for energy savings.
The specific tasks that were addressed in the past two years include:
- build a pilot scale CEHRF greenhouse on Clarkson University's campus;
- design, build and integrate all of the system components that comprise the pilot greenhouse;
- operate the greenhouse to prove the concept and refine operating protocols; and,
- develop a business plan for the next larger scale for the CEHRF system.
All of these components were completed by students who participated in the project through research, classwork, paid positions or volunteer assignments.
Summary/Accomplishments (Outputs/Outcomes):
The pilot greenhouse was constructed during the Fall 2010 semester and began operation in January 2011. Lettuce and microgreens were successfully grown during the winter months with tomatoes, herbs and peppers grown in the summer.
The greenhouse structure was designed based on passive solar principles. Three of the walls, the floor and the roof are fabricated from R-30 structural insulated panels (SIPs) and the south wall is made from R-3 corrugated polyethylene. Collectively, these two materials strive to maximize daylight and minimize heat losses. Heat gains from the sun were substantial, even in February, when temperatures inside the greenhouse were over 70°F without supplemental heat.
- Growing System: The aeroponic growing system was designed and constructed by our student leader, Daegan Gonyer. It provides intermittent spray (~5 seconds each minute) and drains excess water back into the water supply tank for conservation of water and nutrients. The greenhouse currently has ten 2" x 4" aeroponic units.
- Sensors and Controls: The students designed, purchased and installed all of the sensors and controls for the greenhouse system. The heating and lighting systems are controlled to provide appropriate amounts, while still conserving energy to the extent possible. Other systems (water pH and electric conductivity, water depth, and humidity) are measured continuously and recorded, but not controlled.
- Heating System: An external "energy cabin" provides renewable heat with solar thermal and pellet boiler hot water/glycol system. The hot water is pumped from the energy cabin to the greenhouse through standard radiators that are thermostat controlled.
- Lighting system: An LED lighting system has been installed with 75% red and 25% blue light spectrum bulbs. This system is designed to provide only the wavelengths required for photosynthesis, and not waste electric energy on wavelengths that are not important to plants. The efficiency of the system is further enhanced by turning on only enough of the lights to meet the lighting needs of the particular plant. For example, on a grey day, ~25-50% of the lights will be off.
The building includes three rooms, two of which are identical to enable controlled experiments with different conditions in the separate rooms. There are also two vertical layers of aeroponic units in each room. The nutrient solution and water spray, and temperature can be studied between the rooms and lighting, and planting methods can be studied within a single room.
Lettuce (Black-seeded Simpson) is being used as the primary crop for research to define the yields and to grow in the vertical distributed aeroponic system. Four of the 10 aeroponic units have been dedicated to this research, with the other units used to explore other crops that thrive in this system. Different types of commercial liquid nutrient mixtures from natural sources and treated digester effluent were used to nourish the plants. Experiments have been conducted with 4 ~ 6 weeks of lettuce growth, with different nutrient types and concentrations, light intensities and durations, transplanting and harvest time, and harvest method among the four experiments. The mass of roots, yield of root-free plants and marketable leaves in each aeroponic unit was measured. From the results, Pureblend pro for Grow (PBG) nutrient was selected as the most appropriate nutrient for using in aeroponic system. However, preliminary results suggest that treated digester effluent, which is free, can successfully support the lettuce growth. Further research on this is on-going. The highest yield of leaves (322 g/m2/d) was achieved, with the lowest cost of $3.7 per kilogram leaves for electricity and nutrients, compared with the expected local sales price of $12.8 per kilogram of leaves. The growing conditions used to achieved this yield including transplanting lettuce after 2 weeks, extended growing time of 46 days, low TIN (total inorganic nitrogen) concentrations (130 ~ 170 mg/L-N), and light input (12 h/d, 250 μmol*m-2*s-1). The goals of this coming winter's research includes replicating the findings of last year to enable sufficient data for publication and continue to consider how to treat digester effluent for a nutrient source.
The focus on effluent from an anaerobic digester has resulted from the integration of the greenhouse developed through this P3 grant with the energy cabin (donated after a research study) and an anaerobic digester that is being retrofitted to handle campus food waste. This digester was developed for grocery stores as a pilot project and donated to our campus. The resulting integrated food waste-food production system with the energy cabin for renewable heat is unique and has generated significant discussion about a truly sustainable, industrial ecology approach. The material and energy flows between these components are highlighted in the graphic below.
Analysis of the energy and materials inputs through the greenhouse versus importing lettuce from California is not yet complete. This comparison will be completed in the Spring 2013 semester. Sufficient data for our system were not available last spring semester to complete that comparison. On the business development front, three of the students initially involved in this project have started their own business - Blue Sphere Industries, Inc. to expand the development and operation of CEHRF greenhouses in cold climates. The business plan for the next size system - 100 aeroponic units - was developed and was submitted to three business plan student competitions. Students have received several prizes for this work that helps to supplement the EPA P3 funds and get the fledgling student business off the ground. The 100-unit system will also be on Clarkson's campus and will explore the value of renovating under-utilized building space for food production. This expansion has been funded through a $250,000 zero-interest loan from a Clarkson alumna who is interested in the development of a similar system in the Rocky Mountains of Colorado. Clarkson's Shipley Center for Innovation and Reh Center for Entrepreneurship have been instrumental in developing the business side of this project.
Conclusions:
The EPA P3 project is now fully operational and making a difference on campus as part of our showcase integrated food production and food waste project The system has been fully institutionalized and used to both meet the educational needs of our students and address sustainability issues on campus Overall, we have accomplished more than we set out to complete.
The incorporation of a new business stemming from the P3 Phase II project creates the potential to bring local, fresh and organic food production to people in areas that previously relied on imported food The project has provided an opportunity to develop both the technology and business aspects of this concept, as well as a great educational environment for an interdisciplinary group of students The project will continue throughout the next several years as more data are collected to quantify the system inputs and outputs, thereby enabling the business plan and environmental assessments to be refined and reconsidered.
References:
- Polland, M., In Defense of Food: An Eater's Manifesto, The Penguin Press, New York, 2008.
- Despommier, D., et al. “Energy In, Energy Out.” Columbia University, Spring 2005. http://www.verticalfarm.com/plans-2k5.htm
- Kratsch, H., Graves, W. and Gladon, R. "Aeroponic system for control of root-zone atmosphere." Environmental and Experimental Botany 55. 2006: 70-76.
- Ziegler, R. “The vertical aeroponic growing system.” Synergyii International Inc. 2005.
- Wikipedia, “Aeroponics” http://en.wikipedia.org/wiki/Aeroponics
- NASA Tech Briefs, "Progressive plant growing has business blooming." 2006.(http://www.techbriefs.com/component/content/article/1294).
Journal Articles:
No journal articles submitted with this report: View all 9 publications for this projectSupplemental Keywords:
local food, energy efficiency, LED lighting, aeroponics, greenhouse, controlled environment high rise farming, passive solar, wood pellet boilerRelevant Websites:
CEHRF Clarkson University Project Page Exit
Progress and Final Reports:
Original AbstractP3 Phase I:
Sustainable Year-Round Food Production in Cold Climates | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.