Grantee Research Project Results
Final Report: Developing Alternative Power to Drive a Partitioned Aquaculture System for Intensive Food Fish Production
EPA Grant Number: SU834320Title: Developing Alternative Power to Drive a Partitioned Aquaculture System for Intensive Food Fish Production
Investigators: Leavitt, Dale F. , Riley, Linda A. , Thomas, Charles R. , Roy, Adam , Schork, George , Pica, Jessica , Boisclair, Joshua
Institution: Roger Williams University
EPA Project Officer: Page, Angela
Phase: I
Project Period: August 15, 2009 through August 14, 2010
Project Amount: $9,834
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2009) RFA Text | Recipients Lists
Research Category: P3 Awards , Sustainable and Healthy Communities , Pollution Prevention/Sustainable Development , P3 Challenge Area - Sustainable and Healthy Communities , P3 Challenge Area - Air Quality
Objective:
It is incumbent on developed nations to improve and expand capacity to produce food in an environment sustained for future generations. One production strategy that has high potential for providing high quality protein is aquaculture. Our challenge was to refine and optimize an intensive pond-based aquaculture production system (the Partitioned Aquaculture System or PAS) such that it is driven by low-impact renewable energy sources. We designed, modeled, and optimized the system to remove the need for commercial electrical power to the PAS by installing photovoltaic energy generation supplying a battery-based power source. This project has far-reaching consequences in terms of advancing the state of aquaculture production globally and can significantly improve sustainable food production worldwide. Data collected, such as fish production rates and construction/operating costs, allowed us to evaluate the predictions generated by our modeling activities in Phase I as well as provide real estimates of cost/benefit for the application of alternative PAS technology in temperate water conditions. Food production, energy use, resource allocation, and environmental hazards all were within the scope of the current project. Each of these research areas provided “teachable moments” for the student team to expand their knowledge, as they disseminate their project to stakeholders.
To achieve Phase I of our P3 project, the RWU student team investigated adapting an existing partitioned aquaculture system that currently is operating via power supplied from a 15kW diesel generator such that it can operate in its entirety on an alternative energy source. The current configuration consists of an 8-foot paddlewheel “pump” exchanging water between the fish raceways and the pond at a rate of approximately 900 gpm; thereby, turning over the volume of the fish raceways in a 6-minute interval. We designed and modeled a system to remove the need for the diesel generator by installing a photovoltaic electrical generation system supplying a battery-based power source.
Summary/Accomplishments (Outputs/Outcomes):
There were many modifications made to the present PAS to identify the best approach for creating a sustainable PAS. The first decision involved the type of sustainable energy to use to power the system. We found that solar energy was the optimal choice for this application because wind energy is expensive and not well suited for the topology of the target area. The fish rearing raceways were redesigned to evenly distribute water flow, provide dissolved oxygen, and minimize the amount of energy needed to move water through the system. We ultimately concluded that water should flow straight through the raceways rather than changing the direction of flow, as originally designed. After much research on alternative methods for aerating and moving water through the system, a device fabricated by Modern Air was identified as the best fit for our design. From Modern Air, it combines an airlift apparatus with a 1-hp blower. We decided that we would use the airlift apparatus and combine it with a smaller ¾-hp blower from another company because that amount of power was not necessary for the system. The final design, the SPAS (Sustainable Partitioned Aquaculture System), is a combination of a redesigned fish raceway system, solar panels, batteries, charge controller, airlift pump, and a regenerative blower to power the system.
Conclusions:
The SPAS satisfies all the elements of people, prosperity, and the planet. The final SPAS design consists of fourteen 225W solar panels that connect to a ¾-hp blower to aerate and push water through the system. The batteries are controlled by a charge controller that regulates the amount of energy stored in the eighteen 12V batteries. The batteries store enough electricity for powering the system with 2 days of no sunlight and limited to a 50% discharge. Land will be excavated to create a new pond that will be sealed with a liner and the foundation will be placed along the side of the pond. The fish raceways will be constructed of wood. People will benefit from the newly designed SPAS by having a source of high-quality protein to eat or by generating a profit from selling the fish. Because the system is completely sustainable and off the grid, there are no contributions to harmful carbon emissions. Furthermore, there are minimal environmental repercussions from using the SPAS. With a net present value over 20 years of $13,601.00 and an annual profit of $680.05, there is significant potential for farmers to increase their crop diversity and earn additional income.
Proposed Phase II Objectives and Strategies:
The program proposed for Phase II is focused on developing a collaboration of undergraduate students, primarily from the Roger Williams University School of Engineering, Computing, and Construction Management and from the RWU Feinstein College of Arts and Sciences Biology Department, to participate in the implementation of a proof of concept of an intensive aquaculture production method that can be driven by low-impact renewable energy sources (i.e., photovoltaic power [PV]). By combining new intensive fish farming technology with non-carbon consuming power sources, the result (the Sustainable Partitioned Aquaculture System – SPAS) will be a viable food production system that can be applied throughout the world, requiring a minimum of technical infrastructure while providing a substantial harvest of fish for local consumption and/or for processing for broader markets.
As noted above, the Phase I component to the RWU EPA P3 grant focused on designing an energy-efficient intensive fish rearing facility adapted from conventional pond culture technologies. Upon the completion of Phase I, we are poised to undertake the proof of concept implementation of the Phase I design. The first objective is for the PV-powered SPAS system to be constructed as designed in partnership with a local cranberry farm (DoubleM Cranberry Co., Rochester, MA). Our purpose is two-fold, in that, by constructing the proof of concept model at a local farm, it will provide a mechanism for us to evaluate the system in terms of application for remote installations in developing countries while providing a local demonstration of opportunities for crop diversification in regional farms. Both outcomes, new sustainable technology for food production in developing countries and crop diversification using low impact technology at U.S. farms, are completely in line with the positive impacts required of the P3 Program.
The second objective of the Phase II undertaking, once constructed, is to evaluate the performance of the SPAS to produce market size fish in an independent and economical manner. To gauge the success of this project, we propose to evaluate the SPAS capacity to grow fish to market size in a timely and effective manner. Timely entails maximizing the growth rate of the fish, relative to published performance measures of other systems to grow a similar species of fish. Effective describes the ability of the system to sustain good growth with negligible mortality in the system while minimizing the ecological footprint of the operation, both locally and globally. To meet the second objective, we propose to operate the SPAS through a complete growing cycle while monitoring key environmental, biological, and economic parameters to evaluate the operations of the redesigned system. These data will be used to gauge the overall success for producing fish while allowing us to fine tune the system prior to further evaluation in a more challenging environment, i.e., installation in a less advantaged location.
Educational opportunities abound with the proposed Phase II Program. Undergraduate students have been directly involved in the design and will continue to be involved in the construction and evaluation of the SPAS. The program will be interdisciplinary, with biology students providing information to engineering and construction management students and/or vice versa. Furthermore, the system will be used as a case study and demonstration project for courses in sustainability and aquaculture associated with two new minors at RWU. The demonstration farm will be utilized for workshops and other outreach tools for technology transfer to the regional farming community by agricultural extension personnel in the region. Lastly, the technology will be transferred to international aid groups to evaluate and implement the technology for high quality protein, i.e., fish, production in developing countries.
Supplemental Keywords:
Aquaculture, alternative energy, fish farming, photovoltaicP3 Phase II:
Developing Alternative Power to Drive a Partitioned Aquaculture System for Intensive Food Fish Production | 2011 Progress Report | 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.