Sustainable Low-Cost Heating for Season Extension Structures

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2007: $14,928.00
Projected End Date: 12/31/2007
Region: Southern
State: Tennessee
Principal Investigator:
Steve Hodges
Clinch Appalachian Farm Enterprises


  • Vegetables: greens (leafy), peppers, tomatoes


  • Animal Production: housing
  • Education and Training: extension, farmer to farmer, on-farm/ranch research, participatory research, workshop, technical assistance
  • Farm Business Management: cooperatives, marketing management
  • Production Systems: general crop production
  • Soil Management: earthworms, composting, organic matter
  • Sustainable Communities: urban/rural integration

    Proposal summary:

    A variety of factors is creating a growing demand for local produce in schools in our northeast Tennessee project region. The experience of farmers in the Clinch Appalachian Farm Enterprises is that local school child nutrition directors are eager to buy more fruit and vegetables from local farmers as one way of meeting new stricter federal guidelines for school nutrition as well as the growing demands of parents for healthier food, while winning community support for helping the local economy. But a big obstacle to increasing sales of local produce to schools is that the local growing season coincides with only half of the school year. Child nutrition directors want to be able to put fresh produce on salad bars throughout the year. Efforts in getting local farmers to employ season extension technology and methods are meeting with only modest progress, with a major obstacle being the cost of heating the season extension structures such as high tunnels, hoop houses and green houses in order to increase the variety of produce as well as the growing season of produce available for sale to schools and other institutions. Will Allen of Growing Power, in Milwaukee, Wisconsin has developed a system for transferring the heat from composting bins into greenhouses, as a way to supplement solar heating of the structure and thus allow a wider variety of produce to be grown, and a longer growing period than if this supplemental heating were not used. A system of using multiple compost heaps allows for one heap to take over heating as another cools down. Another result is rich compost that provides a cost-effective product that further assists the extended growing effort. Project Coordinator with assistance from Project Cooperators will provide technical assistance to participating farmers as they develop season extension structures and begin using them to grow; access to season extension cost share funds; and help setting up recordkeeping and reporting systems so that records of the costs of setup and operation, heat efficiency of heating systems, and sales of produce grown as a result of season extension can be kept for evaluation, publicity and outreach purposes. Will Allen will return part way through the winter to help review progress of participating farmers, revise technical assistance plans, and provide any other training or advising assistance as needed. An Outreach Field Day will be held on one or more farms of participating farmers. The Field Day will be advertised in local general and farm media and locations likely to reach farmers. Local farmers, farmer groups, and agricultural professionals will be individually invited. At the Field Day, the sustainable low-cost heating system for season extension structures will be demonstrated, and samples of compost and outreach information will be distributed to attending farmers and media. Farmer packets and Media packets will be prepared for handing out, which will include information on costs of developing season extension structures and the composting heating system, cost of operating the heating system, heating efficiency results observed, and resulting increase in sales of produce attributable to the extended growing season (sales data from farmers will be reported as aggregate and typical sales, without breaching confidentiality of individual farmer sales data.) In addition, farmer packets will include information on how to begin participation in the farm-to-school project, in season extension, and an annotated list of web and print resources and contact information for technical assistance providers. Media packets will include background information suggesting the implication of project results for agriculture in the region, and an annotated list of sources for more information. Photos will be taken of the project to enable development of a PowerPoint presentation, which will be made available on CD-Rom. The goal of this project is to enable more local farmers to grow and sell more produce to local schools for more of the school year by eliminating a key barrier to season extension: the prohibitive cost of heating their season extension structures. The method used by this project will be to train and to assist local farmers in planning and carrying out low-cost heating of season extension structures on their farms. We will demonstrate this solution works by relying on reports from participating farmers to track the increase in sales of local produce during “off-season” months to local schools, institutions, and other markets; to track the cost of setting up and operating these season extension structures and their low-cost heating systems; and to track the efficiency of these low-cost systems in heating season extension structures.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.