A Scalable Environmental Controller with Integrated Solar Thermal Storage and Extraction for Field Protected Agriculture

High Tunnels (commonly called poly tunnels or hoop houses) are a type of field protected agriculture. They are essentially an intermediary between the full environmental risk-taking of outdoor production, and the controlled conditions, and relatively high energy use, of a conventional greenhouse. There are hundreds of thousands of acres in cultivation under high tunnels across the world. Domestically, the technology is rapidly expanding and this trend is likely to continue for a number of reasons: increased consumer demand for local produce, strong government support, rising diesel fuel prices, more frequent incidences of extreme weather, and increasing aridity and water shortages in major produce growing regions. Growers adapt high tunnel technology because it allows them to extend the season, boost yields, produce new crops, and improve overall quality without the large capital expenditures of greenhouses. Lacking precise, automated control of the growing environment, however, poly tunnel agriculture will be limited in size in many regions of the country. The research attempts to address this problem by designing and developing affordable, rugged technologies tailored made for high tunnel growers. The first objective of the researchproject is to modify the early prototype control system developed in the previous phase so that it can monitor and manage multiple tunnels. The second objectiveis to design a method of retrofitting tunnels with solar thermal heating systems that are completely integrated by the control systems. As part of this objective, we will design and develop unique air distribution manifolds that transfer fluids from the solar collector to the thermal mass. The technology will impact US agriculture by making high tunnel processes more efficient and cost-effective. It will reduce labor expenses, lower on-farm energy inputs, minimize risks and increase yields. This in turn will allow for greater domestic expansion of poly tunnel agriculture. Production will be able to move closer to major markets in the Midwest and Northeast, thereby reducing carbon emissions associated with food transportation. The expansion of tunnel agriculture will also provide growers a means to adapt to changing climate conditions such as more extreme weather and pronounced droughts.