Thermal Storage for Small Farms

Energy expenses are typically a significant portion of a farm's budget - often as much as 10 percent of total costs. Agriculture has been hit hard by recent energy price increases, with small farms feeling the negative effects the most. This project will assess the feasibility of using long-term thermal storage where renewable energy can be captured when available and cached into a thermal storage medium for later use. Typically, energy is harvested from solar thermal collectors, but other farm-based energy sources such as biomass can also supply heat. Depending on the storage duration and the recovery temperature, a number of different storage media are available. For short term storage, sensible heat storage is the simplest solution, but suffers from thermal losses over time. For longer term storage, options include storing heat in phase change materials or via thermo-chemical reactions. The selection of the optimum storage media depends on which energy-intensive farm process it supports. This project will match the optimal storage media to various farm activities ranging from grain drying, water heating, anaerobic digester heating and building heating. Thermal energy is recovered from the thermal cache when needed, decreasing a farm's reliance on energy generated off-farm.