Integration of a geothermal system in a winery: preliminary assessment

The wine-production sector is characterised by the need, at certain stages of the vinification process, to keep temperatures that are constant and different from the ambient temperature, to control the biological fermentation processes that take place in the must. One of the possibilities for making the entire sector more sustainable from the energy point of view is to use, as far as possible, renewable sources in the process stages that require thermostatation. The present study investigates the effective possibility of using a low-enthalpy geothermal system (i.e., with a horizontal development) as an integrative thermal system, drawing some conclusions on its concrete applicability to a mediumsmall experimental winery (total volume of fermenters: 2800 L) and the possible scale effect(s) occurring for larger installation sizes. What emerges from this study is the need to have at disposal a site of at least 54 m2 to be excavated to a depth of 3 m in order to guarantee a thermal power integration of 20 kW in cooling mode, against an installed nominal pumping power of only 550 W (hence granting a useful effect 36 times higher, i.e. a COP equal to 36). The preliminary evaluation concerned also the precise quantification of the costs for investments (materials/components purchase, ground excavation, pipelaying/ installation of components), resulting in an interesting overall investment cost coefficient of 1.273 EUR/W.