On the use of encapsulated phase change materials pebbles and pellets as freeze protection method for low-stature plants/crops

Abstract

The use of phase change materials (PCMs) in encapsulated pebbles or pellets as freeze protection method for low-stature plants/crops is proposed and discussed at the conceptual level. Utilizing a simplified geometrical model, it is shown that, for practical applications, small encapsulated-PCM pebbles/pellets of 1-cm sized could provide the necessary heat to prevent the freezing during typical freezing time. Taking into account the balance between the loss of energy on a typical frost night and the latent energy stored in the encapsulated PCMs-pebbles/pellets, the amount of such pebbles/pellets per unit of soil-area was calculated and resulting in the use of less than 2% of the soil-area. The preliminary results at conceptual level are encouraging, however, additional work and R&D is require before its real practical efficacy can be put to test. The choice of the suitable crops, the specific environmental conditions during the freezing time, the manufacture recyclability and environmental impact of the pcm-pebbles/pellets are some of the aspects which must be carefully addressed.