Optimization of packing factor for maximum electric power and crop yield in greenhouse integrated semi-transparent photo-voltaic thermal (GiSPVT) system in desert land: An experimental study

Abstract

It is well known that food and energy requirement for human beings is increasing day by day due to the fast increase of population in the world. This can be met by (i) increasing the yield of crop per unit area, (ii) post-harvest losses, and (iii) using the barren land, which is about 19% for crop/vegetable production. The barren land consists of the desert (unfertilized), dry salt flats, beaches, sand dunes, and exposed rocks, etc. The barren land can be used by erecting a self-sustained greenhouse integrated semi-transparent photo-voltaic thermal (GiSPVT) system which can provide both electrical energy as well as crop yield through channel/pot cultivation. In this paper, an attempt has been made to design and install a 30 kWp semi-transparent photo-voltaic module with different packing factors as the south roof of uneven glasshouse over unfertilized land with an effective area of 80 feet by 120 feet. The six crops namely bottle gourd, cucumber, tomatoes, capsicum, broccoli, and French beans have been chosen for off-season cultivation (winter month) inside GiSPVT. The cultivation has been carried out by using the brick channel as well as pot as manure storage over unfertilized land. Parametric studies namely temperature, relative humidity, solar intensity, growth of each plant, root media preparation, etc for maximum yield have been experimentally studied for maximum each crop over a period of October 2020 to February 2021. It has been observed that maximum crop yield has been obtained with the following conditions:(i) Packing factor area of 25% of semi-transparent PV module(ii) The ratio of soil, sand, and organic fertilizer as 40%, 40%, and 20% respectively(iii) The maintaining of CO2 level inside GiSPVT by burning local dung cake(iv) The temperature inside GiSPVT is maintained by an earth heat source, burning local dung cake and reducing heat losses from GiSPVT to ambient air