Economic feasibility study of semitransparent photovoltaic technology integrated on greenhouse covering structures

This study investigates the application of semitransparent photovoltaic (PV) technology integrated on the cover of an east-west oriented greenhouse. With reference to the average greenhouse features identified through a preliminary survey over several greenhouse farms in Northern Sardinia (Italy), the study considered the application of grid-connected PV systems based on modules with light transparency ranging from 50 to 75%. A feasibility analysis was performed with different overlay levels on the roof, in order to assess their energy potential and the economic convenience of the investment. By covering south oriented roofs only, the maximum power to be installed is between 94 and 188 kWp, corresponding to a shading level respectively of 10 and 19%. Annual electricity production of PV systems considered has been estimated between 112,800 and 260,200 kWh. Considering the yearly radiation intensity examined, the potential electrical output of PV systems, for all solutions considered, is higher than the power demand of an average floriculture farm (21,600 kWh). The best economic results have been obtained with the 188 kWp PV system, with a Net Present Value amounting to 1,112,692 €, which is much higher than the investment cost (832,000 €). Payback time ranged from 10 to 13 years, respectively for the 188 kWp south oriented and for the 94 kWp PV system installed both in north and south oriented roofs.