Energy and economic analysis for the design of greenhouses with semi-transparent photovoltaic cladding

Abstract

Abstract Photovoltaic (PV) greenhouses generate solar electricity while providing a suitable environment for crop production. Energy and life cycle cost (LCC) analysis were employed to study the potential for installing semi-transparent photovoltaic (STPV) cladding on the roof of a greenhouse that employs supplemental lighting located in Ottawa, Ontario, Canada (45.4°N). The study was conducted using current and future projected (future projection study) values for the efficiency of PV and horticultural lighting technology. The STPV cladding generated solar electricity but also caused internal shading that was counteracted by augmenting supplemental lighting by as much as 84%, which in turn reduced heating energy use by up to 12%. Although STPV cladding increased lighting electricity use, it generated 43.7% of the electricity that was consumed for supplemental lighting in the present study and 107.2% in the future projection study. Therefore, in the future, a STPV roof could potentially displace all the greenhouse’s electricity needs for supplemental lighting. Currently, STPV cladding would not an economically attractive investment. However, a nearly 23% reduction in LCC was achieved in the future projection study. STPV will increasingly become a promising cladding alternative for improving energy efficiency and economics of greenhouse operations.