*Article* **Analysis of the Viability of a Photovoltaic Greenhouse with Semi-Transparent Amorphous Silicon (a-Si) Glass**

**José-Ramón Aira <sup>1</sup> , Sara Gallardo-Saavedra <sup>2</sup> , Marcia Eugenio-Gozalbo <sup>3</sup> , Víctor Alonso-Gómez <sup>4</sup> , Miguel-Ángel Muñoz-García <sup>5</sup> and Luis Hernández-Callejo 2,\***


**Abstract:** For decades, society has been changing towards an energy mix that enhances the use of renewable sources and a more distributed generation of energy. The agricultural sector is included in this trend, which is why several studies are currently being carried out focused on the use of solar energy in greenhouses. This article aims to demonstrate the viability of a greenhouse that integrates, as a novelty, semi-transparent amorphous silicon photovoltaic (PV) glass (a-Si), covering the entire roof surface and the main sides of the greenhouse. The designed prototype is formed by a simple rectangular structure 12 m long and 2.5 m wide, with a monopitch roof, oriented to the southwest, and with a 35◦ inclination. The greenhouse is divided into two contiguous equal sections, each with an area of 15 m<sup>2</sup> , and physically separated by an interior partition transparent wall. The surface enclosure of one of the sections is made of conventional glass, and the one of the other, of PV glass. How the presence of semitransparent PV glass influences the growth of horticultural crops has been studied, finding that it slightly reduces the production of vegetal mass and accelerates the apical growth mechanism of heliophilic plants. However, from a statistical point of view, this influence is negligible, so it is concluded that the studied technology is viable for horticultural production. The energy balance carried out indicates that the energy produced by the PV system is greater than the energy consumed by the greenhouse, which shows that the greenhouse is completely viable and self-sufficient for sites with the adequate solar resource.

**Keywords:** sustainable greenhouse; semi-transparent photovoltaic panels; amorphous silicon; building-integrated photovoltaics; distributed generation; microgrid
