Amorphous single‐junction cells for vertical BIPV application with high bifaciality. Issue 3 (28th April 2016)

• Record Type: Journal Article
• Authors: Reininghaus, Nies; Feser, Clemens; Hanke, Benedikt; Vehse, Martin; Agert, Carsten
• Is Part Of: Energy science & engineering. Volume 4:Issue 3(2016)
• Page Start: 183
• Page End: 189
• Publication Date: 2016-04-28
• Subjects: a‐Si -- bifacial -- multijunction solar cell -- PECVD -- thin film; Energy industries -- Periodicals; Energy development -- Periodicals; Power resources -- Periodicals; 621.042
• DOI: 10.1002/ese3.116
• Languages: English
• ISSNs: 2050-0505

Abstract

Abstract: Solar cells used in building integration of photovoltaic cells (BIPV) are commonly made from crystalline wafer cells. This contribution investigates the challenges and benefits of using bifacial solar cells in vertical installations. We show that those cells get up to 13% more irradiance compared to optimum tilted south facing monofacial modules in Germany. The role of the n‐layer in thin amorphous bifacial single‐junction cells intended to be used as bifacial cells in BIPV applications is investigated. In contrast to the superstrate cell design, a transparent n‐layer and back contact play a key role to achieve high bifaciality. We therefore increased the transparency of the n‐layer by adding CO2, increasing the PH3 flow in the deposition gas and tested different thicknesses. With those measures, we reached a bifaciality of 98% for short‐circuit current density and 99% for open‐circuit voltage. Abstract : In this contribution, we propose to use bifacial solar cells in vertical installation for BIPV. We demonstrate that a vertical plane, regardless of orientation, gets more irradiance from both sides than a plane from one side in optimum tilt and orientation. We show that the removal of the back reflecting layer and a slight tuning of the n‐layer can turn single a‐Si:H solar cells into good bifacial cells with a high bifaciality which offer a lot of advantages for BIPV applications.