Building integration of semitransparent perovskite-based solar cells: Energy performance and visual comfort assessment Alessandro Cannavale a,⇑ , Maximilian Hörantner b , Giles E. Eperon c , Henry J. Snaith b , Francesco Fiorito d , Ubaldo Ayr a , Francesco Martellotta a a Department of Civil Engineering and Architecture (DICAR), Politecnico di Bari, via Orabona 4, 70125 Bari, Italy b Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, UK c Department of Chemistry, University of Washington, Seattle, WA 98105, USA d University of New South Wales, Faculty of Built Environment, Sydney, NSW 2052, Australia highlights  Innovative transparent perovskite-based BIPVs cells were studied.  Yearly energy yield and visual comfort benefits were calculated.  The effect of different climate conditions was also investigated.  Energy yield varied between 10 and 30 kWh/m 2 per year.  PV cells behaved like solar control films. article info Article history: Received 25 November 2016 Received in revised form 22 February 2017 Accepted 2 March 2017 Keywords: Building-integration of photovoltaics Perovskite-based solid-state solar cells Energy saving Daylighting Visual comfort abstract This study presents a prediction of the yearly energy production and visual comfort benefits deriving from the adoption of building integrated semitransparent photovoltaic windows. Measured electrical and optical properties of neutral-colored solid-state planar heterojunction perovskite cells, characterized by promising transparency and photovoltaic conversion efficiency, were applied to a hypothetic photo- voltaic glazing. Such experimental data were used as input to estimate annual energy production and visual comfort effects. The effect of different climate conditions was also investigated. A south- oriented test-room was modelled, assuming two window-to-wall ratios (WWRs) for office buildings, 19% and 32%, respectively. Energy yield was calculated at different locations showing figures between 20 and 30 kWh/m 2 per year, with negligible reduction (not exceeding 3% in the hottest climates) when cell temperature was taken into account. Visual comfort assessment was carried out using two typical metrics: Useful Daylight Illuminance (UDI) and Daylight Glare Probability (DGP), comparing the perfor- mances of a photovoltaic glass with those of a commercial solar control glass and of a clear glass, acting as a reference. We found that the use of photovoltaic glass, independent of the location latitude, showed a significant increase in UDI values respect to clear glasses and performances comparable to solar control glasses. With reference to DGP, the use of photovoltaic glass allowed the reduction of occurrence of high DGP values (>0.45) of about 12–23%, depending on the location. Finally, we compared the annual energy production of building integrated photovoltaic cells to the annual use of electric energy for artificial light- ing, finding that in most of the cases the annual energy production overcomes the amount of electric energy used for artificial lighting. Ó 2017 Elsevier Ltd. All rights reserved. 1. Introduction According to the agreement of COP21, global warming should be kept below 2 °C by means of a massive reduction of greenhouse gas emissions (GHG). All new buildings will have to be nearly zero energy, as defined by the European Directive 2012/13/EU, i.e. http://dx.doi.org/10.1016/j.apenergy.2017.03.011 0306-2619/Ó 2017 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail address: Alessandro.cannavale@poliba.it (A. Cannavale). Applied Energy 194 (2017) 94–107 Contents lists available at ScienceDirect Applied Energy journal homepage: www.elsevier.com/locate/apenergy