Evaluating energy generation of a building-integrated organic photovoltaic vertical façade: A case study of Latin America's pioneering installation

Building-integrated photovoltaics play a key role in the reduction of greenhouse gases emission towards sustainability in the building and construction sector. Organic solar technology holds several advantages such as lightweight, flexibility and semitransparency, suiting well for this type of application. When integrated into windows and facades, it provides a dual benefit: it acts as a solar radiation barrier, improving indoor thermal comfort, while also generating off-grid power. Besides that, organic devices are known to be more efficient than traditional photovoltaics based in silicon in diffuse and low light conditions. Nevertheless, only a few studies have been conducted in the area employing large-area commercial modules, in real operational conditions and for a long-term period. This work has the purpose of reducing this gap and shine a light on this debate bringing an analysis based on real data of a set of organic panels laminated in glass in a vertical pioneer installation in Latin America. For this, several linear regression models were tested to predict the energy generation from meteorological data and solar position throughout four years of operation, and the best models developed achieved 0.76 and 0.81 values for R2 with validation data, respectively for simple and multiple regressions. A visual analysis showed that the OPV system produced more energy in winter due to lower solar altitude, despite lower global radiation levels. The most significant variables in the models were the global solar radiation and the solar altitude. The use of glass lamination and vertical orientation likely preserved the performance of the panels, keeping energy generation consistent over four years, akin to the first year.