# A Holistic Approach for Design and Assessment of Building-Integrated Photovoltaics Systems
## 1 Introduction  
Buildings consume at least 40% of global energy and are responsible for 36% of all CO\({}_{2}\) emissions and 28% of greenhouse emissions [1; 2]. Therefore, it is necessary to develop strategies to achieve the different goals of energy savings and mitigating global warming. Renewable energy sources have become a competitive option to face the current energy and environmental challenges. In particular, photovoltaic (PV) technology has become increasingly popular due to improvements in recent years. Consequently, the levelized cost of electricity (LCOE) of new PV projects at the utility-scale fell 13% in 2021 [3]. In addition, governments promoted incentives for renewable energy, demonstrating more interest in PV technologies. In recent years, worldwide solar energy has maintained a constant and exponential growth trend [4]. The evolution of the global installed capacity and annual additions over the last 12 years was described in [5], where China, the USA,and Europe have taken advantage of this rising tendency. However, in 2020, the trend changed due to the global crisis, and the distributed PV additions dropped slightly. The total cumulative installed capacity for PV at the end of 2020 reached at least 760.4 GW [6]. Annual solar PV additions globally are expected to accelerate during 2023-2025, due to faster recovery of distributed PV applications as the global economy improves. PV systems in buildings are widely used since rooftops and ceilings provide a suitable location to place PV panels. Such installations correspond to the BAPV (Building AppliedPV Systems) concept. However, they are not the only way of using PV generation in buildings. BIPV (Building Integrated PV System) is an option to produce energy while meeting architectural limitations, taking advantage of facades and fenestration [7]. Moreover, shading devices and decorative components can be used for this purpose. Different types of solar cells are commonly used for BIPV and BAPV, among them: polycrystalline, monocrystalline, amorphous, and thin films on a foreign substrate. Thin film (TF) solar cells, in particular, use amorphous silicon (a-Si), cadmium telluride (CdTe), copper indium sulfide (CIS), and copper indium gallium diselenide (CIGS) and have the advantage that the semiconducting material is deposited on a substrate [8]. In BIPV applications, photovoltaic modules are integrated into the surface of the building envelope because of their features (size, flexibility, shape, and appearance). These photovoltaic elements can be used together with common materials in architecture, such as glass or metal, in opaque as well as semitransparent surfaces [9]. Worldwide, the BIPV market has significant energy potential. However, there is an established market in most European countries,, such as Germany, Spain, France, Switzerland, and Italy. In these countries, approximately 20% of the BIPV installation is on facades, and the remaining 80% is on rooftops [10]. BIPV's worldwide growth rate over the past seven years is approximately 50% of installed capacity in each year [11]. For other regions, such as China and Japan, the increase in investments will be slower but will still represent attractive markets [12]. Despite the many advantages of BIPV technology for the building and its occupants, the implementation of such technologies is not widely used in certain countries. This is the case in Colombia, where the weather conditions are favorable for photovoltaic generation due to the good radiation levels throughout the year. More than half of the country has an average solar irradiation of 194 W/m\({}^{2}\) and an average solar radiation of 4.5 kWh/m\({}^{2}\)/d. These values exceed the global value of 3.9 kWh/m\({}^{2}\)/d of solar radiation [13]. However, BIPV applications in Colombia are not widely implemented or studied. Moreover, there is no official record of studies that present a technical and economic analysis of BIPV system installation.