## 1 Introduction  
The global building integrated photovoltaics (BIPV) market is likely to expand from USD 6.7 billion to USD 32.2 billion by 2024, witnessing a compound annual growth rate (CAGR) of 23.4% over the forecast period [1]. This growth trend is due to both the increasing availability of new and innovative BIPV products, and the growing attention of the architects, city planners, property developers, and governments towards the sustainable construction practices and the integration of renewable energy generators into urban landscapes. At the same time, the worldwide annual energy consumption continues to grow, and is projected to exceed 0.74 billion TJ by 2040, with the generation contributions from fuels other than coal (mainly renewables) being on the increase [2]. Global warming-related concerns and environmental protection trends and policies also continue to favor the development of renewable energy generation and storage facilities [3; 4; 5; 6]. At present, the BIPV technologies and products are only beginning to experience their expected widespread adoption, and a range of different novel technologies are being introduced into the well-established market of construction materials [7; 8; 9; 10; 11; 12]. The benefits of distributed energy generation (an approach based on employing a combination of small-scale technologies to produce electricity close to the end users of power) include the avoidance of significant transmission-line losses and the provision of blackout resistance. Generating electricity at the point of its use can also lead to making the urban built environments potentially grid-independent, even if this energy supply independency is provided only on limited time-scales. Multiple recent literature sources emphasize the importance of distributed generation networks and the development of sustainable microgrids [13; 14; 15]. Advanced building-scale integration of renewable energy generators utilizing most of the available deployment areas, including walls and windows, can lead towards future city-scale distributed generation networks in \"smart cities\". Additionally, the emergent concept of \"smart facades\" that provide locally window-embedded self-powering environmental sensor systems integrated with window-powered equipment, such as motorized blinds, is gaining increasing attention in commercial engineering circles [16]. The most desired attributes of building wall-integrated PV are either the highly-transparent, perfectly-clear visual appearance, or a possibility of significant (active or passive) control over their transparency, appearance, and color. A number of recent and detailed reviews of the current trends in BIPV are available [17; 18; 19; 20], with the most recent sources underscoring the importance of transparent photovoltaics and solar windows, which have just started to appear on the market at present, packaged as installation-ready framed systems suitable for long-term environmental exposure. The importance of energy-efficient construction practices is currently gaining substantial attention from multiple governments and research groups worldwide, leading to the emergence of a large range of principally new construction materials and their components, such as advanced coatings which ensure improved thermal insulation and/or change transparency in response to external conditions [21]. It is the combination of the energy saving and energy generation functionalities possible to be engineered in modern windows that is of primary interest for leading architects and property developers. In early 2019, Vicinity Centres (a real estate investment trust company based in Melbourne, Australia) has installed 18 transparent solar windows supplied by Clearvue Technologies Ltd. (Perth, Australia), into a refurbished entrance porch of Warwick Grove Shopping Centre in Warwick (a northern suburb of Perth), in order to evaluate their suitability and practical application potential in commercial property settings.