## 1 Introduction
### System Configuration Features and Preliminary Modeling Results  
Three principal deployment areas were available on-site for the installation of 16 unshaded solar window units: (i) An East-facing tilted roof section, with 4 parallel-connected windows; (ii) a North-facing vertical wall section, containing 8 windows, and (iii) a West-facing tilted roof section with 4 windows. An additional deployment area on the east-facing vertical wall housed 2 more window units, which were strongly shaded by the nearby car-park roofing during most of the daylight hours. The shopping center atrium installation at Warwick Grove Shopping Centre (Figure 1) was completed in early 2019 [32], and a systematic study of its energy harvesting performance commenced in May 2019, following a short period of initial configuration tests and some reconfiguration of the microgrid equipment and circuitry used. Vicinity Centres has stated their commitment to achieving Net Zero carbon emissions by 2030 [33], and solar energy harvesting can be expected to play a major role in reaching this objective. Vicinity Centres' giant solar energy program and roadmap of renewable energy installations have led to winning the \"People's Choice\" award at the Property Council of Australia/Rider Levett Bucksnall Innovation and Excellence Awards 2019 [34]. Figure 2 shows a graphical summary of the microgrid circuitry details and equipment configuration installed, as well as sample plots of the daily power generation and use waveforms recorded by Enphase Energy's Enlighten Systems applications programming interface (API) over several days in May 2019. Four Enphase microinverters (Enphase Energy Inc., Fremont, CA, USA) were installed to service the four separate solar window installation areas described above; each microinverter collected the combiner-box bundled parallel-connected electric output from the windows placed into each installation area. A LED TV panel (powered by the generated energy stored in batteries) was installed in the shopping center entrance foyer and was configured to display a graphic summary of the system operation state (also shown in Figure 2). The main system parameters displayed, related to the generation of energy and carbon offset capacity, were also configured for online live internet broadcasting at [[http://tcp.iotstream.io/vicinity-warwick](http://tcp.iotstream.io/vicinity-warwick)]([http://tcp.iotstream.io/vicinity-warwick](http://tcp.iotstream.io/vicinity-warwick)) Grove/index.php. The live power generation data are being refreshed every 15-20 minutes, and the amounts of daily and total generated energy (since May 14, 2019) are also shown. Electric loads other than LED TV included a computer system (Intel NUC small-form mini PC), modem (D-Link GSM), and two 30 W LED ceiling lamps within the foyer area, used continually for about 12 h daily. The energy storage was enabled by installing twin LiFePO\({}_{4}\) Enphase AC batteries providing 1.2 kWh capacity each. The Enphase Envoy-S Metered(tm) communications gateway system delivered the real-time solar production and energy consumption data to Enphase Enlighten(tm) monitoring and analysis software for comprehensive, remote maintenance and management of the complete microgrid system. Fuses were installed into each window's output cabling lines to safeguard against any possible issues related to the accidental (however unlikely) electric faults leading to the high reverse-current loading of any individual modules. These protective components were necessary, considering the high maximum I\({}_{\text{sc}}\) (\(\sim\)0.75 A) generated by individual PV windows, and the numbers (up to 8) of the parallel-connected window modules installed into bundles. Parallel electric connection of the individual windows placed into the same deployment areas (presumed uniformly lit in clear weather conditions) has been selected to improve the stability of the combined electric output to differential shading effects, originating from the possible glass surface  
contamination and variable cloud-related shading.