Techno-Environmental Analysis of Facade Integrated Photovoltaics and Electric Vehicle Charging for University Building

Faculty of Mechanical and Automotive Engineering Technology, Universiti Malaysia Pahang, 26600 Pekan, Pahang, Malaysia Automotive Engineering Centre, Universiti Malaysia Pahang, 26600 Pekan, Pahang, Malaysia Centre of Excellence for Advancement Research Fluid Flow (CARIFF), Universiti Malaysia Pahang, 26300 Kuantan, Pahang, Malaysia Energy Centre, Maulana Azad National Institute of Technology, Bhopal 462003, India


Introduction
Electric vehicles (EVs) are developing as an e ective answer to pollution issues in transportation. However, increasing EV penetration causes grid issues such as power losses [1], voltage variations [2], and decreased power quality [3]. In this context, developing alternative, energy-e cient sources for EV charging to avoid extra burden on the grid, particularly private vehicles, must be prioritized. e building already accounts for around 28% of overall energy-related CO 2 emissions, with two-thirds coming from electricity production for building use. e use of fossil fuels in buildings contributes about 9% of global energy-related CO 2 emissions [4], whereas the primary source of transportation energy is gasoline and other liquid fuels [5], which accounts for 24% of direct CO 2 emissions [6]. With the pace of urbanization, many countries will face challenges in meeting the needs of their growing urban populations, including housing, transportation, energy systems, and other infrastructure [7]. Due to that, the global passenger car eet is projected to double by 2050, with the majority of growth in developing markets, where an estimated three out of four cars will be found [8]. To accomplish a cleaner transportation sector, electric vehicles are being encouraged. In 2020, there will be 1.7 million Passenger EV which is expected to reach 25 million by 2030 [9]. According to the Stated Policies Scenario, in 2030, global electricity demand from electric vehicles for LDV will reach 377 TWh, about a seventeen-fold rise from 2019 levels of 21 TWh [10]. Electric vehicles promote a shift away from CO 2 -emitting fossil fuels, and solar-powered EV Charging reduces dependency on energy derived from electrical power sources generated through fossil fuels. Much technological and regulatory work has been done in recent years to increase EV adoption [11]. Recently, Government in Malaysia announced Electric cars to be exempted from all import, registration, and sales taxes, and individuals will be eligible for up to RM2,500 in income tax relief on the cost of EV charging infrastructure acquisition, installation, rent, hire purchase, and subscription fees [12], which will increase the EV adoption rate. However, higher pricing, a lack of charging infrastructure, and ambiguous regulation are said to be limiting the adoption of EV's in Malaysia. By decarbonizing the transport sector including EVs and charging through renewable energy, e-mobility will create a cleaner, healthier, and more affordable future for everyone [13].
Higher education institutions play a significant role in developing and promoting renewable and sustainable energy sources. Sustainable development must be integrated into all campus activities, which is the job and obligation of institutions [14]. e university has a multifaceted objective in attaining the educational system's aims; many approaches incorporate environmental education in their curriculum and support a sustainable way of life on campus, such as using renewable energy sources for power generation [15]. With their vast surface area on flat rooftops, industrial sites and office buildings have a lot of potential for photovoltaic (PV) panels. Examples are warehouses, industrial buildings, institutions, factories, and other structures. is potential is now mostly untapped [16]. Institutional solar projects, on the one hand, save electricity costs by utilizing available space on campus, and on the other side, they help the institute's reputation. ere has been a lot of research done on the subject of large-scale photovoltaics all around the world, and some of it has included university institutions as well [17]. Parks, woodlands, and an artificial lake make up the majority of campus landscapes, which are also an excellent example of establishing the notion of sustainable development known as a green campus [18].
ere have been previous studies regarding large-scale PV plants for power generation and voltage stability improvements of weak national grids [19]. Various studies have been carried out on large-scale SPV integration into the power grid. A review of important power system stability issues associated with large-scale SPV integration into the power grid has been carried out in [20]. e authors in [21] proposed a techno-economic approach to enhance solar PV connectivity. Furthermore, the study carried out in [22] indicates that solar PV systems with improved controllers can improve dynamic reactive power response, thereby enhancing the long-term voltage stability of the grid. Datadriven intelligent and sensor-based models are increasingly being used to monitor electrical power systems, DC microgrids, converters, and piping systems [23][24][25]. Such techniques can also be applied to EV Charging and large-scale PV systems for energy management [26,27]. Also, different authors have studied the feasibility of large-scale PV plant Installation on universities campus to meet the building demand, as represented in Table 1. is study focuses on the feasibility of the BIPV system's energy generation potential on the rooftop of Universiti Malaysia Pahang (UMP), which is located in Pekan, Malaysia, with a large area (652 acres) [33] can be made "net positive campuses" or "green campus" to become more selfsustainable. Based on internal electricity consumption data, UMP consumed 25,290,106 kWh of power between October 2018-September 2019 and 29,785,332.20 kWh of electricity in 2020 [34]. UMP Campus can accommodate nearly 10000 students and 2000 staffs [33]. Assuming that the total number of 2000 parking slots is available. Charging the EVs will increase the energy consumption, increasing the additional burden on the grid. Also, most of the staff cars are parked at the university for 7 to 8 hours, which provides an opportunity to design a system suitable to meeting EV Charging, and any excess energy can be supplied to the grid. Selected building of Faculty of Mechanical and Automotive Engineering Technology Kampus UMP, the university has been considered in this study which is located in the south of campus. Many studies have focused on BIPV energy potential in residential and nonresidential buildings, but most studies were limited to building energy consumption. ere is limited research available on EV charging in the university campus.

EV Charging.
Researchers have emphasized the benefits of switching from ICE-powered cars to Electric Vehicles (EVs) to reduce the transportation sector's greenhouse gas emissions. Many environmental and financial benefits come with the paradigm change from conventional to electric vehicles. One of the biggest obstacles to the adoption of e-mobility is the absence of sufficient infrastructures, such as stations for charging. e demand for charging, however, is rising along with the growth in EVs. However, the construction of charging stations adds to the demand on the power grid because the distribution network's operating characteristics will deteriorate due to the high charging loads of fast EV charging stations [35]. e most popular parking lots, such as garages, eateries, lodging facilities, cottages, campgrounds, shopping malls, business parks, sports facilities, or other establishments with parking, are undoubtedly preferable places to install charging stations [35,36]. Depending on the availability of charging stations at work [37] or at their university may help the driver choose an EV and reduce driving range anxiety.
e key to extending the range of EVs is strategically placing public charging stations [38][39][40] and enabling and promoting EV use in the neighborhood [39][40][41].
Additionally, the owner must pay a significant premium for the tariff if billing occurs during peak hours. A PV-grid charging system is suggested [36] to ease this burden. When PV power is available, the spinning reserve capacity decreases, and grid stability increases [37]. Additionally, in the absence of a vehicle, the PV system's electricity can be sent to the grid for financial advantage [42]. Hence, developing a sustainable solar-powered charging infrastructure without affecting the grid operation has become necessary to meet the requirements of EVs. To move toward an entirely carbon-free future by integrating e-mobility into the transportation sector, it is crucial to allow the integration of renewable energy sources in the growing need for electric vehicle charging infrastructure.

EV Charging
Infrastructure. EV charger specifications have been defined in standards SAEJ1772 and IEC62196 [35,36], which specify that a dedicated EV socket-outlet and plug must be permanently installed with control and protection functions. Level 1 charging is inexpensive since it uses a regular 110-volt outlet, allowing EV owners to use the charging wire set that comes standard with most electric vehicles practically anywhere. is charging method takes the longest and is typically used as a backup or emergency charging solution [37]. Depending on the 1.4 kW power a typical 120 V wall socket offers at 12 amps, recharge durations are 3 to 5 miles of range per hour [42]. Level 2 chargers are specific solutions for residential and commercial/workplace settings. Most offer higher power output than Level 1 chargers and have additional functionality not available with Level 1 chargers [37]. Level 2 chargers are the most common type found at public charging stations. 220-240 V plugs usually offer around 40 amps and are traditionally more specifically placed in homes [42]. DC fast chargers are the most influential electric vehicle chargers available. ey are frequently utilized as range extenders for long-distance excursions and in urban locations to help drivers who do not have access to home charging or who drive a lot. Most DC fast chargers on the market charge at 25-50 kW. DC fast chargers that are now available require inputs of 480+ volts and 100+ amps (50-60 kW) and can charge an EV with a 100-mile range battery in less than 30 minutes (178 miles of electric drive per hour of charging). New generations of DC fast chargers, which can provide 150-350 kW of power, are gaining favor [42].
It is clear from the context of the previously mentioned literature that there is a sizable gap in designing a solarpowered EV charging station. To close those gaps, this article will focus primarily on the following goals:

Objective of Research.
is paper aims to provide the feasibility of BIPV installation in the university FTKMA building, UMP, and thus specifically focus on the following objectives: (i) To design a sustainable grid-connected system suitable for Charging EVs at the university campus. (ii) To analyze and compare the techno-environmental performance for two installation scenarios

Methodology
e design methodology, parameters, and technical specifications for the solar BIPV in the university campus for EV Charging have been discussed in this section. e detailed methodology of the study is presented in Figure 1. UMP is situated on the east coast of Peninsular Malaysia, in the state of Pahang, which is the largest of Peninsular Malaysia's state.

Site Selection and Climate Profile.
e site UMP-Pekan has been taken into consideration for analysis. e daily average solar radiation at the site, as per the solar radiation  Figure 2).In this study, the university FTKMA faculty building has been chosen ( Figure 3), with a sloped roof 10°and a few flat roof buildings with a total area of approximately 7000 m2.
Pahang has a Tropical rainforest climate (Classification: Af ). e city's yearly temperature is 28.05°C (82.49°F), which is -0.23% lower than Malaysia's average. Pahang typically receives about 138.06 millimeters of precipitation and has 235.09 rainy days annually. Malaysia benefits from ample sunshine and hence high solar radiation. e geographical location of the city, weather data, and solar related parameters are presented in Tables 2-4. Figure 4 represents selected buildings to include sloped roofs in the study, and Table 5 provides the available area for each structure and the direction of each top facing. It can be analyzed from Table 6; the building's roofs are facing in 2 directions East of North East (ENE), West of South West (WSW).

BIPV Module Selection.
CIGS thin-film has been chosen for the study with 360 Wp. e technical specification of the panel is presented in Table 7. CIGS in-film panels have high light absorptivity and can absorb up to 90% of the solar spectrum, high electricity-generation capacity and stability, low production cost, and short energy recovery period [46]. AM1.5 cell efficiencies for CIGS of up to 22.6 percent, as certified in 2016, are the result of ongoing research and development [47]. e CIGS-based PV technology has not yet reached its full potential despite its highefficiency level. An efficiency level close to 30% would be technically possible if all loss mechanisms were addressed simultaneously [48]. A global record for any thin-film technology, the CIGS solar cell efficiency of 22.6 percent is even greater than that of polycrystalline silicon (21.9 percent) [49]. Preliminary data has shown that CIGS has lesser Global warming potential (GWP) than other technologies.
e average values for GWP CIGS are 23.92 gCO 2 eq/kWh, for a si is 31.5 gCO 2 eq/kWh, for CdTe is 24.1 gCO 2 eq/kWh, for Mono-Si, the average values for GWP is 64.8 gCO 2 eq/ kWh and for poly-si is 54.6 gCO 2 eq/kWh [50]. Penetration of thin film is currently 5% of the total PV market share [38].

BIPV Plant Capacity. Installation Method:
Two different installation methods will be analyzed in this paper, as represented in Figure 5.
Scenario 1: BIPV integrated with fully insulated back (No ventilation).
Scenario 2: Free mounted modules with air circulation. e input data for the simulation of the BIPV system is presented in Table 8.

ermal Loss Factor and Cell Temperature.
e cell temperature of PV modules affects its operational efficiency  and the thermal loss in the PV array due to the difference between the cell temperature and the ambient temperature of the PV array. e thermal loss factor (U) is connected to the cell temperature (T cell ) and the ambient temperature (T a ) according to the models used in PVSyst for the thermal behavior of PV module are as follows [39]:        Mathematical Problems in Engineering where U is the thermal loss factor, α is the absorption coefficient, η is the efficiency of PV at the Standard testing condition, and G in W/m 2 is the solar radiance on the tilted plane of the module. Furthermore, U consists of constant loss factor (U 0 ) and wind loss factor (U v ). In PVSyst, U v is set to 0, (U v � 0) hence U � U 0. T herefore, PV cell temperature can be found as per the below equation: Default values in PVSyst are as follows: U 0 � 15, U 1 � 0 for integration with a fully insulated back, U 0 � 29, U 1 � 0 for free mounted modules with air circulation [39].

BIPV Module Installation Layout.
e design of the PV power system examined in this study is depicted in Figure 6.
e Maximum BIPV panel installed in each structure is shown in Figure 7.
Total number of panels required for the 1.069 MW system is 2970 covering a module area of 6984 m 2 having array configuration as shown in Figure 8. e total number of modules in series 9 and the number of strings 330 are considered for the BIPV design. e operating characteristics of the array at 50°are U mpp 482°V and I mpp 2065 A with P mmp 995 kWp.

Inverter Selection.
For the above configuration of arrays, Siemens Sinvert 1000 MS inverter has been selected, which matches the specification's requirements. e inverter's power must be chosen according to the sum of all loads' power. It must not exceed the rated capacity of the inverter. Also, the inverter must supply 1.069 MW power to BIPVpowered EV charging parking. Table 9 refers to the inverter specification.

Daily EV Charging Energy Requirement.
Presently, several EVs are available in the Malaysian market supporting Type 2 charging. To estimate number of EV's that can be charged, the parameters shown in Table 10 have been assumed, e.g., car model, Daily commute distance, number of parking slots available on the university campus, and EV battery size.where BC is Battery capacity, D is daily commute distance, and R is EV range.
Based on the above calculation, the daily EV charging requirement is approximately 2.44 kWh. e total energy required by 2000 EVs is approximately 4.88 MWh.

Result
PVSyst (Student) software was used to analyze the input data for yearly energy generation. Available energy has been simulated to be used for EV charging in both scenarios. Table 11 below depicts the actual energy available at Array output after considering the losses for both Scenario 1 and Scenario 2.

BIPV Energy Performance.
e simulation results that annual energy production from the system is 1587 MWh and 1669 MWh for respective scenarios. Figure 9 shows monthly energy generation, monthly user consumption, and energy supply to the grid at inverter output for both systems. For the user, energy consumption only on weekdays has been considered, and excess energy generated during weekends has been deemed to be fed to the grid.

Performance Ratio.
Performance ratio (PR) is the ratio of measured output to expected output for a given reporting period based on the system name-plate rating. Performance ratios of the two scenarios have been estimated by PVSyst and compared in Figure 10. is enables the system quality to be compared between installation methods.

Capacity Utilization Factor.
e Capacity Utilization Factor (CUF) for a Solar Photovoltaic (PV) project is the ratio of actual energy generated by the PV project over the year to the equivalent energy production at its rated capacity. e number of clear sunny days and solar radiation, measured in kWh/sq m/day, determine the amount of energy generated by the SPV project. Solar Cell output is measured in Watt Peak (Wp) and corresponds to nominal power under Standard Test Conditions (STC) (1000 W/m 2 , 250C, 1.5 AM) [51].
where P Cap is plant capacity operated for 24 hours and 365 days, P Size is Plant size in kW, P OUT Actual output of the plant in kWh, CUF of the BIPV plants is estimated using the above equation, which is 16.9% and 17.8% in case of scenario 1 and 2. Figure 9, energy generated monthly by the two BIPV scenarios, further evaluation of EV charging has been done using energy generated daily shown in the table below.

Mobility Demands: EV Charging Potential. As shown in
where P 1 is the power requirement when all the EV's are connected, P Charger is Charger output, and N 1 is the number of EV, which is 2000 for case 1. e power requirement for charging for all cars is very high and exceeds the system size and not a feasible solution.
erefore, several charging stations should be optimized to utilize the system. Since it is a grid-connected system, all excess energy will be taken from the grid.
Time required to charge each car.
where t is time required to charge each EV which is approximately 0.25 hr � 23 minutes considering no losses. e case is not a feasible solution as after 15 minutes. All the charging stations will become idle. ere will be a sudden peak in power demand. erefore, Case 2 has been proposed for optimizing the number of charging stations and utilizing its full potential.
Case 2. If the cars are charged based on need. Charging stations can be separated into Zones to balance the load. As the staff or student's cars will be parked for 6 to 7 hours, the number of charging stations can be optimized as below:

N �
Car parking hours t ,

Mathematical Problems in Engineering 7
where N is the number of charging station zones is approximately 16 with 125 Charging points (total 2000). Power requirement for 125 EV at the time of connection where P 2 is the power required by the EV at the time of connection which is 0.775 MW, which is lower than the size of the system. N 2 is the number of EV connected in 125 charging points. is scenario provides an optimized solution for EV charging. Intelligent charging can also be introduced to balance the power output from the BIPV plant and input to the EV charging [52]. Figure 11 compares the daily energy requirement for 2000 EV's and average daily energy generation in both scenarios 1 and 2 and excess energy to/from to grid.

Energy Supply to Grid.
From the above figure, it is clear that the energy generation is positively impacting the overall consumption and can meet the energy requirement of 2000 EV's for daily charging and any excess energy fed to the grid. Consumption on weekends (Saturday and Sunday) has been assumed to be zero. ere all energy will be supplied to the grid on weekends. e total annual energy fed to the grid for both scenarios has been plotted in Figure 12 to analyze the overall positive impact of the system. e number of working days is considered 261, excluding all weekends.
where E EV-Total is the annual energy required for EV charging.
Annual energy for scenario 1 is 1587 MWh and for Scenario 2 is 1669 MWh. 0.8% panel degradation has been applied for 25 years to analyze total energy generation for a lifetime, as shown in Figure 12. e power drawn or fed to the grid can be expressed as given below: where E Grid is Energy fed to the grid. E PV-Total is total annual energy generated by the plant. Total energy supplied to the grid during the lifetime of 25 years will be 4247 MWh for Scenario 1 and 6112 MWh for scenario 2.

Environment Analysis.
e most significant environmental advantage of using solar power to generate clean electricity is that it substitutes energy from conventional power plants. Also, charging EV through PV power helps in achieving net-zero transportation. Since the BIPV Plant uses solar energy to meet the EV charging need, the carbondioxide emissions reductions from not utilizing grid electricity are calculated using emission factors. An emission factor is the average rate of a particular GHG emission for a specific source in terms of units of activity [53]. e grid emission factor for Malaysia is expected to rise from 570 gCO 2 e/kWh to 622 gCO 2 e/kWh between 2018 and 2023 because of the addition of new coal and gas electricitygeneration plants [54].

GHG Savings.
Total annual GHG savings for the Scenario 1 and Scenario 2 comprise GHG savings due to the BIPV system and the use of EV is presented in Figure 13. Grid emission of 622 gCO 2 e/kWh has been used for GHG emission savings. Total energy generation over the lifetime of 25 years in Scenario 1 is 36,089 MWH, and scenario 2 is 37,954 M. e equivalent saved CO 2 emissions for BIPV System has been calculated using the below formula:  An average consumption of 5 liters/100 km then corresponds to 5 l × 2392 g/l/100 per km � 120 g CO 2 /km [55]. For estimation of GHG savings due to gasoline avoidance, 2000 cars, 24 km daily for 261 days has been considered for 25 years.  Figure 9: Comparison of monthly available energy at inverter output, monthly consumption, and monthly supply to the grid.

Mathematical Problems in Engineering
where GHG EV is GHG savings by using EV avoiding gasoline in (tCO 2 e), N is the number of cars, D Com is daily commute distance, F Gas is CO 2emission /Kilometer, and Y is number of years.
e limitation of the GHG emission includes the GHG emitted during the fabrication of PV modules cells; BOS transportation and disposal are not considered here. Also, emission during the production of EV has been excluded from the study.

Discussion
e paper presented the full potential of the selected building in Universiti Malaysia Pahang, Pekan campus. Two scenarios were analyzed: scenario 1 having a BIPV system fully integrated (No ventilation) and scenario 2 having BIPV with air circulation, which generated higher annual energy than scenario 1. Figure 11 compares the daily energy requirement with the energy requirement for EV charging, where higher daily energy was generated during April, and the lowest energy was generated in November. Both proposed systems can nearly meet the daily charging requirement of 2000 EV's with the amount of daily energy generation. During November, excess energy will be required from the grid to meet the demand of EV charging, with 38% in scenario 1 and 35% in scenario 2. On an annual basis, both systems could supply the excess energy to the grid. From Figure 13, it can be concluded that there is a 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Figure 11: Average daily energy generation, energy consumption and excess energy to/from grid. significant reduction in CO 2 emission compared to the CO 2 emitted if the same amount of energy is generated by a coal plant. ere are a few limitations to the research, as shown below: (i) Minor inaccuracies could be possible due to manual measurement using the Google Earth tool. Little variation in total energy generation is possible. (ii) e cost of the system has been excluded in the study as this study focuses on the energy generation potential for the number of EV charging and the environmental impact of the installed BIPV plant. (iii) Losses during EV charging have not been considered in the study. (iv) e scope is limited to studying the energy potential of roof-mounted BIPV. (v) e generalizability of the findings in this work to other universities is unknown, even though the procedure can be used at other campuses. (vi) Another limitation to the study is the number of variables that can affect EV charging requirements, i.e., Battery state of charge at the time of charging. (vii) Moreover, this study considered only a few possible assumptions, such as commute distance and car battery size.
is research provides an opportunity to contribute towards achieving sustainable development goal, which is SDG 7 "affordable and clean energy, SDG11 "sustainable cities and communities and SDG 12 "responsible consumption and production" [56]. It will serve as baseline data for practical implementation and may invoke enormous interest among the research community and stakeholders. Charging electric vehicles using renewable energy decreases the grid's excess load and helps achieve net-zero mobility.

Conclusion and Future Scope
Charging electric vehicles at a university campus or workplace using solar energy gives a long-term sustainable mobility solution. It allows for direct use of BIPV electricity throughout the day and uses the solar potential of university building rooftops. e energy and environmental performances of the BIPV Plant for the EV charging system have been evaluated for UMP, Pekan Campus. For the proposed BIPV system, two different installation method was studied-Scenario 1 Fully Integrated Panel with No ventilation and Scenario 2 Free mounted with Air circulation with the same panel rating of 360 kWp. e results from the study include the following.
(i) e maximum annual energy yield of the 1 MW BIPV Plant was estimated to be 1587 MWh and 1669 MWh for Scenario 1 and Scenario 2. (ii) BIPV System in scenario 2 has a 50% lesser loss due to temperature because air ventilation underneath the BIPV panels affects the final output. (iii) e performance ratio of the two BIPV Plant is between 82.6% and 86%. e system in Scenario 2 has higher PR. (iv) Capacity utilization is between 16.9% and 17.8%, where the BIPV plant in scenario 2 has a higher CUF than in scenario 1. (v) e project can meet the charging requirement for 2000 EVs, which is 80% of total annual generated energy in scenario 1 and 76% in scenario 2. Available excess energy is considered to be fed to the grid. (vi) Despite having the same panel in both scenarios, the BIPV system in scenario 2 has better performance in terms of energy generation; both systems in scenario 1 and scenario 2 have shown a significant impact on the environment GHG emission savings of 52.201 tCO 2 e for scenario 1 and 53,361 tCO 2 e for scenario 2 compared to grid emission over the lifetime of the system. (vii) e scope of this paper is limited to the FTKMA Building only, which can be extended to other Faculty buildings to evaluate the full potential of the campus to meet the total energy requirement of the campus. (viii) e future scope of this paper may include a Battery storage system to avoid grid dependence and intelligent charging of EVs for load scheduling that can solve the issue of system overloading.

Data Availability
e data used to support the findings of this study are included within the article.
Disclosure is manuscript's opinions, facts, insights, and discussions solely involve the authors. It does not necessarily reflect the policy and standpoint of any organization directly or indirectly. e authors are not responsible for any consequences of the information presented in this work.

Conflicts of Interest
e authors declare that they have no conflicts of interest.