Study on Implementation of Rooftop Photovoltaic Power Plant as an Effort to Attain a Sustainable Campus

The concept of Green Campus means that the University has implemented environmental preservation activities, energy efficiency, and deliver comfortable conditions to support learning and work activities. The activity to harvest renewable energy is one of several approaches towards a sustainable campus. This study aims to analyze the technical and economic feasibility of a solar power plant erected on the roof of buildings within the campus area. Based on the University of Samudra development master plan, it has carried a technical and financial feasibility study with the assists of the System Advisor Model (SAM) software. The analysis shows that the current roof area is possible to generate electrical power of 3 MW, with economic calculations of electricity production costs of 11.7 cents/kWh.


I. INTRODUCTION
Global warming phenomena have concerned scientists and people around the world, while at the same time environmental conservation gains more popularity each year.Communities around the world are trying to reduce damage to planet Earth through many methods.Future development should consider a coping strategy in line with the vision of "green technology" which focuses not only on saving electricity consumption, landscaping, and ecological friendly food grown in the local area, but also includes the separation of waste.Public should know they are part of an overall way of life that ensures greater economic stability.
The university should realize that it must act as a pioneer in the development of the urban environment and being an integrated part of the modern city.Most campus landscapes comprise parks, forests and an artificial lake which are also becoming a good example of developing the concept of sustainable development known as a "green campus".This concept ensures the implementation of environmentally friendly building construction, the practice of waste separation and recycling facilities, and the design of a "zero emission of heat" building.Scientist define the concept of green campus as an environmentally friendly campus that integrates environmental science into the policies, management and activities of higher education.It has Published on November 8, 2019.R. Thaib is a Senior Lecturer in the Department of Mechanical Engineering, Universitas Syiah Kuala, Banda Aceh, Aceh, Indonesia.(email: razalithaib@unsyiah.ac.id).
intellectual capacity and resources in integrating the knowledge and values of the mind into its mission and programs.It must also be an example of implementing the integration of environmental science into all aspects of management and best practices of sustainable development (Hudaini in Puspadi, 2016).The concept also means that the University has implemented activities aimed at preserving the environment such as waste collection, energy efficiency, promotion of non-emission vehicles, and creating comfortable conditions for study and work.Implementing sustainable development is a joint effort of the entire academic community at the University.
There have been a good deal of research conducted regarding to the utilization of solar energy as a source of electrical energy in well-known campuses to materialize the concept of the Green Campus [1], [2], [11], [12], [3]- [10].Song [9] has revealed a study on the use of Rooftop Photovoltaics as an electricity provider for several university buildings in Busan, South Korea.The results concluded that the photovoltaic (PV) system not only functions as a provider of electricity but also has a significant influence in contributing to the mitigation policy of diminishing greenhouse gas emissions and environmental impact issues.
The university has a multidimensional mission in achieving the goals of the education system, various methods undertaken not only include environmental education in their curriculum but also encourage a sustainable way of living on campus, such as electricity production utilizing renewable energy sources [4].
Most of these campuses own an extensive land area, and the sun relatively spread across and not blocked by other buildings, therefore, very potential as an energy source for rooftop solar photovoltaic power plants (RSPPP).
Rooftop photovoltaic is a system that uses one or more photovoltaic panels, installed on the roof of a residential or commercial building, to convert sunlight into electricity.This system comprises several components including photovoltaic modules, regulatory systems, electrical cables, solar inverters and other electrical accessories.
The campus environment provides a large amount of empty roof space and can inherently circumvent potential land use and environmental problems.Total projected amount of the solar radiation received by PV panels highly influenced by the exposed time during a year, weather, shadows from adjacent buildings, the slope and shape of the roof.
For high power, it arranges PV panels in series and/or parallel in a certain panel area (module).The literature review of PV systems connected to the network as implemented by the campuses shows an increase in total installed capacity continuously.[13], [14].The Masterplan of Universitas Samudra (UNSAM), the new state university which nationalized in 2013, has accommodated the Green Campus concept in its infrastructure development plans.Implementing renewable energy resources as a source of energy for producing electricity is the key element of the approach which also support future activities including greening and waste management.The main aim of this study is to analyze the potential use of the building roof for the installation of PV systems.II.ANALYSIS METHOD UNSAM has a land area of 49.8 hectares which geographically sited at 4.446950 ° North Latitude, and 97.974833°East Longitude, with an elevation of 13 meters above sea level.
Figure 1 depicts the design of the PV power system analyzed in this study.The plan shows that the entire PV panel is mounted on the rooftop of each building.Figure 2 displays the building site plan in the University of Samudra environment.In most industrial-scale power plants, the use of polycrystalline PV panels is more desirable.However, this study will use the Renesola PV model -JC260M-24/Bbh-b, with a total power of 4,999 Wp at STC and 4498 Wp at operating conditions (at 50 °C).The operating characteristics of the array are Umpp 591 V and Impp 7609 A. The degradation rate of the panels is 0.5% per year.PV panels commonly installed on flat or sloped roofs.For applications in the Northern Hemisphere, the panels installation must face south.When the module is tilted relative to the roof surface, shadows usually formed and therefore an adequate space must be available in between the rows of the module to minimize loss of energy collection due to shade.For the selected inverter the selected production of ABB Corporation, the ULTRA 750-TL-OUTD-2-US690-M/S model, operates at 470-600 V, and has a nominal power of 600 kWac.The analysis of the PV panel array on the rooftop is then taking place.By using PV panel dimensions' data, then the sum of PV panels required for the entire project has been calculated, and System Advisor Model (SAM) software analyze the whole energy production.

III. RESULTS AND DISCUSSION
The calculation results show that total area of the roof installed with PV panels reaches 21,500 m2, with a total number of PV panels of 13,062 panels.Table 2 shows the total electric power from the solar power system generated.Figure 4 shows the estimated results of energy production generated by the rooftop solar power system.The graph shows that the lowest production occurred in November, while the highest was in May.The position of the sun has a great deal of influence on solar energy received by the PV panel.
The simulation shows that the energy production received by the system is 38,476,608 kWh/year, while the electrical energy consumed is 4,506,304 kWh/year.Energy efficiency in the SPPP system is 12.31%.The biggest energy loss (10,364%) is mainly caused by the conversion of energy from the sun to the DC current.The analysis then continued with a financial analysis of the feasibility of PLTS construction on the roof of the building at Universitas Samudra.The amount of initial required investment costs comprises the costs of buying PV panels, inverters, and equipment.Based on data prices got from Renesola [15], and ABB [16] Table 3 shows the amount of the initial investment cost and total installed cost per Wdc is around $1.33.Financial analysis in this research uses all the parameters shown in Table 4.The scheme assumed that 70% of the capital costs for the RSPPP installation will accept an investment from the Bank, with the interest rate of 7% and an installment period of 25 years.The time required for a payback period is 15.4 years, with cash flow payback as shown in Figure 5. Therefore, the use of RSPPP will benefit the campus for 10 years, where the excess electricity generated sellable to the State Electricity Company. The installation of RSPPP on the roof of the campus building will produce 3 MW of electricity.Since most of the electricity usage on campus is for daytime requirements, the installation of RSPPP needs to be considered. From the analysis, with an initial investment of $4,522,952, all electricity usage costs through state electricity company significantly reduced, and if calculated, will return the initial investment for 15.4 years.

Fig. 1 .
Fig. 1.Solar Power Generation System (SPGS)Figure3depicts the method for laying PV panels.The slope angle proposed for solar power plants is the same as the location latitude, and it is the optimum absorption of solar radiation.The planned location of the building's latitude is 4.45°, therefore, the tilt angle is ~ 5°.

Figure 3 .
Figure 3. SPGS equipment series available in various types of PV panels and used in various solar power plants.In most industrial-scale power plants, the use of polycrystalline PV panels is more desirable.However, this study will use the Renesola PV model -JC260M-24/Bbh-b, with a total power of 4,999 Wp at STC and 4498 Wp at operating conditions (at 50 °C).The operating characteristics of the array are Umpp 591 V and Impp 7609 A. The degradation rate of the panels is 0.5% per year.PV panels commonly installed on flat or sloped roofs.For applications in the Northern Hemisphere, the panels installation must face south.When the module is tilted relative to the roof surface, shadows usually formed and therefore an adequate space must be available in between the rows of the module to minimize loss of energy collection due to shade.For the selected inverter the selected production of ABB Corporation, the ULTRA 750-TL-OUTD-2-US690-M/S model, operates at 470-600 V, and has a nominal power of 600 kWac.The analysis of the PV panel array on the rooftop is then taking place.By using PV panel dimensions' data, then the sum of PV panels required for the entire project has been calculated, and System Advisor Model (SAM) software analyze the whole energy production.

Table 1
below present the Study on Implementation of Rooftop Photovoltaic Power Plant as an Effort to Attain a Sustainable Campus Razali Thaib, Munira Amudy, and T. A. Rizal summarize of several results about the application of PV panels on campuses

TABLE I :
USE OF PV ON CAMPUSES

TABLE II :
CALCULATION OF THE POWER GENERATED BY SPPP

TABLE III :
INITIAL COST INVESTMENT

TABLE IV :
PARAMETERS OF FINANCIAL ANALYSIS

Table 5
summarizes the analysis of electricity production costs.The electricity production costs are 11.7 cents/kWh.regarding to the Decree of the Indonesian Minister of Energy and Mineral Resources Number 55 K/20/MEM/2019 concerning the principal costs of electricity generation by PT.PLN in 2018, the amount of the basic cost of electricity generation using SPPP is 11.74 cents per kWh.Therefore, plan to develop RSPPP at Universitas Samudra is viable.

TABLE V :
RESULTS OF FINANCIAL ANALYSIS