Table 1. Solar Panel Description
Today, India is in the developing stage and the requirement of electrical load demand is increasing day-by-day. In order to meet these load demands, existing available resources have some limitations to fulfill these demands. As, solar energy plays a major role in the generation of electricity, as it is a clean, inexhaustible and environment friendly resource compared to all renewable energy sources, this paper gives an idea about how to select the solar power plant for the electrical load demand and also an analysis of 5 kW grid connected roof top solar plant has been provided. The grid-connected system was synchronized with the commercial grid with the help of net meter for electricity transfer under no load condition. The monthly energy generation by proposed grid connected roof top solar power plant is also calculated.
In grid connected rooftop solar system, output power is dependent on various factors, such as its location, orientation of the roof panel, efficiency, and ambient temperature. Solar photovoltaic (PV) panels convert the sunlight into electricity. The electricity generated by the PV panels is Direct Current (DC) and it is converted into Alternating Current (AC) using an inverter. The inverter in solar system uses source of power as a reference voltage and in case of power failures, the solar power system cannot generate power. The inverter is using only grid power as a reference voltage and in case of absence of grid input power then inverter will not be able to work and the solar plant will not generate any power. The inverter output is connected to the three phase distribution box for commercial or residential use. In case the excess power is available then it supplies to the grid through net metering and this can be done as per the rules and regulations of state government. The solar system supplies power in day time only in synchronisation with the grid system. If the capacity of solar system is not sufficient due to climate condition (bad weather), the power is drawn from the grid. The selection and analysis of 5 kW grid connected system is presented.
The objective of this paper is that even common people can understand the selection and installation of a power plant.
During literature survey, various authors state their ideas about the solar power plant like, why today solar power plant is important, its necessity, basic types of solar power plant, etc., which are well explained in (Ramakumar & Bigger, 1993; Bolduc, Lehmicke, & Smith 1993; Kurokawa, Kato, Ito, Komoto, Kichimi, and Sugihara, 2002). In paper (Shetty & Kulkarni, 2014), a case study for 500 kW has been presented. The cost analysis is also explained. Roman, Alonso, Ibañez, Elorduizapatarietxe, and Goitia (2006) have given an idea about connection of intelligent PV Module for Grid- Connected PV systems. The various case studies are available in (So, Jung, Yu, Choi, & Choi, 2007; Albadi et al., 2014) by considering 3 kW and 50 kW solar power plants. This paper gave the design and analysis of solar power plant. Performance of plant was also calculated. The 1 kW solar system has been considered by authors in paper (Ahsan, Javed, Rana, & Zeeshan, 2016), where payback period for the plant is also calculated (Attari, Elyaakoubi, and Asselman (2016) gave an overall performance analysis and investigation of a grid connected plant, which is design for city. The practical performance is well explained by the authors Lhendupa, Wangchukb, Norbub, Rinzinb, and Lhundupc (2016) presented performance of 5.5 kW grid-connected and 7 kW standalone photovoltaic (PV) power plants, which is simulated by using the simulink and discussion on result is presented. The grid-connected system was connected with the commercial grid. The modeling of the system is done through TRNSYS 17 and it was simulated for getting hourly climate data from Solar GIS. Then the simulated performance was compared with outputs from other HOMER model, which obtained an average data on monthly climate condition from NASA.
From above literature survey, it clears how to install and how to select a solar power plant. But still there are some questions for common people like whether it is suitable for Home, small industries, is it beneficial when one gets their invested money back and hence this paper presented the things in simple manner.
In simulation and performance analysis of 110 kW grid- connected photovoltaic system for residential building in India: A comparative analysis of various PV technologies was performed by Shukla, Sudhakar, and Baredar (2016). They explain the simulation of power plant, which is necessary to check the feasibility of Solar system power plant for given location. The paper presented its study to check the feasibility of rooftop solar photovoltaic system for a residential Hostel building at MANIT, Bhopal, India (Latitude: 23o 16’ N, Longitude: 77o 36’E). The study is done on the use of Solarg, a PV Planner software which is tool to analyse the performance a 110 kWp solar photovoltaic rooftop plant and also it compares the performances of various PV technologies based on simulated energy yield and performance ratio.
In a study on design and performance analysis of solar PV rooftop standalone and on grid system using PVSYST by Rekhashree, Rajashekar, Naganagouda (2018), they discuss various opportunities towards the environmental friendly energy generation. In this paper, it mainly demonstrates the solar based model for a grid connected solar PV system, which is used for domestic and commercial applications. The solar irradiation in Karnataka state is around 1266.52 W/sq m. The 1 KW solar rooftop plant will generate on an average for the period of five year around 5 KWh of electricity per day (5-6 sunshine hours). The case study for 2.5 KW solar PV plant is presented in this paper. The installation of rooftop plant for home application is done and it gives generation of around 9.3 kwh/day units, which is demonstrated using PVSYST software that gives solar radiation yield of 5.94 kwh/m2/day. This method helps during power interruption, as it stores backup energy into the batteries, which can be used for the load. Therefore, this power plant system gives the clean energy for energy conservation and sustainable development of the society.
In feasibility for small scale rooftop solar Photovoltaic system in heritage buildings of Jaipur by Dr. (Ar.) Vibha Upadhyaya (2016), it describes how the interest among people for adopting Renewable energy technologies for energy generation has increasesd due to various reasons, which includes saving in electricity bills, getting investment subsidies, availability of net metering, and also other government schemes, which support the use of renewable energy sources. It discussed the application for small building by mounting solar PV system and compared it with the thermal power system that is general with the study of Solar Photovoltaic. The consumption of electricity increases day by day for residential buildings due to large use of electrical equipment for betterment of human work, which completely changes life. In this paper, survey is conducted for 100 Households (electrical equipment) in the old city of Jaipur and after identifying their energy consumption, suitable solar system capacity is calculated with their costing and payback period. Mainly in this article, the feasibility of grid connected rooftop solar PV systems was presented in all point of view like cost, feasibility, etc. In the conclusion part it was mentioned that besides initial cost of the solar system is very much high, but for long term point of view, it is more effective than any other power plant it also gives comment on the payback period with net metering in which Govt. gives subsidies, so it is a viable option.
In Performance evaluation of 10 MW grid connected solar photovoltaic power plant in India by Kumar and Sudhakar (2015), performance analysis, designing, operating, and maintenance of grid connected system was presented. A 10 MW solar power plant mounted at Ramagundam is one of the largest solar power plants. It is situated in a place, where it received good average solar radiation of 4.97 kW h/m2 /day and an annual average temperature of about 27.3 degrees centigrade. In this paper, the authors have studied the design of PV plant with its performance during the complete period of year. The different types of power losses like temperature, internal network, power electronics, and grid connected are calculated. It also calculated performance results of the plant and are compared with the simulation values, which are obtained from PV system and GIS software. The final yield of solar plant is obtained from 1.96 to 5.07 h/d and annual Performance Ratio (PR) of 86.12%. It has 17.68% CUF with annual energy generation of 15 798.192 MW h/Annum.
In estimation of cost analysis for 500 kW grid connected solar photovoltaic plant: a case study by Shetty and Kulkarni (2014), cost analysis for 500 kW grid connected solar photovoltaic plant is presented. They presented a system 2 for a chosen area of 10,1533 m (present Built-up area). The calculated result for plant and based on that the feasibility of mounting a power plant is also discussed. From the cost of power plant, they suggested whether it is suitable for the given load.
In optimal site selection for a solar power plant in the central Anatolian region of turkey by Akkas, Erten, Cam, and Inanc (2017), it gives various options to explore the use of renewable source of energy. They also presented the situation of RES in today's scenario by identifying solar and wind power plant as the best option. It also gives discussion on high costs of power plant, its feasibility for locating large systems with available resources, land and other aspects during the initial stages of plant. In their studies, they suggested how to identify site location, which is an important stage in mounting the solar plant. The different criteria for selection of the appropriate location is also analysed by using Multi Criteria Decision Making (MCDM) methods and the results are also evaluated for five different cities in the Central Anatolian Region of Turkey. In their conclusion, they suggested the power plant for the city which is suitable.
In optimal site selection for solar PV power plant in an Indian State using Geographical Information System (GIS) by Khan and Rathi (2014) presented how to locate capable sites for large-scale Solar PV plants and also discussed on different methodology in selection of various factors. They classified their factor as “analysis Criteria” and “exclusion Criteria”. The above criteria well explained for how to check availability of solar radiation, availability of vacant land, calculate distance from highways, distance from existing transmission lines, etc. They also considered change in the climate condition; quality of soil, location of site, etc., are important criteria. They selected Rajasthan for their case as it received the highest solar radiation available in India. The GIS software is utilized for obtaining the various results. The area which is situated at 26.92o N, 70.900o E with the maximum summer temperature of 43 oC has been chosen as the most suitable site for SPV plant in Rajasthan.
In the characteristic analysis of the solar energy photovoltaic power generation system by Liu, Li, Niu, Jin, and Liu (2017), an illumination model and a photovoltaic power station output power model were established, and simulation analysis was conducted using Matlab and other software. The analysis is done based on the condition of solar energy resources available in Baicheng region in the western part of Jilin province, China. The study of different characteristics was presented in the paper using simulation. It was shown that the monthly average output power of the photovoltaic power station is affected by seasonal changes; the output power is higher in summer and autumn, and lower in spring and winter.
In a comparative analysis of energy costs of photovoltaic, solar thermal, and wind electricity generation technologies by Dale (2013), the results of various power plants based on solar and wind were discussed. They calculated various parameters to assess energy technologies like full day capital cost, operating and running costs, and cost of electricity. By calculating the values based on the above parameter, they suggested a suitable power plant.
In exergetic analysis of a solar thermal power plant by Wu, Zhu, Wang and Zhu (2013), simulation model of the 5 MW solar thermal power system is presented. The simulation is carried out for solar plant and it is compared with the actual thermal power plant, and after analysing based on heat and the energy loss of the system, various suggestions are mentioned. After calculating the results they describe that heat loss of the condenser is maximum upto 72%. From the above reason, they suggested that concentration is important while establishing the power plant. The loss of solar energy when it collected by solar collector is how affected is also mentioned. So they discuss from the energy efficiency point of view, how the solar collector system has the potential for energy saving. Finally, thermal efficiency and energy efficiency of a solar thermal power plant system is calculated and found to be highest at full-load.
The selection of solar power plant depends upon the amount of energy needed. Based on this, solar plant is selected and other factors are also considered during plant selection like site location, plant size, amount of sunlight available, etc. The consumption of electricity in the whole day also plays an important role in its selection, whether it is used for whole day or connected to light load, heavy load, or to use in the night. Type of the solar panels is also important from its efficiency point of view; generally crystalline panel is used because of its high efficiency, whereas it can generate 4 kWh of power per day from 1 kW solar power system. The placing of panels into right direction is also important. The solar panels mostly face towards south roof direction for maximum sunlight. The total plant requirement is calculated by identifying load and daily electricity consumption. Here the authors have selected a 5 kW plant, which is situated on a two floor building in which most of the load is single phase like lights, fans, computer, charging points, and sometimes three phase AC machine is operated.
The total energy requirement per day (Wh) for load is calculated as;
= Wattage of appliance * No. of appliances * Hours of working.
This should be divided by 1,000 to be converted into kWh/day.
Considering the above formula, the daily consumption is calculated and near to this value, the authors have a made a conclusion to establish a 5kW power plant. The size of power plant is decided by site selection and panel capacity by the load requirement; they calculate the daily load requirement and adds safety margin into given load 2 by assuming safety margin to be 4 kWh/m /day. The size of the system is calculated as,
System size= (Energy Requirement*1.3) /insulation level
From the above equation, the number of panels required for solar power plant is calculated.
Number of Panels = System size/Panel Rating
So, the total installed plant capacity is 5000 W and we use 20 solar panels each of rating 250 watt and 48 V, so total panels required is 20. Generally, a 1 kW power plant requires 100-130 square feet hence the 5 kW power plant is situated on a 500-650 square feet shade free roof area. The size of power plant is also decided by efficiency of solar panels. More the efficiency of plant less the area required. The panels are connected in series. All this structure is mounted in the solid cement pillars with the help of iron rods. This will protect it from high wind and also from direct animal attack. The output of panels is DC, which is then converted into AC with the help of an inverter. During the selection of inverter, we assume the safety margin about 20% to 25% more than the required capacity. Assuming that plant provides maximum capacity of 5000 watt, and then the inverter size is calculated as,
Required Inverter size = Total Wattage of all appliances * (1+20%)
Size of inverter is selected as 5.5 KVA for the given solar power plant. The output of inverter is connected to three phases, 440 V distribution box and through this box it is supplied to net meter for fulfilling the load requirement.
The following are the major components of the system,
These are high efficiency polycrystalline solar cells having following specifications as given in Table 1.
Table 1 represents the actual mounted solar panel at Prof. Ram Meghe College of Engg & Management, Badnera- Amravati.
Table 1. Solar Panel Description
Solar panels are mounted on iron fixtures so that they can withstand wind and weight of panels. The maximum power output depends upon proper designing of power plant. If the mounting structures are not proper, the power output from the PV plant will not be maximised. The mountings of buckle and the panels are always mounted towards the sun.
Inverter is a very important component of rooftop solar PV plant because they determine the quality of AC power at the output. The inverter is fed from solar array (D.C) and output to the load (A.C) is provided. The detailed specifications are given in Table 2.
Table 2 represents the actual mounted inverter at Prof. Ram Meghe College of Engg & Management, Badnera- Amravati.
Table 2. Inverter Description
The cables are generally used with maximum output (minimum losses) and also it can resist high temperature. The 3C * 2.5 Sq.mm PVC copper wire is used. The short circuit temperature is 250°.
Junction box is usually used on both DC and AC sides of solar photovoltaic power plant. The metal sheet and water proof material is used. One array junction box and one main junction box are installed. All the array structure is properly grounded with good number of grounding kits. All metal casing of the plant is also grounded to ensure safety of the power plant.
Figure 1 shows the Grid-connected Solar System, adapted from “Study, Design and Performance Analysis of a Grid- Connected Photovoltaic System,” by Arina Makarova, 14 Nov. 2017, Helsinki Metropolia University of Applied Sciences.
Figure 1. Grid-connected Solar System (Makarova, 2017)
In the analysis of grid connected system, the generation of solar energy is selected from the month of January to December. For these purpose we consider the data for only one year. The generation of solar energy is different for every month as it is affected by the weather condition; the maximum generation of energy is when clean sunlight is available and reduced mostly in the rainy season.
The solar power consumption for different months is plotted on the graph and it gives the consumption of solar power for various months. The graph is plotted considering the consumption from January 2017 to December 2017 and January 2018 to July 2018. The maximum generation for 5 Kw solar system consumes 600 units for one month.
From Table 3 and Figures 2 and 3, it is observed that the unit generation from the month of December to July is more in the year as compared to the remaining months. In August to November, the generation is somewhat less due to rainy season or cloudy condition, but still generation of units are obtained.
Table 3. Solar Energy (Unit) Consumption
Figure 2. Monthly Solar Unit Consumption Jan-17 to Dec-17
Figure 3. Monthly Solar Unit Consumption Jan-18 to Jul-18
The solar unit generation is less due to certain problems like inverter malfunction problems, weather condition, etc.
Table 3, Figures 2 and 3 give actual generation of solar units from the month of Jan 2017 to July 2018. The obtained data is from actual grid connected solar system, which is mounted at Prof Ram Meghe College of Engineering & Management, Badnera-Amravati.
The cost of solar plant included inverter cost, solar panel cost, and cable cost. The total cost of the plant depends on these factors. There is provision subsidy for solar plant depending on rules and regulation of state government.
Cost of one solar panel (250 watt) is around 
15000. A total of 20 solar panel sale required for 5 Kw system, hence the total cost of solar panel is 15000*20 = 3,00,000.
Similarly, cost of three phase inverter for one watt is around 40. The capacity of inverter is 5.5 KVA, therefore the total cost of inverter is 40*5.5 KVA = 2,20,000.
The cost of wire, fuses, etc., is considered to be 20% of the total plant cost, so total cost of set up is 5,20,000 * 0.2 = 1,04,000.
Hence, the total power plant cost is 6,24,000.
When monthly production is more than consumption then the generated unit is supplied to distributed transformer (grid) through net meter, which is bidirectional energy meter that can read the units consumed during the off load and finally these units get adjusted into the electricity bill.
The maximum generation of 5 kW power plant is 600 units, if these units are not consumed by load then it is supplied to the distribution transformer (grid). In a month, almost 50 to 80 units are transferred to distribution transformer (grid). Based on this, the authors have calculated the payback period by considering the cost of each units paid by state government to be approximately 10. Almost around 80 units were supplied in the month. So saving cost for one year is 6000 to 9600. Hence payback period is total cost of the plant divided by saving cost by the plant and therefore approximately pay-back period for the above case will be 7 to 10 years.
The selection and analysis of the 5 kW solar power plant is provided. The unit consumption during the month is also given over the period of year. It gives an alternate option to the thermal power plant in future for the generation of electricity. Whenever load requirement is less than the produced power from the solar plant, it is fed to grid and the consumer is benefitted from solar plant and when the load requirement is more, power can be drawn from the grid. The cost analysis and payback period is also calculated for 5 kW solar power plant.