A Comparative Study on Installation of Solar PV ...

Proceedings of 11th Global Engineering, Science and Technology Conference 18 - 19 December, 2015, BIAM Foundation, Dhaka, Bangladesh ISBN: 978-1-922069-92-4

A Comparative Study on Installation of Solar PV System at Garments Roof top Md. NurAlam*,Rezaul Karim# and Mohammed Rafiqul Islam$ In a developing country like Bangladesh energy consumption is one of the major challenge/issue. There is a gigantic difference between the demand and production of power. Only 62% of people have the access of grid electricity in Bangladesh. Even fortunate people who have access to grid connection do not receive the power most of the time in summer due to unbearable load shedding. The garments industries provide the single source of economic growth in Bangladesh’s rapidly growth developing country. Exports of textiles and garments are the principal source of foreign exchange earnings here. So, uninterrupted power supply is mandatory here. Garments industries consumed overwhelmingly of electricity. Most of the power stations of Bangladesh are run by natural gas. In Bangladesh, natural gas is the most important indigenous source of energy that accounts for 63% of the country.At present, the reservation of gas has fallen to such an alarming level that if no new gas fields are discovered, then this reserve may last for maximum a decade. So, to reduce the dependency on natural gas, alternative energy resource must be explored. Bangladesh is known to have a good potential for renewable energy especially solar energy. Bangladesh has taken a plan to generate 5% of total power generation from renewable sources by 2015 and it will go up to 10% by 2020. The renewable energy systems in Bangladesh start with Solar Home System at rural areas where no grid line is available. Now it can expand by solar mini grid system, solar irrigation system, and also solar mega grid system. But for solar mini grid and solar mega grid system need large land area for installation. So solar mini grid and solar mega grid is not feasible at urban areas. The objectives of the paper are to evaluate the potential of solar mini grid system at Garments rooftop. This paper also contains possibility of solar energy from solar panels installed at garments roof top.

Field of Research: Renewable Energy

I. Introduction Being a developing nation, Bangladesh has seen a decent growth in its economy over the past few years. Its economy is ranked as the 36th largest in the world in terms of Purchasing Power Parity (PPP) and has achieved an estimated GDP growth of 6% over [1]. The Industrial sector alone contributes 27.9% to this accomplishment [1]. There are a total of 4296 garments factories operating in the country now (Year 20142015) [2]. Garment exports, the backbone of Bangladesh's industrial sector, accounted for 81.71% of the total exports earnings and surpassed $25 billion in 2014-2015 [3] and acts as a catalyst for the development of our country.Indisputably, it plays a major ___________________________________________________________________ Shift Engineer #, Everest Power Generation Co. Ltd.#, [email protected]#, Shift Engineer$, Unique Cement Power Plant Ltd.$, [email protected]$, Research Engineer*, Centre for Energy Research*, [email protected]*,

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Proceedings of 11th Global Engineering, Science and Technology Conference 18 - 19 December, 2015, BIAM Foundation, Dhaka, Bangladesh ISBN: 978-1-922069-92-4 role in promoting Bangladesh’s economic growth. Now, the supply of continuous electricity is the main challenges to keep promote Bangladesh’s economic growth. So, availability of power supply is one of the most important factors of the country’s economic growth. Only 62% percent of the entire population has access to power supply and the per capita power consumption is only 321 KWh [4]. Bangladesh aspires to be a middleincome country by 2021. This will require increasing GDP growth to 7.5 to 8 percent per year based on accelerated export and remittance growth. Government has set up the goal of providing electricity to all by 2020 and to ensure reliable and quality supply of electricity at a reasonable and affordable price [5]. The total power generation in Bangladesh is almost entirely dependent on natural gas, which accounts for about 62.59% of the electricity generation of the total installed capacity as on September,2015 is 11877 MW [6]. At the current rate of increase in consumption (natural gas), the reserve of natural gas may not last more than a decade if new gas field is not discovered. Bangladesh Power Development Board (BPDB) Statistics indicates that demand is increased 100% by only 8 years duration from 2007 to 2015 [7]. So, one decade later we will be need more than 15000 MW electricity, but we will face huge crisis if alternative power solution is not discovered. Development of Renewable Energy is one of the important strategies adopted as part of Fuel Diversification Program. In line with the Renewable Energy policy 2009, the Government is committed to facilitate both public and private sector investment in Renewable Energy projects to substitute indigenous non- renewable energy supplies and scale up contributions of existing Renewable Energy based electricity productions. A dedicated policy, Renewable Energy Policy of Bangladesh, has been in force since 2009, which envisions having 5% power from renewable energy sources by 2015 and 10% by 2020. To achieve this target, the government has established Sustainable and Renewable Energy Development Authority (SREDA) to promote renewable energy and energy efficiency. Under the existing generation scenario of Bangladesh, Renewable Energy has a very small share to the total generation. The share of Renewable Energy exceeds more than 1% till now. The present Government is placing priority on developing Renewable Energy resources to improve energy security and to establish a sustainable energy regime alongside of conventional energy sources [9]. REN21's Renewable 2014 Global Status Report indicates that renewable energy provided an estimated 19% of global energy consumption in 2012 compared to 16.7 % in 2010 [10]. The possible scenario was drawn with solar energy covering nearly 30% of global energy demand by 2050, and nearly 70% by 2100. Bangladesh is situated between 20.30 and 26.38 degrees north latitude and 88.04 and 92.44 degrees east longitude, which is an ideal location for solar energy utilization. Bangladesh receives an average daily solar radiation in the range of 4-6.5 kWh/m². Encouraged by the availability of solar radiation, Power Division has initiated a program to generate 500 MW of solar-based electricity [11]. Long term power development Strategy for Bangladesh Plan is to realize a low carbon society by introducing high efficient power supply and low CO2 emission technology [8]. Most of the Bangladeshi Garments are located at urban areas like Dhaka city, the Dhaka EPZ, Chittagong city, the Chittagong EPZ etc due to access for skilled labor, easy and continuous access of power supply and gas, proximity to suppliers, 2

Proceedings of 11th Global Engineering, Science and Technology Conference 18 - 19 December, 2015, BIAM Foundation, Dhaka, Bangladesh ISBN: 978-1-922069-92-4 subcontractors, machine repair technicians and support business etc. But solar minigrid and mega grid need large land area, so it is not feasible at urban areas. In the fiscal year 2010-2011, Bangladesh Power Development Board (BPDB) had installed 32.75 kWp solar PV Roof Top systems at WAPDA Building, Motijheel, Dhaka city and the fiscal year 2011-2012, BPDB had installed 37.5 kWp Solar Roof Top System on 15th floor of Bidyut Bhaban, Segunbagicha, Dhaka city [9]. Garments industries which is situated at urban areas, we can implement solar mini grid system on roof top of that garments. In this paper, we will discuss about the possibility of the implementation of solar mini grid system on the roof top of garments. We will discuss a study on installation of solar PV Roof top system at Al Muslim group garments which is located at Savar (Beside Dhaka-Aricha Highway), near Dhaka city.

II.

Motivation and background

There are many countries including Bangladesh who installed solar system on building rooftop. World largest solar mini grid rooftop system has installed in Italy, which project name is CIS (Centro Ingrosso SviluppoCampano) in Nola, Located in Nola - Naples, Italy, Nominal Power is 25 MWp , Annual Production is 33 GW.h and which has completed in 2013 .Now this project is in operation[12] . In Asia, Largest Rooftop Solar PV Plant has installed on rooftop made of asbestos sheet of area 94,000 sq. m., Located in Punjab, India, Nominal Power is 7.52 MWp and which has commissioned in June 2014. Now, it is in operation [12]. World's first solar-powered cricket ground name is Bengaluru's Chinnaswamy stadium. The Karnataka State Cricket Association (KSCA) has commissioned a 400KW solar plant on stadium gallery roof to power the entire stadium except for the highintensity floodlights [13]. In Bangladesh, BPDB has first installed solar mini grid system on building roof top. In the fiscal year 2010-2011, Bangladesh Power Development Board (BPDB) had installed 32.75 kWp solar PV Roof Top systems at WAPDA Building, Motijheel, Dhaka city and the fiscal year 2011-2012, BPDB had installed 37.5 kWp Solar Roof Top System on 15th floor of BidyutBhaban, Segunbagicha, Dhaka city [9].

III.

Climate Study

Apart from the solar radiation availability the climatic (ambient temperature, humidity etc.) and microclimatic parameters (wind speed, dust level etc.) make significant impact on the performance of solar PV system. A. Average Temperature Maximum and minimum temperature significantly impact on voltage production in solar panel therefore it is important to consider in design. Figure 1.8 shows the average 3

Proceedings of 11th Global Engineering, Science and Technology Conference 18 - 19 December, 2015, BIAM Foundation, Dhaka, Bangladesh ISBN: 978-1-922069-92-4 maximum and minimum temperature of the project site where minimum temperature is 7 degree Celsius in January and maximum temperature is 41.6 during month of Mar. Figure Error! No text of specified style in document..1: Monthly Average Temperature of the Site (NASA Surface Meteorology) 35 Minimum

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Proceedings of 11th Global Engineering, Science and Technology Conference 18 - 19 December, 2015, BIAM Foundation, Dhaka, Bangladesh ISBN: 978-1-922069-92-4 There is an adverse effect of too much humidity in the atmosphere on the PV module performance too. It becomes worse when humidity starts condensing on the panel in night and dust got deposited on the panel, and reduces the amount of solar radiation reaching on the solar cells. This will reduce the power output from the plant. Hence special consideration should be given for the cleaning of the solar panels. Here in the power output calculation from the PV plant is considered by taking in to account the effect of the humidity as well. Figure Error! No text of specified style in document..3: Average Humidity of the plant location (NASA Surface Meteorology)

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Basic Block diagram

The whole system is completely lucid and easy to install. The basic block diagram of a solar PV system at Garments rooftop is shown in figure 1.4. Here are the different blocks such as On-grid solar panels, Grid Inverter, Grid lines, off grid inverter, battery bank, Charge controller, off grid solar panels, national grid and garments light load (i.e, light at different floor, fan etc). Let us see each block in detail. Fig 1.4: Block Diagram of the system

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A. Solar Panel Solar panel is a compiled and connected assembly of photovoltaic cells that transmutes solar energy into electrical energy [6]. It can be used as a constituent of a bigger photovoltaic system to create and distribute electricity in mercantile and residential applications. Each panel is rated in accordance with its DC output power under standard conditions, and typical specification ranges from 100 to 320 watts. We espouse a collection of 285 watt panels to form more than 850 kWp. The conjectured efficiency of these panels is 80% and thus we could postulate that a figure of 800 watts may be collected from this section. A photovoltaic system conventionally comprehends an array of solar panels, an inverter, and an optional battery. i.

On grid solar panels

The purpose of on grid solar panels is to generate electricity from sun energy only for day loads. When sun is available this panels will generate electricity for load. If the generation of electricity is larger than demand of load at garments, than the excess electricity will use for battery bank or injected to national grid. ii.

Off grid solar panels

The purpose of off grid solar panels is to generate electricity from sun energy only for battery bank charging. When sun is available this panels will generate electricity for battery bank. If the generations of electricity are less than the demand of battery banks, than the excess demand will fill by on grid solar panels or national grid. 6

Proceedings of 11th Global Engineering, Science and Technology Conference 18 - 19 December, 2015, BIAM Foundation, Dhaka, Bangladesh ISBN: 978-1-922069-92-4 B. Battery A storage battery is an ilk of electrical battery. It is a genre of energy accumulators that comprising of more than one electrochemical cells [7]. It is known as a secondary cell since its electrochemical reactions are electrically rescindable. Rechargeable batteries are used by grid energy storage applications for load-leveling, where they accumulate electric energy. For sustainable energy uses, the energy stored during day time can be used during peak load hours at night. Load-leveling mitigates the eradication of the desideratum for expensive culminating power plants and aids in amortizing the cost. We use a couple of batteries, each of 2V and 1540Ah capacity forming 48V and 1540Ah capacity. C. Inverter A power inverter is a converter which transmutes direct current (DC) to alternating current (AC). The converted output can be made to any voltage and frequency according to the applications and desiderata. We use inverter with standard output specifications of 20-240V, 50Hz to suit our requirements. i.

On grid inverter

The purpose of the on grid inverter is to convert DC power from on grid solar panels to AC power, which will injected to garments light load. If the demand of electricity will less than the generation of electricity from on grid solar panels, than execs electricity will injected to battery bank through off grid inverter or national grid. On grid inverter only convert DC to AC. ii.

Off grid inverter

The purpose of the off grid inverter is to convert DC power from battery bank to AC power, which will injected to garments light load when sun is not available. If the demand of battery bank is larger than the generation of electricity from off grid solar panels, than execs demand will fill by on grid inverter or national grid. So off grid inverter is bi directional inverter, which can convert AC to DC or DC to AC. D. Control Circuit In the system there must be a scheme to detect when a cell reaches full charge (change in terminal voltage, temperature, etc.) and to stop charging before harmful overcharging or overheating occurs [5]. We can incorporate cooling fans if needed to keep the cells from heating. Here we use a control circuit with voltage level sensors to obviate a detonation. E. Load In this system our main purpose to supply electricity from solar panel to garments light load like lights at different floor, fans etc which are being using as a load.

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Proceedings of 11th Global Engineering, Science and Technology Conference 18 - 19 December, 2015, BIAM Foundation, Dhaka, Bangladesh ISBN: 978-1-922069-92-4 F. National Grid Supply of electricity from the solar panel totally depends on whether condition of the atmosphere. If sunshine is not available then supply of electricity for load will be supplied from battery and than the national grid.

V.

Design Calculation

In this paper will discuss how much solar panels can install in a particular garments rooftop. Here we select one of the garments of Al-Muslim Group, which is one of the largest Garment factories in Bangladesh. And also we do not consider all of the building of Al-Muslim garments, which situated at Savar, Dhaka. We select the largest building of Al-Muslim garments. We calculate the area of that building from Google earth, which we select for our solar PV system. Figure 1.5: Arial view of Al Muslim Group Garments (From Google Earth)

Al Muslim Garments has situated at 23.8°N latitude and 90.4°E longitude (from Google earth). The area of the garments are approximately 30 acre, where garments rooftop are available approximately 7150 m2 (calculate from Google earth). So we can easily installed solar mini grid system at Al Muslim Garments roof top.With 23° tilt angle, we can install 3045 solar panel with capacity 285 Wp each (model: JAM6 (L)-60-285/PR). This will produce 868 kWp dc power and 650 kW ac power. The plant will add approx. 1417 MWh of green energy to the national grid each year (from PVsyst simulation result). From PVsyst result, there are 21 modules in series and 145 strings are parallel, Vmpp 601 volts and I mpp 1302 Amperes. Numbers of inverter required 52 of sunny tri-power 25000TL, which will generate 650 kW ac power. A. Load Calculation 8

Proceedings of 11th Global Engineering, Science and Technology Conference 18 - 19 December, 2015, BIAM Foundation, Dhaka, Bangladesh ISBN: 978-1-922069-92-4 Here we are measure the light load of that garments. First we calculate how much solar panels can be installed in the roof top. Than we divide the load into two categories. One is day load and another one is night load. We consider night load, because most of the garments run more than 12 hours in a day. In Bangladesh average we get only 6-8 hours of sunlight. So that we need also battery backup system for night loads. i.

Day Load

From Google earth, we see that total area of the selected building is more than 7000 m2. Where we can be installed more than 850 kWp solar panels. For day load 2/3 of total capacity is considered, so 550 kWp (approximately 2/3 of 850 kWp) of solar panels is considered for day load. For day load total unit will generate in day 550 X 8 = 4400 kWh, which can be used for light load of garments at day time. If the Load demand of a particular garment is less than 4400 kWh, than excess generation of electricity will injected to Battery bank or national grid. ii.

Night Load

1/3 of total capacity is 300 kWp (approximately 1/3 of 850). So night load total unit will generate in a day 300 X 8 = 2400 kWh, which can be used for light load of garments when sun is not available especially in night. If the night load demand will more than that of 2400 kWh, than surpluses demand will fill up by the national grid or any other alternate source like generator etc. B. Battery Calculation The battery calculation is done by night load calculation, because battery only need for night load. Total off grid capacity is 2400 kWh (for night load). Let consider battery bank voltages is 48 V, than total battery bank capacity will be 2400 kWh/ 48 V = 50,000 Ah. After considering DOD 70% and Battery life cycle 80%, than battery bank capacity will increase by 2. Now total capacity of the battery bank will be 50000 X 2 = 1, 00,000 Ah. Each battery bank capacity will be 48 V, 1540 Ah. No of battery bank will be 100000/1540 = 64.94 or 65. 48 V, 1540 Ah battery is very large. So we make battery bank by 2 V, 1540 Ah. Connect 24 2 V, 1540 Ah in series. So total battery will be required 65 X 24 = 1560 of 2 V, 1540 Ah battery.

C. Inverter Calculation In our solar PV system, we use two types of inverter one is on grid inverter and another one is off grid inverter. On grid inverter can convert Solar DC power to AC power only. But off grid inverter can convert DC to AC as well as AC to DC. For on grid inverter we will us sunny tri power (STP) 25000 TL (25 kW). So, no of STP required 550 kWp / 25

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Proceedings of 11th Global Engineering, Science and Technology Conference 18 - 19 December, 2015, BIAM Foundation, Dhaka, Bangladesh ISBN: 978-1-922069-92-4 kW = 22. And for off grid inverter we will be used Sunny Island 6000VA. So no of Sunny Island required 300 kW/6 kW = 50.

VI.

PVsyst Simulation Result

After Hand calculation we also simulate our project by PVsyst software, which is one of the well know Solar PV system simulation software. A. Input Data The shadow effect should be considered in PV array design, which should be wakened or eliminated. The general requirement is that, at the time of the winter solstice, when the longest shadow in a year appears, the spacing between the two rows of PV arrays should be big enough that the shadow of the PV array in front would not block the array behind, especially from 8 a.m to 5 p.m. Local latitude angle has been considered for the inclination or tilt angle of the PV module facing towards the equator (south). Al-Muslim group is located at 23o latitude and in northern hemisphere. So, to get the maximum of the incident rays of the sunlight, the module should place at a tilt angle equal to local latitude and facing towards south. Figure 1.6: Inclination angle of PV panel

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Figure 1.7: Input data of PVsyst software

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Proceedings of 11th Global Engineering, Science and Technology Conference 18 - 19 December, 2015, BIAM Foundation, Dhaka, Bangladesh ISBN: 978-1-922069-92-4 According to PVsyst software the system will produce 1417MWh/year with Performance ratio 83.6% Figure 1.8: Simulation Result (Yearly power generation of the system)

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Figure 1.8: Simulation Result (Yearly loss diagram of the system)

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Proceedings of 11th Global Engineering, Science and Technology Conference 18 - 19 December, 2015, BIAM Foundation, Dhaka, Bangladesh ISBN: 978-1-922069-92-4 VII.

Study

The price of electricity and gas is increasing day by day. In this paper, we implement a solar based system and find out the feasibility of the idea and the monetary profits of using it rather than using electric supply for light load. The project if successfully implemented, operated and maintained will have significant environment benefits mainly derived from the switch of power generation from a fossil fuel (diesel) source to a renewable source (solar energy). The only type of physical work is installing solar power generation systems on top of existing buildings. Apart from this the project will also impact in social perspective as described below. A. Job Creation To operate the PV system therefore there will an employment opportunity for local people. In addition, during construction a considerable number of manpower will be required to construct the project maximum of the workforce could be avail locally. B. Use of unused rooftop The rooftop of building to be used for the proposed 850kWp grid connected solar power system is now mostly unused. Therefore, implementing the power plant the land can be used in an efficient way to produce power approximately 1417MWh annually. C. Avoidance of Carbon dioxide emissions Solar PV technology is an environmentally friendly technology. It does not emit carbon when generates power converting the sun light. The amount of carbon dioxide can be avoided throughout the period of the plant lifetime. Grid emission factor of Bangladesh is 0.67 ton per MWh. D. Increased Energy security Bangladesh is an energy striving country. There is a considerable gap between demand and generation of power. Building such power plant can improve the scenario and reduce dependency on imported fuel significantly.

VIII. Conclusion Renewable energy plays an important role in the transition towards a low carbon economy and the provision of a secure supply of energy. Many years of research and development have brought a number of renewable energy technologies to a stage where they are technologically mature and ready for a more widespread market introduction. However perceptions of the associated risks have constrained the progress of renewable energy. The project is based on solution of real life problem. Such system can be beneficial in our life not only because it saves money but also because it is an application of utilizing solar energy which is renewable. 16

Proceedings of 11th Global Engineering, Science and Technology Conference 18 - 19 December, 2015, BIAM Foundation, Dhaka, Bangladesh ISBN: 978-1-922069-92-4 IX.

References

[1] http://www.worldbank.org/en/country/bangladesh/overview [2] https://en.wikipedia.org/wiki/Electricity_sector_in_Bangladesh [3] Bangladesh Power development Board “Key statistics” as on September, 2015 [online].Available:http://www.bpdb.gov.bd/bpdb/index.php?option=com_content&vie w=article&id=5&Itemid=6 [4] BPDB “Maximum generation” Bangladesh Power development Board 2015, [online], Available in URL: http://www.bpdb.gov.bd/bpdb/index.php? option= com_ content&view=article&id=126&Itemid=17. [5] Cousins PJ,Smith DD, Luan HC, Manning J, Dennis TD, Waldhauer A, Wilson KE, Harley G and Mulligan GP, Gen III:Improved performance at lower cost, 35th IEEE PVSC, Honolulu, HI, June 2010 [6] A.Zahedi, "Energy, People, Environment, Development of an integrated renewable energy and energy storage system, an uninterruptible power supply for people and for better environment," The International Conference on Systems, Man, and Cybernetics, 1994. 'Humans, Information and Technology', Vol. 3 pp. 2692-2695, 1994. [7] Ahmad Yafaoui, Bin Wu and Richard Cheung, Photovoltaic energy Systems-An Overview, IEEE Canadian Review-Spring/Printemps 2009. [8] The World Fact Book :https://www.cia.gov/library/publications/resources/the-worldfactbook/geos/bg.html [9]BGMEA Websites [online]. Available:http://www.bgmea.com.bd/home/pages/tradeinformation#.VXHbvM9Viko [10] Data Source Export Promotion Bureau Compiled by BGMEAhttp://www.bgmea.com.bd/home/pages/tradeinformation#.VXHbvM9Viko [11] https://en.wikipedia.org/wiki/Electricity_sector_in_Bangladesh [12] BPDB “Power System Master Plan 2010 Summery” Bangladesh Power development Board, [online],Available in URL: http://www.bpdb.gov.bd/download/PSMP/PSMP2010(Summary).pdf [13] BPDB “Development of Renewable technologies by BPDB” Bangladesh Power development Board 2015, [online], Available in URL: http://www.bpdb.gov.bd/bpdb/index.php?option=com_content&view=article&id=26&It emid=24 [14] Online in URL: http://www.thedailystar.net/development-of-renewable-energy-inbangladesh-49670

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