Introduction: The energy plays a pivotal role in our daily activities. The degree of development of a country is measured by the amount of utilization of energy by human beings. Energy demand is increasing day by day due to increase in population, urbanization and industrialization. The world's fossil fuel supply will be depleted in a few hundred years. The rate of energy consumption increasing, supply is depleting resulting in inflation and energy shortage. This is called energy crisis. Hence alternative or renewable sources of energy have to be developed to meet future energy requirements. The principle of solar power plants is quite simple. They consist of a field of solar photovoltaic modules connected them in series and parallel and connected to one or more inverters. Solar energy is directly transformed into electricity and then connected to the Low Voltage distribution grid in the academic area of BIET.

Advantages of renewable energy:1. Renewable energy is, well, renewable: This means it has infinity

of sustainability and we will never run out of it. Other sources of energy like coal, oil and gas are limited and will run out some day. Renewable energy can reduce our dependence on fuels and energy from foreign governments. Strong winds, heat within earth, moving water, shining sun can provide a vast and constant energy resource supply.

2. Economic Benefits: Renewable energy is also cheaper and more economically sound than other sources of generated energy. Thousands of jobs have already been created in numerous European countries like the United Kingdom and Germany, who have adopted measures to manufacture renewable energy. Renewable energy amenities require a less amount of maintenance, which reduces the costs. Switching to renewable energy sources also means that the future of our energy is returned back to the people: to communities, families, farmers, and individuals.

25 KWp SOLAR ON GRID POWER PLANT IN BIET COLLEGEDATE :23/9/2016 – 6/10/2016

A 25 KW Solar Power Plant installed by ROY CONSTRUCTION & FUJISUN ENERGY in BIRBHUM INSTITUTE OF ENGINEERING AND TECHNOLOGY in 2016 at the roof of the E- Block of the college buildings.

Presented by: Suraj Chowdhury Roll: EE 23/13Department: Electrical Engineering

Project Summary

A. Project location: BIET

B. Project Type: ON GRID

C. Size of Installation :25 kwp

D. Type of roof: Open

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Site assessment & Understanding: Mainly solar Plant are installed in vacant space so that Module can able to withdraw more photons. They are may be rooftops, open garden, backyard etc. Most important part is that structure must be South facing so that it receives maximum sunlight. Radiation is also a part in generation of solar energy. Radiation will be different in different places. In BIET solar plant is installed in rooftop of E-block of College building. It is install in around 28mtr 400mm x 12mtr 900mm. 25 structures are installed, each structure produce 1kwp means 25 X 1kwp =25kwp

BIET COLLEGE ROOFTOP

Bill of material with Quantity:1. 25 kwp Solar structure (Qty x 25)

MKD NO SECTION LENGTH QTY

C-1 L 65 X 65 X 6 1065 1

C-1X L 65 X 65 X 6 1065 1

C-2 L 65 X 65 X 6 615 1

C-2X L 65 X 65 X 6 615 1

C-3 L 40 X 40 X 5 250 4

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A-1 L 40 X 40 X 5 1115 2

A-2 L 40 X 40 X 5 2788 2

D-1 L 50 X 50 X 6 1200 2

S-1 L 40 X 40 X 5 4000 2

2. PVC pipes: PVC pipes as needed for casing DC wires on rooftop.

3. MC4 : As per connection needed

MC4 CONNECTER

This solar plant is mainly consisting of

i. 100 Solar Panelsii. DC String Array and Combiner Box iii. Two Inverters (SAJ 20 kw & 5KW) iv. AC Distribution Box v. Plant AC Energy Metervi. Data Acquisition System

250 watt solar PV solar panel

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Project details:

Structure fitting:

Basically this structure is mainly make of 16 parts and all parts are fitted with nut and bolts. In India Modules are align in 22~23 degree with structure to receive more radiation whole day. In BIET structure were setup in two days.

Structure Alignment:

Structure must be facing south to receive maximum radiation throughout daylight. There must be same distance between the structures in column wise to eliminate shadows. I have shown it in given below picture.

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Civil foundation:

All the structures after fitting & drilling in legs to give better support, civil foundation has been done, mean get concrete at four leg of each structure. Mostly this structure Can have carried out up to 280 km/hr of wind. After two days Painting had been done in civil foundation to give proper look.

Module fixing:Module fixing is very vital part, each structure carries 4 modules. Modules are fitted with nut and bolt. Each module will be series connected with other MC4 connecter providing male and female connecter.

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Therefore 1 structure O.C voltage = 40*4 = 160 V DCCurrent = 7 A

Here we have taken four 5 kw parallel connection means so wattage = 5 x 4= 20 kw O.C Voltage of each 5 kw =40 x 4 x5 =800 V DC

Again two 2.5 kw parallel connections wattage = 2.5 x 2 =5kw O.C Voltage of each 2.5 kw =40 x 10 =400 V DC Therefore, total wattage =20+5 =25 kwp

Solar panel connection diagram:

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DC CONNECTION (AJB):

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 Array junction (DC combiner) boxes that provide interconnection between the input leads from the solar PV modules, and the output lead to the re-combiner box or inverter. The combiner box is customized for different configurations, based on the number of strings of solar PV modules used in the PV layout. For a set of 10 PV modules arranged two in series and five in parallel, a 5:1 configuration combiner box is selected.

1. Fuse Protection for StringsDC fuses rated from 2A to 25A from leading manufacturers are used in the combiner box to provide overcurrent protection. Fuses can be provided with or without indication.

2. Surge Protection Device  Surge Protection devices or SPD’s in the combiner/junction box protects electrical and electronic equipment from the power surges and voltage spikes.  Surge protection devices divert the excess voltage and current from transient or surge into grounding wires. SPD’s used by Nordic Asia in the combiner boxes meet Type 2 regulations, and are typically rated between 600 to 1000V.

3. DC Disconnect/Isolation:An accessible disconnect/isolator switch is recommended for placement before the inverter to disconnect the DC side of the system when maintenance is being performed on the inverter.

Piping: Total 12 wire piping has been done to AJB (8 wire of 20 kw and 4 wire of 5kw). From AJB to inverter 6 wire has been done. Basically piping must be done for DC Cable protection.

INVERTER DETAILS: 1. SAJ Sununu TL5K - 5kW Single Phase Inverter: The SAJ Sununo-TL5K solar inverter offers a range of benefits, including the high speed MPPT for real-time power tracking and improved energy harvesting. The transformer less solution gives the highest efficiency up to 97.7%. The wide input voltage range makes the inverter suitable to low power installations with reduced string size. Features:

1. Brand: SAJ - Original Ref number: Sununo TL5K 2. Nominal Output Power: 5000W 3. Maximum nominal output power: 5000W 4. Max input voltage range: 120-500V5. Maximum input voltage: 5200V 6. Startup input voltage: 150V 7. Number of independent MPPT channels: 2 8. Max input current for each MPPT: 16A9. Dimensions: 525x425x190mm 10. Weight: 26kg - Maximum Efficiency: 97.7%11. Packaging: 5% pallet 2. SAJ Suntrio TL20K

20kW Three Phase Inverter: The SAJ Suntrio-TL20K solar inverter is a transformer less inverter with efficiency of up to 98.1%. The device comes with multi-MPPT inputs providing higher flexibility for the project installation. Stainless steel housing and IP65 protection guarantee use both indoor and outdoor for long. The SAJ Suntrio-TL20K is ideally suited for medium and commercial PV projects of up to MW range.

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Features: 1. Brand: SAJ2. Original Ref number: Sununo TL20K 3. Nominal Output Power: 20000W4. Maximum nominal output power: 20000W5. Max input voltage range: 240-800V 6. Maximum input voltage: 1000V 7. Startup input voltage: 300V 8. Number of independent MPPT channels: 29. Max input current for each MPPT: 22A10. Dimensions: 480x680x200mm - Weight: 42kg 11. Maximum Efficiency: 98.1% - Packaging: 5% pallet

INVERTER PRINCIPLEA power inverter, or inverter, is an electronic device or circuitry that changes direct current (DC) to alternatingcurrent (ac). The input voltage, output voltage and frequency, and overall power handling depend on the design

of the specific device or circuitry. The inverter does not produce any power; the power is provided by the DC source. A power inverter can be entirely electronic or may be a combination of mechanical effects (such as a rotaryapparatus) and electronic circuitry. Static inverters do not use moving parts in the conversion process.

Output frequency: The AC output frequency of a power inverter device is usually the same as standard power line frequency, 50 or 60 Hz. If the output of the device or circuit is to be further conditioned (for example stepped up) then the frequency maybe much higher for good transformer efficiency. In our project this is a on grid project, so the frequency is 50Hz.

Sununo-TL5K Suntrio-TL12K/15K/17K/20K

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ACDB connection:

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Conclusion:

The practical experience that I have gathered during the 25 kwp on GRID solar plant installation in BIET by RCC & fujisun energy in two weeks will be very useful as a stepping stone in building bright professional career infuture life. It gave me large spectrum to utilize the theoretical knowledge and to put it into practice. The troubleshooting activities in operation and decision making in case of crisis made me more confident to work in the industrialatmosphere. Moreover, this overview workshop and team work has also given a self-realization & hands-on experience indeveloping the personality, interpersonal relationship with the professional executives, staffs and to develop theleadership ability in industry dealing with workers of all categories. I would like to thank everybody who has been apart of this project, without whom this project would never be completed with such ease.