4.872 KW GRID-CONNECTED PV SYSTEM RESULTS AND TESTING AT RAJAMANGALA UNIVERSITY OF TECHNOLOGY (RMUT), THAILAND Napat Watjanatepin Rajamangala University of Technology Suvarnabhumi THAILAND Phone:+66-2969-1521, Fax:+66-2525-2682 e-mail:
[email protected]
ABSTRACT This paper is to present 84 panels of amorphous silicon (a-Si) Solar cells that has 58 W 63 V per panel (Kaneka Solar PV) and the total power is 4.872 kW. The solar panels installed on building top of the Electrical Engineering Building at Rajamangala University of Technology (RMUT), Nonthaburi, THAILAND is 71 m2. This project has two important objectives. 1. Installation and testing results of 4.872kW Grid-Connected PV System (GPV), to find out the efficiency of PV array , Inverter and Overall. 2. Measurement generating energy in 12 months and calculate generating cost , save cost and average power generation. Three 2.2 kW single-phased Grid-connected inverter generated supply to the distribution system. The control and monitoring system use the Leonics Apollo View Software. The 4.872kW GPV can potentially produce 6,444 kWh of electricity per year and it can save electric cost for Bt15,010.40 (US$375.26) per year. The cost for generated electric energy is Bt8 (US$0.2) per kWh , average power generation is 0.25 kWh/m2/day. The overall efficiency of this system is 32.60% , efficiency of PV arrays is 40.12% and efficiency of Grid-Connected inverter is 81.39%. Keywords : amorphous silicon , Grid-Connected inverter , Building top , GPV 1. INTRODUCTION Between 1992 to 2001, 928MWp of solar PV had been installed in twenty of IEA-PVPS [8] participating countries. Almost 70% of these installations are connected to the grid. Since 1992,the growth rates of solar PV applications have risen from 20% to 40%. In 2001 alone , 257MWp of PVs were installed where 79% of the systems were installed in Japan and Germany. Thus, Japan recorded the highest PV power per capita of about 3.6 Wp/capita.
Chaiyant Boonmee Rajamangala University of Technology Suvarnabhumi THAILAND Phone:+66-2969-1521, Fax:+66-2525-2682
Recently, the majority of the PV installations are as gridconnected PV system (GPV). This is due to various Government and utility supported programmes that drive the rapid rise of distributed GPV application in Japan, Germany, USA and Netherlands.[7] In 1983 the first GPV project of Thailand installed at Phuket province by Electricity Generating Authority of Thailand (EGAT) , has generated electric power 11.34 kW. After that have many solar projects about stand alone system , GPV and Hybrid system [1] in Thailand. In 2000 The National Energy Policy Office (NEPO) of Thailand explored all of Solar (PV) project in Thailand , they found out that the total power is 5.217 MWp. What was used for telecommunication system is 36.5% , for battery charging system is 32.5% , for GPV only 5.3% and another system is 27.5% as show in Figure 1. 0.5% 5.3% 3.8% 2.4% 36.5% 19.0%
32.5% Telecommunication System Battery Charging System Water Pumping System Distance Learning System Hybridge System Grid-Connected / Stand-alone System ect.
Figure 1: The proportion of PV for used in Thailand (2000) Source:NEPO However , Grid-Connected are interesting system because its cost is lower than the stand-alone system. So , the Rooftop Grid-Connected PV system (RGPV) project in United States of America , Japan and Europe if to succeed can grow up to be next the project example 1 million houses in USA, 100,000 houses in Europe and 70,000 houses in Japan.
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In 1987 Thailand had a PV project from EGAT and NEPO to cooperate for RGPV, this project installed 2.5 kW-2.8 kW of PV system at 10 houses and the next project was brought to the 100 houses during 2002 -2003. [3] This project got the budget from Thai government in 2003 , for installation and testing of the 4.872 kW GPV. It was installed on building top of the Electrical Engineering Building at Rajamangala University of Technology (RMUT) , Nonthaburi , Thailand. We used amorphous silicon (a-Si) Kaneka Solar PV product of Japan and used LEONICS 2.2 kW Grid-Connected Inverter model Apollo G-300 for convert DC power to AC power , it’s product of Thailand.
2.1.2 Junction box The PV system has three subarrays , each subarray has water proof junction box. The junction box used for connecting electric cable and install seven blocking diode rate is 3 A 1000 V to protect reverse current when there’s shade on the top of PV array , as show in Figure 4.
2. PRINCIPLE OF OPERATION 2.1 System Configuration The System block diagram of Grid-Connected PV System as show in Figure 2. It consisted of 5 main parts are Solar Array Junction box Grid-Connected Inverter Production meter and protection system Control and Monitoring system Solar Array
Junction box RS-232
∼
∼
kWh/SP
kWh/SP
∼
kWh/SP
Monitoring System Figure 2: The system block diagram
Figure 4: Junction box and Blocking diode 2.1.3 Grid-connected Inverter The Grid-connected Inverter used to convert DC power from PV array to AC power on grid. This project have three LEONICS Inverter model G-300 , its rate is 2.2 kW single phased input 165-300 VDC , output 220 V 50/60 Hz , Power factor >0.98 , low harmonic distortion
