Download Design Installation and Testing of 1.6 kWp GPV System Napat Watjanatepin

Design Installation and Testing of 1.6 kWp
GPV System
Napat Watjanatepin
Rajamangala University of Technology Suvarnabhumi Nonthaburi Campus THAILAND
Phone:+66-2969-1521, Fax:+66-2525-2682
Email:[email protected]
ABSTRACT
This paper is to present the amorphous silicon (aSi) solar cells that has the total power is 1.6 kWp. The
solar panels installed on top of the Electrical
Engineering Building at RMUTS is 23.7 m2. This
project has three important objectives.
1. Installation and testing results of 1.6 kWp
Grid-Connected PV System (GPV), to find out the
system efficiency by comparison with average test and
peak test.
2. Measurement generating energy in one year and
calculate generating cost , cost save and average energy
generation
3. Comparison average electricity output by GPV
system that installed in European countries , in Japan
and in Malaysia
The 1.6 kWp GPV System can potentially produce
2233.55 kWh of electricity per year and it can save
electric cost of Bt5360.52 per year. The cost for
generated electric energy is Bt8.83 per kWh , average
energy generation is 0.262 kWh/m2/day. The overall
efficiency of this system is 33.04/67.33%
(average/peak), efficiency of PV arrays is
40.58/79.64% and efficiency of Grid-Connected
inverter is 81.43/84.58%.
The average electricity output per year is 1375
kWh/kWp higher than in Malaysia , Japan and Europe.
Keywords : Amorphous silicon , GPV,
Grid-Connected inverter
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 has risen from 20% to 40%. In
2001 alone , 257MWp of PVs were installed where
79% of which were in Japan and Germany. Thus ,
Japan recorded the highest PV power per capita of
about 3.6 Wp/capita. Recently, the majority of the PV
installations are as grid-connected 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 of 11.34 kW.
After that many solar projects about stand alone system ,
GPV and Hybrid system [1] were installed 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 36.5% , for battery
charging system 32.5% , for GPV only 5.3% and another
system 27.5%.
However , Grid-Connected are interesting system because
it cost 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 the next project: For example in 1 million houses in USA,
100,000 houses in Europe and 70,000 houses in Japan.
In 1987 Thailand had a PV project from EGAT and
NEPO to cooperate for RGPV, this project installed 2.5 kWp
- 2.8 kW of PV system at 10 houses and the next project was
brought to the 50 houses during 2002-2003. [3]
This project we designed installed and tested using 1.6
kWp GPV on top of the Electrical Engineering Building at
Rajamangala University of Technology Suvarnabhumi
Nonthaburi Campus. We used amorphous silicon Kaneka Solar
PV product of Japan and LEONICS 2.2 kW Single phase
Grid-Connected Inverter model Apollo G-300 to convert
DC power to AC power , all products of Thailand.
2. PRINCIPLE OF OPERATION
2.1 Design Procedure
The design procedure conform to the GPV System
Design review and approved procedures of Florida Solar
Energy Center (FSEC-GP-70-01). This procedure comprise
of six design processes.[5]
1. System design document
2. Electrical design
3. Mechanical design
4. Modules / Arrays
5. Inverter
6. Utility Interconnection
2.2 System Configuration
2.4 Junction box
The System block diagram of GPV System is
shown in Fig 1. It consisted of 5 main parts; PV Array,
Junction box,Grid-Connected Inverter , Production
meter, protection system and Monitoring system
PV array
(28 modules)
The PV system 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 shown in
Fig 4. We select the rating of diode by short circuit current
of each PV panel is 1.12 A (manufactory data sheet), and
chose safety factor is 200% the rating of diode need to more
than 2.24 A
Junction box
RS-232
DC
Grid – Connected
AC Inverter
Production meter
&
Protection system
Monitoring
System
Single phase utility grid
Fig 1: The system block diagram
Fig 4: Junction box and Blocking diode
2.3 PV Array
2.5 Grid-connected Inverter
The existing PV array is comprised of 28 Kaneka
Solar PV amorphous silicon modules . The system
consists of one set of PV array of 28 modules ,
arranged in four columns and seven rows , as seen in
Fig 3. The modules are connected in series strings of
four groups of seven parallel–connected modules, for
nominal voltage of 252 Volts dc as show in Fig 2. The
output of PV array is connected to a LEONICS 2.2 kW
Grid-connected Inverter.
The Grid–connected Inverter used to convert DC power
from PV array to AC power on grid. This project have
LEONICS Inverter model G–300 , its rate is 2.2 kW single
phase output 220 V 50/60 Hz input voltage is 165 – 300
VDC , Power factor > 0.98 , low harmonic distortion <4% and
MPPT control. The system was designed to generate power
that would be injected directly to the MEA electric grid as
show in Fig 5.
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
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⌧ 
  


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  

⌧ 
TO
UTILITY GRID




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Fig 2 : Single line diagram
Fig 5: Single phase Grid–Connected Inverter
2.6 Production meter and protection system
The single phased kilowatt–hour meter were installed for
measuring electric energy from Grid–Connected Inverter,
we call it Production meter. The protection system consist
of circuit breakers set in DC and AC part , set of surge
protection devices were installed at output of inverter to
bypass the high voltages induced by lightning. Those
equipments were installed in the steel cabinet as show in Fig
6.
Fig 3: The PV array has 28 PV–panels
The electric cables were installed with rigid and EMT
conduit between junction box and production meter box ,
approximately the distances are 30 meters from the control
room.
Fig 6: Production meter
2.7 Control and Monitoring System
The control of Inverter operating function depends on
the Inverter Specification. This means that the Inverter
will be turned on in the morning and will automatically
synchronize to the electric grid. After that it was operated
all day until evening, it will just automatically shut down.
So , the measurement system has current sensors , voltage
sensors and data recorder that were include in the function
of the Inverter , the data has been recorded after the set up
of parameter by software. The monitoring system used
LEONICS Apollo View software , it has local and
Remote monitoring with PC ,and display value of current ,
Voltage , Power and energy as shown in Fig 7.
Fig 8: Galvanized Structure and grounding system
The Grid-connected Inverter were installed in the
control room and single phase output of Inverter were
connected directly to distribution system, as show in Fig 9.
Fig 9: Installation Inverter and Production meter
3.2 System Operating
Fig 7: LEONICS Apollo View Software
3. INSTALLATION AND SYSTEM OPERATION
3.1 Installation
28 Solar panels were installed on the Galvanized Steel
Structure. This structure has a slope of 15 degrees
facing South. The area installed is 23.7 m2 , it uses
stainless bolts fitting between PV panels and steel
structure , and install Grounding System for thunderbolt
safety , as show in Fig 8. Four workers and one
technician worked for five days on May , 2003.
The system operating in this project single phase output
of Grid–connected Inverter will be connected to the electric
grid, at sunrise. When the sunligth concentrate is enough to
make the PV arrays, it can generate DC voltage
approximately 165 V at 6.30 am to 7.00 am. The Inverters
are operated until 6.00 pm (approximate) , because the
sunlight is low, it means that the PV voltage is less than 165
V, and then the Inverters are shut down. The Inverter output
has the single phase kWh–meter for measuring the electric
energy generated.
So, The GPV needed to have distribution system all the
time. If the distribution system has a problem like shut
down or unusual problem, the Grid – Connected Inverter will
stop operating for 1/50second. This operation is made for
operator safety.
The electrical data were measured by measurement
function of Inverter and the examples are current and
voltage. Those data sent to the Microcontroller for
calculation and send all of data into the data logger. Its
capacities can save data for 180 days. So , we can setup
recording time and location of data text file by software. In
the same way when we want to load data from the
Inverter , we can use local monitoring by RS-232 cable
or remote monitoring function by modem , and save the
data into text file. The details of data file and can take
any data to make graph is found in the next step.
4. TESTING AND RESULTS
4.1 System testing
This project has three objectives.
1.Installation and testing results of 1.6kWp GPV
System , to find out the efficiency of the system.
2.Measurement generating energy in one year and
calculate generating cost , cost save and average energy
generation.
3.Comparision average electricity output by GPV
system that installed in European countries in Japan and in
Malaysia
The tested period during June , 2003 to May , 2004.
The way to find out the efficiency of 1.6 kWp
GPV is random electrical data for 5 days (to be
specific),October 20 th , 2003 , November 24 th , 2003 ,
December 19 th , 2003 , January 7 th , 2004 and February
24 th , 2004.These data in turm of average value and
peak value.
The measure electrical parameter thus , DC
operating voltage , DC operating current , DC power ,
Inverter AC output (kW) , Inverter AC voltage , Inverter AC
current and Inverter AC output (kVA). After that PV
array-DC power efficient (Compare with kWp) ,
Inverter-AC power efficiency and Overall efficiency is
calculated. So , the energy data in 1 year was brought to
calculate electric cost per year , cost for generated energy
per kWh and average energy generation.
4.2 Results
Energy (kWh)
198.
12
Table 1: Inverter and Operation Parameter (Peak Test)
Parameter
DC Operating Voltage (V)
DC Operating current (A)
174.
70
178. 186. 179. 156.
01
22
16
55
194.
17
184. 226. 175.
00
88
38
Test Number
1
2
3
4
5
5.07
6.63
5.48
7.14
3.86
1147.28 1537.48 1240.52 1634.68 907.08
Inverter AC Output (kw)
983.50 1255.70 1012.49 1423.97 785.46
Inverter AC Voltage (V)
229.05 230.06 231.07 235.13 231.07
Inverter AC Current (A)
Inverter AC Output (kvA)
Power Factor
Average
225.20 234.12 229.25 230.36 233.81
DC Power (kw)
4.16
5.49
4.40
6.15
3.46
952.85 1263.03 1016.71 1446.05 799.50
1.0
1.0
PV array - DC Power efficency (%)
70.65
94.67
76.39 100.66
55.85
79.64334975
Inverter - AC Power efficency (%)
85.72
81.67
81.62
87.11
86.59
84.54349059
Overall efficency (%)
60.56
77.32
62.35
87.68
48.37
67.3332679
1.0
1.0
1.0
Table2: Inverter and Operating Parameter (Average test)
Parameter
The results are maximum output 226.38 kWh of
electric energy on April , 2004 and 198.40 kWh on June
, 2003. So , the minimum output 156.55 kWh of energy
on January , 2004 and 174.70 kWh on September ,
2003 , annual PV energy yield as show in Fig 11.
198. 181.
40
96
In one year , a 1.6 kWp GPV can potentially produce
2,233.55 kWh of electric energy. The cost of investment for
the production of electric energy is Bt8.83 per kWh (US$0.22
exchange rate US$1 per Bt40) , it can save electric cost of
Bt5,360.52 per year (US$134) and average energy generation
of 0.262 kWh/m2/day.
The result of Inverter and System operating
parameter and calculating efficiency for each PV system [4]
and then average value calculated is PV array (DC power)
efficiency is 40.58/79.64% (Average / Peak) , Inverter (AC
power) efficiency is 81.43/84.54% and the overall efficiency
of this system is 33.04/67.33%.
The investment cost of this project is Bt394,800
(US$9870), divided by the PV module cost is Bt308,560
(US$7714), the inverter cost is Bt60,000 (US$1500) and
the installation cost is Bt26,240 (US$650). That means that
the PV module cost is 78.15% the inverter cost is 15.19%
and the installation cost is 6.66% of the projects total cost.
DC Operating Voltage (V)
DC Operating current (A)
DC Power (kw)
Inverter AC Output (kw)
Inverter AC Voltage (V)
Inverter AC Current (A)
Inverter AC Output (kvA)
Power Factor
PV array - DC Power efficency (%)
Inverter - AC Power efficency (%)
Overall efficency (%)
Test Number
1
2
3
4
5
222.08
2.95
655.15
527.17
231.77
2.31
535.39
1.0
40.34
80.47
32.46
225.77
3.89
878.25
708.85
230.34
3.13
720.96
1.0
54.08
80.71
43.65
222.80
3.11
692.94
557.28
232.79
2.45
570.34
1.0
42.67
80.42
34.32
229.00
2.83
648.12
540.11
234.42
2.32
543.85
1.0
39.91
83.33
33.26
228.71
1.84
420.83
345.99
230.24
1.55
356.87
1.0
25.91
82.22
21.30
Average
40.582389
81.430141
33.046297
0
5. CONCLUSION
0
Ju
Jul Au Se
03
03
03
03
O
t
03
No De Ja
03
03
04
Fe M Apr Ma
b
il
04 04 04 04
Fig 11: Annual PV Energy Yield
(June – Dec , 2003 Jan – May , 2004)
The problem about energy supply and environmental pollution
have always been great concerns to the world.
Subsequently , the United Nation Frame work Convention
on Climate Change (UNFCCC) and Kyoto Protocol were
signed and ratified by many countries , as
a sign of
commitment to reduce greenhouse gasses (GHG) emission.
Electricity generation is one of the main contributors to
GHG emissions. [7] Therefore , Solar energy is one of
the solutions to combat the greenhouse effect. Solar PV
technology is used to generate electricity and provides an
effective solution to reduce GHG.
This project is in agreement with the Thai
government policy , and got budget on 2003. The 1.6 kWp
GPV was installed in May , 2003 on top of the building
of RMUTS Nonthaburi , Thailand. In one year , it can
potentially produce 2,233.55 kWh of electricity (1,375
kWh/year per 1 kWp GPV). This output is higher than
the average electricity output compared to the systems
installed in European countries (800 kWh/year average) , in
Japan (1,000 kWh/year average) or Malaysia (1,200
kWh/year average). [7]
In one year , the electricity savings is Bt 5,360.52
electricity production cost per kWh is Bt8.83 and average
energy generation is 0.262 kWh/m2/day. The PV array
efficiency is 40.58% , the Inverter efficiency is 81.43%
and the overall efficiency is 33.04%
6. REFERENCES
[1] Electricity Generating Authority of Thailand
(EGAT) , 1993 , Solar and Wind Hybridge
Generating System at Phuket , Research and
Development Institute , Bangkok.
[2] Chai Chewagate , 2000 , Solar PV Generating
Electricity, The National Energy Policy Office
(NEPO), Jurnal 49th (Jul-Sep 2000).
[3] Electricity Generating Authority of Thailand
(EGAT) , 1997 , Roof Top PV System Demonstration
Project , Research and Development Institute ,
Bangkok.
[4] Florida Power Corporation (FPC), 1998 , Diagnostic
Test Report on Florida Power Corporation’s 15
kWp Amorphous Silicon Photovoltaic System .
[5] Florida solar Energy Center , 2003 , Grid-Connected
photovoltaic System Design Review and Approval.
[6] Florida solar Energy Center , 1999 , Evaluation of
Grid-connected Photovoltaic System at the Nature
Conservancy-Disney Wilderness Preserve.
[7] Ahmad Hadri Haris , 2003 , Building Integrated
Photovoltaic (BIPV) Applications in Malaysia :
Current Status & Achievements , TNB Research
Sdn Bhd.
[8] IEA-PVPS, 2002, Trends in Photovoltaic
Applications in Selected IEA Countries between
1992 and 2001 , Task & Report IEA - PVPS T1 – 11
: 2002.
Napat Watjanatepin received
the B.S.Tech.Ed.(Electrical
Engineering) from Institute of
Technology Vocational
Education,Thailand in 1985,
and M.S.Tech.Ed (Electrical
Technology) degree from King
Mongkut ’s Institute of Technology
North Bangkok, Thailand in 1991. His research
interests include digital control system, power
electronics drives and the PV system .