SYSTEM SIZING OF A STAND-ALONE

HYBRID SOLAR SYSTEM

FACULTY OF ELECTRICAL ENGINEERING

NAME : AHMAD FATEH BIN MOHAMAD NOR

MATRIC NUMBER : M011110003

COURSE : MEKP - MASTER OF ELECTRICAL

ENGINEERING (INDUSTRIAL POWER)

SUPERVISOR : ENGR. PROF. DR. MARIZAN BIN SULAIMAN

INTRODUCTION • Electricity is one of the most important basic

needs for humans.

• However, the use of fossil fuel such as natural gas and coal in electricity generation has its own drawbacks such as:-

the emission of carbon dioxide that can cause climate change and global warming

the uncertainty of fossil fuel prices

• Moreover, there are some areas especially in the rural and remote areas in Malaysia that have no access to the utility grid.

INTRODUCTION (CONT'D)

• Hence, in 2001 under the Eighth Malaysian Plan, the government introduced the Five Fuel Policy where renewable energy was recognized as the fifth fuel.

• The previous policy which was Four Fuel Policy. It was a diverse generation mix of hydro, natural gas, coal and for electricity generation.

• Renewable energy can be defined as the energy produced from natural processes that can replenish continuously and quickly.

• There are five sources of renewable energy which are from wind, palm oil industry, biomass, solar radiation, and hydro power.

• In Malaysia, the renewable energy from solar radiation is very promising because Malaysia receives high solar radiation and has mild ambient temperatures.

LITERATURE REVIEW • Ahmed and Sulaiman (2003) state that every component of the

solar system must be designed and sized by using proper

procedures and calculations before implementing the system.

• Sunderan et al. (2011) emphasizes that the stand-alone

photovoltaic electricity generation system must be properly sized

and designed before the system is being installed.

• Solar Power Mart (2007) states that the costs of solar systems are

not cheap and usually the final cost of the system will exceed the

expected cost. The costs of solar systems with basic features start

at around RM45 000 but the costs for most of the systems are in

between RM60 000 to RM100 00 depending on the types and

components of the system.

MOTIVATION OF RESEARCH • The demand for energy especially electricity in Malaysia is increasing

rapidly as Malaysia moves towards into becoming a fully developed

nation by the year 2020.

• However, the current method used for generating electricity in Malaysia

consumes fossil fuel such as natural gas and coal as the main energy

sources.

• This fossil fuel will eventually run out completely.

• This fossil fuel also releases carbon dioxide that can cause climate change

and global warming.

• Besides that, there are some areas especially in the rural and remote areas

in Malaysia that have no access to the utility grid.

MOTIVATION OF RESEARCH(CONT'D)

• Hence, an alternative energy source that is renewable, cleaner,

more portable, more flexible and more environmentally friendly

is needed to replace or at least to reduce the use of fossil fuel to

generate electricity.

• Solar energy meets all of these requirements due to some reasons

as follows:

Fossil fuel is very limited and has the possibility to run out completely, but sunlight is available abundantly in Malaysia all year long.

No carbon dioxide or other harmful gases that can contribute to the greenhouse effect are released during generating electricity.

A solar system can be installed in every house even houses in the rural and remote areas as long as there is sunlight.

A solar system can be designed and sized according to the requirements of the consumers.

OBJECTIVE OF RESEARCH

1. To develop a software that has the ability to design and analysis

solar system.

2. To simulate a system sizing of a stand-alone hybrid solar system

in Malaysia, in order to determine the optimum size of the system

that is capable to supply the load requirement completely.

3. To study the return on investment of stand-alone hybrid solar

system compare to grid utility bills.

4. To create a complete Graphical User Interface (GUI) based using

Visual Basic 2010 for teaching and learning package.

SCOPE OF RESEARCH

• The type of solar system used in this research is a stand-alone hybrid

solar system which is a combination of solar array and diesel generator

as the power sources.

• The diesel generator will act as a backup gen-set when the capacity of

the battery bank is low and the solar array cannot produce energy.

• The stand-alone hybrid solar system is designed according to

Malaysian conditions.

• The software will be developed by using Visual Basic 2010 Express.

SCOPE OF RESEARCH (CONT'D)

• The simulation results will give the recommended value of the components of the

stand-alone hybrid solar system only. Other details such as size and type of wires

use, the installation area’s size will not be covered.

• The methods and equations used for sizing the stand-alone hybrid solar system

will be based on the methods and equations used by Roberts (1991), Dunlop

(2010), Hankins (2010), Stauffer and Rosenberg (2009) and Abdulqader (2006).

• The listed prices for the components are based on various website such as

http://solarpower-mart.com/ and are for references only. Actual price may be

different.

SYSTEM DESIGN & DEVELOPMENT

Configuration of the Stand-Alone Hybrid Solar System in this Research

SYSTEM DESIGN & DEVELOPMENT(CONT'D)

Recommended PV System

Solar Charge Controller Sizing

Battery Bank Sizing

Main Menu

Load Analysis

Inverter Sizing

PV Array Sizing

PV Tilt Angle

Start

Hybrid Component Sizing

A

Finish.

Comparative Studies with TNB Grid Connection

Hybrid PV System Cost Estimation

Hybrid PV Configuration

A

Procedure in sizing a stand-alone hybrid solar system

TEST 1 RESULTS

Data Software Dunlop (2010)

Total AC energy consumption 7568 Wh/day 7568 Wh/day

Total AC system energy requirement 8408.89 Wh/day 8409 Wh/day

Total AC power 5388 W 5388 W

Weighted operating time 11.19 hr/day 11.2 hr/day

Comparison between software’s load analysis results and Dunlop (2010)

Comparison between software’s solar array sizing results and Dunlop (2010)

Data Software Dunlop (2010)

Required solar array current 33.94 A 33.9 A

Required solar array voltage 64.20 V 64.1 V

Number of solar modules connected in parallel 7 7

Number of solar modules connected in series 2 2

Total number of solar modules 14 14

.

TEST 1 RESULTS (CONT'D)

Comparison between software’s battery bank sizing results and Dunlop (2010)

Data Software Dunlop (2010)

Rated battery bank capacity 571.01 Ah 571 Ah

Number of batteries connected in series 4 4

Number of batteries connected in parallel 2 2

Total number of batteries 8 8

TEST 2 RESULTS

Comparison between software’s load analysis results with Solar Energy International (2007)

Data Software Solar Energy

International (2007)

Total AC energy consumption 3527.26 Wh/day 3527 Wh/day

Total daily energy consumption 3919.18 Wh/day 3918.9 Wh/day

Total AC power demand 3712 W 3712 W

Weighted operating time 4.97 hr/day 4.97 hr/day

Comparison between software’s inverter sizing results with Solar Energy International (2007)

Data Software Solar Energy

International (2007)

Recommended inverter power rating 5000 W 4000 W

Recommended inverter current rating 45 A Not available

Recommended inverter input voltage 48 VDC 48 VDC

Recommended inverter output voltage 120 VAC 120 VAC

TEST 2 RESULTS (CONT'D)

Comparison between software’s solar array sizing results with Solar Energy International(2007)

Comparison between software’s PV tilt angle results with Solar Energy International (2007)

Data Software Solar Energy

International (2007)

Required solar array current 24.89 A 24.9 A

Required solar array voltage 53.22 V Not available

Number of solar modules connected in parallel 5 5

Number of solar modules connected in series 4 4

Total number of solar modules 20 20

Data Software Solar Energy International (2007)

Tilt angle 29.4239° 29.4239°

Direction of tilt Facing south-east Not available

TEST 2 RESULTS (CONT'D)

Comparison between software’s solar charge controller sizing results with Solar Energy

International (2007)

Comparison between software’s battery bank sizing results with Solar Energy International

(2007)

Data Software Solar Energy

International (2007)

Recommended charge controller nominal voltage 48 VDC 48 VDC

Recommended charge controller current rating 40 A 40 A

Recommended charge controller power rating 1600 W Not available

Data Software Solar Energy

International (2007)

Rated battery bank capacity 653.20 Ah 652.8 Ah

Number of batteries connected in series 8 8

Number of batteries connected in parallel 2 2

Total number of batteries 16 16

SIMULATION 1 RESULTS

Simulation 1 load analysis results

Simulation 1 inverter sizing results

Data Result value

Total AC power 5130 W

Total AC energy consumption 11705 Wh/day

Total AC system energy requirement 13005.56 Wh/day

Weighted operating time 6.66 hr/day

Data Result value

Calculated inverter power rating 6156 W

Calculated inverter current rating 28.5 A

Recommended inverter input voltage 24 VDC

Recommended inverter output voltage 240 VAC

SIMULATION 1 RESULTS (CONT'D)

Simulation 1 solar array sizing results

Data Result value

Type A Type B

Required solar array maximum power current 134.22 A 134.22 A

Required solar array maximum power voltage 33.51 VDC 33.51 VDC

Required solar array maximum power 3631.99 W 3631.99 W

Number of solar modules connected in parallel 27 26

Number of solar modules connected in series 1 2

Total number of solar modules 27 52

Actual solar array rated current 137.43 A 139.1 A

Actual solar array rated voltage 36.3 VDC 37.5 VDC

Actual solar array rated power 4988.71 W 5216.25 W

Solar array estimated price RM 24 975.00 RM 31 200.00

SIMULATION 1 RESULTS (CONT'D)

Simulation 1 PV tilt angle result

Simulation 1 solar charge controller sizing result

Data Result value

Tilt angle 15°

Direction of tilt Facing south-east

Data Result value

Recommended charge controller nominal voltage 24 VDC

Calculated charge controller current rating 171.79 A

Calculated charge controller power rating 4122.96 W

SIMULATION 1 RESULTS (CONT'D)

Simulation 1 battery bank sizing result

Data Result value

Type A Type B

Battery bank rated capacity 2139.07 Ah 2139.07 Ah

Selected battery nominal voltage 12 VDC 12 VDC

Selected battery rated capacity 200 Ah 65 Ah

Number of batteries connected in series 2 2

Number of batteries connected in parallel 11 33

Total number of batteries 22 66

Actual battery bank capacity 2 200 Ah 2145 Ah

Actual battery bank nominal voltage 24 VDC 24 VDC

Actual solar array rated power RM 17 600.00 RM 36 762.00

SIMULATION 1 RESULTS (CONT'D)

Simulation 1 hybrid components sizing result

Simulation 1 PV system cost estimation result

Data Result value

Calculated battery charger size 201.67 A

Calculated diesel generator size 5130 W

Data Result value

Estimated total cost of components RM 56 825.00

Estimated wiring and installation cost RM 17 047.50

Estimated maintenance cost RM 14 774.50

Estimated grand total RM 88 647.00

SIMULATION 1 RESULTS (CONT'D)

Simulation 1 comparative studies with TNB grid connection result

Data Result value

Total grid connected energy consumption 25 310 Wh/day

Total grid connected energy consumption for 1 month 759.30 kWh

TNB estimated bill RM 267.31

TNB estimated bill for 1 year RM 3 207.72

Return on investment 27.64 years

SIMULATION 2 RESULTS

Simulation 2 load analysis results

Simulation 2 inverter sizing results

Data Result value

Total AC power 590 W

Total AC energy consumption 4430 Wh/day

Total AC system energy requirement 4922.22 Wh/day

Weighted operating time 9.13 hr/day

Data Result value

Calculated inverter power rating 767 W

Calculated inverter current rating 3.55 A

Recommended inverter input voltage 24 VDC

Recommended inverter output voltage 240 VAC

SIMULATION 2 RESULTS (CONT'D)

Simulation 2 solar array sizing results

Data Result value

Type A Type B

Required solar array maximum power current 50.8 A 50.8 A

Required solar array maximum power voltage 33.51 VDC 33.51 VDC

Required solar array maximum power 1374.65 W 1374.65 W

Number of solar modules connected in parallel 10 10

Number of solar modules connected in series 1 2

Total number of solar modules 10 20

Actual solar array rated current 51.1 A 53.5 A

Actual solar array rated voltage 36.3 VDC 37.5 VDC

Actual solar array rated power 1854.93 W 2006.25 W

Solar array estimated price RM 9 250.00 RM 12 000.00

SIMULATION 2 RESULTS (CONT'D)

Simulation 2 PV tilt angle result

Simulation 2 solar charge controller sizing result

Data Result value

Tilt angle 15°

Direction of tilt Facing south-east

Data Result value

Recommended charge controller nominal voltage 24 VDC

Calculated charge controller current rating 63.88 A

Calculated charge controller power rating 1533.12 W

SIMULATION 2 RESULTS (CONT'D)

Simulation 2 battery bank sizing result

Data Result value

Type A Type B

Battery bank rated capacity 809.58 Ah 809.58 Ah

Selected battery nominal voltage 12 VDC 12 VDC

Selected battery rated capacity 200 Ah 65 Ah

Number of batteries connected in series 2 2

Number of batteries connected in parallel 5 13

Total number of batteries 10 26

Actual battery bank capacity 1000 Ah 845Ah

Actual battery bank nominal voltage 24 VDC 24 VDC

Actual solar array rated power RM 8 000.00 RM 14 482.00

SIMULATION 2 RESULTS (CONT'D)

Simulation 2 hybrid components sizing result

Simulation 2 PV system cost estimation result

Data Result value

Calculated battery charger size 80 A

Calculated diesel generator size 1000 W

Data Result value

Estimated total cost of components RM 23 050.00

Estimated wiring and installation cost RM 6 915.00

Estimated maintenance cost RM 5 993.00

Estimated grand total RM 35 958.00

SIMULATION 2 RESULTS (CONT'D)

Simulation 2 comparative studies with TNB grid connection result

Data Result value

Total grid connected energy consumption 8250 Wh/day

Total grid connected energy consumption for 1 month 247.50 kWh

TNB estimated bill RM 59.46

TNB estimated bill for 1 year RM 713.52

Return on investment 50.40 years

SUMMARY OF RESULTS

• Test 1 and Test 2 results indicates that the software can be used to calculate specific values in system sizing.

• The simulations results designates several findings as listed as follows:

• The electrical load requirements play an important role in influencing the total cost of the solar system.

• The overall cost of the stand-alone hybrid solar system in Simulation 1 is RM 88 647.00 and the overall cost in Simulation 2 is RM 35 958.00.

• Since the load requirements in rural areas are lower than non-rural areas, the stand-alone hybrid solar system is more suitable to be built in the rural areas.

• The long-term of payback period in both Simulation 1 and Simulation 2 tells that it is more saving to pay electricity bills every month than to allocate a huge amount of money to build a stand-alone hybrid solar system.

• It is only worth it to build the stand-alone hybrid solar system at areas without grid connection such as in rural and archipelagos areas.

CONCLUSION

• The output of the research shows that system sizing is a very important matter. The solar system need to be sized very carefully so that the energy produces is enough to meet the load requirements. The research output also shows that the cost of the solar system could increase due to any mistakes during the system sizing.

• Besides that, the GUI that is used to present all of the procedures of system sizing makes the software package user friendly. The software package can be applied for teaching and learning purposes especially for engineering students in undergraduate programs and practicing engineers.

• This research also shows that green technologies such as the stand-alone hybrid solar system are very suitable for rural areas without grid utility connection such as in archipelagos areas.

THANK YOU