This paper is submission to assignment during postgraduate course.

1. Abstract— Energy is an important factor for economic
activities. Due to the high usage trend in energy, emission of
pollutants (carbon dioxide) resulted from combustion of fossil
fuel in the increasing trend. Hence, Malaysia has put in initiative
to encourage the use of renewable energy such as solar PV, hydro
energy and biomass. The locality and weather of Malaysia has
made solar PV in growing trend. Malaysia initiative under
keTTHA has appointed SEDA to take care of renewable energy
related matters. Firstly, Feed-in Tariff (FiT) mechanism is
implemented and secondly, Net Energy Metering (NEM) scheme.
This paper describes about the design of suitable solar
photovoltaic at a house by considering related aspects and Net
Energy Metering (NEM) module. Then the result is compared
with system without NEM. Technical characteristic such as
excess in energy generation, cost of system and cash flow are
analyzed for comparison purposes between both with and
without NEM. The advantages will be faster in return of
investment (ROI).
Keywords—FiT, NEM, Renewable energy, SARES, Solar
Photovoltaic.
I. INTRODUCTION
HE high usage trend in energy for recent years has caused
energy crisis in the world. Despite the high usage trend in
energy from fossil fuels, it has supported the economic growth
in different countries. However, the world is threatened due to
emission of pollutants resulted from combustion of fossil fuels
and increase of carbon dioxide in the atmosphere [1]. Hence,
renewable energy is necessary to sustain the rapid increase of
energy consumption and carbon dioxide. Renewable energy is
such as solar photovoltaic, wind turbine, geothermal and
biomass. In effort to promote renewable energy, Malaysia
government has appointed authority and introduce renewable
energy policies to draw attention from consumer and
industries.
Malaysia is a tropical country situated in between one and
seven degrees north of the equator. Therefore, Malaysia is
suitable for solar energy harvesting. Furthermore, Malaysia
received an average of six hours sunlight a day [2]. Due to
reason above, solar PV is popularly used in Malaysia.
Solar Photovoltaic (PV) installation is rising in residential
and commercial building when government sets the policy of
Feed in Tariff (FiT). Continuous growth can be seen
especially in East Malaysia, Sarawak due to the
implementation of Sarawak Alternative Rural Electrification
Scheme (SARES). Part of the effort is application of off-grid
solar PV system to light up the rural area / villagers [3]. PV
has the characteristics of durability, minimal maintenance and
generates maximum supply during peak load demand. This
paper describes about the design of suitable solar photovoltaic
at a house by considering related aspects and Net Energy
Metering (NEM) module. Then the result is compared with
system without NEM.
II. BACKGROUND OF STUDY
2.1 Definition of Solar Energy
Solar energy is defined as radiant light and heat from the
Sun that is harnessed using a range of solar PV. There are few
solar technologies namely solar photovoltaics (PV), solar
thermal electricity and solar heating. Solar PV is modular in
technology which allows for a wide range of applications. The
size can be as small as calculators or off-grid applications such
as utility-scale power generation facilities. In the year 2016,
the global power output statistic for cumulative solar PV
capacity had reached almost 300 GW and generated over
310TWh which is 1% total power output. This is 26% higher
than in 2015. 55% of total PV installed capacity is utility scale
and the rest is distributed applications such as residential,
commercial and off-grid. Solar PV is expected to lead
renewable electricity capacity growth, expanding by almost
440 GW in the next five years [4]. The forecast cumulative
capacity by region, 2016-2022 is shown in Figure 1 below.
Kelvin Yong Hong Chien
Fakulti Kejuruteraan Elektrik (FKE),
Universiti Teknologi Malaysia,
Email: yhckelvin@yahoo.com
Mollie Anak Urai
Fakulti Kejuruteraan Elektrik (FKE),
Universiti Teknologi Malaysia,
Email: whiteazury@gmail.com
Design Analysis for Residential Solar Photovoltaic with
and without Net Energy Metering (NEM) Scheme in
Sarawak
T

2. Figure 1: Solar PV generation and cumulative capacity by region,
2016-2022
2.2 Energy policies in Malaysia
In Malaysia, there is a ministry monitoring energy which is
Ministry of Energy, Green Technology & Water (KeTTHA)
[5]. In 1979, National Energy Policy is launched where three
principal energy objectives are established. These are the
instrumental to guide the future energy sector development.
The three principals that has established are namely: the
Supply, Utilization and Environmental Objectives. There is
several revisions on the National Energy Policy in lieu with
the development and the changes. Furthermore, RE was
recognised as the fifth fuel in 2001 in the new Five Fuel
Strategy in the energy supply mix [1].
RE is targeted to contribute 5%, equivalent to 500 MW
generation capacities, of the country’s electricity demand by
the year 2005. In order to meet this goal, the Small Renewable
Energy Programme (SREP) was launched under the initiative
of the Special Committee on Renewable Energy (SCORE)
aimed at supporting the government development of RE as the
fifth fuel resource. The primary focus of SREP is to facilitate
the expeditious implementation off grid-connected RE
resource-based small power plants [1]. Under KeTTHA, an
authority was appointed to take care of renewable energy
related things known as Sustainable Energy Development
Authority Malaysia (SEDA). SEDA has implemented
initiative such as Feed-in Tariff (FiT) and Net Energy
Metering (NEM) scheme.
1. Feed-in Tariff (FiT) Mechanism
Since this paper describes about residential Solar PV which
is also called individual system. Hence, the focus will be
narrow to application in house. In 2011, FiT mechanism was
launched to residential and commercial premise’s owner to
harvest solar energy and the energy is then sell back to the
grid in unit. Malaysia's Feed-in Tariff (FiT) system follows the
system where Distribution Licensees (DLs) to buy renewable
energy from Feed-in Approval Holders (FIAHs) at FiT rate.
The DLs will pay for renewable energy supplied to the
electricity grid for a specific duration. It is a long-term
investment for companies industries and also for individuals
[5].
Under the FiT mechanism, homeowners can installed solar
PV systems with an installed capacity of up to 12kW within
their residential compounds by applying through the
individual quota [6]. Demand for individual quota far
exceeded supply, thus SEDA introduced e-balloting for the
2016 and 2017 quota whereby the individual queue number is
determined randomly by an automated system.
Currently, the available quota capacity in MW installed for
the year 2018 till 2023 as shown in Table 1. Based on the
Table 1, there is no available quota for community, individual
and non-individual category.
Table 1: Available MW installed capacity for FiT application [5].
FiT project timeline is 21 years from the commencement
date. Hence as shown in Table 2 shows the rate for solar PV
(Individual). Table 3 FiT rates for Solar PV (Individual) 21
years from FiT commencement date considering installed
capacity and items used which has Bonus FiT rates. The
effective date is 1st
January 2018.
Table 2: FiT rates for Solar PV (Individual), 21 years [5]
2. Net Metering (NEM) Scheme
After certain period of implementing FiT, Malaysia started
with 500MW capacity on Net Energy Metering (NEM)
scheme. NEM is another program to complement current
Feed-in Tariff (FiT) mechanism. It also works as a platform to
continuously encourage the deployment of renewable energy

3. (RE). The period of implementation is between November
2016 until 2020 with 100MW capacity limit a year in
Peninsular Malaysia and Sabah. Energy consumer still can
benefit from their own energy harvesting via solar PV by net
metering scheme. This is necessary to step as the world wide
cost of solar PV system continues to fall significantly each
year [5].
NEM scheme works in such a way that energy harvested
from the owner solar PV system will be used first. If there is
excess energy, it will be sent or sold to grid based on
prevailing Displaced Cost sets by Energy Commission. This
scheme is applicable to all domestic, commercial and
industrial sectors [5].
Based on previous experience, solar PV is a technology that
has high growth rate compared to other Renewable Energy
(RE) technologies due to minimal construction and declining
cost of solar PV. Furthermore, application of solar PV
technology is easier with NEM mechanism. Solar PV
technology helps in climate change by generating the clean
energy. In a long run, reduction of energy usage from fossil
fuel powered generators. Figure 2 is the concept of NEM
scheme [6].
NEM has many benefits. When energy generated from the
solar PV system is more than the energy supplied from grid.
Hence, consumer with NEM can self-consume and reduction
in electricity bill. Consumers with high electricity
consumption will benefit from this scheme. Excess energy
generated will export to utility grid and paid. This is more
significant to commercial buildings and industry that is not
operating during weekends and have excess energy to be
exported. Thirdly, NEM also help in reduction of Carbon
Dioxide gas emission by generating green energy. [5]
Figure 2: Concept of NEM scheme
III. LOCATION AND SOFTWARE USED
Based on the review earlier on, it is known that the quota of
FiT is running out and NEM has been implemented in
Malaysia. However, the implementation only subject to
Peninsular Malaysia, Sabah and Labuan only. Sarawak is
excluded in this scheme. Hence, this paper discuss only on the
grid connected solar PV with NEM and without NEM. In
Malaysia year 2015, primary production of energy by fuel
types with total of 100,721 ktoe. Solar is only 0.1% out of the
total amount [7]. The primary production of energy based on
types of fuel for the year 2015 is as per shown in Figure 3. The
energy from solar PV will expect to grow in the long run.
Figure 3 Primary production of energy based on types of fuel
3.1 Location and details
Kuching is a capital in Sarawak and operates on the BORT
time zone. The location is at latitude 1°33′36″N, longitude
110°20′42″E and it is situated at elevation 10.2 meters above
sea level. Figure 4 shows location of Kuching at map. The
mean daily hours of sunshine at Kuching is about 5.0 to 5.5
hours. Kuching receives on average 155 till 185 W/m2
of
Global Irradiance annually. Kuching's relative humidity is
85%.
Figure 4: Location of Kuching in map

4. 3.2 System Advisor Model (SAM)
National Renewable Energy Laboratory's System Advisor
Model (SAM) is software used to tabulate the finance model
and performance to help in implementing renewable energy
system. This software predicts performance and estimates the
cost of energy for power projects by considering, installation
and operating costs and system design parameters of the input.
SAM is applicable to retail customer or single buyer. Retail
customer can buys and sells electricity at retail rates. Single
buyer can sells electricity at a price negotiated through a
power purchase agreement (PPA). SAM also has the
performance models for PV systems, battery storage systems
for PV, biomass power, geothermal power and etc. In this
paper, SAM is used to design grid connected solar PV system
based on the input given, the output and financial details are
monitored. [8]
IV. DESIGN OF SOLAR PHOTOVOLTAIC SYSTEM
This case study is based on the double stories terrace
intermediate house at Taman Moyan Indah, Kuching. The
solar PV is proposed to be installed at the second floor roof
top. It is supplied with power supply feeding from Sarawak
Electricity Supply Corporation (SESCO) LV distribution line.
Two proposal initiated are Solar PV without NEM scheme
and Solar PV with NEM scheme. The case study include NEM
scheme even though it is still not available in Sarawak. It is
used for comparison purposes. The house is shown in Figure 5
below.
Figure 5 Proposed house to install the solar PV system
4.1 With NEM Scheme
4.1.1 Profiling of load
This house has electrical appliances (kettle, rice cooker),
water heater and air conditioning system. Estimated peak
loads are calculated from January to December in order to
predict load variation and maximum load for one year as per
Table 3.
Table 3: Estimated peak load for one year
4.1.2 Design of system and characteristic of Solar PV
SunPower Solar Energy Mono-c-Si N 72 SPR-240E-WHT-
D rated 240W has been chosen. The solar PV is using Mono-
c-Si with characteristic at reference condition of total
Irradiance = 1000 W/m2
, Cell temp = 25 o
C as shown in
Figure 6 and Figure 7.
Figure 6: Characteristic at reference condition
Figure 7: SunPower Solar Energy Mono-c-Si N 72 SPR-240E-WHT-
D model performance curve
In this design, the main aims is to achieve 7kW capacity
solar PV system with 6.484kWdc nameplate capacity, nine
modules per string with three strings in parallel are used and
simulated to supply the house as shown in Figure 8. The PV
system is installed at fixed position with tilt angle 15o
.

5. Figure 8: Design of system for PV modules
4.1.3 Characteristic of Inverter
Most of the loads in the house is AC load with 240V voltage
level. Hence, in this design an inverter is needed to convert the
output solar PV to 240VAC for the loads and send to grid.
SMA America: SB4000US 240V [CEC2007] is selected. The
inverter efficiency curve and inverter parameters are shown in
Figure 9 and Figure 10.
Figure 9: Inverter technical parameters
Figure 10: Inverter efficiency curve
4.1.4 System Cost
In this design, there are three types of costing, which are
direct cost, indirect cost and maintenance cost. Direct cost
consists from solar PV and inverter including cost of
manpower. In this design, the contingency 5% margin of the
direct cost is considered. It is about $ 21,106.90.
Indirect cost consists of permit to work, environmental
studies, consultation fee, connection charges, cost of land and
sales tax. As per Table 4, requirement for a mandatory study
based on kWp of installation, this project only consists of size
7kWp. Hence, no environmental studies required [6]. Since
this project will use own land, no land cost. 5% will be
charged for connection charges to grid as it is grid connected
solar PV system.
Table 4: Requirement for a mandatory study based on kWp of installation
The system design should have minimal maintenance
required since it is grid connected PV. Hence, no allocation
for fixed maintenance cost but contingency budget of 5% out
of total direct cost is considered.
4.1.5 Differences of mechanism between NEM and without
NEM
According to [9], the displaced cost for NEM in Peninsular
Malaysia is RM0.31 per kWh when there is excess energy
generated from solar PV after deducts the usage. In Sarawak,
NEM scheme is not covered. SESCO and Electrical
Inspectorate Unit (EIU) [10] allowed the excess of energy
generated from solar PV to be carried forward in kWh unit for
the period of 2 years. Once it is more than two years, it will be
forfeited. Both system design with or without NEM scheme is
exactly the same.
V. CHAPTER 5: RESULTS AND DISCUSSIONS
This paper introduced two case study of solar PV grid
connected with NEM and without NEM. Both case is
simulated. The simulation is based on 25 years calculation,
Table 5 shows the summary in designing overall solar PV
system with NEM. The annual energy produced in year one is
approximately 7,017kWh with capacity factor of 12.4%. It is
also same for system without NEM, the summary in designing
overall solar PV system design as per Table 6. The monthly
energy production projection annually is also simulated using
SAM as per Figure 11 [11]. This is important as selection of
PV module needs to be based on weather condition to shorten
the Return of Investment (ROI). SAM also can calculate the
energy loss as shown in Figure 12. Both systems with or
without NEM have the same energy losses.

6. Figure 11: Energy production by solar PV in monthly
Figure 12: Energy loss of solar PV system
Degradation rate in this design is considered. It starts
applied to the system on year two onwards where the total
annual kWh output will reduce. In this simulation, 0.5%/year
is sets as the degradation rate. Annual energy production for
25 years with degradation rate 0.5% / year is shown in Figure
13. The excess of kW generation will be sold to the grid
connected. SAM also can simulate the estimated total amount
of excess generation for every year shown in Figure 14 for
both cases.
Figure 13: Production of annual energy generated by solar PV system
Figure 14 Cumulative excess energy generated annually from Solar
PV
By grid connected system, this house with NEM case can
have net saving of electricity bill estimated annually is
about $309. For system without NEM, there is zero saving
as the excess energy cannot be sold. It is shown in Table 5
and Table 6 as well. Both the total net capital cost for solar
PV with NEM and without NEM is about $22,373.
The value shown in Figure 15 and Figure 16 is a capital
investment in annual calculation. After maintenance cost
and operation cost is considered the net present value for
system with NEM is -$2,467 and payback period after 16.8
years as Table 5. There is huge different as compared to
system without NEM because the net present value is -
$5,404 and payback period after 19.9 years as in Table 6.
Figure 15: After tax cash flow – system lifetime for 25 years with
NEM

7. Figure 16: After tax cash flow – system lifetime for 25 years without
NEM
Table 5: Design summary of Solar PV System with NEM
Table 6: Design summary of Solar PV System without NEM
VI. CHAPTER 6: CONCLUSION
The solar PV design is successful in this matter where two
cases are simulated. The payback period will be shorter by
three years if NEM is applied. In order to be more saving,
proper planning of energy such as application of energy
efficient program is critical.
The system without applying NEM scheme will have
longer time payback period because the excess energy only
can be carried forward in unit to next year not for sell. In
Sarawak since there is no NEM scheme, the study can be
further conducted by integrating battery or hybrid solar PV
that is feasible by considering the climate and weather
conditions.
VII. REFERENCES
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Renewable Energy Potential in Malaysia,” in IEEE First
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the Efficiency of Polycrystalline Solar Cells," IEEE Journal,
28 Nov 2006.
[3] S. W. Tan, “Sarawak to use SARES to light up remote
communities - Abg. Johari,” The Borneo Post, April 11, 2018.
Available: Borneo Post,
http://www.theborneopost.com/2018/04/11/sarawak-to-use-
sares-to-light-up-remote-communities-abg-johari/
[4] International Energy Agency, “Solar Energy”, 2017.
[Online]. Available:
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30, 2018]
[5] KeTTHA, 'National Energy Policy', 2017. [Online].
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8. [9] Renewable energy (recovery of moneys by distribution
licensee) (Amendment) Rules 2014.
[10] Ministry of Utilities Sarawak, “Electrical Inspectorate
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