Potential of Solar Energy in Indonesia

Abstract

Indonesia is the largest archipelagic country in the world which is located in the SouthEast Asia area. The geographical condition of Indonesia is extremely suit for developing of renewable energy in general and solar energy in specific. This report aims to review the recent situation of energy using in Indonesia and potential to utilize the solar and energy. Case studies of solar power systems in Medan, Indonesia using PVGIS indicate high energy yield during the year. Also it show that the crystalline silicon solar cells with inclined tracking system is the best combination.

Full text

Potential of Solar Energy in Indonesia
Minh-Quan Dang
June 28, 2017
Abstract
Indonesia is the largest archipelagic country in the world which is located in the South-East
Asia area. The geographical condition of Indonesia is extremely suit for developing of renewable
energy in general and solar energy in specific. This report aims to review the recent situation of
energy using in Indonesia and potential to utilize the solar and energy. Case studies of solar power
systems in Medan, Indonesia using PVGIS indicate high energy yield during the year. Also it show
that the crystalline silicon solar cells with inclined tracking system is the best combination.
Keywords:Indonesia,Solarenergy,Solarcelltechnology,Suntrackingsystem
1

Contents
1 Introduction 5
2 Current situation and policy framework of Indonesian energy sector 7
2.1 Energyconsumption ...................................... 7
2.1.1 Energy consumption in Industrial sector . . . . . . . . . . . . . . . . . . . . . . 9
2.1.2 Energy Consumption in Household Sector . . . . . . . . . . . . . . . . . . . . . 9
2.1.3 Energy Consumption in Commercial Sector . . . . . . . . . . . . . . . . . . . . . 10
2.1.4 Energy Consumption in Transportation Sector . . . . . . . . . . . . . . . . . . . 11
2.2 PrimaryEnergysupply .................................... 12
2.3 Currentpolicyframework ................................... 13
3 Solar energy potential in Indonesia 15
3.1 Photovoltaictechnologies ................................... 16
3.1.1 Typesofsolarcells .................................. 16
3.1.2 FixedstandPVsystem ................................ 17
3.1.3 Sun-trackingPVsystems ............................... 17
3.2 Site Selection and methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3.3 Maximum Solar energy in Medan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
3.4 Photovoltaic solar system with Fixed Stand . . . . . . . . . . . . . . . . . . . . . . . . . 20
3.5 Photovoltaic solar system with Tracking system . . . . . . . . . . . . . . . . . . . . . . . 21
4 Discussion and recommendation 24
2

List of Figures
1 MapofIndonesia........................................ 5
2 Total final energy consumption of Indonesia by region 2013 . . . . . . . . . . . . . . . . 7
3 Breakdown total energy consumption in 2014 . . . . . . . . . . . . . . . . . . . . . . . . 8
4Energyconsumptionbysectorsin2010and2014......................8
5Shareoffinalenergyconsumptioninindustrialsector...................9
6 Energy source for Industrial sector in 2014 . . . . . . . . . . . . . . . . . . . . . . . . . . 9
7Shareoffinalenergyconsumptioninhouseholdsector...................10
8Energysourceforhouseholdsectorin2014.........................10
9Shareoffinalenergyconsumptionincommercialsector..................11
10 Energy source for commercial sector in 2014 . . . . . . . . . . . . . . . . . . . . . . . . 11
11 Share of final energy consumption in transportation sector . . . . . . . . . . . . . . . . . 12
12 Energy source for transportation sector in 2014 . . . . . . . . . . . . . . . . . . . . . . . 12
13 Primary Energy Supply by Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
14 Direct Normal Irradiation in Indonesia . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
15 Global Horizontal Irradiation in Indonesia . . . . . . . . . . . . . . . . . . . . . . . . . 16
16 Pictures of solar street lighting and traffic signal in Medan . . . . . . . . . . . . . . . . . 18
17 Casesstudysummary ..................................... 19
18 Monthly average solar energy yield in Medan 2005-2016 . . . . . . . . . . . . . . . . . . 19
19 Energy yield from PV systems on fixed stand . . . . . . . . . . . . . . . . . . . . . . . . 20
20 Energy yield from PV systems on fixed stand with optimal setting . . . . . . . . . . . . 21
21 Energy yield from PV systems with Vertical and Inclined tracking . . . . . . . . . . . . 22
22 Energy yield from PV systems with Two axes tracking . . . . . . . . . . . . . . . . . . 22
23 Average daily generated power in March and December . . . . . . . . . . . . . . . . . . 23
3

List of Tables
1 ForeignInvestmentLimit ................................... 13
2 Indonesian Target for Renewable Energy . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3Maximumsolarenergyonareaselectedsite.........................19
4 Solar energy yield from 100kW with fixed stand . . . . . . . . . . . . . . . . . . . . . . . 20
5 Solar energy yield from 100kW with tracking system . . . . . . . . . . . . . . . . . . . . 22
6 Improvement from fixed stand to tracking system . . . . . . . . . . . . . . . . . . . . . . 22
4

1 Introduction
Indonesia is the largest archipelagic country in the world which is located in the South-East Asia
area. According to Indonesia’s National Coordinating Agency for Survey and Mapping, the total
number of islands in the archipelago is 13,466, of which 922 are permanently inhabited. The country
has total area of 1 904 569 km2, from 60Nto11
oSandfrom95
oEto141
oE . The equator crosses
through Indonesia providing them abundance solar irradiation necessary for developing and exploiting
solar energy. Especially Indonesia stays on the edges of the Pacific, Eurasian, and Australian tectonic
plates, therefore, there are 127 active volcanos (in 2012). The country also suffers frequent earthquakes
every year.
Indonesia has 2 seasons: dry and rain with the average temperature 280Cinthecoastalplainsand
230C on the higher mountain region. The temperature is relatively constant over seasons and also the
length of daylight hour. The rain amount is 238.35 mm/month [world bank(2017)].
Indonesia is a republic with a presidential system with power is concentrated in the central govern-
ment. There are 34 provinces in Indonesia from which 5 have special status (autonomy). All province
has their own legislature and governor [Wikipedia(2017)].
Figure 1: Map of Indonesia
Data from World bank indicate that population of Indonesia in 2015 is 257.56 million with pop-
ulation growth at 1.01%. The GDP in 2015 is US$ 861,93 billions (2017 US$) with GDP growth
2014-2015 was 4.8%. GDP per capita is US$ 3,346.5 and increase 3.5% annually [WorldBank(2017)].
This growth was the lowest in the period 2010 to 2015. The reason is decline in Indonesian oil and gas
production, the lower exchange rate between Indonesian Rupiah and US dollar and the rise in inflation
[Sugiyono(2016)].
The geographical condition of Indonesia is extremely suit for developing of renewable energy in
general and solar energy in specific. The energetic and fast growing economy 4.8% increase in GDP
5

2014-2015 with slow down population increase promise a higher living standard for the Indonesians.
Along with this the issues with pollution and higher demand in energy will be a major drive for more
wide and deeper utilization of solar energy in Indonesia.
Goals of study
This report aims to fulfill the requirement of the Erasmus student exchange program to Indonesia.
The main purpose are:
•Review the recent situation of energy demand and supply in Indonesia by sectors.
•Review the policy, subsides and other encouragement for developments of solar energy.
•Research the solar energy potential in Indonesia and provide recommendations.
6

2 Current situation and policy framework of Indonesian energy
sector
The energy sector in Indonesia is strongly controlled by the government. In electric power sector the
state-owner enterprise PLN (Perusahaan Listrik Negara, “State Electricity Company”) was a monopoly
in the power market for many years. From 1985, the Indonesian government allowed private sector par-
ticipation in power generation. According to the 2016-2025 Electricity Supply Plan, the Independent
Power Producer will be assigned 45.6 GW from total 80.5 GW new install capacity [MEMR(2017)].
Now PLN still responsible for transmission and distribution of electricity in whole Indonesia. The
electricity prices are set by the government.
2.1 Energy consumption
Indonesia is the largest energy user in the South-East Asia region with energy consumption is: 1033.24
Million BOE in 2015[IRENA(2017)]. Most of the energy consumption in Indonesia takes place on the
Java island where is also the most populated region in Indonesia. Sumatra island shares 25% and the
other island account for the remain.
Figure 2: Total final energy consumption of Indonesia by region 2013
Energy consumption can be divided into 5 sectors : industrial, households, commercial, transporta-
tion, other and non-energy utilization.
•Energy consumption for household, not including consumption for private car.
•Energy consumption of commercial sector such as commerce, hotels, restaurants, financial insti-
tutions, government agencies, schools, hospitals, etc.
7

•Energy consumption of industry in the iron and steel, chemical, non-iron metal, non-metal pro-
duction, machine and equipment, non-energy mining and quarrying, food, paper, wood, petro-
chemical, textile, etc. -
•Energy consumption for transportation covers all transportation activities in all sectors of econ-
omy.
•Energy consumption for non-energy uses, covering lubricating oils, petrochemical industry, raw
materials (naphtha, natural gas, and cokes), and gas used as raw material for petrochemical
products (methanol and ammonia/urea).
Figure 3: Breakdown total energy consumption in 2014
From Figure 3, in 2014 the energy co n s u m p t i o n o f h o u s e h o l d ( 3 3 % ), i n d u s t r y ( 2 3 % ) a n d t r ans p o r t a -
tion (30%) account for most of the energy consumption in Indonesia (86%). The energy consumption
of non-energy uses (9%), commercial (3%) and other uses (2%) account for only 14% of total energy
consumption in 2014.
Figure 4: Energy consumption by sectors in 2010 and 2014
Figure 4 shows the trend of energy consumption between 2010 and 2014. Within three biggest
consumption sector the transportation and household consume more energy over four years, which
8

growth 19% for household and 31% for transportation consumption. However, the energy consumption
in industrial use dropped about 28%. The total energy consumption increase 5% from 2010 to 2014.
2.1.1 Energy consumption in Industrial sector
Total demand in 2014 wa s 3 5 6 , 8 m i l l i on BOE. P r i m a r y e n e r g y s o u r c e f o r i n d u s t r i a l s e c t or incl u d e
biomass, coal, briquette, gas, fuel (oil product), liquefied petroleum gas (LPG) and electricity. The
energy from LPG and briquette are small. Main energy come from electricity, fuel, gas, coal and
biomass. The utilization of processing technologies, such as boilers, furnaces, and motors require large
amount of fuel and causes industrial sector has the largest demand of energy. Since 2010, the amount
of coal used in industrial reduces significantly over 67.5%. One reason for this reduction is adoption
of Indonesian manufacturer to use geothermal, solar thermal and renewable energy [MEMR(2016)].
Figure 5: Share of final energy consumption in industrial sector
Figure 6: Energy source for Industrial sector in 2014
2.1.2 Energy Consumption in Household Sector
Total demand in 2014 was 369 million BOE. Biomass, which most of it is traditional biomass, takes
73.71% of total energy consumption. The electricity and LPG contribute about 20%. Electrification
ratio in reached only 84% and continue to be improved [Sugiyono(2016)]. Along the improvement
9

of electrification ratio, people will use more electricity and less traditional biomass in the future.
Therefore, development of solar energy focus in production of electrical power is likely flourishing in
the next few years. The specific movements of Indonesian gorverment will be discuss in the section 2.3
below.
Figure 7: Share of final energy consumption in household sector
Figure 8: Energy source for household sector in 2014
2.1.3 Energy Consumption in Commercial Sector
Energy demand in commercial sector will increase in line with the growth in business activity such
as hotels, restaurants, wholesale and retail, bank and nancial institutions, nancial services, building
rental, service companies, government and public services.
In 2014, total final energy consumption of commercial sector reached 29.7 million BOE which 78%
of it is in the form of electricity used for lighting, air conditioning and more, followed by diesel oil
(11%) as fuel generator. The rest is in the form of LPG, Gas and biomass about 3 to 4 % each.
10

Figure 9: Share of final energy consumption in commercial sector
Figure 10: Energy source for commercial sector in 2014
2.1.4 Energy Consumption in Transportation Sector
Transportation is one of the key sectors in supporting all energy users. Therefore, energy demand of
transportation sectors is not only affected by population growth and social welfare, but also affected by
the development of agriculture, construction, commercial, and industrial sectors. Fact that Indonesia
is an archipelagic country and the increasing public welfare is expected to continue to push the use of
airplane as the potential means of transportation. Transportation sector is still dominated by oil fuel-
base technology. Therefore energy demand in this sector is still dominated by fossil fuels, especially
gasoline and diesel oil. In 2014, the energy demand for transportation sector was 334 million BOE.
88.74% of it came from fuel, the rest came from bio fuel and gas. A very small percentage belong to
electricity.
11

Figure 11: Share of final energy consumption in transportation sector
Figure 12: Energy source for transportation sector in 2014
2.2 Primary Energy supply
To fulfill energy demand, primary energy supp l y was amounted to 1591 million BOE in 2014. Fo s s il
fuels dominated energy supply with a share of 71% in 2014 (Figure 13). Renewable energy in 2014
was from biofuel, biomes hydro, geothermal. Other type of renewable energy such as wind, solar was
inconsiderable. Among the dominance of fossil fuels in energy supply, coal occupies the highest position
due to its usage as fuel in industrial sector and power plants. Coal dominance is followed by oil which
mostly used in transportation sector with growth increase by 14% during 2010-2014 period. Whereas,
among renewable energy, biofuel has the highest growth rate of 211% during 2010-2014 period.
12

Figure 13: Primary Energy Supply by Source
2.3 Current policy framework
Indonesian target for Solar energy
In July of 2016, the Indonesian Ministry of Energy and Mineral Resources (MEMR) issued decree
no 19/2016 (Permen 19) to establish the first utility scale solar PV feed-in-tariff(FiT) regulation.
This regulation aims for the small national quota of 250 MW as the first phase of much larger target
(6500MW). The FiT is awarded according to the region that the project is built.
Feed-in tarifffor 250 MW of capacity, with 150 MW in Java and the remaining 100 MW spread
over other locations. Feed-in tariffs range from USD 0.145/kWh in Java to USD 0.25/kWh in Papua
for 20 years.
Although there are limitations on foreign ownership as stated on Table 1
PV Power Plant Size Foreign Investment Limit
<1MW Domestic investment only
1-10 MW Maximum 49%
>10MW Maximum 95%
Geothermal PP 10MW Maximum 67%
Table 1: Foreign Investment Limit
Along with ownership limitation, the local content of each project is state on the Ministry of
Industry and Trade ’s regulation as minimum 44%. The project size is limited by the regional quota.
For region has 10MW quota then there is no lim i t . Fo r 1 0 - 1 0 0 M W t h e n t h e p r o ject size mu st b e
smaller than 20% of regional quota. For region has more than 100MW quota the maximum project
size is 20MW.
Project Milestones [Susanto(2016b)]:
1. Announcement of the quota offer and the project quota registration opening date will be done
4monthspriortoopeningaccesstotheprojectregistrationwebsite(onlyforeligibleregistered
Solar PV Developer Candidate will receive access)
13

2. Pending document very cation, the company that registered earliest as noted in the online sys-
tem will receive the FiT and appointed as the Solar PV Developer ( first come first served).
Verification will b e d o n e by an integrated assessment team consisting of DGNREEC, DGE and
PLN. Verification process will take a maximum of 2 months from the online registration date
(a) Application requirements:
i. Self-assessment of the project’s local content
ii. Test certifications for the solar PV modules and inverters
iii. Feasibility Study (ToC provided in Permen 19)
iv. Interconnection Study (ToC provided in Permen 19)
3. PPA must be signed within 30 days after the Solar PV developer is appointed. – No MEMR
Sanctions; MEMR through DGNREEC will step in and assist
4. Financial close must be done within 6 months from the PPA signing. – MEMR Sanction: re-
vocation of status as Solar PV Developer; May have other implications depending on the PPA
content such as forfeiting of any bonds (with PLN)
5. Apply for an electricity supply business license (IUPTL)
6. By 30 days prior to Commercial Operation Date, need to submit a third party very cation of
the self-assessed project local content value – MEMR Sanction: PPA tariffcalculated based on
the achieved percentage of the requirement. Up to 60 days to replace the components to comply
with the project local content requirement before the sanction is applied
7. Commercial Operation Date (COD) must be achieved within 12 months (project size up to
10MW) and 24 months (above 10MW)
Targets for 2025 Regulation
Overall targets
Renewable Energy in TPES 23% No. 79/2014
Renewable energy in 25% RUKN 2015-2034
Power generation
Large hydropower 18.3 GW MEMR No. 03/2015
Small hydro power 3.0 GW MEMR No. 19/2015
Bioenergy power 5.5 GW MEMR No. 21/2016,
MEMR No. 44/2015
Geothermal power 7.1 GW MEMR No. 17/2014
Solar PV 6.4 GW MEMR No. 19/2016
Wind 1.8 GW
Table 2: Indonesian Target for Renewable Energy
14

3 Solar energy potential in Indonesia
Estimates of total solar PV capacity in Indonesia vary, from 42 MW by the end of 2012 [MEMR(2014)]
to 80 MW installed in 2010 and 2011 [IEA(2015)]. For the on-grid component, the installed capacity
is estimated at around 10 MW. The largest power plants are located in Bali (2 MW), Kupang (5 MW)
and Gorontalo (2 MW) [Kosasih(2016)]. By mid-2016 there was over 700 MW in memorandums of
understanding as well as commitments by PLN to develop utility-scale solar PV systems in Indonesia.
Some involve private sector developers such as Savills, Quantum Energy Indonesia and Akuo Energy,
as well as Indonesia’s state-owned Pertamina [Kurniawan(2016)]. The announcement in July 2016 of
anewfeed-intarifftosupport250MWofsolarPVinstallationislikelytofurthersupportthemarket
in the coming years [Susanto(2016a)].
Figure 14: Direct Normal Irradiation in Indonesia
Figure 14 and Figure 15 respectively show the direct normal irradiation and global horizontal
irradiation in Indonesia. From the Figure 15 it can be seen that the global irradiation in Indonesia
is equally distributed. Most of the regions have higher that 1600 kWh/m2per year. The Figure 14
indicates that the Southern islands of Indonesia including Java and Bali island have very high direct
irradiation. The Eastern parts such as Papua also have high irradiation. This regions has biggest
potential for developing the solar PV power plant because of its remote, low people density and large
land field advisable.
The following section will evaluate the actual solar energy potential for a location in Indonesia.
Because of uniformity in irradiation level distribution in Indonesia, the other location in Indonesia will
be expected results with high similarity.
15

Figure 15: Global Horizontal Irradiation in Indonesia
3.1 Photovoltaic technologies
Solar photovoltaic (PV) systems have the possibilities to solve enormous energy problems if instated
and used correctly. Solar PV devices convert sunlight (photons) into electricity, voltage, through
movement of electrons. Typical solar panels are made from silicon, since it is currently the most
efficient material. A solar cell is multilayered, and manufactured to have an electron imbalance. With
one layer negatively doped, n-type, and another layer positively doped, p-type, an electric eld is created.
When photons hit a solar panel electron-hole pairs are created. Electrons move to the n-type layer
while holes, positively charged particles, move to the p-type layer. This electron creates a current, so
when attached to a circuit power is created.
3.1.1 Types of solar cells
•Crystalline Silicon Solar Cells: is the most popular type of solar cell. Crystalline silicon has
band gap energy 1.12 eV. The c-Si is its relatively poor ability to absorb light, which encourages
the use of thick and brittle wafers. These cells have up to 27.6% [NREL(2017)] efficiency in the
lab and can be easily mass production.
•Thin film cadmium telluride (CdTe): has the 1.46 eV band gap energy of cadmium telluride
is very close to maximum theoretical efficiency and this material also lends itself very well to
the manufacture of thin-film solar cells. Cadmium telluride exhibits excellent stability and no
degradation secondary to the effects of light. Such cells have attained up to 22.1% [NREL(2017)]
efficiency in the lab and are relatively easy to manufacture. However, cadmium (Cd) is eco-
logically unfriendly, and even if only very thin cadmium films are needed, some cadmium solar
16

cells may not lend themselves to proper disposal as hazardous waste at the end of their service
lives; this in turn will result in some of the highly toxic cadmium ending up in the environment
without having been disposed of properly [Häberlin(2012)].
•Thin film copper indium gallium deselenide (CIS): has band gap energy is around 1 eV,
CIS also exhibits high stability under the effects of light. But unfortunately indium is a very rare
element. With their relatively low band gap energy, CIS and CIGS are highly suitable for use as
back-side solar cells behind a high-band-gap-energy front cell in tandem arrays [Häberlin(2012)].
3.1.2 Fixed stand PV system
The PV modules are fixed on the mounting system, this system could be install on the roof top or on
the ground. Parameters for fixed stand PV system could be defined as follow:
•Mounting position: is the way the modules are mounted will have an influence on the temperature
of the module, which in turn affects the efficiency. Experiments have shown that if the movement
of air behind the modules is restricted, the modules can get considerably hotter (up to 15°Cat
1000W/m2of sunlight).
•In the application there are two possibilities: free-standing, meaning that the modules are
mounted on a rack with air flowing freely behind the modules; and building-integrated, which
means that the modules are completely built into the structure of the wall or roof of a building,
with no air movement behind the modules. Some types of mounting are in between these two
extremes, for instance if the modules are mounted on a roof with curved roof tiles, allowing air
to move behind the modules. In such cases, the performance will be somewhere between the
results of the two calculations that are possible here.
•Slope of PV modules: This is the angle of the PV modules from the horizontal plane, for a fixed
(non-tracking) mounting. For some applications the slope and azimuth angles will already be
known, for instance if the PV modules are to be built into an existing roof. However, if you have
the possibility to choose the inclination and/or azimuth, this application can also calculate for
you the optimal values for inclination and azimuth (assuming fixed angles for the entire year).
3.1.3 Sun-tracking PV systems
The PV modules mounted on supports that move the modules during the day so the modules face in
the direction of the sun. These sun-tracking systems can be divided into different types:
•Vertical axis tracking: In this type of system the PV modules are mounted so they always have
the same slope angle from horizontal, but they modules are turned so they face east in the
morning, gradually moving towards west in the evening.
•Inclined axis tracking: Here the modules are mounted along a rotating axis. In the morning
the modules are nearly vertical facing east, at noon they face upwards at an angle equal to the
axis slope and then gradually turn towards west, again being nearly vertical in the evening. The
azimuth (orientation) of the inclined axis is always in the direction of the equator (due south in
the northern hemisphere and vice versa).
17

•Two axis tracking: In these systems the modules can be moved so they always face directly
towards the sun. This will give the highest energy yield, but the tracking system is generally
more complicated and more expensive than the single-axis tracking systems.
3.2 Site Selection and methodology
The location for case study is the city of Medan. Medan is one of the biggest city in Indonesia which
have population over 2 million people and density 7900/km2[Wikipedia(2017)]. Medan is the capital
of North Sumatra province in Indonesia, located along the northeastern coast of Sumatra Island. The
site location is (3.590, 98.674) and elevation is 27 m. Some solar applications was already install in
the city of Medan which could be seen below.
Figure 16: Pictures of solar street lighting and traffic signal in Medan
The tool will be used to evaluate the solar potential of Medan is Photovoltaic Geographical Informa-
tion System (PVGIS). PVGIS provides a map-based inventory of solar energy resource and assessment
of the electricity generation from photovoltaic systems in Europe, Africa, and South-West Asia.
With the supporting of PVGIS, the power yield from a 100 kWp photovoltaic solar system will be
evaluate with following cases:
1. Theoretical Solar energy yield in Medan
2. Photovoltaic solar system with fixed stand
3. Photovoltaic solar system with tracking system
Each case will be evaluate with different PV module technology namely Crystalline Silicon, CSI and
CdTe. The electrical losses of the PV system will be assumed at 14%.
Further more for cases with fixed stand system the energy output under 3 pairs of slope-azimuth will
be evaluate, which are 00-0
0(horizontal-south facing), 900-0
0(vertical-south facing) and 10(optimal).
For case 3: tracking system will be evaluated with 3 options Vertical axis tracking, Inclined axis
tracking and Two axis tracking.
18

Figure 17: Cases study summary
3.3 Maximum Solar energy in Medan
Figure 18: Monthly average solar energy yield in Medan 2005-2016
Maximum solar energy in Medan by a 100 kWp solar system is equal to amount of energy on a plane
with area 114 m2(because 14% system loss). The different between energy yield on horizontal plane
and optimal plane is minor. During the period from April to September the direct irradiation has huge
contribution in global irradiation. From October to March the diffuse irradiation is higher. This fact
will influence on the decision to choose the proper solar cell’s technology. For the materials require
high band gap energy then the diffuse irradiance could not enough to supply necessary energy for
photovoltaic process.
Horizontal plane Vertical plane with south facing Optimal plane
202720.5 kWh 81012.2 kWh 202777.5 kWh
Table 3: M a x i mum solar energy on area select e d s i t e
19

3.4 Photovoltaic solar system with Fixed Stand
As stated on the section 3.2, three cases are studied depend on characteristics of the routing system.
•Case 1: Slope = 0oand Azimuth = 00(Horizontal plane)
•Case 2: Slope = 90oand Azimuth = 00(Vertical plane with south facing)
•Case 3: Slope = 1oand Azimuth = 390(Optimal setting)
Horizontal plane Vertical plane with south facing Optimal setting Optimal Slope - Azimuth
c-Si 133200 kWh 47140 kWh 133100 kWh 10and -540
CSI 131340 kWh 45340 kWh 131340 kWh 20and 1260
CdTe 143300 kWh 46980 kWh 143300 kWh 00and -1400
Table 4: Solar energy yield from 100kW with fixed stand
Energy yield will be plotted with theoretical maximum energy on the same plane which solar
panels are installed. The figure 19 shows results for case 1 and 2 when the solar panels are installed
on horizontal and vertical planes. The figure 20 shows result for case 3 when the solar panels are on
the optimal setting.
Because the different on slope between case 1 and 3 are small; therefore, there are no significant
differences between these two cases. The fact that the different in energy yield between case 1 and 3
only under 1%.
The next issue is how the change in slope and azimuth angle effect on the energy yield. The
monthly average energy losses in horizontal plane setting was 34.3% for c-Si, 35.2% for CSI and 29.3%
for CdTe. The similar losses observed when optimal setting was used. At the vertical plane setting the
losses was 39.1% for c-Si, 41.5% for CSI and 40% for CdTe. It could be seen that the higher the slope
the higher the losses value. The CdTe solar panels suffers the most effect when the slope is increase
because CdTe has high bandage energy which require the direct radiance; however the level of direct
irradiance decrease with the increment of slop angle.
Figure 19: Energy yield from PV systems on fixed stand
20

Figure 20: Energy yield from PV systems on fixed stand with optimal setting
When PV panels was set on the optimal setting, the month with highest energy yield is March,
which is 12700 kWh for c-Si, 12600 for CSI and 13600 for CdTe. The month with lowest energy yield is
December with 9640 kWh for c-Si, 9380 kWh for CSI and 10200 kWh for CdTe. Solar panel from CdTe
seem to have the highest efficiency compare to the other, the next position belong to c-Si technology
and CSI is the less efficient technology.
However, closer look on the ratio of the highest and lowest energy yield provide result of 31.7% drop
for c-Si, 34.3% for CSI and 33.3% for CdTe. From these results, it could be said that c-Si technology
provide more stable energy yield than other technology, and the worst is CSI again.
Another question could be answer from the results above is if it is necessary to change the slope
of the panels during the year. Of cause the question will depend on many other factors such as
maintenance cost, accessibility to the panels site, staff’s quality. However if depend only on the energy
yield drop during the year the adjustment in slope angle is might be not necessary.
Weather could has influence on energy yield depend on type of solar cell’s technology. The study
on correlation between difference of energy output and average temperature monthly shows that tem-
perature affect the most on c-Si (0.363) and less on CdTe (0.342) technology.
3.5 Photovoltaic solar system with Tracking system
As stated on the section 3.2, three cases are studied depend on characteristics of the tracking system.
•Case 4: Vertical tracking system
•Case 5: Inclined tracking system
•Case 6: Two axes tracking system
21

Vertical track i n g Inclined tracking Two axes tracking
c-Si 156700 kWh 158300 kWh 162200 kWh
CSI 154800 kWh 156400 kWh 160000 kWh
CdTe 169900 kWh 171900 kWh 176200 kWh
Table 5: Solar energy yield from 100kW with tracking system
Figure 21: Energy yield from PV systems with Vertical and Inclined tracking
Figure 22: Energy yield from PV systems with Two axes tracking
Figure 21 shows monthly energy yield from solar power system equipped with vertical and inclined
axis tracking. Figure 22 shows monthly energy yield from solar power system equipped with two axis
tracking. In general, the CdTe still generates the high yield of energy, c-Si is on the second place and
final is CSI.
Vertical Track i n g Inclined Tracking Two a x e s t r a cking
c-Si 15.1% 15.9% 17.9%
CSI 15.2% 16.0% 17.9%
CdTe 15.7% 16.7% 18.7%
Table 6: Improvement from fixed stand to tracking system
22

From the table 6 the maximum improvement occurred with two axes tracking system when solar
cells is CdTe is 18.7%. The smallest improvement when install vertical tracking system on c-Si solar
panel (15.1%). Vertical tracking system has lower effect than inclined tracking system. The different
are 0.8% for c-Si and CSI and 0.9% for CdTe. This value are small; therefore, it could be conclude
that type of 1 axis tracking will not have strong effect on the final energy yield. The tracking system
has the most effect on CdTe solar panels and less effect on c-Si solar panels.
With two axes tracking system the same influent on c-Si and CSI (17.9% improvement). The
improvement from inclined tracking and two axes tracking system is about 2% at all cases. This raise
a question whether the 2 axes worth to installed. The answer depends on the difference in cost 1 and
2axistrackingsystemandthesizeofwholesolarpowersystem.
Figure 23: Average daily generated power in March and December
Figure 23 shows the average daily generated power from the solar power system in the case of
optimal fixed stand and 2 axes tracking. The 2 axes tracking system generates more power in the
morning and the afternoon. However, the differences is not big (16% in March and 19% in December)
because of the geographical condition of Medan.
23

4 Discussion and recommendation
•Potential problem with government structure.
–The autonomy provides in Indonesia could become obstacle for national plan when there are
differences between the central government and local. The authorization of each stakeholder
must be well described by regulations and law to avoid and to solve conflict of interest in
the future.
•The household and commercial sectors are most promising for solar energy utiliza-
tion.
–The solar energy is most useful for supplying electricity or heat. In the case of Indonesia the
household, commercial are two of to most energy demand sectors which are and will require
more electricity. Deployment of solar power system similar like case study in section 3 at
utility level or at off-grid small scale level will help to sastify the need of electrical energy
without making harmful impact on residential environment.
•Solar energy is able to provide energy demand for household and commercial sectors.
–The total energy demand for household and commercial sectors is 408 million BOE in 2014,
which equivalent to 693.4 GWh. In order to provide this energy the area of 44.8 km2solar
panel with 2 axes tracking should be installed. Of course not all the energy need is under
electrical energy form and also solar power system could not be install everywhere at least
under economical point of view.
•The Indonesian government is having encouraging movements.
–Indonesian government has great determination to build and encourage solar energy with
6500 MW plan until 2025. The actual movement is introduction of Feed-in-tariffpolicy by
regions. In the other hand, reduction in electrical price’s subside will be a driven force to
move into renewable energy sources to reduce the cost.
•Crystalline Silicon technology should be use.
–Crystalline Silicon still be the best option because it less depends on slope, temperature and
usually price is cheaper than thin film technology. While tracking system is too costly, c-Si
solar cells provide relatively stable energy output around the year. Other option is CdTe
thin film panel which provide higher efficiency however more sensitive with slope and more
expensive.
–Another reason to use c-Si technology because of the limitation of local content of solar
power project in Indonesia must be at least 44%. The production of crystalline silicon is
more simple than thin film technology then low to localize the solar panels of new projects.
•Inclined tracking system should be considered
24

–From cases study the tracking system have imp r ove m e nt on energy yield from 15.1% to
18.7%. The decision whether to use tracking system depend on the cost and size of the power
system. The inclined tracking system should be choose because the higher improvement
compare to Vertical tracking system. The two axes tracking does not show significant
improvement from the Inclined tracking system.
•Power grid operator should prepare for high penetration of distributed power sources.
–Even under control of PLN only, the power grid in Indonesia are highly fragmented because
of their nature and in the remote area the grid is small and weak. In the future when higher
solar power systems are installed all over Indonesia, the transmission and distribution system
could suffer the problem of highly penetration distributed power source.
25

References
[Häberlin(2012)] Häberlin, H., 2012. Photovoltaics System Design and Practice. Wiley.
URL https://books.google.cz/books?id=c0zVo-2ky7MC
[IEA(2015)] IEA, 2015. Indonesia 2015, oecd/iea, paris. Tech. rep.
[IRENA(2017)] IRENA, S., 2017. Renewable energy prospects: Indonesia. Tech. Rep. March.
[Kosasih(2016)] Kosasih, F. U., 2016. Kupang houses indonesia’s largest solar power plant. global
indonesian voices.
URL http://www.globalindonesianvoices.com
[Kurniawan(2016)] Kurniawan, R., 2016. Pertamina to build 1,000 mw of solar power plant. Rambu
Energy.
URL http://www.rambuenergy.com/2016/03/pertamina-to-build-1000-
mw-of-solar-power-plant/
[MEMR(2014)] MEMR, 2014. Solar pv feed in tariffin indonesia: Regulation and framework condi-
tions, memr, jakarta, indonesia. Tech. rep.
[MEMR(2016)] MEMR, 2016. Handbook of Indonesia’s Energy Economy Statistics. MEMR.
[MEMR(2017)] MEMR, 2017. The 2016-2025 electricity supply plan: Rencana umum penyediaan
tenaga listrik - ruptl. Tech. rep.
[NREL(2017)] NREL, 2017. Best research cell efficiencies.
URL https://www.nrel.gov/pv/assets/images/efficiency-chart.png
[Sugiyono(2016)] Sugiyono, A., 2016. INDONESIA ENERGY OUTLOOK 2016.
[Susanto(2016a)] Susanto, A., 2016a. New government decree to accelerate the indonesian solar market.
Solarplaza,.
URL www.solartrademissionindonesia.com
[Susanto(2016b)] Susanto, A., 2016b. A review of indonesia’s latest solar pv feed in tariffregula-
tion (17), 1–11.
URL www.solartrademissionindonesia.com
[Wikipedia(2017)] Wikipedia, 2017. Indonesia. https://en.wikipedia.org/wiki/Indonesia.
[world bank(2017)] world bank, T., 2017. Climate change knowledge portal. The world bank.
URL http://climateknowledgeportal.worldbank.org/
[WorldBank(2017)] WorldBank, 2017. Indonesia. Tech. rep.
URL http://data.worldbank.org
26