Final Report - Energypedia · 2017. 5. 23. · with the simulation tool PVSyst. The simulation reports show 260 Wh/day per households and 161 Wh/day per streetlight as a load assumption

Final Report

Review on Design and Specification of PV Mini-grid Systems 2016

Final Report: Review on Design and Specification of PV Mini-grid Systems | i

Imprint

In cooperation with:

Directorate General for New, Renewable Energy and Energy Conservation (DG NREEC)

under Ministry of Energy and Mineral Resources (MEMR)

Published by:

Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH

Energising Development (EnDev) Indonesia

De RITZ Building, 3A Floor

Jl. HOS. Cokroaminoto No. 91

Menteng, Jakarta Pusat 10310

Indonesia

Tel: +62 21 391 5885

Fax: +62 21 391 5859

Website: www.endev-indonesia.info

Compiled by: Fraunhofer Institute for Solar Energy Systems ISE

On behalf of Energising Development (EnDev) Indonesia, GIZ

Layout/Design: Syifa Astarini Iskandar | Jr. Communication Advisor

Graphs and photos are properties of GIZ

Printed and distributed by GIZ

Jakarta, January 2017

Final Report: Review on Design and Specification of PV Mini-grid Systems | 0

Contents

Imprint ..................................................................................................................................................... i

Introduction .................................................................................................................................... 1

1.1 Background ............................................................................................................................. 1

1.2 Objectives................................................................................................................................ 1

Scope ............................................................................................................................................... 1

Approach ......................................................................................................................................... 2

Results ............................................................................................................................................. 2

4.1 Preliminary Review of the Existing Specification .................................................................... 2

4.2 Compilation of National and International Standards ............................................................ 2

4.3 Site Visits ................................................................................................................................. 2

4.4 Focus Group Discussion (FGD) ................................................................................................ 3

4.5 Gap Analysis on Feasibility Study ............................................................................................ 3

4.5.1 Site Identification ............................................................................................................ 3

4.5.2 System Sizing ................................................................................................................... 4

4.6 Gap Analysis to Increase the Quality of the Components and Systems ................................. 5

4.6.1 System Components ....................................................................................................... 5

4.6.2 System Installation ........................................................................................................ 13

4.6.3 Monitoring .................................................................................................................... 18

4.6.4 Recommendations for Monitoring Off-Grid Systems ................................................... 19

Quality Assurance ......................................................................................................................... 25

Summary and Recommendations ................................................................................................. 29

Annex ............................................................................................................................................ 31


Introduction

1.1 Background

During the period from 2013 to 2015 the GIZ undertook a technical review and baseline survey of

more than 300 PV mini-grid systems installed in Indonesia, on behalf of the Directorate General for

New and Renewable Energy and Energy Conservation (DJEBTKE). Review findings were evaluated,

summarised and submitted to DJEBTKE for further processing and follow-up. The analysed PV mini-

grid sites are technically almost identical from year to year with capacity ranging from 15 to 150 kWp,

either DC or AC-coupled system using lead-acid battery storage.

The intensive technical review towards over 300 PV mini-grid schemes in the past three years has

shown enormous learnings. One of the conclusions and recommendations from the technical review

was for DJEBTKE to refer to and includes national standards and, where possible, international

standards in the future PV mini-grid initiative. This shall include the materials/components

requirements as well as the installation which shall adhere to best practices. Also, a standard design

should be agreed and enforced for on-site system component parts and fittings as well as lightning

protection should be improved.

1.2 Objectives

The objective of this assignment was to review and analyse the technical design and specification of

PV mini-grid systems, ranging from 15 to 150 kWp installed capacity, formulated by the Indonesian

government. The assessment covered the overall PV mini-grid system with highlights on the PV

generation components, battery storage, balance of system, safety and system protection, as well as

the civil work requirements.

Scope

The scope of this assignment comprises seven activities as listed in the following:

Activity 1: Carry out a preliminary review to the existent Technical Specifications

Activity 2: Compile the existent international and national standards

Activity 3: Conduct one site visit

Activity 4: Conduct one stakeholder consultation meeting (focused group discussion (FGD))

Activity 5: Carry out a review and analysis of all relevant information

Activity 6: Conduct one stakeholder video meeting (replaced by individual discussions

between GIZ and DJEBTKE)

Activity 7: Compile and submit a Final Executive Report


Approach

Figure 1 gives an overview on the project workflow.

Figure 1: Overview of the project workflow.

Results

4.1 Preliminary Review of the Existing Specification

As a basis for the gap analysis and for developing recommendations the following documents were

preliminarily reviewed:

Executive Overview Indonesia Solar Mini-grid Program

Technical Specifications (see section 0 Annex)

Inspection guide

Final reports 2014 and 2015 concerning technical inspection of “photovoltaic village power”

(PVVP)

Final executive reports 2013, 2014, 2015 concerning technical inspection of PVVP

4.2 Compilation of National and International Standards

Additional information was gained by a comprehensive compilation of national (Indonesian) and

International (IEC and ISO) standards relevant for PVVP. The result is a list of international standards

related to PVVP which is part of the annex of this report.

4.3 Site Visits

Two site visits of PVVP villages in Riau Province of Sumatra were conducted together with Bagus

Ramadhani from GIZ, Syed Jarrar from DJEBTKE and Dakhpriadi from the Riau province government.

An overview of the visited sites is listed in Table 1; the location of the sites is shown in Figure 2.

Table 1: Overview of the sites visited.


Site Location Year of build Capacity Configuration

RiauS09 Pangkalan Indarung 2013 100 kWp AC Coupled

RiauS15 Gajah Bertalut 2015 20 kWp DC Coupled

Figure 2: Map showing the visited sites in Sumatra (yellow stars).

4.4 Focus Group Discussion (FGD)

In a stakeholder meeting organized by GIZ and attended by DJEBTKE, Puslitbang KEBTKE, BPPT,

Technical Commission of BSN, GIZ staff and Fraunhofer ISE the preliminary results of the review of the

specification, inclusion of standards and findings of the site visits were intensively discussed.

Also, a meeting with the two contractors SEI and INTI provided further insights for the study. A visit of

BPPT and of possible testing capabilities completed the Focus Group Discussion.

4.5 Gap Analysis on Feasibility Study

A feasibility study called “blue book” concerning general technical bases for the PVVP program exist.

It contains some basics regarding site identification, system sizing, components and system layout. A

feasibility study concerning the individual off-grid villages is conducted by local government with

support by a local consultant. The results are somewhat below expectation, e.g. inaccurate

geographical information concerning the site and the number of households, see the following

subchapters.

4.5.1 Site Identification

Currently a high risk and thus costs are given to construction companies due to not having sufficient

information about the site of the villages. Often the sites and their accessibility are unknown and for

example the inclination of the provided area for the PV installation is high which supports erosion and

increases installation efforts (mainly civil works). A detailed geographical information including

accessibility from each village can reduce risks and thus costs.


4.5.2 System Sizing

Load estimation

The blue book assumes a daily load of 300 Wh/day for a household and 600 Wh/day for public

facilities. The energy limiter of the individual houses limits the daily energy consumption to

260 Wh/day. From our point of view this assumption and limitation is too low because the range of

energy consumption in rural households should be in between 250 Wh/day and 1000 Wh/day. A well-

designed Solar Home System deliver approximately 250 Wh/day of DC energy; in PVVP, the output is

AC voltage and is used to supply bigger appliances such as televisions and/or a refrigerator. For using

such appliances an energy target of 260 Wh/day is just too low. This was confirmed by the site visit in

RiauS15 where a part of the villagers used small diesel gensets in the past which supplied several

households. These village people said that 260 Wh/day does not satisfy their needs.

At the stakeholder meeting DJEBTKE reported that in the future (2017) the individual household

consumption should be increased to 600 Wh/day and the consumption of individual public facilities

to 1000 Wh/day. If in the rule-of-thumb and in detailed sizing a growth rate of 30 % is included, then

the values are sufficient.

To get a better picture of the user’s demand and expectations we recommend to perform a baseline

field study in advance of a village electrification and – in a second step – to use these data to optimize

the system size by running additional simulations. Such a user survey lets the people also feel that

they are taken seriously and thus leads to more satisfaction with the PV system. Ideally these

simulations shall be done by EBKT in order to provide the contractors with a clear target about the

system size in the tender documents.

System, Component Sizing and Selection

The blue book suggests a rule-of-thumb for system and component sizing. We compared this with

the detailed simulation of RiauS10 – a 15 kWp system. The simulation was done by the contractor

with the simulation tool PVSyst.

The simulation reports show 260 Wh/day per households and 161 Wh/day per streetlight as a load

assumption. Obviously a very high safety margin (or growth factor?) was figured in as the simulation

reports indicate. The simulation showed a yearly average of unused energy of approximately 100%

of the load demand – this leads on the one hand to a perfect solar fraction of 100% in the yearly

average (meaning that the households can be supplied with electrical energy throughout the year

without any load shedding) but on the other hand this will lead also to high PV system costs.

Therefore, it seems that there might be a high potential of optimization – either in increasing the

available energy per household and day or in supplying additional loads like mills or workshops for

productive use to generate income.


A brief glimpse on the rule-of-thumb (RoT) used by EBTKE to estimate the system size and a

comparison of the RoT with the results of the system simulation of RiauS10 showed that the RoT works

quite nicely. With an underlying 30% of overall losses the tool overestimates the load demand by

approx. 30%, on the other hand it underestimates the energy production by approx. 10% (also here

the underlying loss factor is too high)1. The battery sizing could not be compared because the size of

the batteries was set by a consultant during a feasibility study instead of using an exact calculation.

In summary, one can say that the RoT gives a quick estimate on system size and load estimation but

does not replace an elaborate simulation. The simulations should be based on user surveys and

performed by EBTKE.

Many simulation tools (like PVSyst, PVSol, or HOMER) offer the possibility of sizing system components

based on a few assumptions like load demand, geographical place and a first guess of the battery size.

Sizing components using such tools is an iterative process with several repetitive steps. A further

benefit of such tools is that they also provide information about wire sizing and component

mismatches. Instead of only calculating using RoT, EBTKE should consider to conduct more

comprehensive simulation using one of the above-mentioned software.

In sections 4.6.1 and 4.6.2 we give some hints for the correct sizing and selection of system

components such as PV modules, charge controllers, batteries, inverters, cabling, protection system,

and lightning protection.

4.6 Gap Analysis to Increase the Quality of the Components and Systems

The following gap analysis on components and systems is done according to the order of the existing

Technical Specification provided by GIZ Indonesia.

4.6.1 System Components

PV Modules

Table 2: PV module efficiency: specification, problems and recommendations.

Topic PV module efficiency

Current specification (as-is) Efficiency of the module should be greater than 16%

Problem Only few of PV module manufacturer 16% of module efficiency.

Recommendation (to-be) Reduce the efficiency to minimum of 15% for mono and polycrystalline and

minimum of 10% for Thin-film

Analysis and Discussion

The efficiency of PV modules currently available on international markets varies from 13% up to 20%

whereby it is ambitions to achieve module efficiencies of >16% especially for local manufacturers in

Indonesia. There is a risk that too less local manufactures can fulfil this requirement (BPPT reported

that Indonesia PV module manufacturers have problems to achieve 16%). Also for a cost point of view

1 Remark: this assessment does not claim to be a scientific analysis of the RoT – the idea was to give a kind of “gut feeling” about the performance of the RoT.


this requirement could be counterproductive because modules with higher efficiencies are more

costly.

Since in the case of PVVP available space on site is not really an issue we recommend to go for a

lower efficiency requirement: 15% for mono and polycrystalline and a minimum of 10 % for thin-film

modules. This would open the field for more PV module suppliers/manufacturers without having

significant disadvantages.

Table 3: PV module hot-spots current specification, problems and recommendations.

Topic Hot spots

Current specification (as-is) No reference standard for testing the PV modules is in place

Problem Review of Final Executive Report states that hot spots were recognized with

some PV generators

Recommendation (to-be) PV modules should be certified tested against the standards IEC 61215 and IEC

61646


It is recommended to add the testing standards IEC 61215 (Crystalline silicon terrestrial photovoltaic

modules – Design qualification and type approval) and 61646 (Thin-film terrestrial photovoltaic

modules – Design qualification and type approval).

By applying these standards, the PV modules must be tested concerning environmental conditions like

high temperature, humidity, shadowing and also presence of by-pass diodes. This would help to avoid

hot-spots and on the longer run the risk of premature failure of modules.

Because of missing equipment BPPT cannot perform PV module testing but within the cooperation

with SERIS (Solar Energy Research Institute of Singapore) this tests could be carried out. It is not

recommended to establish a test facility for PV module testing in Indonesia, because the equipment

is very expensive, high skilled personnel is necessary and a high usage rate is necessary for an

economic operation of such a test facility.

Table 4: PV module cracked modules: current specification, problems and recommendations.

Topic Cracked modules

Current specification (as-is) Procedure for spare modules is not available

Problem Review of Final Executive Report states that cracked modules were observed

from time to time

Recommendation (to-be) Order/deliver 2 % surplus of PV modules


It was reported that cracked modules were observed which happens during transport, mounting or

handling from time to time. It is recommended to order or deliver 2% of surplus of PV modules in

order to have a sufficient number of PV modules available at site.


This would help to avoid time delays for reordering modules caused by difficult transportation

channels and defect modules could be replaced by the same type. The performed site visits however

showed that the PV modules provided by iSOLAR were all okay.

Charge Controllers

Table 5: Charge controller standards: current specification, problems and recommendations.

Topic Quality Standard

Current specification (as-is) Requires IEC 61683 (Photovoltaic systems – Power conditioners – Procedure

for measuring efficiency).

Problem IEC 61683 does not cover specifically charge controllers

Recommendation (to-be) Charge controllers should be certified tested against IEC 62509 (Performance

and functioning of PV battery charge controllers)


The required standard IEC 61683 in the Technical Specification does not really apply for charge

controllers. This standard covers only a specific topic (efficiency) but does not provide overall quality

tests for charge controller. Thus, it is recommended to replace IEC 61683 with IEC 62509.

Table 6: Charge controller power capability: current specification, problems and recommendations.

Topic Power Capability

Current specification (as-is) The total nominal output is based on the capacity of the plant

Problem Unspecific requirement may lead to under sizing of charge controller capacity

or the charge controller can be overloaded

Recommendation (to-be) Minimum 90% of total PV power


The current Technical Specification does not specify clearly the power capability requirement for

charge controllers. In order to avoid overloading of charge controllers, or to avoid power reduction of

PV in case of the charge controller has an active power control, it is recommended to add a

requirement for the power capability.

The power capability should be ≥ 90% of total the PV STC power2. Because of temperature induced PV

power reduction caused by relatively high ambient temperature in Indonesia a smaller value than

100 % is suitable.

Table 7: Charge controller temperature compensation: current specification, problems and recommendations.

Topic Temperature Compensation

Current specification (as-is) Missing: requirement for temperature compensation.

Problem Missing temperature compensation of end-of-charge voltage thresholds can

overstrain batteries

Recommendation (to-be) temperature compensation of the end-of-charge voltage should be -4 to -6

mV/(cell K)

2 STC power: power of the module measured under Standard Test Conditions (E = 1000 W/m², Module temperature = 25 °C, AM 1.5)



Especially in hot environments there is a risk of overcharging batteries when no measures are taken

to reduce the end-of-charge voltage threshold3.

In order to increase lifetime – that is to protect the batteries against overcharging – it is recommended

to include a requirement for solar charge controller to have a so called “temperature compensation”

of the end-of-charge voltage. The compensation could be in the range of -4 to -6 mV/ (cell K).

Table 8: Charge controller not active: current specification, problems and recommendations.

Topic Charge Controller Not Active

Current specification (as-is) Training by manufacturer missing

Problem Review of Final Executive Report states charge controller not active

Recommendation (to-be) The inverter manufacturer or supplier shall train the installers


It is highly recommended to oblige the system integrator that he takes care about appropriate training

of his staff. Ideally training can be provided by the charge controller manufacturer, e.g. at his

Indonesian branch or sales partner.

Grid Inverter

Table 9: Grid inverter standard: current specification, problems and recommendations.

Topic Standard

Current specification (as-is) IEC 61727 Photovoltaic (PV) systems - Characteristics of the utility interface

Problem Not relevant for off-grid systems

Recommendation (to-be)

Add the standard EN 50530 (Overall efficiency of grid connected photovoltaic

inverters) and 62109-1 /-2 /-3 (Safety of power converters for use in

photovoltaic power systems. Part 1: General requirements. Part 2: Particular

requirements for inverters. Part 3: Particular requirements for electronic

devices in combination with photovoltaic element)


The standard IEC 61727 is not relevant for off-grid systems because it describes the characteristics of

the utility interface which does not exist in off-grid systems. The efficiency of a grid inverter should be

measured concerning EN 50530 (see reference in datasheet). The standard 62109-1 /-2 /-3 describes

the electrical safety of power converters for use in photovoltaic power systems (see reference in

datasheet). It is recommended that these two standards should be referenced in the data sheet of the

inverters in order to achieve high efficient, good performing and reliable PV systems.

Table 10: Grid inverter power capability: current specification, problems and recommendations.

3 Battery charging is an electrochemical process and from an electrochemical point of view high heat reduce charge acceptance of lead acid batteries, that is gassing starts at lower voltages. Keeping the end-of-charge voltage at normal level at high ambient temperatures would lead to excessive outgassing, disproportionate oxidation of the plates and reduced life-time in the end.


Topic Power Capability

Current specification (as-is) The total nominal output is based on the capacity of the plant

Problem There is a risk that the inverter will be oversized according to the specification

because the output value and not the input value is specified

Recommendation (to-be) The input power capability of the inverter should be at minimum 90 % of total

PV power


The current Technical Specification specify the output power capability requirement for grid inverters.

Because the input power capability is higher in comparison to the output power capability the inverter

can be too big, which can cause higher electrical losses and higher costs. To avoid this, it is

recommended that the input power capability should be ≥ 90% of total PV STC power. Because of

power reduction of PV caused by high ambient temperatures in Indonesia a smaller value as 100% is

suitable.

Table 11: Grid inverter not active: current specification, problems and recommendations.

Topic Inverter not Active


Problem Review of Final Executive Report states inverter not active



It is an obligation for the system integrator to conduct appropriate training of his staff. Ideally training

can be provided by the inverter manufacturer, e.g. at his Indonesian branch or sales partner.

Site visit RiauS09: Two of five of the well-known SMA showed on the display “surge arrester defect”

but they still work well and need no maintenance to continue operation after the lightning strike which

perhaps damaged the internal overvoltage protection of battery Inverter

Table 12: Battery inverter standard: current specification, problems and recommendations.

Topic Standard

Current specification (as-is) The battery inverter does not have to comply any standard

Problem No quality assurance of the battery inverter

Recommendation (to-be) Add the standard IEC 61683 (Photovoltaic systems - Power conditioners –

Procedure for measuring efficiency)



Battery inverter should be tested according to IEC 61683 to guarantee that the battery inverter will

work properly for village power supply.

Table 13: Battery inverter power capability: current specification, problems and recommendations.

Topic Power capability

Current specification (as-is) Requirement for power capability is missing

Problem Overloading or unwanted trip of the battery inverter

Recommendation (to-be) Specifying the nominal power based on the power demand of the village


The current Technical specification does not specify a power capability for battery inverters. In order

to avoid overloading of the battery inverter and to operate the inverter at high efficiency, it is

recommended to specify the nominal power based on the power demand which is simultaneously

needed by the village. Demand assessment during feasibility study needs to be improved to get a more

accurate load estimation and thus optimally use the inverter.

Table 14: Battery inverter not active: current specification, problems and recommendations.

Topic Inverter not active


Problem Insufficient troubleshooting knowledge of the battery inverter



Paralleling multiple battery inverters requires a robust and reliable communication. Each inverter type

has their own way to establish a communication between master and slave. From the inspection, it

was observed that one of the frequent problem is synchronization fault. This might be the use of

unsuitable communication cable or insufficient knowledge in configuring the parameter. Therefore,

the battery inverter manufacturer or supplier shall train the installers to ensure that they can install,

considering the critical aspects, configure the parameters, and troubleshooting in the correct way.

From the site visit in RiauS09, the well-known SMA was working well and needs no maintenance after

a lightning strike whereas in RiauS15, the unknown manufacturer KEHUA was required a technician to

do service after a lightning strike.


Battery

Table 15: Battery standard: current specification, problems and recommendations.

Topic Standard

Current specification (as-is) No requirement to comply with any specific standard

Problem Insufficient information concerning the quality of battery


Introduce the following standards to be complied:

1) IEC 60 896-21 /-22 (On Stationary lead-acid batteries: Part 21/22: Valve

regulated types – Methods/Requirements).

2) IEC 61 427 (Secondary Cells and Batteries for Photovoltaic Energy

Systems (PVES) – General Requirements and Methods of Test)

3) IEC 62 485-2 (Part 2: Safety requirements for secondary batteries and

battery installations: Stationary Battery)

4) Introduce the following formulation for the VRLA battery:

Stationary VRLA with tubular plates and gel type


In order to have a set of batteries that meet minimum quality standard of Valve Regulated Lead Acid

(VRLA) battery, the battery should be tested according to IEC 60896-21/-22 as well as IEC 61427. Since

only few manufacturers have complied with IEC 61427 due to time consuming cycling tests at different

state of charge and also limited market of Photovoltaic Energy System (PVES) batteries, it is optional

that the battery should comply with this standard.

In the scope of IEC 60896-21/-22, it is mentioned that the part is not applicable to lead acid batteries

used for solar photovoltaic energy systems. It is due to the existence of dedicated standard for

Photovoltaic Energy System which is IEC 61427, and thus the dedicated standard is more suitable to

be used for testing battery in PV application.

However, since the procedure for estimating the nominal capacity in IEC 60896-21/22 is quite similar

to IEC 61427, it is acceptable to use IEC 60896-22. The only advantage if a battery passes the test in

accordance with IEC 61427 is that the probability in achieving a long lifetime in solar application is

higher in comparison to a battery which does not pass this test.

Another way to solve this difficulty with the standards is to specify exactly the best lead acid battery

type for photovoltaic village power. The most suitable battery for this application is stationary lead

acid battery with tubular plates and immobilized electrolyte by gel4. The pressure of gas inside this

type of battery is regulated by a valve which is the reason for the name valve regulated lead acid

battery. The type of the lead acid battery which is VRLA with tubular plates and gel type should be

included into the specification.

The battery banks should also be installed according to IEC 62 485-2 to ensure the safety installation

of battery. The standard also mentions the minimum ventilation for the battery room.

4 D.U. Sauer, G. Bopp, M. Bächler, W. Höhe, A. Jossen, P. Sprau, B. Willer, M. Wollny, What happens to Batteries in PV Systems or

Do we Need one Special Battery for Solar Applications ?, 14th European Photovoltaic Solar Energy Conference, Barcelona, Spain, 1997


The battery type from Nipress (Indonesian manufacturer) which is NS Accelerate seems to have a

good quality. The datasheet mentions that the battery was tested according to IEC 60 896-21 /-22

and is a stationary VRLA with tubular plates and gel type.

Table 16: Battery warranty period: current specification, problems and recommendations.

Topic Warranty period

Current specification (as-is) Minimum warranty period of 10 years

Problem Too ambitious for lead acid battery

Recommendation (to-be) Reduce to 7 years for lead acid and 10 years for lithium ion


It is known that the service life and cycle performance of a battery is closely related to the operating

temperatures as well as the depth of discharge of each cycle. Higher operating temperature may

increase the usable capacity, but on the other hand reduces the lifetime of the battery. In the case of

Indonesia, where the average ambient temperature is about 25 to 30°C, specifying minimum warranty

of 10 years for lead acid is difficult to achieve.

By considering operating temperature and typical battery depth of discharge for PV mini-grid in

Indonesia, seven years of warranty for lead acid or roughly 2500 cycles and 10 years for lithium ion

would be more reasonable.

Table 17: Battery protection: current specification, problems and recommendations.

Topic Protection

Current specification (as-is) Fuse is sized based on the minimum capacity

Problem Unwanted burnt during normal operation

Recommendation (to-be) DC Miniature Circuit Breaker (MCB) with rated current 150% of battery

inverter input current


Protection devices are required at the battery side to protect the battery banks against overload and

short circuit. A correct sizing of protection is necessary to avoid unintentional interruption or burnt

fuse during normal operation or insensitive protection device to the overload. The rating of protection

devices should be sized at 150 % of the rated DC discharging (input) current of battery inverter.

Moreover, as one of the main challenges in rural electrification is the availability of spare parts,

replacing the fuse with MCB will dismiss the need of spare fuses.

In case of lithium ion battery, the protection requires additional battery management system (BMS)

which communicates with the charge controller and the battery inverter. The BMS will monitor and

protect each lithium ion cell against overcharge, undercharge, and over temperature.

During the site visit, it was found that the installed battery fuses are rated at 150% of the nominal

input current of the battery inverter which is in the expected range.


Table 18: Battery capacity: current specification, problems and recommendations.

Topic Battery capacity

Current specification (as-is) Based on load calculation

Problem Review of Final Executive Report states battery voltage too low

Recommendation (to-be) Improvement of the adaption between demand, supply, and storage.


Sizing and selection of the battery type should consider the electricity demand, required days of

autonomy, and lifetime expectancy of the battery. If the size of the PV and the battery is too small in

comparison to the load, the battery cannot be recharged sufficiently which results in a low battery

voltage and the risk of damaging the battery. On the other hand, when the size of the battery is too

big, the usable capacity of the battery would not be used efficiently. Therefore, an improvement in

load estimation and system sizing is needed to have a more efficient system with long lifetime (see

also section 4.5.2).

4.6.2 System Installation

Based on the review of the Technical Specification, site visits and the stakeholder discussion meeting

we got the impression that the most important issues are linked to the system installation part. This

mainly concerns lightning protection and cabling. Thus, in the following these two topics are

elaborated in detail.

Lightning Arrester

Regarding lightning protection we see a strong need for improvements because of the following

reasons:

The executive report describes problems with insufficient grounding and lightning protection.

The two site visits confirmed this problems

The risk of a lightning strike in Indonesia is 10 times higher compared to Germany; this means

probably 30 – 40 lightning strikes per square kilometer landscape and per year!

PV generator, electronic equipment like charge controllers or inverters could be destroyed by

a lightning strike into the PV array.

How a lightning protection system (LPS) can be implemented:

Design a lightning protection concept.

Install an external lightning protection system for the PV system, like high rod.

Install an internal lightning protection system for the PV system, like a surge protection device

(SPD) in the combiner box.

Install a good grounding system for the external and internal lightning protection system.

A grounding of the individual houses is not mandatory. The current state of the art for

individual small private houses in rural areas does not include an external lightning protection

system thus a grounding system would not be required. The risk of a lightning strike into small

private houses in rural areas is relative low because the trees in such small villages are in most

cases higher in comparison to the houses and the lightning prefers all higher parts. When

lightning strikes an individual house only the house and/or the electric appliances can be


destroyed, the far away PV system is protected by the surge protection devices at the AC

output of the PV system.

Recommendations:

Design a lightning protection concept for PVVP in Indonesia. It is not sure if this was already

done in a detailed way. The feasibility study guide and the Technical Specification indicate that

parts were realized. A detailed concept should include a comparison concerning the risk of a

strike into the PV system with one high lightning rod or with several lower rods.

Establish or offer lightning protection trainings especially for PV. Fraunhofer ISE has been

teaching staff in Germany in this field for 15 years.

Table 19: Grounding resistance.

Topic Grounding resistance (topic of lightning arrester and cabling and grounding)

Current specification (as-is) Grounding resistance < 5 Ohm

Problem

A grounding resistance < 5 Ohm is difficult to achieve. The appropriate IEC

60 364-5-54 (Electrical installations of buildings – Part 5-54: Selection and

erection of electrical equipment – Earthing arrangements, protective) is

missing


Include IEC 60 364-5-54 and a table how to reach 5 Ohm of earth resistance

with rods and rings for different soils. Explain the difference of rods and a ring

in detail and provide support how to calculate the number of rods and the

diameter of the ring. A lightning protection study should be conducted.


The earth resistance depends on the ground type, see Figure 3. The ground type of the two sites which

were visited is farmland, loam, with an earth resistance of approx. 100 Ohmmeter.

Figure 3: Specific earth resistance ρE of different ground types

[Source: Lightning Protection Guide, 3rd updated version, 2015, Dehn, Neumarkt, Germany]


For grounding, a rod or a ring of galvanized steel or copper can be used, see e.g. Figure 4.

Figure 4: Example of grounding with rods (left) or with a ring (right).

Figure 5: Earth electrode resistance RA of earth rods as a function of their length l at different specific earth resistances ρE

[Source: Lightning Protection Guide, 3rd updated version, 2015, Dehn, Neumarkt, Germany]

Figure 5 shows the earth electrode resistance of a vertical rod in dependence from the drive-in depth

(vertical length) into the earth at different specific earth resistances. It is obvious that a value of 5

Ohm, which is required in the Technical Specification, needs about 20 m (!) vertical drive-in depth or

one has to connect a lot of earth rods with 2 m drive-in depth (2 m can be done fairly straightforward

with a sledgehammer) in parallel.

Another solution which needs less length is to use a ring of galvanized steel or copper buried in the

ground around the power house or the PV array. It is recommended to conduct a lightning protection

study in order to precisely analyze the necessary measures to be performed for an efficient grounding.


Table 20: Grounding

Topic Grounding

Current specification (as-is) It is advised to not connect the grounding system of the high rod and the PV

system

Problem

If the high rod collect a lightning strike the different grounds experience

different electrical potential which can destroy electronic equipment like

charge controllers and inverters

Recommendation (to-be) Connect all individual grounding systems together especially the high rod and

the PV system by “equipotential bonding”


In order to reduce the effect of a lightning strike it is very important that all parts of the system should

have the same electrical potential (e.g. from a lightning strike’s point of view all components should

be installed on an “equipotential copper plate”). This means an equipotential bonding of all grounding

rods and cables and a connection of the ground of the high lightning rod with the ground of the PV

system is necessary5.

Illustrations of the problem from the site visit RiauS09: The equipotential bonding of all grounding

rods and all grounding cables is missing. The connection of the ground of the high lightning rod with

the ground of the PV system is missing (see Error! Reference source not found.).

RiauS15: The equipotential bonding of all grounding rods and all grounding cables is done. The

connection of the ground of the high lightning rod with the ground of the PV system is missing (see

Error! Reference source not found.).

Figure 6: Missing equipotential bonding of the grounding

rods.

Figure 7: Correctly installed earth rail for equipotential

grounding

5 The next edition of IEC 62 305-3 mentions in chapter D 5.1.1 Dangerous sparking: Isolated and not isolated lightning protection systems should always be connected to the conductive elements of the structure and to its equipotential bonding system at the ground level


Table 21: Surge protection device (SPD) in combiner box

Topic Surge protection device (SPD) in combiner box

Current specification (as-is) No voltage protection level for SPD specified

Problem Too high protection voltage (e.g. 500 V for a 48 V device) does not protect

device

Recommendation (to-be) The voltage protection level of the SPD should be 120 - 150% of open circuit

voltage at STC of the PV string


A too high protection voltage level of the external SPD type T2 (e.g. 500 V for a charge controller with

a 48 V PV input voltage) will not be able to protect the charge controller. It is because the internal

protection circuit/SPD of the device is of type T3 and cannot absorb the high energy of an indirect

lightning strike. The external SPD has to be sized correctly to achieve a high-energy absorption

capability at a voltage level which does not destroy the device. It is recommended to select the voltage

protection level of the external SPD of type T2 in between of 120 to 150 % of the open circuit voltage

of the PV string.

Site visit RiauS15: We observed a too high protection voltage level (500 V) of the SPD in the combiner

box. Thus the 48 V charge controller is not protected against lightning strikes. Additionally, the SPDs

in the combiner box are not connected to earth.

Cabling

Table 22: Connector installation (routing of cables)

Topic Connector installation (Laying of cable)

Current specification (as-is) Interconnection between PV modules should be installed inside cable trays or

trunks.

Problem The executive reports mention bad cabling and wiring practices and some

cables are not installed inside cable trays or trunks.

Recommendation (to-be) Include pictures which show good and bad cabling and wiring practices.

The cables which are used outside should be UV and water resistant.


If the cables are not installed inside a cable tray or trunk they can be damaged which can cause an

electric shock or interruption of power. The standard IEC 60 364-5-52 (Erection of low voltage

installations – Part 5: Selection and erection of electrical equipment – Chapter 52: Wiring systems,

table A.52.1 Selection of wiring systems) describes in a relative theoretical manner the correct

installation of cables. It is assumed that the installation in some cases is done by not very skilled staff,

thus it is recommended to include pictures which show good and bad cabling and wiring practices

instead of only mentioning the right standard. Additionally, training of the staff for improving their

installation skills is recommended.


Since the cables used outside cannot be protected totally against sun’s radiation and water, the

cables should be UV and water resistant.

Table 23: Losses (cable type)

Topic Losses (cable type)

Current specification (as-is) Diameter is based on current and no concrete maximum losses is given only

the general SPLN/SNI standard is mentioned

Problem

Undetailed in specifying cable diameter may lead to undersized cable. This

may harm the system protection coordination, risk the installation, and

increase of distribution losses.


The total power losses of the cabling inside the power house including

interconnection between the solar modules should be less or equal 4 % at full

power.


To find an appropriate figure for losses in the general SPLN/SNI standard is difficult, because it

depends on the application and PV is not described in these standards. In PV applications, often 3 %

(of nominal system voltage) is suggested. The Appendix G of IEC 60 364-5-52 suggests 4 % as a general

recommendation. Because the power house contains a lot of cabling 4 % losses at full power for the

whole cabling is suggested.

4.6.3 Monitoring

General Information on Monitoring Systems

Monitoring systems are very important for a reliable operation and sustainability of the whole

electrification program PVVP. The main purpose of monitoring is to evaluate the performance of the

PV systems and to get meaningful information if the system works properly, requires maintenance,

meets the expectations of the villagers and the government and last but not least if it fulfils the

Technical Specification of the tender.

Results of the Technical Review Report

In the Report on Technical Review [Source: Final Executive Report MSP for PVVP 2015] it was reported

that only 2 of 83 sites have an ‘active and functioning’ remote monitoring system. That is too few for

the money spent for the monitoring equipment and with regard to the importance of the data.

Field Visits and Review of Final Executive Reports

The online monitoring of the first system (RiauS09, SMA) was not working, but on site the SD card had

data collected. The energy meter on site was also not working. In the second site (RiauS15 no data

were available from the monitoring system but the energy meter was working. In discussions with

installation companies, we found that often there is no or poor cell phone reception. Thus no online

data transmission is possible. Furthermore the monitoring systems often have failures. Data

transmission is often interrupted; causes may be due to bad installation, unfavorable environmental

conditions, bad mobile network, and disturbances because of electronic interferences.


Findings

There are built-in monitoring systems in some of the components (SMA). But the data of the different

components like inverter and irradiance sensor are mostly not put together in one file, or sometimes

inability to access and read the data out of the components. The Technical Specifications are not

sufficient, with regard to monitoring. Specific parameters which should be monitored are not defined

in the specification. Only basic requirements like “access and user interface” and “communication

interface” is defined. There is a lack of specific information in what kind of format the monitored data

should be made available (e.g. csv file with specific header and data arrangement). Training of the

installers should be improved and testing of the proper function of the monitoring system should be

intensified.

The system performance database of the EBTKE is already established. However, the current database

consists only of a few parameters that do not indicate much about the system performance. Data

processing and analysis should be improved and set to a certain standard for all systems.

As a final conclusion, we like to emphasize that with regard to a conclusive performance evaluation of

the electrification program, the acquisition of reliable and correct field data is absolutely prerequisite.

4.6.4 Recommendations for Monitoring Off-Grid Systems

General recommendation: Monitoring only makes sense if the acquired data are examined.

Monitoring does not only take considerable invest costs there are also expenses for operating and to

maintain the monitoring system and especially to process and analyze the data. Data needs to be

edited and bring in a proper way to obtain reliable information about the system, to see errors and to

learn from the data. This is a big gap in the project. For a reliable electrification program monitoring

is essential.

We recommend establishing a monitoring database, provide personnel for data acquisition and

processing the data, and to report findings to responsible persons of the system maintenance team.

In general, we recommend the following procedure to acquire a minimum of data from the field:

A) Check the system manually

The operator in the village should note manually (logbook) the following parameters each month

and send it additionally via SMS to the responsible person of the monitoring team:

Parameter Symbol Unit

PV energy to load E kWh

Hours of operation t h

Number of Blackouts Blackouts -


Figure 8: Overview of measuring points in the system. Left: DC coupled system; right: AC coupled system.

With this information one can get a rough overview if the system is working and if it is sized not too

small for the size of the village. Figure 8 shows an overview about the measuring points

B) Optional: Establish a remote monitoring system

In addition, a remote monitoring system can be installed and the following parameters should be

recorded:


PV energy output EPV kWh


PV inverter energy output E kWh

Battery voltage Vs V

Battery current Is A

Battery temperature Tbat °C

In-plane irradiation GI W/m2

Ambient temperature Tam °C

Figure 9 gives an overview about the measuring points in the system.

Figure 9: Overview of the measuring points for the remote monitoring system. Left: DC coupled system; right: AC coupled

system.

With this data basic performance parameters like performance ratio and state of charge can be

calculated. Also failures or underperformance can be recognized. To calculate performance


parameters please refer to IEC 61 724 standard or the literature list mentioned at the end of this

section.

For the majority of the systems the monitoring procedure described above is sufficient, but we also

recommend to perform an in-depth analysis with a few selected systems representing the overall

variety in system power, system technology (DC / AC coupled) and type of inverters and batteries of

the PVVP. For this, a more sophisticated measurement system and data processing is required. The

following parameters should be measured (Figure 10 shows an overview of the measuring points):

AC coupled systems (in red the difference to DC coupled systems is marked)


In-plane Irradiance GI W/m2

Ambient temperature Tamb °C

Module temperature Tmod °C

Wind speed Sw m/s

PV array output voltage VDC V

PV array output current IDC A

PV array output power PDC kW

Utility grid voltage VAC V

Current to utility grid IAC A

Power to utility grid PAC kW

Durations of system outage toutage s




Battery room temperature Tam,bat-room °C

Battery SOC SOC %

Load voltage VAC V

Load Current IAC A

Load Power PAC kW


Battery inverter current IBatInverter A

Battery inverter voltage VAC V

Battery inverter Current IAC A

Battery inverter Power PAC kW

DC coupled systems (in red the difference to AC coupled systems is marked)


In-plane Irradiance GI W/m2

Ambient temperature Tamb °C

Module temperature Tmod °C

Wind speed Sw m/s


PV array output voltage VDC V

PV array output current IDC A

PV array output power PDC kW

PV inverter current IDC A

PV inverter Power PDC kW

Durations of system outage toutage h




Battery room temperature Tam,bat-room °C

Battery SOC SOC %

Load voltage VAC V

Load Current IAC A

Load Power PAC kW


Battery inverter current IBatInverter A

Battery inverter voltage VAC V

Battery inverter Current IAC A

Battery inverter Power PAC kW

Figure 10: Overview about the measuring points in case of systems of higher power. Left: DC coupled system; right: AC

coupled system.

For example, with additional records of the module temperature one can verify simulation results and

expected PV output power and to identify the deviation in output power.

The IEC 61724 standard can be used to monitor an AC coupled system with additional parameters to

cover load and battery monitoring. The IEC 61724 covers only monitoring of the PV part of an off-grid

system. In DC coupled systems we think the standard is not valid because AC parameters are measured

behind the battery system and the battery system is influencing the performance calculation of the

PV part (see Figure 10).


Data base

Table 24: Data base

Topic Data base

Current specification (as-is) There is no specification available -

Problem Database is already established with very limited data

Recommendation (to-be) Improve the database to collect more information or data and analyze more

key performance indicators from all villages

Data analysis

Table 25: Data analysis

Topic Data base

Current specification (as-is) There is no specification available -

Problem At present no data processing and analysis is done, thus no findings of the

system performance in the field can be derived.


(1) Establish data processing and analyzing for all villages.

(2) Establish automatic data analysis to instantly recognize errors /

malfunctions of the system.


Monitoring only makes sense if the acquired data are analyzed. Monitoring does not only take

considerable investment costs, there are also expenses for operation and maintenance of the

monitoring system, especially to process and analyze the data. Usually data needs to be edited and

brought in a proper way to obtain information from the system, identify errors and also learn from

the data. We also suggest to rely on a defined data processing way such as performance ratio, state

of charge, etc. For more information concerning performance calculation please refer to different

literatures; our Institute also appreciates to offer specific workshops on monitoring and data analysis.

Final Remarks to Monitoring Systems and Literature Advise

For a reliable electrification program, monitoring is essential. We recommend establishing a

monitoring database, establish a monitoring and system maintenance team which provides personal

for data acquisition and processing and reports findings to EBTKE in a quarterly manner. As a final

conclusion, we would like to emphasize that with regard to a conclusive performance evaluation of

the electrification program the acquisition of reliable and correct field data is absolutely prerequisite.

Actually, the missing monitoring is a real gap in the project.


To recommend an improved monitoring system we advise the following literature:

No Literatures Description

1 IEC standard (IEC 61 724)

Provides photovoltaic system

performance monitoring guidelines for the

measurement, data exchange and analysis

of different parameters. Though this

standard refers to grid connected PV

systems parts of it can also be used for off-

grid systems.

2 (IEA 1) Analytical Monitoring of Grid-

connected Photovoltaic Systems Good

Practices for Monitoring and Performance

Analysis, IEA PVPS Task 13, Subtask 2

Report IEA-PVPS T13-03: 2014 March 2014

Overview of monitoring and performance

evaluation in general.

3 (IEA 2) A user guide to simple monitoring

and sustainable operation of PV-diesel

hybrid systems, Handbook for system users

and operators IEA PVPS Task 9, Report IEA-

PVPS T9-16: 2015

Handbook for a very simple manual

monitoring procedure, but interesting as

the performance parameter calculation is

explained in a simple way but complete.

4 Baring-Gould, I. (2001). Development of

Test Procedures for Benchmarking

Components in RES Applications, in

particular Energy Storage Systems. Golden

Colorado, USA: National Renewable Energy

Laboratory.

General information about monitoring in

off grid applications.


Quality Assurance

Regarding Quality Assurance (QA), we see that the importance of having a well-established QA system

and is already considered by EBTKE. Nevertheless, some gaps were identified which have a significant

influence on the reliability of the whole village electrification program.

Table 26: Site specific tenders

Topic Site specific tenders

Current specification (as-is) Very limited information about the site

Problem (1) Sizing

(2) Geographical information is missing


(1) Adapt call for bids to specific sites (see also sizing chapter)

(2) Comprehensive site inspection for gathering local information

(where to build up the system, erosion conditions, etc.) would

reduce difficulties and risks for contractors, thus lower system prices

would be possible.


Load profile analysis, system dimensioning and component selection actually is not specific enough

for a proper system sizing of a specific village. The feasibility study including site visits must be more

sophisticated and a standard could be defined to gather technical information, social information and

geographical information in a detailed way

Actually, a lot of risk and thus costs are given to contractors by not knowing much of the villages. Often

the geographical condition of planned sites is unknown. For example, the inclination of the planned

area for PV installation is high, and therefore resulting in increase of supports erosion and installation

efforts.

Table 27: Component testing

Topic Component testing

Current specification (as-is) -

Problem (1) Untested zinc-air battery

(2) No Monitoring system

Recommendation (to-be) (1) Test all component groups before sending it to remote places

(2) See monitoring chapter


Our experience shows that there is a big difference between tests in a laboratory - especially if it is

owned by the manufacturer of the device - and the “real world” operation conditions. We thus

strongly recommend not putting components of very recent technologies without pre-field tests into

the field. Such a pre-field test can be the installation of one or a few of new components in the

laboratory and one or a few at an off-grid village which is easily accessible directly by car.


Table 28: Commissioning

Topic Commissioning


Problem No extensive commissioning is performed, thus only 2% of monitoring systems

are working and problems with groundings and lightning protection.


Perform a very detailed commissioning: it is recommended to adapt from

the technical inspection protocol from GIZ and add protocol for monitoring

systems.

The contractor should provide a reliable and complete monitoring data in

a certain period as part of the commissioning

Perform capacity building of the villagers and operators.


A detail commissioning is very important as to verify if the system works properly and will last long.

Unfortunately, it is found that the commissioning of the EBTKE’s systems were not done in

comprehensive procedure. It is recommended that at least the following should be done:

1) A technical inspection and commissioning (with checklist) of the system including visual

appearance, component compliance, and performance verification. The protocol can be adopted and

expanded from the GIZ technical inspection guideline.

2) Verification of remote monitoring system for functionality with a testing phase of about two

months. The data should be received by a central monitoring data base (see monitoring chapter) to

ensure the communication and data reliability. In case if the site is not accessible by mobile network

or internet connection, the contractor should provide the two months logged data with monitoring

parameters as listed in section 4.2.4.

Moreover, the following documents should also be available on site:

- User manual of all components

- Wiring diagrams of the complete system including the grounding scheme

- Labelling of all components that correspond to the labelling in the wiring diagram

In addition, a wiring diagram should be easily accessible in the power house for maintenance teams

and to support troubleshooting.


Table 29: Operating & maintenance

Topic Operating & maintenance


Problem

(1) Responsibility unclear

(2) Reliability of the system is not ensured

(3) Monitoring not implemented and not controlled

(4) (Commissioning see table above)


(1) Clarify all responsibilities at the very beginning of all projects. Else

the project will fail.

(2) Implement a maintenance contract and a tariff structure to replace

all system components at the end of their lifetime, especially the

battery system.

(3) Develop a monitoring concept and a monitoring data base, analyze

monitoring data continuously, check the monitoring system during

commissioning

(4) See commissioning part above


Operating & maintenance (O&M) cares for an overall reliability of the program but also for each

individual village electrification system. The most important thing is a very clear defined responsibility

of each task for operating and maintaining the system. We recommend establishing maintenance

contracts with a yearly maintenance period. According to the discussion with several contractors,

some contractors are able to establish regional service points for maintenance.

A reliable tariff structure is needed to gather money for maintenance and very important to exchange

the battery after about five to seven years. Continuous monitoring is recommended as a preventive

measure.

If there is no plan how to proceed after the guarantee expires there is a high risk that the project will

fail. A discussion with villagers concerning the sustainability of the project in required.

A lot of different Tariff systems are worldwide available, Fraunhofer ISE made a tariff review within a

project for two different Nepalese villages. One example of the possible tariff is the cross-subsidy.

Cross-subsidy can be done by establishing two different tariffs, one low tariff and one high tariff. High

tariff should be much more expensive. Thus, the high tariff subsidizes the low tariff. With this scheme,

everybody will have access to basic service with low tariff. Also, energy efficiency is supported to stay

in the cheap low tariff. For people with more money and need more energy, the high tariff gives the

possibility to have more energy if willingness and ability to pay is available.


Table 30: Capacity building

Topic Capacity building of different involved parties


Problem

(1) High level policy –implementation of untested zinc air battery

(2) Installation of grounding and lightning protection- good know how of

engineers in the companies, but implementation has some shortcomings

(3) Technical knowhow and system understanding of the villagers


(1) Political consulting: how to generate understanding of village

electrification programs and process to support reliable decisions, e.g. test

prototype batteries before implementation; put stronger focus on

reliability with quality assurance regarding monitoring O&M and capacity

building

(2) Put stronger focus on grounding and lighting protections during

commissioning. Working out a lightning protection concept, see chapter

4.6.2.1 and train the engineers and the installers.

(3) Capacity building of villagers, technical and socioeconomic training is

necessary.


We recognized that all involved parties show excellent know-how perhaps in high level politics a sound

understanding of the problems and complexity of such a program should be influenced. For the

villagers, their know-how should be improved. Nevertheless, capacity building is always and

continuously necessary as technology and circumstances change. Further, the know-how of the

different single people in each party is somehow vary. Sharing knowledge and trying to improve

overall knowledge of solar off-grid systems, both technical and socio-economic knowledge and

understanding is recommended.

The main gap is maybe the involvement of villagers and the improvement of technical know-how.

Villagers need to understand how a reliable operation of the PV system is possible, what the benefits

are, and they should gather a sound understanding about the real costs. They also should learn when

they have to replace the battery system and the cost. Only by understanding this, they can care for a

reliable operation and realize the reason why they are only allowed to consume limited power (explain

benefits in comparison to diesel generator).


Summary and Recommendations

In comparison to other worldwide PV village programs e. g. the China township program (2000 - 2005),

the Indonesia Solar Mini-grid Program runs well. This means the quality of the components and the

installation is predominantly good. On the village level, the collection of the fee for electricity and the

responsibility for the system operation by an operator is well organized. Especially the technical

inspections which were organized and financed by GIZ help to improve the quality of the existing and

future installations by learning from the mistakes and the possibility to improve faults. This should be

continued to enrich the experiences and learning from the sites.

Nevertheless, some topics for improvement have been identified. A more detailed prefeasibility study

for each village concerning detailed geographical and load data is suggested. This helps to satisfy the

energy demand of the villagers by improved adaption between energy demand of the village and the

PV system size. Also, off-grid PV installations nearby the grid < 5 km can be avoided and the contractors

can better calculate the offer for the system, since they know the detailed geographical conditions.

In the technical specification, some standards are missing, we tried to carefully integrate the relevant

standards for PV and the PVVP project in the detailed gap analyses. It is important not to mention too

many standards in the future tenders because it increases the risk to lose the view of what really

matters. In some cases, the electrical installation could be improved. In the detailed gap analyses we

made suggestions for an improvement of the installation which can be integrated into the technical

specification. Nevertheless, training for the installers is necessary.

In some cases, the workmanship should be improved. This cannot be fixed solely by more standards

or better technical specifications. The workmanship can be best improved by the following

recommendations:

Sharing the inspection results with the contractors.

Using of pictures which compare a good installation with a not satisfying one.

Selecting suppliers which have a technical sales partner in Indonesia in order to provide training.

Training of the staff.

Retaining 5-10% of the contractual amount till the acceptance of the system by inspection.

A lot of lightning strikes with negative impact to the components and the system function were

reported in the executive inspection reports and observed at our field trips. In order to reduce the

number of lightning strikes and especially the negative impact to the components and the system, the

design of a lightning protection concept and training of the engineers and installers concerning

grounding and lightning protection are strongly recommended.

The executive inspection report mentions that only 2% of the monitoring systems run well. Because

regular monitoring can improve future installations (by learning from errors and allow recognizing if

maintenance or repairing is necessary), it is recommended to pay more attention to establish a reliable

and working monitoring systems. For analyzing the data, training of EBKTE and/or the contractors is

recommended.


Be very carefully by installing components of new technology concepts like the Zinc-air battery in very

remote villages, because the longtime reliability is unknown. Start with one or some examples in the

laboratory and with one or a few test samples at a near-by off-grid village which is easily accessible.

To ensure a sustainable operation of the systems, the extension of the warranty period by the

contractor from 12 to 24 month is recommended. However, the most important task is to develop a

quality assurance plan for the time after the warranty period. It should include the following topics:

Establish a yearly maintenance concept perhaps by the contractor and payed by the villagers,

maybe partly subsidized by the government.

Availability of spare parts shall be guaranteed, perhaps by a service point of the contractor or

another PV or electric company located at the village or nearby.

Collecting money for replacement of at least one set of batteries, maybe subsidized by the

government.

Well defined responsibilities for all this tasks.


Annex

Annex A: Existing technical specification of DJEBTKE PV Mini-Grid

Annex B: List of recommended international standards related to PV Mini-grid

Annex C: Meeting summary of the Stakeholder Focus Group Discussion

Summary of PV Micro-grid Specification

Source: Pembangunan PLTS Terpusat di Provinsi Papua I.docx

No Component Parameter Value Remark

Type Off-grid Hybrid ready, Grid-tied readyConfiguration DC or AC couplingDocuments - Scanned of original brochures or

catalogue including the datasheet of all components- Single line diagram with captions- Wiring diagram - Bill of Material- Operational and maintenance manual: *Basic of off-grid PV system *Installation manual *User manual *Maintenance manual

*Troubleshooting

- The wiring diagram will also be used for troubleshooting- Bill of material consists of: name of the component, volume,unit, manufacturer, country of origin,

Type Mono/polycrystalline moduleNominal power ≥ 200 Wp The complete array should contain identical PV

modules with similar brand, type, and characteristics

Efficiency ≥ 16% Label of performance rating should be attached at the back of PV module

Interconnection Plug-in socket Plug-in socket should be rated at minimum of 1000 VDC.Combiner box must be installed at the output of each string.

Warranty 20 years with maximum degradation of 1% per year and maximum of 20% at the end of the warranty periode.

Test result Valid certificate and performance test results (series of product) that is conducted by an accredited testing laboratory

Certification ISO 9002 and ISO 14001 from manufacturer

Nominal output The total nominal output is based on the capacity of the plant.

Number of inverter Minimum 2 unitsElectrical network Up to 20 kWp = single or three-phase,

above 20 kWp = three-phaseThree-phase = 3/N/PE

Output voltage 230/400 VACOutput wafevorm Pure sinusoidalEfficiency ≥ 98%Protection system Input reverse polarity, AC short circuit, AC

overload, overcurrent, over/undervoltage, over temperature

1 General

PV module2

3 Grid Inverter

Technical Specification PV Microgrid EBTKE_3.xlsx Master Specification from EBTK 1 / 10


Indicator LED display showing inverter voltage & current, and load voltage & current

Operating in parallel YesManagement control Yes To control the incoming and outgoing energy from the

inverterData logging YesInterface Yes Communication with remote monitroing systemWarranty ≥ 5 years Factory warranty terms should be providedIP Class IP65Test result Valid certificate or test results (one series

of product) from an accredited independent testing laboratory. The certificate should show the efficiency of the inverter that was tested according to IEC 61727.

Certification ISO 9001 from the manufacturer Provision of copy of ISO 9001

Nominal output The total nominal output is based on the capacity of the plant.

Number of inverter Minimum 2 units for AC coupling and Minimum 3 units for DC coupling

Electrical network Up to 20 kWp = single or three-phase, above 20 kWp = three-phase

Three-phase = 3/N/PE

Output voltage 230/400 VACOutput frequency 50 HzNominal Input DC voltage ≥ 48 VDCOutput wafevorm Pure sinusoidalEfficiency ≥ 95%Total harmonic distortion ≤ 4% for AC coupling and ≤ 5 for DC couplingProtection system AC short circuit, AC overload, overcurrent,

over/undervoltage, over temperature, Indicator LED display showing inverter voltage &

current, and load voltage & currentOperating in parallel Yes Inverter should be able to work in parallel. Inverter

should be able to communicate via AC power line without any additional communication network. Intverter should be featured with Frequency Shift Power Control (FSPC)

Hybrid ready YesGrid-Tied ready YesBattery protection Battery temperature sensor, battery

equalizationBattery equalization to minimize the loss of battery capacity and extend the lifetime of the battery

Management control Yes To control the incoming and outgoing energy from the inverter

Data logging Yes

Interface Yes Communication with remote monitroing system

Warranty ≥ 5 years Factory warranty terms should be provided

IP class IP54

Battery Inverter4



Test result Valid certificate or test results (one series of product) from an accredited independent testing laboratory. The certificate should show the THD and efficiency of the inverter that was tested according to IEC 61683: Photovoltaic Systems-Power Conditioners-Procedure for Measuring Efficiency).


Nominal output power The total nominal output is based on the capacity of the plant.

Number of system ≥ 3 unitsControl strategy Maximum power point tracker For the case of integrated Solar Charge Controller in

the Inverter, the contractor should mention the feature and the integrated SCC should still meet the requirement

Efficiency ≥ 98%Nominal Input DC voltage ≥ 48VDCBattery charging feature Yes Quick and safe chargingProtection system Input reverse polarity, high battery voltage,

low battery voltage, overload, PV ground fault

Additional ground fault protection should be installed if the charge controller is not equipped with integrated ground fault protection

Warranty ≥ 5 years Factory warranty terms should be providedTest result Valid certificate or test results (one series

of product) from an accredited independent testing laboratory. The certificate should show the efficiency of the inverter that was tested according to IEC 61683.


Technology Lithium ion / Zinc Air / VRLALifecycle 1200 cycles at depth of discharge 80% Deep cycle batteryCapacity Based on plant capacity Plant capacity (kWp) | Battery capacity (kWh)

15 kWp | 144 kWh20 kWp | 192 kWh30 kWp | 288 kWh50 kWp | 432 kWh75 kWp | 720 kWh100 kWp | 960 kWh

Nominal voltage per cell 2 VCapacity per cell Minimum capacity stated in bill of quantityFloat service life ≥ 10 years at 20°CWarranty ≥ 10 years The warranty should be valid for PV mini grid

application that considers the environmental condition of the site including temperature and humidity. The warranty covers the after-sales service from the manufacturer which ensures the battery can operate on solar power for 10 (ten) years including on spare parts, delivery and installation.

Factory warranty terms should be providedNominal bank voltage 48 VDC The output range of the battery bank is 46 to 60 VDC

Solar charge controller5

Battery6



Location Safe and environmentally fit to the battery The location must consider safety factor for other components and take into account other technical aspects which can affect battery lifetime

Connector Copper (Cu) or Alumunium (Al) Connector should be protected by isolatorProtection Fuse to protect the load The protection is sized based on the minimum

capacity complies with list of quantity and price for each location, before entering inverter

Holder Made of anti-corrosive metal (not wood) The construction is shielded with minimum separation wall of 10 cm, thus battery can stand solidly

Certification ISO 9002 and ISO 14001 from manufacturer

Test result Valid certificate or test results (one series of product) from an accredited independent testing laboratory.

Access and user interface Ethernet or internet web browserFeatures Data logging from inverter and alarmUser interface Dedicated software or web browser Data from RMS must be shown locally through a PC

with 16" displayCommunication interface RS485, modem GSM/GPRS The RMS could also be connected to a PC locally.Pyranometer Second class, waterproof, field of view180° Pyranometer data is logged by RMS. The pyranometer

should be installed in parallel to the surface of PV module.

Connector installation Interconnection between PV modules should be installed inside cable tray/trunk

The cable tray/truk is located under PV array and mounted on the PV array support

Cable type from Combiner box to charge

controller

NYFGbY (diameter is based on current) According to SPLN/SNI standard

Cable type from Charge controller to

battery

N/A N/A

Cable type from battery to battery inverter NYAF (diameter is based on current) According to SPLN/SNI standard

Cable type from Grid inverter to AC panel

distribution

NYFGbY (diameter is based on current) According to SPLN/SNI standard

Cable type from Battery inverter to AC

panel distribution

NYY (diameter is based on current) According to SPLN/SNI standard

Cable installation from PV array to charge

controller

The cable should be installed underground inside the conduit with minimum depth of 30 cm and entering the power house through the foundation

Technical drawing of the cable conduit position through the foundation should be provided

Cable-end installation Cable terminal and connector should be used for cable connection (Not a direct connection)

The conenctor should fit the cable size and provide good isolation

Grounding system from PV array Type BC 35 mm2 According to SPLN/SNI standard. The grounding cable should be electrically connected (equipped with cable shoe and screwed) to the PV array support.

Grounding resistance ≤ 5 Ohm According to SPLN standard. Several grounding rod can be combined to reduce grounding resistance

Grounding insallation Cable grounding from power house and combiner box are connected together and installed inside grounding control box

The grounding control box is made from stone masonry that is in casted cement and smoothened. The height and cover (with handle) of the box must be designed to be easy for maintenance

Cabling and Grounding8

Remote monitoring

system (RMS)

7



Location Protected from the rainReference standard IEC 61439-1 and IEC 61439-2 The contractor should provide brochure of combiner

box, fuse, isolator switch, surge protection, and other offered protection system

IP class IP 66 made from Polycarbonate that is UV-proof for a long period

Design of the box must consider the humidity that may create condesation inside the box

Voltage rating of cable connection ≥ 1000 VDC According to PV application standardCable connection All the cable connection should meet the

available standard or using spring system to ensure the quality of the connection

Connector plug-in socket should be used for the input from PV string cable

Overcurrent protection Type Fuse gPV with current rating based on the output power

Modular overcurrent protection with functional indicator and maximum voltage of 1000 VDC (IEC 60269-6). Spare fuses (10% of the total fuses) must be provided.

Surge protection Modular and plugable with function indicator

According to EN 50539-11

Isolator switch Voltage rating 1000 VDC To be used during maintenance

Switch Main switch, terminal switch Distribution panel should be equipped with main switch

Busbar Yes Enclosure The upper, bottom, and side part of the

distribution panel should be covered to avoid electrical hazard Free mid clamp

Ventilation Yes, side part of the panel The ventilation should be covered to avoid water and animal get inside the panel

Minimum power Based on the plant capacityMinimum feeder Based on number of feederSystem voltage 380 / 400 VAC for three phase, 220 / 230

VAC for single phaseMonitoring Voltage, current, frequency, and energy

meter/kWh meterLight indicator should be visible at the door of the panel

Protection system Miniature circuit breaker (MCB), Earth leak circuit breaker (ELCB, and Fuse (based on nominal current), surge protection for 220 V/ 380 VAC.

Surge protection should be modular and plugable and equipped with function indicator.Spare fuses (10% of the total fuses) must be provided.

Arrestor type:

Spesifikasi Arrestor AC Arrestor Type = Type 1 + Type 2Operating Voltage = 230 VACMax Discharge current = 100 kA (10/350us)Impuls Discharge Current = 100 kA (10/350us)Protection level = < 0,9 kVResponse Time = < 25 nsIndicator = YesRemote Contact = Yes (NO/NC)

Timer and contactor Yes To operate the system at predefined timeMaterial Metal Fire resistance, moisture resistance, robust with a

minimum thickness of 2 mmLocation Easy to monitor and safeWarning sign Warning sign for electrical hazard should

be attached on the door of the panel

Distribution panel10

Mounting with mid clamp

Combiner box9



Technical drawing Power distribution including all the equipment

Foundation material Smoothen cast reinforced concrete with steel diameter of 10 mm.

Foundation dimension Cross section of 35 x 35 cm and minimum height of 60 cm

Technical drawing should be provided

Depth of the foundation ≥ 40 cm ≥ 20 cm should be visible Support pole material Steel pipe with diameter of 4 inch and 3

mm thickness or L-shaped steel with dimension of 10x10 cm, 4 mm thickness

The pole should be hot deep galvanised on its entire section. Technical drawing should be provided.

Support pole installation Support should be free standing on top of the foundation. The bottom of the poles (foot) must be in square-shape in which the material should be the same as the support pole with minimum thickness of 8 mm and dimension 20 x 20 cm

There should be four holes at all corners of the foot to be used for mounting purposes. The foot should be mounted to the foundation using anchor bolts with minimum depth of 30 cm.

PV module mounting Rail and clip model made of alumunium with minimum thickness of 3.5 mm

Dimension should be based on the dimension of the offered pv module. Technical drawing (mechanical and civil) of mounting system should be provided.

PV support tilt angle Design according to the tilt angle of the PV module

The tilt angle of the PV module is based on the site location to get the omptimum radiation. Optimum tilt angle is obtained from the result from simulation using PC software i.e. PVSyst. The simulation result has to be provided.

PV clamp support PV modules are mounted on the rail with mid clamp (between modules) and end clamp (at the end of the rail) to hold the PV module

Mid clamp is proposed to be mounted at the bottom of the modulem, thus there is no gap between the module. Another option to avoid gap is free mid clamp installation or using rail without mid clamp. The intention of eliminating gap is to protect combiner box from the rain

Height of PV module installation 70 cm between the lowest level of the module and ground

Warning sign Electrical hazard sign should be attached on each arrayThe placement of the array should be neat in a symetrical position. The distance between array should be wide enough to avoid shading on the other array, also between the power house and array.

The distance should also be impassable freely by people during maintenance. PV array layout should be provided.

Construction and material Permanent building or shelter made of Polyurethane and light steel frame.

The power house consists of battery room and control room. Technical drawing of: 1) building construction, 2) layout of equipment in the buiding and 3) electrical installation should be provided.

Foundation (for shelter) Made of river stone or equivalent stone with minimum depth of 50 cm

The dimension foundation should consider extra space of 70 cm and 20 cm for the front side and other sides respectively from the wall. The concrete should be smoothened.

Roof (for shelter) Zinc-Aluminium (ZA)

PV array support11

Power house12



Ventilation (for shelter) Battery room should have sufficient air circulation to keep the temperature below 30°C

Exhaust fans with dimension of 8 - 10 inches and maximum power consumption of 25 watt per fan must be installed on the wall of the battery room. The number of fans should be sufficient to keep the temperature below 30°C during operational state. The fans should be controlled by thermostat. The outer side of the fans must be covered to avoid water entering the room during raining

Ceiling (for shelter) 3 mm plywoodFoundation (for permanent building) Made of river stone or equivalent stone with

minimum depth of 50 cmWall (for permanent building) Made of red brick, plastered and paintedRoof (for permanent building) Asbestos wave sheet with 2nd class wood

frameDoor / window frame (for permanent building)

2nd class wood

Door material (for permanent building) Plywood or aluminium with door lockWindows glass (for permanent building) 3 mmFloor (for permanent building) Ceramic tile For both battery room and control roomCeiling (for permanent building) Plywood 3 mm Minimum height from the ground 3 mEntrance path Concrete or conbrick with minimum width

of 1 meter.From the gate to the door of power house

Wall (for shelter) ≥ 75 mmFloor (for shelter) White ceramic tile 30 x 30 cmElectrical installation Three bulbs and two socket outlets The installation should be protected by 2A MCBLightning protection Lightning rod should be installed closed to

the power house to protect the entire plantFence and post The entire power plant should be protected

by BRC fence with minimum height of 150 cm and equipped with single swing gate.

Minimum diameter of steel is 6mm. The minimum diameter of the round steel post between the fence is 2 inches. The fence should be coated with hot dip galvanized. Technical drawing of the fence must be provided.

Foundation of the fence Cross section = 20 x 20 cm, height = 45 cm, depth = 30 cm (Thus the height of the foundation from the ground is 15 cm)

The foundation is made from stone masonry in casted cement and smoothened

Dimension 1) 15 kWp plant = ≥ 36 m2 ;2) 20 kWp plant = ≥ 36 m2 ;3) 30 kWp plant = ≥ 40 m2 ;4) 50 kWp plant = ≥ 45 m2 ;5) 75 kWp plant = ≥ 50 m2 ;6) 100 kWp plant = ≥ 75 m2 ;

Site name plate The site name plate shows the information of plant size, name of the village, district, province, and budget year.

Technical drawing of the name plate should be provided

Grid type Overhead cable distribution Consisted of power pole and distribution cable.

Wire distribution Overhead distribution cables Technical drawing of the power pole, electrical network, and power pole foundation should be provided.

Distance between power poles 40 meter

Low voltage distribution13



Power pole Made of galvanized steel with height of 7 meter. Installed at a depth of 1 meter and equipped with accessories distribution network

According to SPLN/SNI standard

Power pole foundation The foundation consists of two footings: 1). 20 x 20 cm with height of 10 cm above the ground and 2). 30 x 30 cm with height of 50 cm installed underground. Thus the total height is 60 cm.

Grid cable between power poles Twisted cable 3x35mm2 + 1x25 mm2 + 1x16 mm2

According to SPLN/SNI standard. The 1x16mm2 is for streetlight connection to the contactor and timer inside the power house.

Grid cable from power poles to household NFA 2x10mm2 According to SPLN/SNI standard. Height of ovehead cable installation 4 meter from the groundStreetlight installation A 10-12 W streetlight with efficacy of 100

lumen/W inside a closed enclosure with IP65 every two poles

Streetlight should be controlled by timer starting from sunset with duration of 5 hours daily.

Wire distribution Overhead cable distribution Technical drawing of the power pole, electrical network, and power pole foundation should be provided.

Distance between power poles 40 meterPower pole Made of galvanized steel with height of 9

meter. Installed at a depth of 1 meter and equipped with accessories distribution network

According to SPLN/SNI standard

Power pole foundation The foundation consists of two footings: 1). 20 x 20 cm with height of 10 cm above the ground and 2). 30 x 30 cm with height of 50 cm located underground. Thus the total height is 60 cm.

Grid cable between power poles AAAC-S 70 mm2 According to SPLN/SNI standardHeight of ovehead cable installation 4 meter from the ground

System protection MCB with rated current of 1A and voltage of 220 VAC

Medium voltage

distribution grid

14

Household installation15



Energy limiter Programmable energy dispenser meter that is protected by password

Featured with programmable overload and shortcircuit protections and automatically recovered when the fault is cleared. The limiter should have LCD display to indicate the remaining energy left and an audio notification (beep sound) when the remaining energy reaches the programmed threshold.

1) Input voltage : 220 VAC, 1 phasa, 50 Hz2) Maximum load current : 1 A3) Input self-consumption (AC) : + 15 mA4) Controller : Microcontroller5) Setting : programmable with password6) Alarm : buzzer/beep when the remaining energy is 25%, indicator on the LED display when the quota runs out7) Measurement resolution : 1 watt-hour (Wh), accuracy 5%8) Operating temperature : 0-50°C9) Usage limiter: programmable according to time and power consumption

Distribution box MCB and energy limiter have to be installed inside a sealed metal box.

Load Three bulbs and a socket outlet Spare bulbs (10% of the total bulbs) must be provided to avoid the long duration of warranty claim and shipment.

1) Input voltage : 85-265 VAC 2) Power consumption : 4-6 W3) Luminous : ≥ 400 lm4) Light color : pure white5) Fitting : E276) Product warranty : ≥ 2 years7) Lifetime: 50,000 hours

Cable installation NYM 3x1.5 mm2 and 2x1.5mm2 According to SPLN/SNI standard. Installation should follow SNI Standard

Grounding Every house should be equipped with a good grounding system

Grounding cable should be installed inside cable conduit

Tower Tree angle with guyed wire Technical drawing of tower, tower foundation, and electrical scheme of lightning protection should be provided

Grounding Grounding must be in a good connection and separated from grounding system of PV array and power house

Grounding resistance ≤ 5 Ohm According to SPLN standard. Several grounding rod can be combined to reduce grounding resistance

Grounding insallation Cable grounding from power house and combiner box are connected together and installed inside grounding control box

The grounding control box is made from stone masonry that is in casted cement and smoothened. The height and cover (with handle) of the box must be designed to be easy for maintenance

Lightning counter Installed inside the box Specification of the box is similar to the combiner box

External lightning protection Early streamer emission or collection volume technology (CVT)

Lightning arrester16



Cable Double shielded down conductor 1x70 mm2

Height ≥ 17 m

17 Simulation Energy ouput The complete system with proposed components should be simulated using PVSyst or HOMER to obtain the expected energy generated. Contractor should provide projected energy yield in 20 years with an assumption of a constant annual energy yield drop

Irradiance data is based on available data in the location

Type (TV) LCD 32", 100-240 VAC, 50/60 HzPower consumption (TV) ≤ 100 WMounting bracket (TV) YesWarranty (TV) ≥ 1 yearSolid dish Anti-corrosive, ≥ 6 feetComponent Receiver, positioner, actuatorCable Coaxial and control minimum of 10 mWarranty ≥ 1 year

18 TV and Digital satellite

antenna


Overview on Standards Status: 15.12.2016

No Component / Topic Standard Titel Comments1 General IEC 62 124 PV stand‐alone systems ‐ Design verification

IEC TS 62 257‐9‐2 Recommendations for small renewable energy and hybrid systems for rural electrification ‐ Part 9‐2: Microgrids

Specifies the general requirements for the design and the implementation of microgrids used in decentralized rural electrification to ensure the safety of persons and property and their satisfactory operation according to the scheduled use.

2 PV Module IEC 61 215 Crystalline silicon terrestrial photovoltaic modules ‐ Design qualification and type approvalIEC 61 646 Thin‐film terrestrial photovoltaic modules ‐ Design qualification and type approvalIEC 61 730‐1 Photovoltaic (PV) module safety qualification ‐ Part 1: Requirements for constructionIEC 61 730‐2 Photovoltaic (PV) module safety qualification ‐ Part 2: Requirements for testingIEC TS 62 257‐7‐1 Recommendations for small renewable energy and hybrid systems for rural electrification – Part 7‐1: Generators – Photovoltaic arraysIEC 60 904‐1 Photovoltaic devices. Part 1: Measurement of photovoltaic current‐voltage characteristics PV Modules field test For field testing IEC 61 829 Photovoltaic (PV) array – On‐site measurement of current‐voltage characteristics For field testing

3 Grid InverterOEVE/OENORM EN 50530/AA:2012‐10‐01

Overall efficiency of grid connected photovoltaic inverters (Amendment) In English language only as a draft available

IEC 62 109‐1 / ‐2 / ‐3Safety of power converters for use in photovoltaic power systems. Part 1: General requirements. Part 2: Particular requirements for inverters. Part 3: Particular requirements for electronic devices in combination with photovoltaic element

4 Battery Inverter IEC 61 683 Photovoltaic systems ‐ Power conditioners ‐ Procedure for measuring efficiency

Describes guidelines for measuring the efficiency of power conditioners used in stand‐alone and utility‐interactive photovoltaic systems, where the output of the power conditioner is a stable a.c. voltage of constant frequency or a stable d.c. voltage.

5 Solar Charge Conroller IEC 62 509 Performance and functioning of PV battery charge controllersIEC 62 109‐1 / ‐3 Safety of power converters for use in photovoltaic power systems. Part 1: General requirements, Part 3: Controllers

6 Battery IEC 60 896‐11 / ‐21 / ‐22On Stationary lead‐acid batteries: Part 11: Vented types – General requirements and methods of tests Part 21: Valve regulated types – Methods of tests, Part 22: Valve regulated types – Requirements

IEC 61 427 Secondary Cells and Batteries for Photovoltaic Energy Systems (PVES) – General Requirements and Methods of TestIEC 62 485‐2 Part 2: Safety requirements for secondary batteries and battery installations: Stationary Batteries

IEC TS 62 257‐8‐1Recommendations for small renewable energy and hybrid systems for rural electrification – Part 8‐1: Selection of batteries and battery management systems for stand‐alone electrification systems – Specific case of automotive flooded lead‐acid batteries available in developing countries

IEEE 1361 Practice for determining performance characteristics and suitability of batteries in photovoltaic systems ‐ Field test For field testing7 Remote Monitoring IEC 61724 Photovoltaic system performance monitoring. Guidelines for measurement, data exchange and analysis

IEC 61194 Characteristic parameters of stand‐alone photovoltaic (PV) systems 8 Cabling and Grounding IEC 60 227‐1‐4 Polyvinyl chloride insulated cables of rated voltage up to and including 450 V/750 V‐Parts 1‐4: General requirements

IEC 62 852 Connectors for DC‐application in photovoltaic systems – Safety requirements and testsIEC 62 895 Electric cablesIEC 61 773 Overhead lines – Testing of foundations for structures For field testing

9 Combiner Box10 Distribution Panel IEC 61 439‐1 Low‐voltage switchgear and controlgear assemblies ‐ Part 1: General rules Not clear whether it fits this context …11 PV Array Support12 Power House13 Low Voltage Distribution IEC 60 364 series Low‐voltage electrical installations (32 parts!) see also section 15, Household Installation

IEC 60 364‐5‐52 Electrical installations of buildings – Part 5‐52: Selection and erection of electrical equipment – Wiring systemsprovides also information for cross‐section and and voltage drop

IEC TR 61 200‐52:2013 Electrical installation guide ‐ Part 52: Selection and erection of electrical equipment ‐ Wiring systems

This Technical Report serves as a supplement to IEC 60364‐5‐52:2009 and explains the rulesso as to facilitate the design, selection, erection and maintenance of wiring systems.It is written for everyone concerned with the design, the selection and supply of equipment, aswell as the persons who install, maintain and use electrical installations.

IEC 60 038 IEC defines a set of standard voltages for use in low voltage and high voltage AC electricity supply systems.

recommended_standards_161215_v1.xlsx 1 / 2

No Component / Topic Standard Titel Comments14 Low Voltage Distribution this section is doubled! 15 Household Installation IEC 60 669‐1 Switches for household and similar fixed‐electrical installations. Part 1: General requirements

IEC 60 947 series Low‐voltage switchgear and controlgear (25 active parts)

IEC 60 227‐1‐4 Polyvinyl chloride insulated cables of rated voltage up to and including 450 V/750 V‐Parts 1‐4: General requirementsIEC 60 364‐5‐53 Electrical installations of buildings – Part 5‐53: Selection and erection of electrical equipment – Isolation, switching and controlIEC TS 62 257‐5 Recommendations for renewable energy and hybrid systems for rural electrification – Part 5: Protection against electrical hazardsIEC 60 364‐4‐41 Low voltage electrical installations: Protection for safetyIEC 60 269 series Low‐voltage fuses

16 Lightning Arrester IEC 61 643 Low voltage surge protective devicesIEC 62 305 Protection against lightning

17 same like no 1618 Simulation

19 TV and Digital Satellite Antenna

Others IP IEC 60 529 Degrees of protection provided by enclosures (IP Code)Operation, maintenance and replacement

IEC TS 62 257‐6 Recommendations for small renewable energy and hybrid systems for rural electrification – Part 6: Acceptance, operation, maintenance and replacement

BOS Components IEC 62 093 BOS components ‐ Environmental reliability testing ‐ Design qualification and type approval Includes inverters, charge controllers and batteries

recommended_standards_161215_v1.xlsx 2 / 2

1

Summary

Focus Group Discussion (FGD)

“How to improve the quality of future PV mini-grid systems in Indonesia:

Technical Specification”

Attendees:

1. DJEBTKE

2. Puslitbang KEBTKE

3. BPPT

4. Technical Commission of BSN: PV cluster (represented by PLN Puslitbang EBT)

5. Fraunhofer ISE (FISE)

6. GIZ/EnDev ID

(Attendance list attached)

Topic Information, discussion

Feasibility study (FS) Conducted by local government

Uncertainties on baseline data reliability from the local government

Sampling check by EBTKE (SubDit Program) to ensure data reliability

from local government (only sampling due to limited resources)

Surveys by local consultant are somewhat below expectation, e.g.

number of household data are often inaccurate

EBTKE had published a guide book on how to conduct FS (the “blue

book”) which is currently being reviewed

Simulation software: Mini-grid builder, Homer Pro, Sunny Design

Q: Are there any methodologies to measure willingness-to-pay or

ability-to-pay?

A: GIZ (Kenya) compiled a tool to calculate tariff for PV mini-grid; it

might come up with relatively high tariff, but this reflective tariff needs to

be shared

Proposal Proposal for PV mini-grid comes from local community to provincial

government; should be endorsed/signed by Bupati, but does not

guarantee commitment from government

Commitment from local government and community shall be earned

since the beginning; the community shall be engaged earlier and local

government should prove that a community organisation is formed

before the project/tender started

PV capacity/sizing

(Q7)

The main concern is how to make a good planning for reliable access to

electricity

Battery sizing:

o Previously 3-day autonomy

o New design (for program 2017) will be 2-day autonomy and double

the size of solar panels

Daily energy setup has shifted from 260 Wh/day to 300Wh/day for the

current programme in 2016

System sizing for next tender will be based on 600Wh/day/HH and max

1000Wh/day for public facilities

Streetlight 11W/lamp

PV modules Local produced solar panels can reach 16% efficiency

Measurement of Uoc of each PV string, to identify hotspot

2

PV modules testing

(Q3-5)

Some of PV module have already test their module with TUV Rheinland

Manufacturer pay EUR 80,000 for PV module testing

Measurement of current voltage

Outdoor measurement (instantaneous measurement)

Adaptation of IEC 61 215 to national standard (SNI) has already

completed, BPPT is only able to conduct 8 from 16 tests recommended

by IEC

Inverter SMA will not establish a representative office in Indonesia until the local

market reach 100 MW installed capacity per year

Currently, SMA Australia had held a regional training in Indonesia

Battery inverter In the 2015 tender, specification on inverter efficiency was lowered to

allow local inverter to compete, however, as a consequence some sites

use a non-recommended (Chinese) product brand: Kehua Tech

For next tender, specification shall comply to international standard

Battery Zinc-air claim a 10-year warranty, although is not yet proven as

Indonesia is one of a few countries to test the zinc-air battery

EBTKE is in favour to install a system that could last longer, especially

with batteries, thus zinc-air was considered

Zinc-air battery is partially locally manufactured (fulfil local content

requirement)

Suggestion: zinc-air battery should be tested in more nearby location

because its reliability is not yet proven (unless the supplier could

commit to repair and/or replace the batteries when problem occurs)

Lead-acid battery does not require BMS (Battery Management System),

however ABB requires to include BMS in the (lead-acid) battery system

Lithium-on technology has many standards but needs to be sorted and

filtered because of its relatively new

FISE could assist to handpick the standards for lithium-ion batteries, but

it might be difficult to comply with local content since the best battery

producers for lithium-ion are from Japan

Q: How to detect battery defect after some years of operation? What

parameter(s) should be looked at?

A: Battery condition depends on operational condition of the system of

which is different among sites; battery is near the end-of-life when the

ability of battery to supply energy is reduced (discharge rate is faster)

Battery standard SNI (national standard) for battery is not yet available, although the

international standard exists

IEC 60 896-21/-22 is more common and local manufacturers should

already comply with this

IEC 61 427 is not really mandatory for the project

Battery testing according to SNI is available in BPPT (IEC 61 427), this

becomes requirement under the current technical specification

Lightning protection FISE to include “ring system” drawing for lightning protection

Surge arrester: FISE suggested to include in the Inspection Guide to

look at surge arrester; if it is red, it must be changed immediately

Q: How to avoid lightning strike to the distribution grid?

A: Put lightning arrester in the AC distribution output panel

Cabling According to PLN: losses for distribution grid in rural areas is up to 10%

3

compared to output at powerhouse

Current specification: maximum 3 km distribution grid from powerhouse

FISE suggested to include picture/scheme from existing standard to be

more clear in the specification

FISE suggested up to 4% distribution losses in the powerhouse

Civil structure A manual for array mounting structure existed; it might need adaptation

to off-grid application

Warranty period

(direct replacement)

PV modules: 20 years

Inverter: 5 years

SCC: 5 years

Battery

o Lead-acid: 3 years

o Zinc-air: 10 years

Maintenance period: 1 year (FISE suggested to extend the

maintenance period to 2 years)

During maintenance period the contractors should provide a reliable

contact person to troubleshoot

Design verification

(Q8)

If EPCs quote for the right components based on technical

specification, then tender task force will accept the offer

Request for FISE to include a practical guide in the final report on how

to verify the design

Monitoring system Regular monitoring data (minimum monthly) needs to be sent to local

government

Standard monitoring parameters for off-grid PV mini-system is not yet

regulated by IEC

EBTKE does not require real-time data since there is no resources to

monitor and/or troubleshoot if problems occur; interval requirement is

15-60 minutes

Several issues observed by EBTKE regarding monitoring:

o Monitoring parameters from each product are different

o Operators does not have capacity

o Incompetent installers

EBTKE listed the following required information:

o Daily load

o Performance ratio (how much energy generated), comparison

between energy from the irradiation and actual energy generated

o Battery performance

o Failure history

Recommendation for key performance indicators (KPI):

o Irradiation

o Energy losses

o Energy generated

o Indicator of good performing/non-performing/need adjustment

FISE shall come up with recommendation for minimum parameters to

be monitored

PPHP (system acceptance committee) should download data and read-

out, and able to analyse directly

There is a need for a guideline to identify which parameters to look at

by the operator and what’s the impact

Commissioning (Q9)

and system

Contractor is responsible to conduct commissioning

There is no uniformed commissioning procedures among contractors

4

acceptance There is no verification of result from the commissioning process

ULO (Uji Laik Operasi/Operational Acceptance Test) should be

conducted by contractor (under contract); result should be submitted

before payment

ULO is general for electrical installation, not specific for PV mini-grid

FISE suggested data read-out to be submitted by the contractor during

commissioning

FISE to provide input to improve the Inspection Guide

FISE to suggest critical indicators to accept a system

Rehabilitation Funding for rehabilitation is available, but local government does not

diligently report to EBTKE about breakages occurred

Measurement equipment should be in place (at least camera) to report

Local content Mandate to certify local content is in the Ministry of Industry, EBTKE is

among the users of this certification

One of the parameters of local content is the engineering part

Puslitbang KEBTKE develops PV mini-grid for research scale, of which

the procurement is not limited to local products (no local content

requirement imposed)

General remarks The remote the location, the specification should be higher/better

Three important aspects to consider:

o Technical specification: who will check the quality?

o Quality of people who install it

o Pre-shipment quality assurance

EBTKE is in the process of developing internal inspection team; will

adopt inspection method from GIZ; need GIZ support to transfer

knowledge

FISE shall recommend a maintenance schedule for replacement of

batteries and other components as an overview for EBTKE to plan and

foresee the upcoming needs

Currently the Technical Committee is working on 5 standards: 2 new

standards (regarding inverter and FS) and 3 revisions

Direct follow-up Share the presentation to FGD participants

GIZ to share with EBTKE the O&M expense calculation for grid-

connected project (this calculation can be adopted to mini-grid)

GIZ to share the tariff tool developed by GIZ (Kenya)

Visiting testing facilities in BPPT (meet with Pak Abdul Rosyid)