Energy Loss Assessment on Welding Transformers in Ethiopia

Energy Loss Assessment on Welding

Transformers in Ethiopia

(Draft report)

September 15, 2021

Report Authored by:

On Energy Consult

Bole Sub city, Wereda 13, House No. 1131

Phone no: +251-118220782 /+251-911-516196

Website: www.onenergyet.com

Email: [email protected]

Addis Ababa, Ethiopia

Submitted to:

Ethiopian Electric Utility

Addis Ababa, Ethiopia

http://www.onenergyet.com/

mailto:[email protected]

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OUTLINE

1. INTRODUCTION ..................................................................................................................................................... 1 1.1 Background ...................................................................................................................................................... 1 1.2 Problem analysis .............................................................................................................................................. 1 1.3 Demand assessment ......................................................................................................................................... 3 1.4 Objective .......................................................................................................................................................... 4

1.4.1 General objective .................................................................................................................................. 4 1.4.2 Specific objectives ................................................................................................................................ 5

1.5 Scope ............................................................................................................................................................... 5 2. DESCRIPTION OF METHODOLOGY AND TECHNICAL APPROACHES ....................................................... 5

2.1 Baseline data collection approach .................................................................................................................... 6 2.1.1 Desk Review ......................................................................................................................................... 6 2.1.2 Types of Relevant Data Collected ........................................................................................................ 7 2.1.3 Sampling methodology ......................................................................................................................... 8

2.1.3.1 Target population and Study area .............................................................................................. 8 2.1.3.2 Sampling frame .......................................................................................................................... 8 2.1.3.3 Sample size determination ......................................................................................................... 8

2.2 Data Collection Tools ...................................................................................................................................... 9 2.3 Special Study Tools ....................................................................................................................................... 10 2.4 Logistics Arrangement ................................................................................................................................... 11 2.5 Ethical requirement and field procedure ........................................................................................................ 12 2.6 Data Analysis Approach ................................................................................................................................ 12

2.6.1 Technical approach ............................................................................................................................ 12 2.6.2 Top‐down approach ............................................................................................................................ 12 2.6.3 Bottom‐up approach ........................................................................................................................... 12

3. AN OVERVIEW OF WELDING TRANSFORMERS OR WELDING MACHINES EFFICIENCY ................... 14 3.1 Welding ......................................................................................................................................................... 14 3.2 Historical Development of Welding ............................................................................................................. 14 3.3 Welding transformers or machines ................................................................................................................ 19 3.4 Classification of Welding Processes According To Heat Source .................................................................. 20 3.5 Electric Welding ............................................................................................................................................ 21 3.6 Types of electric welding ............................................................................................................................... 21 3.7 Electric Arc Welding ..................................................................................................................................... 22 3.8 Energy Conservation Potential in Welding .................................................................................................... 26

3.8.1 General Description of Welding Processes ......................................................................................... 26 3.8.2 Worldwide Welding Energy Consumption ......................................................................................... 27 3.8.3 Energy Efficiency in Welding technologies ....................................................................................... 28

4. RESULT AND FINDINGS ..................................................................................................................................... 32 4.1 Welding Machines in Ethiopia ...................................................................................................................... 32

4.1.1 Welding machines in micro, small, and medium manufacturing industries ....................................... 32 4.1.2 Types of Welding machines in Ethiopia ............................................................................................. 33

4.2 Welding machines in the Construction Sector ............................................................................................... 35 4.3 Welding machine in car assembly or manufacturing, and car repairing service provider ............................. 36 4.4 Estimation of the total number of welding transformers ............................................................................... 38 4.5 The energy efficiency level of welding machines in Ethiopia ....................................................................... 38 4.6 Energy Consumption of Welding transformers in Ethiopia ........................................................................... 41 4.7 Estimation of electricity consumption share of welding transformer in Ethiopia .......................................... 45 4.8 Import data from Ethiopian Customs Commission (ECC) ............................................................................ 46 4.9 Local Welding transformer manufacturing and maintenance service providers ............................................ 46

5. WELDING MACHINES ENERGY EFFICIENCY STANDARDS AND REGULATIONS, ETHIOPIAN AND

GLOBAL EXPERIENCE ............................................................................................................................................ 49 5.1 Ethiopian Standard and Regulations .............................................................................................................. 49

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5.1.1 Standard development by Standards Agency ...................................................................................... 49 5.1.2 The regulatory body EEA ................................................................................................................... 50 5.1.3 Testing of welding machines for conformity with the standards ........................................................ 51

5.2 Welding Machines National and International Regulations and Standards ................................................... 51 5.2.1 Analysis of regulations and standards in other countries .................................................................... 51 5.2.2 EU energy efficiency regulation for Welding machine ...................................................................... 51 5.2.3 China’s Energy Efficiency regulation for arc welding equipment ...................................................... 56 5.2.4 Proposed Policy and regulation Options for Ethiopia ......................................................................... 56

6. SETTING UP OF ENERGY EFFICIENCY REGULATION FOR WELDING TRANSFORMERS .................... 58 6.1. The Proposed Energy efficiency requirements of welding transformers in Ethiopia ................................... 59 6.2. Resource efficiency requirements ................................................................................................................. 59 6.3. Estimation of energy saving that can be achieved by the implementation of the proposed Energy Efficiency

measure. ............................................................................................................................................................... 63 6.4. Implementation Schedule ............................................................................................................................. 65 6.5. The possible risks and its mitigation Measures ............................................................................................ 65

7. Reference ................................................................................................................................................................. 68 Annex I ........................................................................................................................................................................... i Annex II ........................................................................................................................................................................ iii Annex III ...................................................................................................................................................................... iv Annex IV ....................................................................................................................................................................... v

List of Tables

Table 1 : power source of welding machines ....................................................................................................... 29 Table 2 : Number of welding transformers in the country ................................................................................... 38 Table 3 : Measured data of each welding machine ............................................................................................ 41 Table 4 : Average time of welding in a day ........................................................................................................ 42 Table 5 :Total estimated amount of energy consumption of welding transformers during welding .................... 43 Table 6 : welding transformers during their idle time ......................................................................................... 44 Table 7 : Energy consumption of welding transformers ...................................................................................... 44 Table 8 : total energy consumption of welding transformers in Ethiopia ........................................................... 45 Table 9 : national electricity consumption by tariff group in the year 2020/2012E.C ........................................ 45 Table 10 : Price of locally manufactured Welding Transformers ....................................................................... 47 Table 11 :- Type of welding machines manufactured in Ethiopia ....................................................................... 48 Table 12 : Manufacturers who do design work ................................................................................................... 49 Table 13 : energy efficiency requirement ............................................................................................................ 52 Table 14 :Welding equipment powered ............................................................................................................... 59 Table 15 . Annual energy saving due to implementation of the proposed energy ............................................... 63 Table 16 : Annual energy saving due to implementation of the proposed energy efficiency measure on the

imported welding transformer. .................................................................................................................... 64 Table 17 : Energy consumption reduction by the proposed regulation ............................................................... 65 Table 18 : Implementation schedule of the proposed energy efficiency measures .............................................. 65

List of Figures

Figure 1 : Causes of low energy efficiency of welding transformers ..................................................................... 2 Figure 2 : Effects of low energy efficiency welding transformers ......................................................................... 3

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Figure 3 : Structural framework ............................................................................................................................ 6 Figure 4 : Head of the sarcophagus of Tutankhamen ............................................................................ 15 Figure 5 : Ukraine steel sword ........................................................................................................................... 15 Figure 6 : Colossus of Rhodes (built c. 292-280 BC) .......................................................................................... 15 Figure 7 : Edmund inventor of acytiline ............................................................................................................. 16 Figure 8 : Metalworks in early 19th c .................................................................................................................. 16 Figure 9 : Carbon arc welding in early 20th c .................................................................................................... 16 Figure 10 : Oxyacetylene welding process ......................................................................................................... 17 Figure 11 : Coated metal electrode ..................................................................................................................... 17 Figure 12 : Automatic welding ........................................................................................................................... 18 Figure 13 : Gas shielded metal arc welding ........................................................................................................ 18 Figure 14 : Laser welding ................................................................................................................................. 18 Figure 15 : Plasma arc welding .......................................................................................................................... 18 Figure 16 : welding without pressure ................................................................................................................. 19 Figure 17 pressure welding ............................................................................................................................... 20 Figure 18 : electric welding................................................................................................................................. 21 Figure 19 : Electric resistance welding ............................................................................................................... 22 Figure 20 : Metal arc welding ............................................................................................................................. 23 Figure 21 : Carbon arc welding .......................................................................................................................... 23 Figure 22 : Atomic hydrogen arc welding ........................................................................................................... 24 Figure 23 : Tungsten inert gas arc welding ......................................................................................................... 24 Figure 24 : Gas Metal Arc Welding (GMAW) or Metal Inert Gas Arc Welding (MIG) ..................................... 25 Figure 25 : Submerged arc welding .................................................................................................................... 25 Figure 26 : Electro-slag arc welding................................................................................................................... 26 Figure 27 : Plasma arc welding .......................................................................................................................... 26 Figure 28 : Welding related activities ................................................................................................................. 28 Figure 29 : welding generator ............................................................................................................................. 29 Figure 30 : Welding transformer ......................................................................................................................... 30 Figure 31 : Welding rectifier ............................................................................................................................... 30 Figure 32 : Inverters ............................................................................................................................................ 31 Figure 33 : Efficiency comparison ...................................................................................................................... 32 Figure 34 : ........................................................................................................................................................... 33 Figure 35 : Welding machines name tag ............................................................................................................ 33 Figure 36 : Machines during welding ................................................................................................................. 33 Figure 37 : Welding transformers in Ethiopia .................................................................................................... 34 Figure 38 : Welding transformers during operation ........................................................................................... 34 Figure 39 : Types of welding transformer ........................................................................................................... 35 Figure 40 : Arc welding ...................................................................................................................................... 35 Figure 41 : Welding transformers in construction sites ...................................................................................... 36 Figure 42 :Welding machine distribution ............................................................................................................ 37 Figure 43 : Manufacturing of welding transformers ........................................................................................... 39 Figure 44 : Poor handling of welding transformers ............................................................................................ 40 Figure 45 : Welding transformers during operation ................................................................................ 40 Figure 46 : Welding transformer manufacturing ................................................................................................ 40 Figure 47 : Imported types welding transformer ................................................................................................. 41 Figure 48 : burned copper wire ........................................................................................................................... 47 Figure 49 : Locally manufactured welding transformers ................................................................................... 48

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1. INTRODUCTION

1.1 Background

There has been a huge improvement in the electricity production of the country in recent years.

However, the electricity supply in the country is still far below satisfying the growing demand.

Electricity demand is growing by more than 25% as studies are showing [4]. This is attributed to

the high population and economic growth, expansion of grid extension to rural towns and villages,

expansion of small and medium manufacturing industries in rural towns and big cities, massive

manufacturing, industrial and infrastructure projects in housing, industrial parks, road, railways,

power, energy, and telecommunication. In parallel to the increasing demand, the country is facing

a huge power loss in transmission and distribution networks, and utilizing inefficient equipment

and electrical appliances in homes, workshops, and offices.

Locally manufactured welding transformers are among the equipment which contributes to the

power loss as indicated by previous studies. There are several under-performance welding

transformers in the country. Some of the indications of this are: the locally manufactured welding

transformers are not well designed and efficient, exhibit high voltage drop, and have less safety

standard and high failure rate[14]. A study in 2009 revealed that there were about 60,000 to 80,000

locally manufactured welding transformers in use all over the country [15]. When these machines

are at the full-load and no-load condition and connected to the electricity grid of the country, the

aggregate losses are huge.

Following this finding, the Ethiopian Electric Utility in collaboration with the Ethiopian Energy

Authority has decided to outsource this baseline study of assessing the Energy loss of welding

transformers in Ethiopia. The assessment will be based on documenting the type and number of

welding transformers used in the market. Plus, the result of the assessment will enable EEU and

EEA to implement energy efficiency measures on the product.

1.2 Problem analysis

The welding industry is, by its nature, energy-intensive. Welding, a family of processes utilizing

heat to cause coalescence between materials is generally recognized to be the most energy-

intensive joining technology. Within the U.S. the metal fabrication industry consumes about 6%

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of the total energy produced [2]. Within this industry, welding is a major industrial process and is

used in the production of nearly all types of fabricated metal products. However, the total energy

consumption by welding processes has not previously been quantified. Welding equipment is

products that deliver energy in the form of electricity to join or cut two or more metals by heating

(often >6,000°C), with or without the use of ancillary materials such as filler sticks, wire, or gases

that shield the welding area from the surrounding air. Welding equipment uses electricity, to

produce an 'arc' to melt, join, braze, solder, and cut materials. Welding equipment in scope can be

stationary or transportable, and consists of linked parts or components, at least one of which moves

and which are joined together to produce coalescence of metals by heating them to the welding

temperature (with or without the application of pressure) or by the application of pressure alone,

with or without the use of filler metal, and with or without the use of shielding gas(es), using

appropriate tools and techniques, resulting in a product of defined geometry.

Figure 1: Causes of low energy efficiency of welding transformers

In Ethiopia, almost all of the locally manufactured welding transformers are arc welding types.

These locally manufactured welding transformers are used in garages and metal and woodworks

for heavy welding purposes. These welding transformers have no power rating. They're made from

the experience of the manufacturer the copper coiled welding transformer is used for heavy-duty.

Low energy efficiency of locally

manufactured welding transformers

Non use of right wiring and coiling

Miss match between primary

and secondary coil winding

Improper use of welding

Heat loss

Lack of research and innoviation

Abcence of standard

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Due to the high heat resistive capacity of copper wire, the welding transformer is made by copper

wire weld or grind for 8 hrs per day. Some manufacturers will mix aluminum wire to the copper

due of the cost of copper wire is raised which can cause heavy sparks during the welding process.

When the coil is aluminum due to the low heat resistivity capacity the coil will melt and burn out.

It can’t be maintained unless the coil is substituted by a new one. But for copper wire, it can be

rewind for a second time.

Figure 2: Effects of low energy efficiency welding transformers

1.3 Demand assessment

Around 15,000 welding equipment units are sold in the UK annually. Welding equipment

collectively consumes a significant amount of energy. The European Commission's preparatory

study[6] states that on average, a typical arc welding unit has a primary continuous power

Low energy efficiency of

locally manufactured

welding transformers

High power demand

High energy consumption

High power

demand

Shortage of power

Intruption of power

High eneergy consumption

Unwanted energy

consumption in national level

Increase cost of electricity in

manufacturing industries

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consumption of 6.2 kVA (arc-on), equaling a 75% efficiency at 200 A and output power of 4.65

kW (23.25 V). It was found that most of these units are used in 1-shift-operations and a realistic

arc-on-time (i.e. operating factor) is 25%. This operating factor might be much lower in smaller

repair shops or in the construction sector, where the welding equipment is used only occasionally

and higher in industrial production, where a similar welding unit might be used at high load in an

automated production line. It is estimated that welding equipment uses 307 GWH per year

(2020/21) in the UK.

A study titled 'PRELIMINARY SURVEY ON ELECTRIC ENERGY EFFICIENCY IN

ETHIOPIA' in 2009 by Mengesha Mamo[10] revealed that metal workshops using locally made

welding transformers have increased all over the country. It has been estimated that the total

number of locally produced welding generators in use to be about 60,000 to 80,000 [11] at that

time. The author has estimated the loss of samples of the locally manufactured transformers to be

on average 1 kW compared to 0.23 kW of equivalent imported transformers.

The author also stated that it is possible to reduce the loss at least by half by proper design and

material selection. If 170 working days and about 2 hrs effective working hours are assumed per

day, the electric energy saving per year will be 10.2 GWH.

In this study, an assessment on the energy efficiency of welding transformers being used in the

country, imported to the country and comparison will be done based on their efficiency and

performance. Finally, a proposal will be given for upgrading the efficiency of welding transformers

being manufactured and imported to our country.

Welding equipment products within the scope of this study draft are generally arc welding which

uses only electricity as a power source and are used in different sectors like in constructions, small

and medium manufacturing industries, metal factories, and in other similar areas. This study

mainly focuses on manual welding-type welding machines.

1.4 Objective

1.4.1 General objective

The general objective of this assignment is to assess the energy efficiency of the existing welding

transformers on the Ethiopian market and their impact on the power distribution system and the

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magnitude of the losses posted by those transformers. In addition, this study will develop the

concept for the development and implementation of energy efficiency improvement options and

address key energy efficiency improvement steps of welding transformers and implementation

guidelines.

1.4.2 Specific objectives

The specific objectives of the study are to:

i. Assess the energy efficiency level of imported and local welding transformers in the

country.

ii. Assess the electricity demand, electricity consumption and consumption patterns,

hours of operation and time of use of welding transformers,

iii. Estimate the magnitude of the losses imposed by the transformers and the impact on

power distribution.

iv. Comparison of the efficiency of locally manufactured welding transformers and the

imported ones among all types of welding transformers and

v. Develop a concept for the development and implementation of energy efficiency

improvement options.

1.5 Scope

The scope of the assessment is to review current related technology, local practice, global

experience, and similar projects executed at national, regional, and international standards of

imported and local manufactured welding transformers in Ethiopia.

2. DESCRIPTION OF METHODOLOGY AND TECHNICAL

APPROACHES

The Special Study’s approach includes two components, namely the baseline data collection and

analysis.

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Figure 3: Structural framework

2.1 Baseline data collection approach

The study implements both primary and secondary data sources to assess and establish welding

machine efficiency levels in the county. All the available data are reviewed in detail by the data

collection team. The following sections present the data collection strategy that is followed during

the study.

2.1.1 Desk Review

The study assessed and reviewed relevant documents and data on the current practice of welding

transformers. The secondary data sources that are used in the study are obtained from the Ethiopian

Revenue and Customs Authority (ERCA), Ethiopian Ministry of Trade and Industry (MoTI), and

Federal Small and Medium Manufacturing Industry Expansion Authority and relevant works of

• Total number and type of welding transformers in Ethiopia

• 8 regional states and 2 administrative states

• 100 WT from small manufacturing, 50 from medium & 10 from big

industries, 20 from construction sites

• Stakeholders identification

• Identify and assess local WT manufacturers

• Assess environmental and health impact

Baseline data

collection

• Compare energy-saving aspects of inverter-based and ordinary

• Compare energy efficiency of locally manufactured welding transformers

with imported

• Calculate energy efficiency and determine baseline for energy loss

• Calculate energy consumption

• Analyze environmental and health impact of locally manufactured

• Identify and analyze best practices of innovators

Analysis

• Provide recommendations and suggestions to set or adopt minimum

performance standard

• Provide procedures, criteria, guideline

• Devlop measurement and verification procedure, communication campaign

• Devlop project implementation budget and activity plan

• Explain the environmental advantage of the program

Energy

efficiency

program

design

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literature. To accomplish the assessment on energy efficiency, reviewing of global and national

parameters and characteristics of welding transformers like the type of transformers, their

efficiency, cost, safety, and other parameters are conducted. The purpose of this review is mainly

to collect relevant information from works of literature, scientific articles, official policy

documents, reports and proceedings of development organizations, existing projects, study reports,

country experiences, and industrial development strategies. The following specific tasks are done

while reviewing relevant documents:

• Assess the different countries' related experiences especially the policies and

regulations on welding transformer efficiency improvement measures and the effect

of the regulation and the possible measures are taken.

• National and international Minimum Energy Performance standards if there is any

or any other energy efficiency standard on welding transformers and effects of the

regulations and implementation strategies currently in use are reviewed.

• National and International (Global) welding machine energy efficiency standards of

NEMA (National Electrical Manufacturers’ Association) of USA or IEC are

reviewed. The effects of adopting the IEC standard are reviewed. Other international

standards are reviewed.

• Recent welding technologies of improved efficiency are reviewed

2.1.2 Types of Relevant Data Collected

The On energy team collected relevant data for the analysis such as the power rating, current,

voltage, type of welding machine, local or imported type, number of welding machine in an

organization where data is collected, country of origin, and other data were collected. In the case

of local welding transformers, there is no any name plate to collect data such as the power rating,

current, voltage and efficiency. Therefore, the on energy team tried to measure some parameters

for the local welding transformers by taking samples.

All the data mentioned above is very important to estimate the total imported transformers, the

total locally manufactured welding transformers, the energy consumption of local and imported

transformers, and to calculate the total energy consumption of welding transformer in the country.

These data were collected by interviews using questionnaire.

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2.1.3 Sampling methodology

2.1.3.1 Target population and Study area

The targeted populations to assess the energy efficiency of welding transformers are end-users,

local manufacturers of welding transformers in the country, and small, medium and large

manufacturing industries. The population is placed in an area where the industrial sub-sectors,

local manufacturers, and potential welding transformers end-users are located. The geographical

scope of the study is in 8 regional and 2 administrative cities in Ethiopia namely Oromia, Amhara,

Addis Ababa, Somali, Harari, Diredawa, SNNPR, Sidama and Afar. Based on economic

engagement the selected cities of these regions are Addis Ababa, Adama, DireDawa, Hawassa,

Bahir Dar, Harari, Jigjiga, and Afar. These regional cities are considered to host multiple factories

where most welding transformers are used in construction projects and manufacturing.

2.1.3.2 Sampling frame

The study uses three major sampling frames to select the samples of welding machines in the

country. The first is the Ministry of Trade and Industry database, to collect the list of the small,

medium, and big manufacturing industries. The information from the Ministry's database is

expected to include several key pieces of information for each sector including the number, type,

and size of welding machines used in the country, geographical location, and contact address of

manufacturing industries, importers, and maintenance service providers and other relevant

information. The second sampling frame is the database of the Ethiopian Revenue and Customs

Authority, to collect the list of all classifications of imported welding machines and import growth

rates, a qualified and energy-efficient standard requirement of importing welding transformers.

This frame will also allow assessing available environmental and health requirements of welding

transformers. The third sampling frame is the Ministry of Construction; to collect data of

construction companies operating in the country. Construction companies are considered users.

2.1.3.3 Sample size determination

The purpose of determining the sample size is to ascertain a representative number of welding

machines in the country. The welding machine in the country is aggregated in small and medium

manufacturing industries, in construction areas, automotive assembling, furniture manufacturers,

metal works workshops, and garages.

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The type and quantity of welding transformers under the same industrial sub-sectors are expected

to be similar, except for individual variations due to the ages and sizes of the factories. To address

this situation, it is prudent to consider one old factory from the old factories and one from the

newly established factories per industrial sub-sector chosen. Likewise, the number of construction

companies in Ethiopia is identified and samples are taken to count the number of welding

transformers in the construction sector. The type and number of the welding machine can be

estimated based on the age and size or grade of the construction company. The same scenario is

used in the other sectors.

In addition to this, all the data from ERCA and major importers of welding machines are utilized

to collect sufficient data on welding machines in the country. The study involves a sample of 112

small and medium manufacturing industries from different sectors, 7 construction companies, 31

garages and 4 car assemblers.

2.1.3.4 Sampling technique

The study employs a non-probabilistic quota sampling technique, where a representative

institution in each industrial sub-sector is chosen based on the predetermined characteristics or

rationale. This technique ensures that the total sample has the same distribution of characteristics

as the wider population. The rationale in this study is welding transformers in different sectors

such as in the industrial and construction sectors are rated and assigned to a specific welding task

requirement of the sector. Welding transformers in the same sector have similar capacity and

efficiency levels (may not be always true) except for the number of welding transformers which

depends on the size of the sector. The other rationale is that in an industrial sub-sector the

institution establishment dates vary. There are old institutions and recently commissioned ones.

For newly established, it is assumed that modern technology of welding transformer is used.

2.2 Data Collection Tools

The study employs data collection instruments including survey forms, observation checklists,

questionnaires, and interview guides. Data record sheets that are useful in recording welding

transformers data of type, current drawn, power, voltage, frequency, power factor, and country of

origin will be prepared.

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The study uses three types of a questionnaire for three groups. These are

• Welding transformers Efficiency Assessment in Ethiopian Market data from

Customers/Users[Annex II]

• Welding transformer Energy Efficiency Assessment in Ethiopian Market data from

Importers[Annex III]

• Welding transformers Efficiency Assessment in Ethiopian Market data from

manufacturers/ Maintenance/ Repair Service Providers[Annex I]

A. Welding transformer users

For each welding transformer, the study collects relevant data used to assess and establish

efficiency levels. The current drawn, power, voltage, frequency, power factor, and country of

origin are measured by using appropriate electrical equipment. These values are recorded on the

survey form that is prepared for this group.

B. Importers and distributors

The type, quantity, country of origin, and cost of imported welding transformers are assessed. It is

assumed that the number of importers of welding transformers is limited and hence the data

collection team assesses all registered welding transformer importers, distributors, and wholesalers

in the country. The survey includes types, country of origin, power rating, current, voltage, and

cost.

C. Welding transformers manufacturers and maintenance service providers

The study assesses local welding machines manufacturers and maintenance service providers in

the country. The data collected are the raw materials, the process of manufacturing, the levels of

rewinding, and the repair and maintenance practices of welding machines.

D. Industry and Engineering sub-sectors

The study assesses the welding transformers in the industrial and engineering sub-sectors. The data

collected grouped according to the size and type of welding transformer as per the below table.

2.3 Special Study Tools

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The data is collected using Android-based tablets/smartphones with the ability to collect data in

the form of manual input, sound recordings, pictures, videos, and geographical locations. The tool

allows Data Collectors to work offline and upload the data into the data repository once they have

an internet connection. The data output is extracted in an Excel format which allows easy cleaning

and analysis of the data.

The data analyst uploads and tests the tool using CSpro (Census and Survey processing) software.

The analyst digitizes the tool before the fieldwork.

2.4 Logistics Arrangement

In close coordination with the Technical Team of the Ethiopian Electric Utility and Ethiopian

Energy Authority, the study has its central headquarters at On Energy's office in Addis Ababa from

where the whole operation will be coordinated. The facility is equipped with essential

communication equipment for coordinating data collection. On Energy's consulting team arrange

vehicles, accommodation, and all necessary data collection equipment for the field study team in

advance.

The overall logistic arrangements are coordinated by the project manager/ coordinator and will be

fully dedicated to this assignment. On Energy ensures that members of the field teams are provided

with survey tools and audio recording tools throughout the data collection period. Data collection

materials such as datasheets, letter of introduction and informed consent, stationery items, and

measuring devices are prepared in advance.

i. Training data collection team

On Energy ensures that all data survey teams have clearly understood the objectives of the survey,

the sample design, the variables requiring analysis, and the data collection techniques. Data

collectors are trained on data collection tools and specifically in taking field data records of electric

power and efficiency of welding transformer.

ii. Forming data collection teams and assigning responsibilities

The data collection teams are formed and the responsibilities of each member are assigned. Each

team has a supervisor, responsible for seeing that activities are carried out as planned, for ensuring

that the necessary materials are at hand, for dealing with situations not foreseen in the planning

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phase, and for controlling the quality of the data collected day. Each of the other members will be

assigned to acquire quality information and help the supervisor to check the recorded data.

2.5 Ethical requirement and field procedure

On Energy team are adheres to the highest standards of ethics in data collection and use and

commits to adhering to the EEU procedure for Ethical Standards in Data Collection. To the extent

feasible, data will be collected making use of the preferred language of the respondents.

2.6 Data Analysis Approach

2.6.1 Technical approach

For this type of analysis most of the time two types of technical approaches are used to make the

best estimate of the number of welding transformers and the associated energy consumption

from the available data. These approaches are a top‐down approach and a bottom-up approach

(Waide and Brunner, 2011).For this specific project the bottom-up approach has been used for

estimating the number of welding transformer and the energy consumption share

2.6.2 Top‐down approach

The methodology applied involves estimating all non-welding transformers’ electricity uses and

assuming the residual part of total electricity consumption of the country is that used by welding

transformers. Explicitly, the approach looks at sector‐level electricity use in the country and

assumes an average fraction of welding transformer usage in each sector. The country’s statistics

of electricity production and annual electricity consumption for all end-use industry sub-sectors

are estimated first, and information about electricity consumption is also estimated. Deducting

these figures from the total electricity consumption results in an estimate of total electricity use for

welding transformers in all sectors.

2.6.3 Bottom‐up approach

The national energy use of welding motors is calculated based on available data and estimates of

the average size, efficiency, running hours, and load factor of the welding transformer stock, which

is then used to calculate welding transformer power demand and efficiency. Electric energy

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consumption of the country stock of welding transformer can be estimated from the bottom‐up by

multiplying the electric power of the transformer in use by the number of full-load hours per year.

E = n × P ⁄eff × h × LF

Where:

E Electricity use by the transformers

P Nominal output power

n Running stock of welding transformers in the installed base

h Average annual operation time

eff efficiency

In addition, the following analysis is conducted

• Comparing energy-saving aspects of inverter-based and ordinary

• Comparing energy efficiency of locally manufactured welding transformers with imported

• Calculating and determining energy efficiency and baseline for energy loss

• Calculating energy consumption

• Analyzing environmental and health impact of locally manufactured welding transformer

• Identify and analyze best practices of innovators

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3. AN OVERVIEW OF WELDING TRANSFORMERS OR

WELDING MACHINES EFFICIENCY

3.1 Welding

Welding is a method of repairing or creating metal structures by joining pieces of metals or plastic

through various fusion processes. Generally, heat is used to weld the materials. Welding equipment

can utilize open flames, electric arc, or laser light. Welding is a fabrication process that joins

materials, usually metals or thermoplastics, by using high heat to melt the parts together and

allowing them to cool, causing fusion[16]. Welding is distinct from lower temperature metal-

joining techniques such as brazing and soldering, which do not melt the base metal. In addition to

melting the base metal, a filler material is typically added to the joint to form a pool of molten

material (the weld pool) that cools to form a joint that, based on weld configuration (butt, full

penetration, fillet, etc.), can be stronger than the base material (parent metal). Pressure may also

be used in conjunction with heat or by itself to produce a weld. Welding also requires a form of

shield to protect the filler metals or melted metals from being contaminated or oxidized.

Many different energy sources can be used for welding, including a gas flame (chemical),

an electric arc (electrical), a laser, an electron beam, friction, and ultrasound. While often an

industrial process, welding may be performed in many different environments, including in open

air, underwater, and outer space. Welding is a hazardous undertaking and precautions are required

to avoid burns, electric shock, vision damage, inhalation of poisonous gases and fumes, and

exposure to intense ultraviolet radiation.

3.2 Historical Development of Welding

Although the modern form of welding that involves the welding tools that we see today was

invented in the 1800s during the Industrial Revolution, the earliest type of welding dates back

thousands of years. Welding existed in some form in the Bronze Age and the Iron Age[24]. The

term 'weld' (the joining of materials by welding) appeared for the first time in the Old Testament

several thousand years BC. Indeed, 4,000 years ago the Egyptians had already developed the art

of welding (the uniting of two or more parts by heat or pressure, or both). Archaeologists have

found small boxes of gold with joints that were pressure welded over two millennia ago. Moreover,

https://en.wikipedia.org/wiki/Fabrication_(metal)

https://en.wikipedia.org/wiki/Metal

https://en.wikipedia.org/wiki/Thermoplastic

https://en.wikipedia.org/wiki/Heat

https://en.wikipedia.org/wiki/Fusion_welding

https://en.wikipedia.org/wiki/Brazing

https://en.wikipedia.org/wiki/Soldering

https://en.wikipedia.org/wiki/Melting

https://en.wikipedia.org/wiki/Weld_pool

https://en.wikipedia.org/wiki/Pressure

https://en.wikipedia.org/wiki/Oxidation

https://en.wikipedia.org/wiki/Electric_arc

https://en.wikipedia.org/wiki/Laser

https://en.wikipedia.org/wiki/Electron_beam_welding

https://en.wikipedia.org/wiki/Friction_welding

https://en.wikipedia.org/wiki/Ultrasound

https://en.wikipedia.org/wiki/Underwater_welding

https://en.wikipedia.org/wiki/Outer_space

https://en.wikipedia.org/wiki/Burn

https://en.wikipedia.org/wiki/Electric_shock

https://en.wikipedia.org/wiki/Ultraviolet_radiation#Human_health-related_effects_of_UV_radiation

http://literacy.kent.edu/eureka/EDR/5/Middletown/Industrial%20Fields/History%20of%20Welding.pdf

http://literacy.kent.edu/eureka/EDR/5/Middletown/Industrial%20Fields/History%20of%20Welding.pdf

15

there is proof that Ancient Egyptians knew how to weld iron together. During the Iron Age, the

Egyptians and people in the eastern Mediterranean area learned to weld pieces of iron together.

Many tools were found that were made in approximately 1000 B.C. The head of the sarcophagus

of Tutankhamen (1361-1352 BC), whose tomb was discovered in 1922 in the Valley of the Kings,

is a good example. Another notable example from history is the famous Colossus of Rhodes (built

c. 292-280 BC), in its time one of the Seven Wonders of the World, which owed its height of 35

meters to a skeleton of welded iron. Also, in Ukraine about 1,200 years ago, craftsmen welded a

magnificent steel sword that has survived to the present day.

Figure 4: Head of the sarcophagus of

Tutankhamen

Figure 5: Ukraine steel sword

Figure 6: Colossus of Rhodes (built c. 292-280 BC)

In the 19th century, breakthroughs in welding were made. Edmund Davy of England is credited

with the discovery of acetylene in 1836. The production of an arc between two carbon electrodes

using a battery is credited to Sir Humphry Davy in 1800[17]. In the mid-19th century, the electric

generator was invented and arc lighting became popular. During the late 1800s, gas welding and

https://www.uti.edu/blog/welding/welding-history-goes-back-farther-than-you-think

16

cutting were developed. Arc welding with the carbon arc and metal arc was developed and

resistance welding became a practical joining process.

Figure 7: Edmund inventor of acytiline Figure 8: Metalworks in early 19th c

Figure 9: Carbon arc welding in early 20th c

In 1890, C.L. Coffin of Detroit was awarded the first U.S. patent for an arc welding process using

a metal electrode. This was the first record of the metal melted from the electrode carried across

the arc to deposit filler metal in the joint to make a weld. The first societies who knew how to work

metal only had available, for assembly, the rudimentary methods of flow and forge welding were

Egyptians. They also practiced brazing.

It was chemical processes that were the first to rejuvenate the art of welding: first thermit welding,

development of flow welding, whereby molten metal is poured (cast) into the joint area to melt the

joint faces and to provide the filler material; then came oxyacetylene welding, which, between

1905 and 1930, became the universal method of welding. From 1925 onwards, the electric arc and

17

resistance welding processes became established, gradually replacing oxyacetylene welding and

allowing mass production and the production of large items. Arc welding could not develop until

there was some method of protecting the arc and molten weld pool from the atmosphere.

Figure 10: Oxyacetylene welding process Figure 11: Coated metal electrode

The first solution, employed at the beginning of the twentieth century, was the covered electrode,

where a metal electrode is covered with a coating whose essential role is to produce, through the

heat of the arc, gases that would protect the molten weld metal from the atmosphere. A coated

metal electrode was first introduced in 1900 by Strohmenger[19].

Automatic welding was first introduced in 1920. Invented by P.O. Nobel, automatic welding

integrated the use of arc voltage and bare electrode wires. It was used for repairing and molding

metals. Several types of electrodes were also developed during this decade.

A new type of welding for seamlessly welding aluminum and magnesium was developed in 1941

by Meredith. This patented process came to be known as Heliarc welding. The gas shielded metal

arc welding or GTAW was another significant milestone in the history of welding which was

developed in Battelle Memorial Institute in 1948.

http://esab.com/

18

Figure 12: Automatic welding Figure 13: Gas shielded metal arc welding

The CO2 welding process popularized by Lyubavskii and Novoshilov in 1953 became a welding

process of choice for welding steels, as it was comparatively economical. Soon, electrode wires of

smaller diameters were launched. This made welding of thin materials more convenient[20].

Plasma arc welding was also invented by Gage during this time. It was used for metal spraying.

The French also developed electron beam welding, which is still used by the aircraft manufacturing

industries of the United States. Some of the recent developments in the welding industry include

the friction welding process developed in Russia and laser welding. The laser was originally

developed in Bell Telephone Laboratories but it is now being used for various kinds of welding

work. This is due to the inherent capacity of lasers in rendering precision to all kinds of welding

jobs.

Figure 14: Laser welding Figure 15: Plasma arc welding

The European Commission's most recent preparatory study on welding equipment concluded that

by 2030, there is potential for significant energy savings by introducing ecodesign regulations to

welding equipment39. There is scope for improvements in the energy efficiency of welding

equipment which would be in line with technological developments. There is also the potential to

use fewer resources and contribute to the circular economy through improved reparability and

recyclability by introducing resource efficiency requirements. Until recently, internationally only

China has legislation that regulates the energy efficiency of arc welding equipment,

regulation/standard GB 28736-2012 (entitled 'Minimum allowable values of energy efficiency and

energy efficiency grades for arc welding machines')[18], which has been in place since 2012. This

standard applies to professional arc welding equipment which enters the Chinese market and

includes both mandatory and voluntary requirements.

https://www.bell-labs.com/

19

3.3 Welding transformers or machines

Welding equipment is products that deliver energy in the form of electricity to join or cut two or

more metals by heating (often >6,000°C), with or without the use of ancillary materials such as

filler sticks, wire, or gases that shield the welding area from the surrounding air[3].

One of the methods of classifying welded joints is the method used to affect the joint between

metal pieces. Accordingly, the methods are:

- fusion method without pressure/ with pressure

- non-fusion method

❖ Fusion Welding

• Without Pressure

A method of welding in which similar and dissimilar metals are joined together by melting and

fusion their joining edges with or without the addition of filler metal but the application of any

kind of pressure is known as fusion welding without pressure.

The joint made is permanent. The common heating sources are:

➢ arc welding

➢ gas welding

➢ chemical reaction (thermit welding)

Figure 16: welding without pressure

• Pressure Welding

This is a method of welding in which similar metals are joined together by heating them to a plastic

or partially molten state and then joined by pressing or hammering without the use of filler metal.

This is a fusion method of joining with pressure. The heat source may be blacksmith forge (forge

welding) or electric resistance (resistance welding) or friction.

20

Figure 17 pressure welding

❖ Non-Fusion Welding

This is a method in which similar or dissimilar metals are joined together without melting

the edges of the base metal by using a low melting point filler rod but without the

application of pressure.

3.4 Classification of Welding Processes According To Heat Source

According to the sources of heat, welding processes can be broadly classified as:

✓ Electric welding processes (heat source is electricity)

✓ Gas welding processes (heat source is gas flame)

✓ Other welding processes (heat source is neither electricity nor gas flame)

a) Electric welding processes can be classified as:

- Electric arc welding

- Electric resistance welding

- Laser welding

- Electron beam welding

- Induction welding

Electric arc welding can be further classified as:

- Metallic arc welding

- Carbon arc welding

- Atomic hydrogen arc welding

- Inert gas arc welding/ TIG

welding

- CO2 gas arc welding

- Flux-cored arc welding

- Submerged arc welding

- Electro-slag welding

- Plasma arc welding

Electric resistance welding can be further classified as:

- Spot welding

- Seam welding

- Butt welding

- Flash butt welding

- Projection welding

21

b) Gas welding process can be classified as:

- Oxy-acetylene gas

welding

- Oxy-hydrogen gas

welding

- Oxy-coal gas welding

- Oxy-liquid petrolium

gas welding

- Air-acetylene gas

welding

c) The other welding processes are:

- Thermite welding

- Forge welding

- Friction welding

- Ultrasonic welding

- Explosive welding

- Cold pressure welding

- Plastic welding

3.5 Electric Welding

This is a process of welding in which the heat energy is obtained from electricity.

❖ The formula for converting electrical energy to heat energy

H = I2RT

Where

H is the amount of heat produced in ‘joules’.

I is the amount of current passing in amps.

R is the resistance of medium in ohms.

T is the time during which the current flows.

This is useful only in the resistance welding process.

3.6 Types of electric welding

I.Electric arc welding

It is a fusion-welding (non-pressure) process in which the welding heat is obtained

from an arc, formed between an electrode and the welding job connected to a suitable

welding machine.

Figure 18: electric welding

22

II.Electric resistance welding

It is a pressure-welding process in which the heat is obtained by passing a heavy

momentary electric current through the inherent electric resistance of the joint to be

welded. When the joint reaches a plastic state, sufficient pressure is applied to produce

fusion and get a homogeneous weld.

Figure 19: Electric resistance welding

3.7 Electric Arc Welding

The electric arc is formed when both the terminals of an electric circuit are brought

together and then separated by a small gap. When a high current passes through an air

gap from one conductor to another, it produces very intense and concentrated heat in

the form of a spark. The temperature of this spark (or arc) is app. 3600°C, which can

melt and fuse the metal very quickly to produce a homogeneous weld. The types of

electric arc welding are as follows.

a. Metallic Arc Welding

This is an arc welding process in which the welding heat is obtained from an arc, formed

between a metallic (consumable) electrode and a welding job. The metal electrode melts

itself and acts as a filler metal.

23

Figure 20: Metal arc welding

b. Carbon Arc Welding

Here the arc is formed between a carbon electrode (non-consumable) and the welding

job. A separate filler rod is used since the carbon electrode is non-metal and will not

melt.

Figure 21: Carbon arc welding

c. Atomic Hydrogen Arc Welding

In this process, the arc is formed between two tungsten electrodes in an atmosphere of

hydrogen gas. The welding job remains out of the welding circuit and a separate filler

rod is used to add the filler metal.

24

Figure 22: Atomic hydrogen arc welding

d. Tungsten Inert Gas Arc Welding (TIG)

In this process, the arc is formed between the tungsten electrodes (non-consumable)

and the welding job in an atmosphere of an inert gas (argon or helium). A separate filler

rod is used to add the filler metal. This process is also called the gas tungsten arc

welding (GTAW) process.

Figure 23: Tungsten inert gas arc welding

e. Gas Metal Arc Welding (GMAW) or Metal Inert Gas Arc Welding

(MIG)

In this process, the arc is formed between a continuous, automatically fed, metallic

consumable electrode and welding job in an atmosphere of inert gas, and hence this is

called the metal inert gas arc welding (MIG) process.

25

Figure 24: Gas Metal Arc Welding (GMAW) or Metal Inert Gas Arc Welding (MIG)

When the inert gas is replaced by carbon dioxide then it is called CO2 arc welding or

metal active gas (MAG) arc welding. The common name for this process is gas metal

arc welding (GMAW).

f. Submerged Arc Welding

In this process, the arc is formed between a continuous, automatically fed, metallic

consumable electrode and the welding job under a heap of powdered/ granulated flux.

The arc is submerged in the flux (invisible).

Figure 25: Submerged arc welding

g. Electro-Slag Welding

The arc is formed between a continuous, automatically fed, metallic consumable

electrode and the welding job under a thick pool of molten flux (slag). This automatic

process requires special equipment and is used only in a vertical position for the

welding of heavy thick plates.

26

Figure 26: Electro-slag arc welding

h. Plasma Arc Welding

In this process, the arc is formed between a tungsten electrode and the welding job in

an atmosphere of plasma-forming gas-nitrogen, hydrogen, and argon. A separate filler

rod is used to add the filler metal to the joint, if necessary. But normally no filler rod is

used.

Figure 27: Plasma arc welding

3.8 Energy Conservation Potential in Welding

3.8.1 General Description of Welding Processes

Welding is defined as "a materials-joining process used for making welds, where the

weld is defined as the localized coalescence of metals or nonmetals produced by heating

the materials to suitable temperatures, with or without the application of pressure, or by

the application of pressure alone, and with or without the use of filler materials[12].

27

The heat source used for welding may be very localized, such as an electric arc, oxyfuel

gas flame, or photon beam, or it may be non-localized, such as a gas or electric furnace.

Various welding processes are characterized by such factors as the type of heat source,

the method by which filler material is added to the weld, the method by which the weld

is protected from oxidation by the atmosphere, and the relative melting temperature of

the filler metal and base metal.

3.8.2 Worldwide Welding Energy Consumption

Small and medium enterprises (SMEs) are recognized as the backbone or engine to the

economic development of any country as they generate employment and wealth [1].

Globally growth of SMEs is a means to attain equitable development of a nation. Even

with their vital contributions to the nation, SMEs face the closure threat on account of

the higher energy consumption and also contribute a lot to the global energy demand

increment that in turn leads to environmental degradation. Therefore, it is very

important to study the present energy consumption pattern in the SMEs to suggest or

for the adaptation of new/modern technology for efficient energy techniques. Welding

machines are one of the major energy-consuming devices especially for small and

medium enterprises with a variety of technologies. Even though the impact of the

energy consumption of welding machines is significant on SMEs, the welding energy

consumption is also very high in heavy industries.

A recent survey in the USA has brought out that about 20% of the energy consumed in

heavy Engineering industries in the United States is for welding-related activities (see

table 28).[12]

28

Figure 28: Welding related activities

It has also been estimated that welding and joining processes, including resistance

polymer and arc welding, represent 4.5 % of the European Union’s gross energy

consumption (EPTA, 2007). A better choice of process or an increased understanding

of this consumption can lead to energy saving. Around 15,000 welding equipment units

are sold in the UK annually37. In the UK, welding equipment collectively consumes a

significant amount of energy.

The European Commission’s preparatory study[6] states that on average, a typical arc

welding unit has a primary continuous power consumption of 6.2 kVA (arc-on),

equalling 75% efficiency at 200 A and output power of 4.65 kW (23.25 V). It was found

that most of these units are used in 1-shift-operations and a realistic arc-on-time (i.e.

operating factor) is 25%. . It is estimated that welding equipment uses 307 GWh per

year (2020/21) in the UK (see Figure29).

3.8.3 Energy Efficiency in Welding technologies

29

Based on the power sources for welding it can be categorized welding machines as

welding generators, welding transformers, welding rectifiers, and inverters. The power

source for welding is discussed in table…..

Table 1: power source of welding machines

Power Source Supply

Welding generator 1. AC or DC

Welding transformer 2. AC

Welding rectifier 3. DC

Inverters 4. DC

1. Welding Generator

• It was popular for many years and are still sometimes used

• High cost and poor efficiency, makes it very difficult to compute with

modern technologies

• It consists of a 3-phase motor directly coupled with a generator

• The welding generator unit is driven by fossil fuel, they are used at sites

without a supply of electricity

Figure 29: welding generator

2. Welding Transformers

With this type of unit, the AC mains voltage is converted to AC, but with characteristics

suitable for welding. Welding transformer steps down the voltage & hence the output

is low voltage high current AC supply. As the output is AC, it has a sinusoidal

30

waveform. Due to its design, it has a lot of circuit power losses like hysterical losses.

Thus a welding transformer operates at low efficiency & hence has a low power factor.

These transformers are used by small-time fabricators & also by process industries

where welding is done for maintenance purposes. However, nowadays rectifiers &

inverters are replacing transformers.

Figure 30: Welding transformer

3. Welding Rectifiers

The welding rectifier provides a DC output by rectifying the low voltage high current

AC output obtained from the step-down transformer. The output is DC which has a

ripple in the DC waveform. With the improvement in transformer design & PCB circuit

controls, the rectifier could offer an improved welding quality & better electrical

efficiency than welding transformers. The machine consumes high power due to its

moderate efficiency & power factor.

Rectifiers are very popular and used by most fabricators in the field of automobiles,

shipbuilding, construction machinery, etc.

Figure 31: Welding rectifier

4. Inverters

31

Welding inverters are a boon to the welding industry. The technology provides the best

quality of welding, birth to new welding processes, power-efficient, lightweight, etc.

The 3 phase AC input supply is inverted to DC by a rectifier. This high voltage DC is

converted to high-frequency AC (HFAC) by a transistor switching device. HFAC is

stepped down by a transformer & inverted again by a rectifier to get a DC output

Figure 32: Inverters

Inverter Advantages

Compared to conventional power sources, inverter-based welding power sources offer

the following advantages:

• Lightweight and portable

• Able to obtain superior Stick welding performance with all electrode types

• Multi-process welding output without sacrificing arc performance in any mode

• Quick response to changing arc conditions (e.g., maintains a steady weld output

even if the operator’s handshakes)

• Superior control over pulsed welding processes

• Line voltage-independent – uses single- or three-phase input power and

multiple input voltages without any manual relinking mechanism

• Better power factor (more efficient use of power from the utility)

32

• Less susceptibility to primary voltage fluctuations (e.g., “dirty power”)

There is another advantage of the inverter power supplies – power cost. The inverter

equipment is much more efficient than transformer equipment. For instance, the current

draw at 200 amperes for the typical Inverter type Welder is 29 amperes on 230 Volt

single-phase Supply. The current draw of an older transformer welder is typically 50 to

60 amperes on a 230 Volt single-phase Supply when welding at similar currents[13].

The efficiency comparison of welding transformer, rectifier welding, and inverter is

shown in figure 33

Figure 33: Efficiency comparison

4. RESULT AND FINDINGS

4.1 Welding Machines in Ethiopia

4.1.1 Welding machines in micro, small, and medium

manufacturing industries

There are different types of welding machines operating in micro, small, and medium

manufacturing industries in Ethiopia having various years of service. Based on the data

obtained from the ministry of trade and industry, the total number of micro, small, and

33

medium manufacturing industries particularly in the wood and metal sectors is about

10636. The total number of welding machines in these industries was estimated

according to the sample data collected. The survey revealed that the number of welding

machine in each stated manufacturing industries are different depending on the type,

capacity, size of the industry. From the sample taken during the survey, 69.6% of the

small manufacturing industries have 1 or 2 welding transformers, 28.6% of the

industries have an average of 4 transformers and 1.8 % have at least 6 transformers

each. The minimum estimated number of welding machines in micro, small and

medium metal and wood manufacturing industries in Ethiopia is estimated to be 24,420.

Figure 34:Percentage of number of transformers in each small metal and wood

manufacturing industry in Ethiopia

Figure 35: Welding machines name tag

Figure 36: Machines during welding

4.1.2 Types of Welding machines in Ethiopia

69.60%

28.60%

1.80%

WELDING TRANSFORMERS IN EACH INDUSTRIES

1 to 2 Transformers

4 Transformeers

At least 6 Transformers

34

There are different types of welding machines operating in Small and Medium

Manufacturing enterprise (SMME) starting from locally manufactured welding

transformers to imported welding machines. This study shows that about 64% of the

welding machines operating in Ethiopia are locally manufactured and the remaining 36%

are the imported ones (Fig 37).

Figure 37: Welding transformers in Ethiopia

Figure 38: Welding transformers during operation

Most of the welding machines in Ethiopia are three types based on the welding

transformer type. These are the locally manufactured ones, welding rectifiers, and

inverter type welding. As discussed in section 1, the electric welding process may be

arc welding type, resistance welding, laser welding, electron beam welding, or

induction type welding. In this study, only the arc welding type is considered.

Depending on how the electrode is used, arc welding may be of a different type. It may

be carbon type, metal, plasma, tungsten inert gas, and so on. The survey revealed that

electric arc welding in Ethiopia is either carbon type or metal arc welding type, the

35

percentage share of the two arc welding types in the Ethiopian market is shown in

Figure 40 and 41

Figure 39: Types of welding transformer Figure 40: Arc welding

4.2 Welding machines in the Construction Sector

In this study, the construction sector was assessed to estimate the number of welding

machines and its energy consumption in the country. It was given attention to Grade 1

construction companies in interviewing and taking samples for the study. According

to the data collected from the ministry of urban development and construction, there

are about 420 grade 1 construction companies and 7 samples were taken for assessment.

The survey revealed that the number of welding machines in each sampled construction

company is different based on the financial capacity and size of the companies. From

the sample taken during the survey, 57% of the construction companies have 1 or 2

welding transformers, 14.3% of the companies have an average of 4 transformers each

and 28.6 % have at least 6 transformers each. Based on this result the total number of

welding machines in construction companies in Ethiopia is estimated to be 1320.

36

Figure 41: Welding transformers in construction sites

4.3 Welding machine in car assembly or manufacturing, and car

repairing service provider

I. Multi-purpose vehicles and parts maintenance service providers and

others

Welding is performed in a variety of industries and trades. Auto body technicians use a

variety of automotive welding techniques to complete structural repairs on various

vehicles and equipment. They may also design a metal component to improve an

existing structure. In global experience, the most common welding methods for

automotive jobs include resistance metal inert gas (MIG) welding, plasma arc welding

(PAW), and tungsten inert gas (TIG) welding.

For this study, questionnaires were distributed for 31 vehicles maintenance service

providers (garages) to assess the number, type, and other conditions of welding

machines. The result shows that 87% of the service providers use 1 to 2 welding

machines and 13% of the service providers have an average of 4 welding transformers

for their day-to-day maintenance works.

37

Figure 42:Welding machine distribution

The data obtained from the ministry of trade and industry, shows that in Ethiopia there

are about a total of 14,405 multi-purpose vehicles and parts maintenance service

providers and others. Based on this data and the above table, the number of welding

machines in the country is estimated to be 26289.

II. Manufacturers of transport vehicles, spare parts, and tires.

Welding is the principal means of fabricating and repairing metal products and is used

in every industry. Amongst the major areas of applications, welding is extensively used

in automotive industries. The most commonly used welding methods for automotive

applications include resistance spot welding (RSW), resistance seam welding (RSEW),

metal inert gas (MIG) welding, tungsten inert gas (TIG) welding, laser beam welding

(LBW), friction welding (FW) and plasma arc welding (PAW).In our country, the

conventional welding methods, welding using electrodes is widely used.

The data collected from the ministry of trade and industry, revealed that there are about

a minimum of 174 manufacturers of transport vehicles, spare parts, and tires. We have

distributed 5 questioners for randomly selected manufacturers, almost all the sampled

manufacturers use imported welding transformers type for their welding process. The

output current and voltage are in the range of 300- 500A and 24-42V respectively. The

average power consumed by the imported welding transformers which are being used

38

by these manufacturers is about 500W. Based on the survey data the average number

of welding transformers used by each manufacturer is estimated to be 9. Therefore, the

total number of welding transformers used by all the manufacturers is about 1566.

4.4 Estimation of the total number of welding transformers

Based on the above data the number of welding transformers in the country is summed

up and tabulated below

Table 2: Number of welding transformers in the country

Estimated number of


Micro, small, medium manufacturing industries 1. 24420

Construction companies 2. 1320

Vehicles maintenance service providers 3. 26289

Car manufacturers 4. 1566

Total number of welding machines in the country 5. 53,595

Therefore, based on this survey the estimated number of welding machines in Ethiopia

is estimated to be in the range of 73595-78595. For the sake of calculation, the average,

76095, is taken in this document. The number of locally manufactured welding

transformers is estimated based on the result of this study where it is revealed that 64%

of the welding machine in Ethiopia is locally manufactured ones. Therefore the

estimated number of locally manufactured welding transformers is about 48700.

4.5 The energy efficiency level of welding machines in Ethiopia

Locally manufactured

Recently, metal workshops using locally made welding transformers have increased all

over the country. Mengesha Mamo, who has done his survey on welding transformers

has measured the loss of samples of the locally manufactured transformers to be on

average 1 kW compared to 0.23 kW of equivalent imported transformers. These

39

transformers are not well designed and the core material used is not the proper material

for the required efficiency [11]. The author also estimated the possible loss reduction

by proper design and material selection. It is possible to reduce the loss at least by half

with proper design and material selection. If 170 working days and about 2 hrs effective

working hours are assumed per day, the electric energy saving per year will be 10.2

GWH.

Figure 43: Manufacturing of welding transformers

This study has found out that in different welding areas, the way of handling the

welding transformers is very poor. The coils of the transformers are bared and subjected

to dirt which leads to a significant power loss (Fig 46). In addition, most of the local

welding machines are not integrated with cooling fans and hence energy is being lost

to the atmosphere in the form of heat and shorten the life of the transformer. As a result

the working area is very hot and not convenient for users.

.

40

Figure 44: Poor handling of welding transformers

The other most important thing that we have observed during the survey was the

transformer coil design and winding arrangement problem. In most of the

manufacturing areas, the transformers' winding arrangement is done not by considering

the energy efficiency issue and some of them also do not take any electrical

measurement during manufacturing.

Figure 45: Welding transformers during

operation

Figure 46: Welding transformer

manufacturing

Imported

Unlike Ethiopian Market, globally many arc welding machines that are on the market

today are new models like the Inverter type. These models use far less energy than older

models, even when they are idling. Newer units fitted with inverter power sources are

lighter, more versatile, and more energy-efficient than those powered by older,

transformer-rectifier power sources.

41

The old, transformer-rectifier equipment had energy conversion efficiencies that range

from 40 to 60 percent and consumed 2 to 5kW when idling. Those with inverter power

sources have energy conversion efficiencies near 90 percent and consume around 0.1

kW when idling [25].

Figure 47: Imported types welding transformer

4.6 Energy Consumption of Welding transformers in Ethiopia

The energy consumption of welding transformers in Ethiopia can be calculated by

estimating first the number of welding transformers in the country and calculate the

power consumption by multiplying the voltage and current measured during welding.

The sample measurements data that was taken for this study on the conventional and

locally made welding transformers is shown on Table 5 below.

Table 3: Measured data of each welding machine

Open circuit

Measurement

The measurement is

taken during

welding

Calculated from the data

Voc Ioc Cos

Øoc Vwel Iwel

Cos

Øwel

Poc (K

w)

Pwel (K

W) Average

eff(%)

Input

power

during

welding

220 5.5 0.1 30.8 101.2 0.8 0.1 2.5 63 3.97

42

222.

2 5.6 0.2 27 111 0.8 0.3 2.4

63 3.81

224 5.5 0.1 30.3 88.5 0.6 0.2 1.6 63 2.54

223 7.5 0.1 32 92.2 0.8 0.2 2.2 63 3.49

229 5.8 0.4 44.1 112 0.7 0.5 3.6 63 5.71

219 5.6 0.5 25 118 0.8 0.6 2.24 63 3.56

228 8 0.1 46 80 0.8 0.3 2.8 63 4.44

215 5 0.6 33 100 0.7 0.6 2.1 63 3.33

225 6.2 0.5 48.2 112 0.7 0.6 3.9 63 6.19

219 6.1 0.1 45.6 120 0.5 0.6 2.5 63 3.97

222.

42 5

0.26

53

36.19

4

103.4

9

0.70

13 0.4 2.6

63 4.13

Average 0.4 2.6 63 4.10

As it is observed from the above table, the average open circuit power or the idle power

consumed by welding transformers is about 0.4KW, and the average power consumed

during welding is calculated to be 4.1 KW.

To calculate the total energy consumption by welding transformer, it is necessary to

estimate the average time of welding in a day. In the survey of this study, users of

welding transformers were requested to provide their estimated approximate hours of

welding in a day (Table 6).

Table 4: Average time of welding in a day

Region

Average Time in an

hour

Total

1.00 -

1.99

2.00 -

2.99 3.00 - 3.99

4.00 -

4.99

Total 152 85 47 9 11

Afar 10 4 5 1 0

Amhara 13 5 2 3 3

Oromia 9 7 1 0 1

Somalia 9 5 2 1 1

SNNP 3 2 1 0 0

Sidama 17 10 7 0 0

43

Harari 10 5 5 0 0

Addis Ababa 71 43 19 4 5

Diredawa 10 4 5 0 1

A total of 152 questionaries are distributed in different regions of the country to

estimate hours of welding in a day and it was found that most of the users of welding

transformers estimates in the range of 1-2.99 minutes. The average hours of welding in

a day is estimated to be2.1hours.

A. Energy Consumption of locally manufactured welding transformers

during welding

The total energy consumption of welding transformers during welding can be estimated

as follows:-

Daily Energy Consumption= Number of welding machines in the country * average

power consumption*hours of welding in a day

If we assume that the number of working days of welding in a year, it is about 300 days.

Therefore the approximate annual energy consumption of welding transformers during

welding is calculated and the result is shown in Table 7.

Table 5:Total estimated amount of energy consumption of welding transformers

during welding

Average power

consumption of

welding

transformers

during welding

(KW)

Estimated

number of

welding

transforme

rs in the

country

Average

hours of

welding

in a day

(hr)

Estimated

number of

working

days in a

year

Total estimated

Energy

Consumption of

welding machines

in

Ethiopia(GWH)

4.1 48700 2.1 300 125.8

Welding transformer also consumes energy even when it is not operated (idle power

consumption). As it is shown in Table6., the estimated average idle power consumption

44

in welding transformer is about 0.4Kw. The total energy consumption of welding

transformers during idle time is calculated and shown in table below.

Table 6: welding transformers during their idle time

Average idle power

consumption(KW)

Estimated number of


in the country

Idle time in a

year

Total Energy

consumption

during idle

time(GWH)

0.4 48700 6*300 35

Therefore the total energy consumption of locally manufactured welding transformers

in Ethiopia is estimated to be 160.8 GWH.

B. Energy Consumption of imported welding machines in the country

Based on the survey, the estimated number of welding machines in Ethiopia is about

76095. The number of imported machines is estimated based on the survey result that

revealed 36% of the welding machine in Ethiopia is imported. Therefore the estimated

number of imported welding machines is about 27394.

According to the survey done by Mengesha Mamo[11], a loss of samples of the locally

manufactured transformers to be on average 1 kW compared to 0.23 kW of equivalent

imported transformers.

Assuming that the same output voltage and current are required whether welding is

done by the local or equivalent imported transformer for a particular welding process,

the input power consumption by the imported welding transformer is less by 0.77KW

than the consumption by the local one. Therefore the average power consumption by

equivalent imported welding machine becomes 3.33 KW.

Table 7: Energy consumption of welding transformers

45

Average power

consumption of

welding

transformers

during welding

(KW)

Estimated

number of

welding

transforme

rs in the

country

Average

hours of

welding

in a day

(hr)

Estimated

number of

working

days in a

year

Total estimated

Energy

Consumption of

welding machines

in

Ethiopia(GWH)

3.33 5. 27394 6. 2.1 7. 300 8. 57.5

From the above table, it can be shown that the estimated amount of the total energy

consumption of imported welding transformers operating in Ethiopia now is calculated

to be around 57.5GWH. Therefore the total energy consumption of welding

transformers in Ethiopia is estimated and tabulated below.

Table 8: total energy consumption of welding transformers in Ethiopia

Type of Welding Machines Energy Consumption(GWH) Total

Locally manufactured 9. 160.8

218.3

Imported 10. 57.5

The total energy consumption of welding machines in Ethiopia in the year 2021GC is

estimated at 218.3GWH.

4.7 Estimation of electricity consumption share of welding

transformer in Ethiopia

The recent data available from the EEU/EEP, the national electricity consumption by

tariff group in the year 2020/2012E.C is indicated in table 11

Table 9: national electricity consumption by tariff group in the year 2020/2012E.C

Year

(E.C)

Domes

tic

Commerc

ial

customers

EEU Own

consumption

Street

Light

HV

Industrial

LV

Industri

al

Total in

GWH

11. 299

6.

3 12. 2613.1 13. 312.4

14. 41.

5 15. 395.2

16. 1036

.0

17. 739

4.5

46

As it is indicated in the above table the total national electricity consumption of the

country is about 7394.5 GWH. Therefore it is possible to estimate the electricity

consumption share of welding transformers as its total consumption in the country has

already been estimated.

Welding transformer consumption share = electricity consumption / welding

transformer electricity consumption*100%

Welding transformer electricity consumption share= 218GWH/7394.5 GWH*100%

= 2.9%

Therefore the electricity consumption share of welding transformers in the country in

the year 2012GC is estimated to be around 2.9%.

4.8 Import data from Ethiopian Customs Commission (ECC)

The data from ECC doesn't contain detail data of the imported welding machines such

as out voltage, current, power factor, and efficiency of welding machines. ECC data

shows that welding machines in Ethiopia are imported from different countries. The

major volume (more than 90%), of imports in the years 2020 is from China. Imported

welding transformers are recorded by Ethiopian Customs Authority for Tax assessment

purposes by type and quantity and International HS code for a range of welding

machines. The detailed data from Ethiopia Customs Authority is not still received

4.9 Local Welding transformer manufacturing and maintenance

service providers

Eleven major welding machine manufacture service providers have been contacted for

the data collection on manufacturing service of welding machines as per the

questionnaire presented in Annex I. The summary of results of data collection from

representative welding transformer manufacturers in the country is presented in

Table10.

47

The manufacturers that are contacted do have not organized data about how many

welding transformers they sold, how many welding transformers they manufacture and

also they do not have enough knowledge of how to measure the electrical parameters

of the welding transformers they manufacture. Concerning the price, the locally

manufactured welding transformers have different prices based on their capacity and

quality. The price of welding transformers is tabulated below.

Figure 48: burned copper wire

Table 10: Price of locally manufactured Welding Transformers

Region Manufacturer

Price In Birr

Max Min Mean

Total 19000 4000 10636.4

Oromia 1 17000 17000 17000

Addis Ababa 10 19000 4000 10000

From Table 12, it is indicated that the maximum price of locally manufactured welding

transformers is about 19000birr and the minimum is about 4000birr. The price is much

less than the equivalent imported welding machines which ranges from 15,000 to

25,000 birr.

The welding machine type that is being manufactured in Ethiopia is a welding

transformer type with AC power input and AC power output. This type of welding

48

machine is the least energy-efficient technology and its efficiency is mainly dependent

on the way it is manufactured like the winding arrangement, type of wire used, poor

insulation, and poor design. In Ethiopia, country most of the manufacturers are not well

experienced, they are not experts on the area and they don't have enough material for

measuring the parameters, and also for winding and other purposes. The following

Table 11 shows the type of welding machines being manufactured locally based on our

survey.

Figure 49: Locally manufactured welding transformers

Table 11:- Type of welding machines manufactured in Ethiopia

Type of Welding machines being manufactured

18. Number of

the

questionna

ire sent

19. Welding

generator

(AC or

DC)

20. Welding

transform

er (AC)

Welding

rectifier (D

C)

Inverter (D

C)

Total 21. 11 22. 0 23. 11 24. 0 25. 0

Oromia 26. 1 27. 0 28. 1 29. 0 30. 0

Addis Ababa 31. 10 32. 0 33. 10 34. 0 35. 0

This study has found out that all of the manufacturers who were contacted for this

survey are manufacturing the welding transformer type. To make this welding

transformer have better efficiency the design work is very crucial. The following table

shows how many of these manufacturers do design work before manufacturing.

49

Table 12: Manufacturers who do design work

Region

Number Of

Manufacturers

Total Yes No

Total 11 1 10

Oromia 1 1 0

Addis Ababa 10 0 10

This study revealed that 90% of the manufacturers are not concerned about the

designing of the welding transformer before manufacturing and they are manufacturing

traditionally.

5. WELDING MACHINES ENERGY EFFICIENCY

STANDARDS AND REGULATIONS, ETHIOPIAN AND

GLOBAL EXPERIENCE

5.1 Ethiopian Standard and Regulations

5.1.1 Standard development by Standards Agency

The Ethiopian Standards Agency is an authorized government organ working on the

standardization of welding transformers in Ethiopia through the development of

standards or adoption of international standards. Ethiopia has adopted IEC welding

machines standards.

50

5.1.2 The regulatory body EEA

EEA is mandated by the proclamation on Energy, No. 810/2013 and regulation

447/2019, on EE regulations and conservation works. To set a Minimum Efficiency

Performance Standard (MEPS) for welding transformers, EEA shall prepare and ratify

a directive regarding the level of MEPS and associated mandatory and non-mandatory

standards clauses. The directive shall be reviewed every few years.

Energy-efficiency labels, informative labels that are affixed to imported and locally

manufactured welding machines' energy performance (usually in the form of energy

use, efficiency, or energy cost) to provide consumers with the data necessary for making

informed purchases, should be developed by the Ethiopian Energy Authority, following

the procedures laid out in the National Standard for Labelling. The lowest level of

efficiency on the label should match that of the MEPS for the welding machines.

EEA has also a mandate to set regulations and directives to regulate the efficiency of

locally manufactured or imported appliances.

51

5.1.3 Testing of welding machines for conformity with the

standards

In Ethiopia, testing of products for conformity with standards is generally carried out

by the Ethiopian Conformity Assessment Enterprise (ECAE) under the organization's

scope.

The Energy Regulations also give EEA the power to request product samples from

manufacturers for energy efficiency testing; the future EEA’s activities may involve

establishing laboratories or structures for testing energy performance. In all cases, this

should be aligned with the Conformity Assessment Enterprise, which should ideally be

responsible for oversight and control of performance testing in the country.

5.2 Welding Machines National and International Regulations and

Standards

5.2.1 Analysis of regulations and standards in other countries

In many countries regulations on welding machine is not still in place even if it

consumes a significant amount of energy and also affects the environment negatively.

The European Union, EU, is the primary body to set a stringent regulations on welding

machines. China is also the first country to set energy efficiency standard regulations

for welding equipment.

5.2.2 EU energy efficiency regulation for Welding machine

In many countries regulations on welding machine is not still in place even if it

consumes a significant amount of energy and also affects the environment negatively.

The European Union, EU, is the primary body to set a stringent regulations on welding

machines.

52

New regulations from the EU addresses the ecodesign requirements of welding

equipment which include the environmental aspects of welding equipment (such as

energy consumption when the product is being used) and ensuring a level of efficiency.

Particularly for welding equipment EU set regulations titled:

'laying down ecodesign requirements for welding equipment under Directive

2009/125/EC of the European Parliament and the Council'.

This regulation has already applied to start from 1 January 2021.

i. Energy efficiency requirement of welding equipment in EU regulations.

From 1 January 2023, the power source efficiency of welding equipment, shall not be

lower than the values set out in Table 13, and the idle state power consumption shall

not exceed the values set out in Table 13.

Table 13: energy efficiency requirement

Minimum

power source

efficiency

Maximum idle

state power

consumption

Welding equipment powered by three-phase

power sources with direct current (DC) output

85% 50W

welding equipment powered by single-phase

power sources with direct current (DC) output

80% 50W

Welding equipment powered by single-phase

and three-phase power sources with

alternating current (AC) output

80% 50W

1. Resource efficiency requirements

53

From 1 January 2021, welding equipment shall meet the following requirements:

(a) Availability of spare parts

(1) Manufacturers, authorized representatives, or importers of welding equipment shall

make available to professional repairers at least the following spare parts for a

minimum period of 10 years after the production of the last unit of a welding

equipment model:

➢ control panel;

➢ power source(s);

➢ equipment housing;

➢ battery(ies);

➢ welding torch

➢ gas supply hose(s);

➢ gas supply regulator(s);

➢ welding wire or filler material drive;

➢ fan(s);

➢ electricity supply cable;

➢ Software and firmware including reset software.

(2) Manufacturers shall ensure that these spare parts can be replaced with the use of

commonly available tools and without permanent damage to the equipment and the part.

(3) The list of these spare parts and the procedure for ordering them shall be publicly

available on the free access website of the manufacturer, authorized representative, or

importer, at the latest two years after placing on the market of the first unit of a model

and until the end of the availability of these spare parts.

(b) Access to repair and maintenance information

No later than two years after the placing on the market of the first unit of a model, and

until the end of the period mentioned under point a.1, the manufacturer, importer, or

authorized representative shall provide the welding equipment repair and maintenance

information to professional repairers in the following conditions:

1. The manufacturer’s, authorized representative’s or importer’s website shall indicate

the process for professional repairers to register for access to information; to accept such

a request, manufacturers, authorized representatives or importers may require the

professional repairer to demonstrate that:

(i) the professional repairer has the technical expertise to repair and maintain welding

equipment and complies with the applicable regulations for repairers of electrical

54

equipment in the Member States where it operates. Reference to an official registration

system as a professional repairer, where such system exists in the Member States

concerned, shall be accepted as proof of compliance with this point;

(ii) the professional repairer is covered by insurance covering liabilities resulting from its

activity regardless of whether this is required by the Member State;

2. The manufacturer, authorized representative, or importer shall accept or refuse the

registration within 5 working days from the date of request by the professional repairer.

Once registered, a professional repairer shall have access, within one working day after

requesting it, to the requested repair and maintenance information. The information may

be provided for an equivalent model or model of the same family, if relevant. The

available repair and maintenance information shall include:

• the unequivocal welding equipment identification information,

• a disassembly map or exploded view,

• a list of the necessary repair and test equipment,

• component and diagnosis information (such as minimum and maximum

theoretical values for measurement),

• wiring and connection diagrams,

• diagnostic fault and error codes (including manufacturer-specific codes where

applicable),

• data records of reported failure incidents stored in the welding equipment (where

applicable), and

• Instructions for installation of relevant software and firmware including reset

software.

Manufacturers, authorized representatives, or importers may charge reasonable and

proportionate fees for access to the repair and maintenance information or for receiving

regular updates. A fee is reasonable if it does not discourage access by failing to take into

account the extent to which the professional repairer uses the information.

(c) Maximum delivery time for spare parts

During the period mentioned under point a.1, the manufacturer, importer, or authorized

representative shall ensure the delivery to professional repairers of spare parts for

welding equipment within 15 working days after having received the order.

This availability may be limited to professional repairers registered under point

(d) Information on the display of welding equipment

55

Where a display is provided for welding equipment it shall indicate the use of welding

wire or filler material in grams per minute or equivalent standardized units of

measurement.

(e) Requirements for dismantling for material recovery and recycling while avoiding

pollution

Manufacturers shall ensure that welding equipment is designed in such a way that the

materials and components referred to in Annex VII to Directive 2012/19/EU can be

removed with the use of commonly available tools.

Manufacturers shall fulfill the obligations laid down in point 1 of Article 15 of Directive

2012/19/EU.

2. Information requirements

From 1 January 2021, manufacturers, their authorized representatives, or importers shall

ensure that the following information is provided in the instruction manuals for installers

and end-users, and for at least 10 years after the first unit of a welding equipment model

is placed on the market, on the free-access websites of manufacturers, their authorized

representatives or importers:

a. the product type;

b. the manufacturer's name registered trade name, and registered address at which

they can be contacted;

c. the product model identifier;

d. the power source efficiency (in %);

e. the idle state power consumption (in watts);

f. a list of equivalent models;

g. information relevant to recycling and disposal at end-of-life;

h. a list of critical raw materials present in indicative amounts higher than 1 gram at

the component level, if any, and an indication of the component(s) in which these

critical raw materials are present;

i. indicative shielding gas utilization for representative welding schedules and

programs;

56

j. indicative welding wire or filler material utilization for representative welding

schedules and programs.

Engweld: The new EU requirements for welding equipment includes new design

requirements which will come into effect from January 2021

5.2.3 China’s Energy Efficiency regulation for arc welding equipment

China has an energy efficiency regulation for arc welding equipment based on the

regulation/standard GB 26736-2012 49 (entitled 'Minimum allowable values of energy

efficiency and energy efficiency grades for arc welding machines). The standard is

currently mandatory for welding equipment to enter the Chinese market (China

Compulsory Certification –CCC, similar to the European CE system).

This standard addresses professional arc welding equipment, and similarly to this

proposed EU Regulation, excludes hobby equipment, resistance welding, and stud

welding.

The Chinese regulation includes both voluntary and mandatory requirements as grades:

·Grade 3 (includes efficiency values limits), the lowest limit is compulsory;

·Grade 2 (includes efficiency and power factor limits), and is voluntary;

·Grade 1 (includes efficiency, power factor, and idle power limits) is voluntary.

The limit values for the grades in the potential Chinese regulation, just like the ecodesign

requirements envisaged for welding equipment in the EU, also depend on the type of

phase of the welding current used (AC or DC).

5.2.4 Proposed Policy and regulation Options for Ethiopia

Energy efficiency policies and programs can help drive the implementation of projects

at minimize or reduce energy use during the operation of a system or machine and/or

production of a good or service.

57

The following are deemed a basis for the proposed Policy.

• The Lack of information for end-users on energy and material efficiency of welding

equipment

• Lack of communication between the welding equipment designers and the actors in

the supply chain involved in repair, refurbishment, and end-of-life treatment.

• The number of welding machines being imported to the country is increasing while

the manufacturing capacity here in Ethiopia is not incentivized or helped by training

or any other strengthening mechanisms to manufacture efficient welding machines

in the country so that importing by hard currency can be reduced.

• As per the survey, the efficiency of welding machines being manufactured in

Ethiopia is very low compared with the imported ones while there is room to

improve the local manufacturers' capacity. For this to happen there should be a

regulation to enhance the capacity of manufacturers

• Thus far, there are no testing facilities and trained manpower for testing welding

machines in Ethiopia. The testing facility should be established and strengthen so

that manufacturers test their product before distributing it to the market.

• There are no directives as to control the types of welding imported during the

importing of wildings and through investment processes.

• There is huge energy efficiency potential if there is a strict and sustainable policy

on manufacturing and importing welding equipment. As the survey revealed 64%

of welding equipment in the country is locally manufactured and its efficiency is in

the range of 60-65% which is very low compared with the modern inverter type

welding machines.

• There are no incentives to improve the efficient design of welding equipment in

terms of energy and materials;

58

• There shall be adequate time for the transition from the existing efficiency level of

locally manufactured welding machines to higher energy-efficient types due to the

time required for awareness creation.

Policy options should be selected in close cooperation with stakeholders. The policy

options defined for welding equipment are below

6. SETTING UP OF ENERGY EFFICIENCY

REGULATION FOR WELDING TRANSFORMERS

Energy-efficiency standards are a set of procedures and regulations that prescribe the

energy performance of manufactured products, sometimes prohibiting the sale of

products that are less efficient than a minimum level.

It is proposed to be similar to that of the European Union regulation. This proposed

regulation addresses professional arc welding equipment, specifically welding

transformer type both locally manufactured and imported ones.

59

6.1. The Proposed Energy efficiency requirements of welding transformers in

Ethiopia

According to this assessment, the efficiency of welding transformers manufactured in

Ethiopia is in the range of 60-65% whereas the efficiency of the imported welding

transformers reaches up to 80%. Therefore, by proper design and material selection, it

is possible to improve the efficiency of welding transformers manufactured locally.

Therefore the following requirements are proposed for the Ethiopian market

The power source efficiency of welding equipment, shall not be lower than the values

set out in Table 14, and the idle state power consumption shall not exceed the values

set out in Table 14.

Table 14: Welding equipment powered

Minimum

power source

efficiency

Maximum

idle state

power

consumption

Welding equipment powered by single-phase

and three-phase power sources with

alternating current (AC) output

36. 70% 37. 100W

6.2. Resource efficiency requirements

Welding transformer shall meet the following requirements:

➢ a. Availability of spare parts

60

(1) Manufacturers, authorized representatives, or importers of welding equipment shall

make available to professional repairers at least the following spare parts for a

minimum period of 5 years after the production of the last unit of a welding

equipment model:

➢ control panel;

➢ power source(s);

➢ equipment housing;

➢ welding torch

➢ welding wire or filler material drive;

➢ fan(s);

➢ electricity supply cable;

(2) Manufacturers shall ensure that these spare parts can be replaced with the use of

commonly available tools and without permanent damage to the equipment and the

part.

Access to repair and maintenance information

1. The manufacturer should give a guarantee for his welding transformers for at least

one year and should have capable experts to maintain the machine during damage

2. The manufacturer, authorized representative, or importer shall accept or refuse the

registration within 5 working days from the date of request by the professional repairer.

Information requirements

manufacturers, their authorized representatives, or importers shall ensure that the

following information is provided in the instruction manuals for installers and end-

users, and at least 10 years after the first unit of a welding equipment model is placed on

the market, on the free-access websites of manufacturers, their authorized

representatives or importers:

the product type;

the manufacturer's name registered trade name, and registered address at which they can

be contacted;

61

the product model identifier;

the power source efficiency (in %);

the idle state power consumption (in watt)

Indicative welding wire or filler material utilization for representative welding

schedules and programs.

These are the proposed requirements in the regulation to be included, however, the

detailed standards will be prepared by a national technical committee in collaboration

with the Ethiopian standard agency. This requirement will be adapted from EU

requirements.

Basic requirements for successful implementation of the proposed regulation

To implement the requirements in the regulation, the Authority should fulfill the

following.

1) Establishment of efficiency testing facility for welding transformers

It should be recognized that testing laboratories play an indispensable role in the

successful implementation of the proposed regulation as it is important to test the

efficiency of the welding transformer to evaluate whether the transformer conforms to

the requirement in the regulation or not. The labs can play the following key roles

• Testing laboratories play a significant role in check testing to ensure that the

products meet the performance criteria

• The testing laboratories as a significant guiding light in the development of

realistic efficiency and performance standards.

• Testing can also contribute towards continuous evolution and up gradation

towards better performance standards.

2) Capacity building program for Manufacturers

62

A standardized prototype welding transformer should be manufactured which meets the

minimum requirement set in the regulation and a continuous capacity building program

should be given to manufacturers which enables them to manufacture standardized

welding transformers that can meet the minimum requirements.

3) Stakeholder Involvement

One of the first steps in designing such type of program should be to convene

representatives of all interested parties and get input regarding how the program should

be designed and marketed.

Below, we briefly describe the main groups of stakeholders who are typically affected

by this regulation and can be approached to help design and promote the program.

Manufacturers

Manufacturers are key stakeholders. They are the source of the products to be regulated

and are generally responsible for testing products. Because they have designed their

products and have, in most cases, tested them extensively according to local and

international test procedures, this regulation needs ongoing dialogue between the

manufacturers and the implementing agency. The primary goal for most manufacturers

is to make products that consumers will want to purchase. Manufacturers have to

balance a wide range of elements of product design, including quality, reliability,

performance, and price. Manufacturers of the most efficient products tend to be more

supportive of the regulation, while those that have large sales of low-efficiency products

tend to be opposed to or less supportive of the regulation.

The implementing agency

The implementing agency is often a government body, in our case Ethiopian Energy

authority. Its role defining the detailed technical requirements in consultation with other stakeholders

• developing and maintaining the legal and/or administrative framework for the

program;

• registering, policing, and enforcing compliance, if applicable, to ensure that the

program remains credible;

63

• providing information to consumers, including ensuring press and TV

involvement in the promotional campaign; and

• Evaluating the program.

Consumers and consumer groups

Consumers are a diverse and diffuse group. It takes significant work to obtain reliable

information about consumer use and understanding of the regulation.

6.3. Estimation of energy saving that can be achieved by the

implementation of the proposed Energy Efficiency measure.

a) Saving the Energy consumption for welding

The proposed energy efficiency measure will be implemented on the imported or the

locally manufactured welding transformer. This proposal will not be applied to other

types of welding machines like welding rectifiers and inverter types.

As a study in Addis Ababa University revealed (Tezarash Yohanes and Getachew Biru

“Performance Evaluation of Locally Made Welding Transformers", an independent

project report, Electrical and Computer Engineering, FoT, AAU, June 2009.) the

average energy efficiency of locally manufactured welding transformers is about 63%

and the imported welding transformers efficiency is in the range of 65 to 70% for the

calculation purpose the average, 67.2%, is taken as the efficiency of importing welding

transformers[26].

The energy consumption reduction due to the implementation of the proposed energy

efficiency measure stated in section 6.1.1 is calculated and tabulated below.

Table 15. Annual energy saving due to implementation of the proposed energy

Average

Power

output for a

specific

task(KW) Quantity

Average

Efficiency

Total

weldin

g hour

in a

year

Annual

energy

consumption

for BAU

(GWh/yr)

Annual Energy

saving for the

proposed energy

efficiency

measure scenario

(Kwh/yr)

64

No measures

were

taken(BAU) 38. 2.6

39. 487

00 40. 63% 41. 630 42. 126 43.

After energy

efficiency

measures 44. 2.6

45. 487

00 46. 70% 47. 630 48. 49. 114

As it is shown in the above table, the annual energy consumption in 2020G.C by locally

manufactured welding transformers was around 126GWH. If the proposed energy

efficiency measure stated in section 6.1.1 is implemented, the consumption will be

reduced and becomes 114GWH. Therefore, an average of 12GWH consumption

reduction per annum can be achieved.

For the imported welding transformers, slightly better in efficiency than the local one,

the annual energy consumption in 2020 was around 31.1GWH. If the proposed energy

efficiency were implemented, it would have been possible to reduce the consumption

to 29.7GWH. The detail is shown in the following table.

Table 16: Annual energy saving due to implementation of the proposed energy

efficiency measure on the imported welding transformer.

Average

0utput Power

demand for a

specific

task(KW) Quantity

Average

efficiency

The total

hour in a year

Annual energy

consumption for

BAU (GWh/yr)

Annual Energy saving

for the proposed energy

efficiency measure

scenario (Kwh/yr)

2.6 12711 67.20% 630 31.1

2.6 12711 70% 630 29.7

b) Idle power saving

Energy is consumed by welding transformers not only during welding but also be

consumed during when it is idle. In the business as usual scenario, the idle power

consumption of welding transformers is around 0.4KW as is calculated in section 6.1.

The proposed energy efficiency measure obliged manufacturers to produce welding

transformers having a maximum idle power rating of about 100W. The saving is shown

in the following table.

65

Table 17: Energy consumption reduction by the proposed regulation

Idle power

in BAU

scenario(K

W)

Idle power

after the

regulation

in place

Idle time

in an hour

per year

Total

welding

transfor

mers

Idle energy

consumption in

BAU

scenario(GWH)

Idle energy

consumption

in

place(KWH)

Possible Energy

Saving in GWH

0.4 50. 0.1 51. 1700 52. 48

7

0

0

53. 33 54. 8.3 55. 24.7

6.4. Implementation Schedule

According to our understanding of the welding manufacturers during the visit, their

awareness of energy efficiency is very low. It is recommended to produce a prototype

welding transformer and conduct theoretical and practical training for the

manufacturers before the implementation of the proposed regulation. Product

standards should also be adopted/ adapted first.

Table 18: Implementation schedule of the proposed energy efficiency measures

No Activities

Time of Implementation

2021 2022 2023 2024

202

5

1 Awareness creation for stakeholders

2

Hire a consultant and produce a

prototype

3 Training for manufacturers

4 Setting of Standards

5 Preparation of the proposed regulation

6 Ratify the regulation

7

Implementation of the proposed

regulation

6.5. The possible risks and its mitigation Measures

No. Risks Rating Mitigation Measures Responsibility

66

1

Lack of awareness in

end-users like the small

and medium

manufacturing

industries, and in other

sectors on the

significance of energy

savings obtained from

the implementation of

the proposed regulation

High

▪ Briefly explain by a different way of

communications tools on different issues

like

• Welding lifetime costs

• Comparison with other efficient

welding machines

• Introducing Higher efficiency

models and standards

▪ Strictly implement the regulation

EEU, EEA

2

The unwillingness of

electric welding

transformer end-users

to buy energy-efficient


due to the high initial

cost

High

▪ Encourage and assist end-users by

introducing the payback period through a

website or other means.

▪ Awareness creation on available

financing, incentives, and government

implementation programs.

▪ Introduce a national campaign in the

country to encourage greater use of

higher efficiency welding through

television, radio, and social media

campaigns.

EEU, EEA and

stakeholders

3

Inadequate incentives

and lack of financing

set aside for importers

and end-users investing

in an energy-efficient

electric motor.

Mediu

m

▪ Establish and look for financing sources

and mechanisms for the implementation of

the program

▪ EEU, EEA, MoWIE, and MoF, and other

stakeholders such as the development

bank of Ethiopia and microfinance

institution and revolving fund

administration to secure medium to long

term financing for the implementation

program

EEU, EEA,

MoWIE MoF,

DBE, and

financial

institutions

4 Low technical financial

capacity of High

▪ Series of capacity-building activities to

enhance the technical capacity of

EEU, EEA and

stakeholders

67

manufacturers manufacturers to make them capable to

manufacture new efficient models based

on the requirement set in the proposed

regulation.

5

Illegal importation of

substandard welding

machines

Mediu

m

▪ Monitoring illegal or contraband

injection of inefficient welding machines

by coordinating with custom authority

and other concerned bodies

EEU, EEA,

ECC, MOTI

7

Delay of the

implementation of the

proposed regulation

Mediu

m,

▪ Awareness creation work for

policymakers

▪ Initiate round table discussions with

stakeholders

EEU, EEA

68

7. Reference

1. WELDING INDUSTRY: POTENTIAL FOR ENERGY CONSERVATION,

Herschel B. Smartt Don W. Hood W. Paul Jensen Published April 1980

2. “United States Energy Fact Sheets, 1971,” U.S. Department of the Interior,

February 1978

3. Impact Assessment of Proposed Eco design Requirements for Electric Motors

and Variable Speed Drives, and Electrical Mains-operated Welding

Equipment.RPC Reference No: RPC-4447(1)-BEIS

4. GB 28736-2012 Minimum allowable values of energy efficiency grades for

arc welding machines from https://www.chinese

standard.net/PDF/English.aspx/GB28736-2012.

5. UK trade data sourced from:

https://madb.europa.eu/madb/statistical_form.htm using HS code for welding

equipment ‘HS 851539’

6. EuP Netzwerk Machine Tools Preparatory Studies. Available from: https:

//www.eup-network.de/product-groups/preparatory-studies/completed

7. P. Kah and J. Martikainen, “Current Trends in Welding Processes and

Materials: Improve in Effectiveness”, Rev. Adv. Mater. Sci., n. 30, pp.

189200, (2012).

8. 6 Langdon, M., “Innovation and invention”, The Motor Ship, October 2004,

pp. 54 – 58, (2004)

9. [14] Tang Y. S., Tsai H. L., and Yeh S. S, "Modeling, Optimization, and

Classification of Weld quality in Tungsten Inert Gas Welding", International

Journal of Machine Tools and Manufacture, Vol. 39, Issue 9, pp. 1427-1438,

(1999).

10. PRELIMINARY SURVEY ON ELECTRIC ENERGY EFFICIENCY IN

ETHIOPIA:- AREAS OF INTERVENTION: Mengesha Mamo Department of

Electrical & Computer Engineering Addis Ababa University

11. Tezarash Yohanes and Getachew Biru “Performance Evaluation of Locally

Made Welding Transformers”, an independent project report, Electrical and

Computer Engineering, FoT, AAU, June 2009.

12. Energy Conservation in Welding By Avinash Abnave Larsen & Toubro

Limited, Heavy Engineering Division, Powai.

https://www.researchgate.net/publication/343395978

13. HANDBOOK ON WELDING TECHNIQUES END USER: Newly Recruited/

Promoted Welders CAMTECH/ E/ 14-15/ Welding/ 1.0 February 2015

https://www.chinese/

https://www.researchgate.net/publication/343395978

69

14. EEPCO‟s Strategic Plan for the period of 1997 to 2002 EFY", volume1 of 2,

pp 25, October 2004.

15. “Performance Evaluation of Locally Made Welding Transformers”, By

Tezerash Yohannes and DR.Ing. Getachew Biru an independent project report,

June 2009.

16. A Concise Anglo-Saxon Dictionary by John R. Clark Hall, Herbert T. Merritt,

Herbert Dean Meritt, Medieval Academy of America -- Cambridge University

17. Lincoln Electric, The Procedure Handbook Of Arc Welding 14th ed., page

1.1-1

18. Hertha Ayrton. The Electric Arc, and D. Van Nostrand Co., New York,

1902.

19. A. Anders (2003). "Tracking down the origin of arc plasma science-II. early

continuous discharges" (PDF). IEEE Transactions on Plasma Science. 31 (5):

1060

20. Great Soviet Encyclopedia, Article "Дуговой разряд" (eng. electric arc)

21. Lazarev, P.P. (December 1999), "Historical essay on the 200 years of the

development of natural sciences in Russia" (PDF), Physics-

Uspekhi, 42 (1247): 1351–1361, doi:10.1070/PU1999v042n12ABEH000750,

archived from the original (Russian) on 2011-02-11

22. "Encyclopedia.com. Complete Dictionary of Scientific Biography". Charles

Scribner's Sons. 2008. Retrieved 9 October 2014.

23. Nikołaj Benardos, Stanisław Olszewski, "Process of and apparatus for

working metals by the direct application of the electric current" patent nr 363

320, Washington, United States Patent Office, 17 may 1887.

24. A History of Welding. weldinghistory.or

25. (https://www.nrcan.gc.ca/energy/products/categories/commercial/arc-

welding/14703)

26. (https://www.everlastgenerators.com/welding-guide-power-efficiency),

https://digital.library.unt.edu/ark:/67531/metadc785757/m2/1/high_res_d/823202.pdf

https://digital.library.unt.edu/ark:/67531/metadc785757/m2/1/high_res_d/823202.pdf

https://en.wikipedia.org/wiki/Great_Soviet_Encyclopedia

https://web.archive.org/web/20110211173732/http:/ufn.ru/ufn99/ufn99_12/Russian/r9912h.pdf

https://web.archive.org/web/20110211173732/http:/ufn.ru/ufn99/ufn99_12/Russian/r9912h.pdf

https://en.wikipedia.org/wiki/Physics-Uspekhi

https://en.wikipedia.org/wiki/Physics-Uspekhi

https://en.wikipedia.org/wiki/Doi_(identifier)

https://doi.org/10.1070/PU1999v042n12ABEH000750

http://ufn.ru/ufn99/ufn99_12/Russian/r9912h.pdf

http://www.encyclopedia.com/doc/1G2-2830903379.html

http://www.weldinghistory.org/whfolder/folder/wh1900.html

https://www.nrcan.gc.ca/energy/products/categories/commercial/arc-welding/14703

https://www.nrcan.gc.ca/energy/products/categories/commercial/arc-welding/14703

https://www.everlastgenerators.com/welding-guide-power-efficiency),for

70

i

Annex I

Welding transformers Efficiency Assessment in Ethiopian Market data from

manufacturers/Maintenance/Repair Service Providers

1. Name of manufacturing/Maintenance Service Provider: ____

2. Address: City________, Woreda______, House No._________, Tel.No________

3. Contact person. _________________________. Tel ______________

4. Please explain the manufacturing process? (Take picture)

5. Types and quantity of welding transformers rewound/manufactured/assembled in

2012 EC (2019/2020GC) in ascending order by Power/current rating

No Welding power

rating

Type

Inverter/welding

trans/rectifier/other

Quantity

repaired/manufactured

Price of a welding

transformer sold (Birr)

KW HP

1

2

3

6. What type of welding transformer does the manufacturer/assembler

manufacture/repair/assemble?

a. Arc welding b.

b. Resistance welding

c. Oxyfuel gas welding

d. Other types

7. If it is arc welding, which type of arc welding

a. Carbon arc b. metal arc

b. plasma arc

c. gas metal arc(MIG)

d. gas tungsten arc (TIG)

8. Please list down the current and voltage ratings (OUT put) of arc welding that

you usually manufacture?

Current Voltage

9. What is the welding power source?

a. Welding generator(AC or

DC)

b. Welding transformer(AC)

c. Welding rectifier(DC)

d. Inverter(DC)

10. What are the most common problems and solutions of welding transformers

coming for repair?

No A most common welding transformer problem Solutions

ii

11. Does the repair service provider believe that standardizing of welding transformer

is useful to his/her business?

a. Yes b. No c. Indifferent

12. Does the manufacture/ the service provider do design work for manufacturing?

a. Yes b. No

13. Does the manufacturer/assembler measure electrical parameters?

a. Yes b. No

14. If the answer for Q11 is yes, What parameters does the manufacturer /assembler

measure after manufacturing or assembling?

a. Current

b. Voltage

c. Power

d. Other

15. How do you know the winding arrangement is correct or not?

_____________________________________________________________________

16. What is the instrument used for rewinding

a. Manual b. Electrical c. Mechanical

17. What do you think is the reason for the efficiency difference between the

imported and locally manufactured welding machines?

_____________________________________________________________________

18. What kind of raw material do you use for welding transformers? And what type

of cable or wire for rewinding?

19. What type of manufacturing/process wastes are there?

_____________________________________________________ _

20. How do you dispose of wastes?

21. Undertake measurement of the samples:

Sample 1: Current__________________

Voltage:________________ Sample 2: Current ______________

Voltage: _______________

22. Additional Notes

iii

Annex II

Welding transformers Efficiency Assessment in Ethiopian Market data from

Customers/Users

1. Name of the user of customer/user of welding transformer : _______

2. Type of industry: ________________________

3. Address: City________,Woreda_______, House No_______,Tel. No_______

4. Contact person. _____________________. Tel _______________

5. Organization’s or company’s number of working days and hours of operation

6. Types and rating of welding transformers used

No Welding power

rating

Type Inverter/ welding

trans/ rectifier/ other

Output

voltage(rating)

Output

Current

KW HP Volt Ampere

1

2

7. If it is arc welding, which type of arc welding

a. Carbon arc

b. metal arc

c. plasma arc

d. gas metal

arc(MIG)

e. gas tungsten

arc (TIG)

8. What are the most common problems you encountered on your welding machine?

_______________________________________________________________

9. Which welding machine (the local or the imported) is suited for you?

a. The local

b. The imported

c. No difference

d. I haven’t noticed

10. For Q No9, if your answer is a or b, what is your reason

a. Less power consumption

b. Easy for welding

c. Light-weighted

d. Other:- mention

11. What is the average time/hours/ mins you take for an instant of welding?

_______________________________________________________________

12. How many times does welding take place in a day on average?

____________________________________________________________________________

13. Do you use safety instruments during welding?

a. Yes b. No

14. Do you have any information regarding the efficiency of welding transformers?

a. Yes b. No

15. If yes, which welding transformer do you think is more efficient?

a. Local b. Imported c. Other

iv

16. Additional Notes

17. Measurement

Annex III

Welding transformer Energy Efficiency Assessment in Ethiopian Market data from

Importers

1. Name of Importer: ________________________________________

2. Address:City_______,Woreda _______,House. No._______ Tel. No

3. Contact person. _________________________. Tel

4. Types and quantity of welding machines Imported in 2012 EC (2019-

2020GC) to be filled in the table below

N

o

Welding

Power

The power source of your welding machine Average price

of single

welding

machine

(Birr)

Welding

generator

(AC or

DC)

Welding

transformer

(AC)

Welding

rectifier

(DC)

Inverter

(DC)

KW/

Amp

ere

HP

1

2

3

4

5

5. For arc welding transformer, which type of arc welding

a. Carbon arc

b. metal arc

c. plasma arc

d. gas metal arc(MIG)

e. gas tungsten arc (TIG)

6. Country of origin of welding machines descending order for a quantity of welding

imported

_____________________

_____________________

_____________________

_____________________

7. The most common application of welding imported

8. What are the most common problems and challenges faced on the import,

distribution, and sales of welding machines?

9. Do you (Importer) believe that standardizing welding is useful to your business?

v

a. Yes b. No

c. Indiffer

Annex IV

List of study participants

NO Name Of User/Manufacturerer/Importer Region Name of City

Telephone Number

1 mulugeta,getachewna guadegnochu addis ababa addis ababa 920966072

2 samuel,sntayewna guadegnochachew addis ababa addis ababa 913922799

3 A.A.A metal work addis ababa addis ababa 911636265

4 Tarekegn addis ababa Addis Ababa 914966216

5 Melaku addis ababa addis ababa 911698682

6 Sntayehu addis ababa addis ababa 912035611

7 Bereket na guadegnochu breta bret addis ababa Addis ababa 911024003

8 sisay addis ababa addis ababa 932515449

9 umer zeyneb ena guadegnochavhew addis ababa addis ababa 911244827

10 Samuel meseret addis ababa addis ababa 911666572

11 mohamed abdu addis ababa addis ababa 911442729

12 fkade gebre gebremedhn addis ababa addis ababa 911692975

13 Tarekegn berihun ena guadegnochu addis ababa addis ababa 910211472

14 Desalegn ena jemal addis ababa addis abeba 911449605

15 gebre kiristos gebre giyorgis addis ababa Addis Ababa 911430199

16 Eshet manufacturing addis ababa addis ababa 912717331

17 Melaku addis ababa addis ababa 911117059

18 adil addis ababa addis ababa 911152664

19 AAE metal work addis ababa Addis Ababa 911636252

20 chagni addis ababa AA 921629604

21 peacock addis ababa AA 911163224

22 tekakenena anestegna addis ababa AA 0

23 Abreham mintesinot ena guadegnochachew

addis ababa AA 0

24 Cambo addis ababa AA 910347978

25 Awet ena Jemal addis ababa AA 911872315

26 Asrat metal work addis ababa AA 911600241

27 Abreham Anteneh ena abreham addis ababa AA 911481516

28 fekremariam ena guadegnochu addis ababa AA 922629411

29 Eyob ena kalkidan addis ababa AA 912174291

30 kedamawi ena eshetu addis ababa AA 911112992

31 Melaku meron ena guadegnichachew addis ababa AA 911428163

32 michael gebretsadik addis ababa AA 911395507

33 Makiba addis ababa AA 912175063

34 michael ena henok addis ababa AA 911484322

vi

35 wendemagegn serkalem ena guadegnochachew

addis ababa AA 913191229

36 fekadu sisay ena guadegnochachew addis ababa AA 911121755

37 Baye hailemariam ena guadegnochachew

addis ababa AA 910550947

38 Tadese girma ena guadegnochachew addis ababa AA 911531415

39 Samuel biruk ena sisay addis ababa AA 911347191

40 Samuel Mesele addis ababa A.A 911476720

41 Alhamdu habesha addis ababa AA 925898623

42 Mesele Tefera addis ababa AA 911646272

43 Biniam and dankel addis ababa AA 9120274418

44 Asrat Asfaw addis ababa A.A 913559657

45 gizate birhane and his freinds addis ababa AA 911985868

46 Fikadu Kinfe addis ababa A.A 911309100

47 Eshetu Hailegiyorgis addis ababa A.A 911481273

48 Birhanu Wakshum addis ababa A.A 911352883

49 Misba Negash addis ababa AA 911075522

50 Yohans Afewerk addis ababa A.A 911675572

51 Yishak, fuad and his freinds addis ababa AA 911215142

52 Biruk addis ababa AA 913044030

53 Adem mehamed addis ababa AA 0

54 Siyum, Behaylu addis ababa A.A 911694587

55 Ambaw asefa addis ababa AA 923149983

56 Kinfe, Samrawit and their freinds addis ababa A.A 923150153

57 Ato Mekbib addis ababa A.A 912164646

58 Negatibeb Selomon addis ababa A.A 911165051

59 Daniel Afework addis ababa A.A 911681212

60 Ato Abebe Tegegn addis ababa A.A 950600397

61 Ato Belay teklu addis ababa A.A 911235323

62 Yidnekachew,sisay,wubot biniyam (shorkina)

addis ababa A.A 911404453

63 Ato Alemeneh addis ababa A.A 911864068

64 Ato Tedros addis ababa A.A 911103892

65 emer metal worek afar Afar 920543492

66 abubeker metal worek afar Afar 914030532

67 ashenafi metal work afar Afar 913967536

68 jemal ali garaje afar Afar 912345323

69 nuru afar Afar 913515274

70 dubai metal worek afar Afar 927182025

71 habetamu garag afar Afar 911675651

72 hayel metal worek afar Afar 936435725

73 abedu afar Afar 913081124

74 kerime metal worek afar Afar 941552131

75 Neguse garaje SNNPR Awassa 916835068

76 damesew garaje SNNPR Awassa 911303144

vii

77 keyo garaje sidama Sidama 916867438

78 aserat garaz SNNPR Awassa 911316184

79 rameto garaje SNNPR Awassa 916533535

80 mule metal &wood work SNNPR Awassa 916116020

81 dolpine metal worek SNNPR Awassa 916040966

82 ayel metal work SNNPR Awassa 924332773

83 mesekerenate metal worek SNNPR Awassa 916822568

84 barekot metal worek SNNPR Awassa 911051942

85 dana metal worek sidama Sidama 926955852

86 berehan metal work SNNPR Awassa 916500333

87 Eloroei metal worek SNNPR Awassa 941032630

88 abel metal worek sidama Sidama 932190242

89 abera metal work SNNPR Awassa 954727282

90 z metal work SNNPR Awassa 919656799

91 jafar metal work SNNPR Awassa 926541400

92 fascia metal work SNNPR Awassa 905444265

93 lukas Garaze SNNPR Awassa 912150574

94 geradi garaz SNNPR Awassa 938071982

95 Asfaw Diredawa Diredawa 913620001

96 Luigi Brolia Diredawa Diredawa 915735482

97 Tsegaye Diredawa Diredawa 0

98 Binam garaj Diredawa Diredawa 983691995

99 Yared Diredawa Diredawa 915750125

100 Kiros garaj Diredawa Diredawa 915004172

101 Birehanu garaj Diredawa Diredawa 914535123

102 yonas Diredawa Diredawa 910082423

103 Musa Diredawa Diredawa 913914700

104 Alemu Diredawa Diredawa 914554355

105 Eyob metal work Hareri Hareri 945997910

106 Frehiwet Getachew Hareri Hareri 913538388

107 Andnet Hareri Harer 923204832

108 netsanet Hareri Harer 900203261

109 Dawit Hareri Harer 934427713

110 Bante furniture Hareri Harer 920905441

111 wendmagegn Hareri Harer 913766995

112 Habtamu Hareri Harer 920268619

113 Abdi Hareri Harer 942790637

114 Esmiel Hassen Hareri Harer 947035503

115 Abebe Somali Jijiga 931261048

116 Belay Somali Jijiga 913556160

117 dere Somali Jijiga 975717130

118 Macruuf Somali Jijiga 955077878

119 kidus Somali Jijiga 915408081

120 Moges Somali Jijiga 910493086

viii

121 Harun Somali Jijiga 955484885

122 Addisu Somali Jijiga 922586555

123 Yohannis Somali Jijiga 912867786

124 Kassahun addis ababa addis ababa 913674167

125 nur addis ababa addis ababa 963800712

126 Chuna addis ababa addis ababa 925478418

127 Ashenafi addis ababa addis ababa 911621070

128 Moges addis ababa addis ababa 911555864

129 Bereket addis ababa addis ababa 942560298

130 meklit Oromia Adama 920936931

131 amare Oromia Adama 910393343

132 Solomon Oromia Adama 910409971

133 Solomon Oromia Adama 911713782

134 Fuad Oromia Adama 930793562

135 bisrat Oromia Adama 919116489

136 Aweke Oromia Adama 910727969

137 Tadesse Oromia Adama 962043601

138 alemayehu Oromia Adama 911917786

139 Gebeyehu Oromia Adama 930960481

140 sunshine addis ababa addis ababa 114450087

141 Midrok addis ababa addis ababa 911207441

142 Orbit addis ababa addis ababa 911205031

143 Equator addis ababa addis ababa 978575757

144 Universal merchentile plc addis ababa Addis ababa 111558387

145 Esmile ture addis ababa Addis Ababa 911686837

146 general tools trading addis ababa addis ababa 911473762

147 Zeki Ahemed general importer addis ababa Addis Ababa 930105839

148 ZS general treading addis ababa Addis Ababa 111558733

149 Afo Trading addis ababa Addis ababa 911519024

150 Jimma interprise plc addis ababa addis ababa 111115273

151 hagbis addis ababa addis ababa 111552233

152 Zeki Ahmed Ibrahim addis ababa Addis Ababa 930098839

153 Universal Construction addis ababa Addis Ababa 914419785

154 Habtamu addis ababa Addis ababa 913550955

155 Kider addis ababa addis ababa 925908485

156 Habtamu addis ababa addis ababa 0

157 yesuf addis ababa Addis Ababa 0

158 Ambachew ena muluken Amhara Bahir Dar 918727329

159 Zewdu ena aynaddis Amhara Bahir dar 918353497

160 yetsedaw demberu Amhara Bahir dar 918312686

161 Mohammed Amhara Bahir dar 918333779

162 desalegn ena daniel Amhara Bahir dar 942846402

163 Lij alem Amhara Bahir dar 912003794

164 getachew ena yichal Amhara Bahir dar 0

ix

165 Yewelsew ejigu Amhara Bahir dar 918783648

166 Medhane Amhara Bahir dar 918307180

167 Rahel Beyene Amhara Bahir dar 918716575

168 Ansuar Amhara Bahir dar 920512052

169 usman workie Amhara Bahir dar 0

170 Bereket Amhara Bahir dar 918760681

Documents

Energy Loss Assessment on Welding Transformers in Ethiopia