Technical Report 2011 Electricity Networks

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Introduction

The transmission network

The distribution network

Health and safety (H&S)


3/143 Regulation & Supervision Bureau | Technical Report 2011 - Electricity Networks

Since 1998 the Abu Dhabi electricity sector has been divided into its threeconstituent services: production, transmission and distribution. The single buyer

(ADWEC) purchases all electricity produced from the various power plants,

and then supplies distribution companies at a cost determined by an annually

reviewed bulk supply tariff (BST).

The electrical system in the Emirate is operated by three network

companies: a transmission company (the Abu Dhabi Transmission and

Dispatch Company, TRANSCO); and two distribution companies (Al AinDistribution Company, AADC; and Abu Dhabi Distribution Company,

ADDC), both of which carry out supply-related activities.

This report presents an overview of the performance of these

companies and the quality of their services during 2011.

Introduction



1. The transmission networkThe transmission network delivers large volumes of electricity from production companies to

users, including the distribution companies.

The sole transmission licensee in the Emirate of Abu Dhabi is TRANSCO.

TRANSCO generates revenue from users via connection fees and a Transmission Use of System(TUoS) tariff that is reviewed annually by the Bureau.

Measuring performanceThe technical performance of the electricity transmission system in Abu Dhabi Emirate compares

favourably with others worldwide. It is quantified using two primary performance measurements:

system unavailability and energy lost.

System unavailability

Transmission system unavailability represents the total time during which the transmission systemis out of service, expressed as a percentage of the total circuit hours in the year.

System unavailability decreased in 2011, compared to 2010. Data analysis indicates that reduced

construction outages were the main cause of improved system availability.

TRANSCO incidents and energy lost

Nine transmission system incidents occurred in 2011, resulting in the loss of 427

MWh - an increase of approximately 390 MWh on the previous year (see Figure 2).

All nine incidents were investigated by the Bureau. The most severe of these

occurred at the Shahama East (SHME) grid station, the Capital Garden (CPGR)

substation and Shamkha mobile.

Figure 1:Transmission system unavailability

0.0%2009 2010 2011

0.2%

1.2%

0.4%

1.4%

0.6%

1.6%

0.8%

1.8%

1.0%

2.0%

Maintenance Construction Users Faults



A major incident occurred at the 220/33 kV Shahama East grid station on 22 August 2011.

Transformer T202 tripped due to mal-operation of restricted earth fault protection, resulting in

the loss of 146MWh.

A second major incident occurred at the 132/11 kV Capital Garden substation on 21 September

2011. It was caused by an internal software error during a database update and resulted in the

loss of 94 MWh.

The third major incident occurred at the 220/33 kV Shamkha mobile transformer at Shamkha

on 19 October 2011, and involved a trip of the 220 kV WathbaShahama 2 circuit. This incident

resulted in a loss of 89 MWh.

A further six minor incidents occurred at Shamkha mobile 220/33 kV, MOS1 132/11 kV,

KhaznaWathba mobile 220/33 kV, Central 220/33 kV, and Mushrif 132/11 kV.

The number of transmission system incidents was five more than in the previous year, and

the total energy lost as a result showed a significant increase over 2010.

Distribution companies - anomalous incidents and energy lost

An incident is considered anomalous when a fault on the distribution network

results in an outage and loss of demand on the TRANSCO network. During

2011, seven anomalous incidents caused supply interruptions on TRANSCOs

assets. These incidents, which are not included in the performance data shown in

Figure 2, resulted in a total loss of 188 MWh.

Figures 3 and 4 show the trend in anomalous incidents for AADC and ADDC in

which the distribution system failed to isolate the faults, causing the transmission

assets to trip.

Figure 2:Transmission system incidents

02009 2010 2011

50

100

150

200

250

300

400

350

450

500

EnergylostMWh

Numberofincidents

Energy lost Number of incidents

0

1

2

3

4

5

7

6

8

9

10



The Bureau and network companies are currently examining the issue of anomalous incidents

with a view to improving performance.

Additional transmission developments

Major transmission system developments

The following major transmission system expansion activities were carried outduring 2011:

Commissioning of 132/22 kV substations on Reem Island.

Commissioning of 132/22 kV substations on Saadiyat Island.

Commissioning of the Raha B 132/22 kV, and Green Head, Mushrif, Souq and

Danat 132/11 kV substations.

Commissioning of two 220/33 kV transformers at Bab.

Commissioning of a 220/33 kV substation at ELXR.

Commissioning of a 220/33 kV substation at ICAD.

New 220 kV cable from AAPS to DHMG.

New 400 kV cable from Saadiyat to ADST grid.

Commissioning of Shuweihat 2 (S2) power plant.

Figure 3:Distribution companies - anomalous incidents

02006 2007 2008 20102009 2011

1

2

3

4

5

6

7

8

9

Incidents

Year

10

ADDC AADC

Figure 4:Energy lost through anomalous incidents

02006 2007 2008 20102009 2011

50

100

150

200

250

300

350

400

MWh

Year

ADDC AADC



Emirates National Grid

The Emirates National Grid, which allows power exchanges between Abu Dhabi, Sharjah, Dubai

and the Northern Emirates, is undergoing further expansion. During 2011 a 400 kV double-

circuit overhead line between Shweihan and Fujairah grid was commissioned. This increased the

cross-border transmission capability between Abu Dhabi and the Northern Emirates.

Commissioning of the GCC interconnection

Commissioning of the 400 kV double-circuit overhead line from Sila to the Shuweihat grid

station was completed, and the UAE transmission system was synchronised with that of

the GCCIA.

The 220 kV double-circuit transmission line from the Al Oha 220 kV substation in Al Ain

to the Mahada 220 kV substation in Oman was completed, allowing the UAE and Omansystems to be synchronised.

The GCC interconnection will improve system security, provide support during emergencies,

reduce generation reserve requirements, and support the development of a common

GCC electricity market.

TRANSCO seven-year planning statement review

The Bureau reviewed and provided feedback on TRANSCOs seven-year planning

statement, released in 2011. Following discussions with the Bureau, TRANSCOincorporated an enhanced strategic plan that provides a long-term view of the

system to 2030. The plan will be updated annually in conjunction with the seven-

year planning statement.

WESTERN REGION

AL AIN REGION

Ras al Khaimah

Dhaid

MadinatZayed

ADNOCSila

Shahama

ShweihanUmm AlNar

Wagen

Arad

Wathba

Musaffah

Sanaiya

Al Ain PowerStation

Samha

Taweelah

Electricity system expansion

Umm El Oush

Hayer

Al Foah

Dahma

Al AinSouthwest

DEWAWarsan

Umm Al Quwain

AjmanSharjah

Qidfa(Fujairah)

DUBAI

Abu Dhabi

SaadiyatReem

Asab

Liwa

Bu Hasa

Bab

Ghaythy

Ruwais

Mirfa

Shuweihat

Interconnectionto Oman (Wasit)

220 kV Lines

400 kV Lines

Under construction

Power Stations

Figure 5:Transmission system



2. The distribution networkThe distribution system comprises the final stage in the delivery of electricity to end-users. As

of 31 December 2011, the total number of customers connected to the two networks was

281,966 (ADDC)1and 123,318 (AADC)2.

Peak demand load in 2011 was 4,260 MW for ADDC3and 1,940 MW for AADC4. ADDC recorded

a growth in peak demand of 9.5% in 2011 over 2010, while AADC experienced a 7.8% rise over thesame period (see Figures 6 and 7).

Figure 6:ADDC maximum demand5

Figure 7:AADC maximum demand6

1 ADDC, Technical Assessment of the Price Control Return Relating to 2011 Financial Year, Final

Report, April 2012.

2 AADC, Technical Assessment of the Price Control Return Relating to 2011 Financial Year, Final

Report, April 2012.3 ADDC, 5 Year Electricity Planning Statement 20132017, June 2012.

4 AADC, 5 Year Electricity Planning Statement 20132017, June 2012.

5 ADDC 5 Year Electricity Planning Statement , op. cit.

6 AADC 5 Year Electricity Planning Statement , op. cit.

02006

2,794

2007

3,099

2008

3,339

2009

3,693

20112010

4,260

3,889

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

4,500

MW

02006

1,400

2007

1,521

2008

1,562

2009

1,683

20112010

1,940

1,799

500

1,000

1,500

2,000

MW



Distribution network assets data7

Quality of supplyEnsuring quality of supply for end-users requires high performance in all three elements of the

network: generation, transmission and distribution. However, distribution is by far the most significant

of these in determining quality of supply.

Since the introduction of performance indicators in 2006, the Bureau has closely monitored the

network performance of AADC and ADDC. The Bureau requires that an independent audit of

annual performance data be carried out by a technical assessor each year.

After reviewing the findings of the 2011 audit, the Bureau noted some improvements in

ADDCs monitoring performance.

AADCs data quality has improved, but many of the recommendations made in the 2010

technical assessment audit have not yet been implemented.

The Bureau utilises two key performance indicators (KPIs) to determine the performance

and reliability of the ADDC and AADC distribution systems:

The System Average Interruption Duration Index (SAIDI), calculated from the

total number of customer minutes lost (CML) in any one year, divided by the total

number of connected customers (at year-end).

The System Average Interruption Frequency Index (SAIFI), calculated from the

total number of customer Interruptions (CI) in any one year, divided by the total

number of connected customers (at year-end).

The distribution companies record customer interruptions and calculate KPIs

according to specific procedures developed by the Bureau.

7 Ibid.; and ADDC 5 Year Electricity Planning Statement , op. cit .

ADDC DISTRIBUTION SYSTEM No. of

units

Capacity

(MVA)

132/22 kV primary SS 12 3,840

132/11 kV primary SS 33 5,080

33/11 kV primary SS 231 6,610

22/0.4 kV distribution SS 122 376

11/0.4 kV distribution SS 13,779 17,287

ADDC CABLE /

OVERHEAD LINE

SYSTEM

Length (km)

33 kV 5,747

22 kV 274

11 kV 13,020

0.4 kV 11,546

AADC CABLE /

OVERHEAD LINE

SYSTEM

Length (km)

33 kV 3,529

11 kV 9,259

0.4 kV 9,945

AADC DISTRIBUTION SYSTEM No. of

units

Capacity

(MVA)

33/11 kV primary SS 150 5,120

11/0.4 kV distribution SS 14,583 8,025



ADDC performance

ADDCs SAIDI and SAIFI KPIs are shown in Figures 8 and 9.

Figure 8:AADC System Average Interruption Duration Index (SAIDI)8

Figure 9:ADDC System Average Interruption Frequency Index (SAIFI)9

Note: An adjustment was made to the 2006-2008 SAIDI/SAIFI figures to facilitate comparison with the2009 figures, owing to a change in ADDCs customer interruption reporting methodology in 2009.

The improvement in ADDCs SAIDI/SAIFI values between 2010 and 2011 was

mainly a result of less planned outages being required during the upgrading and

replacement of the 11 kV distribution switchgears in the central region. The

cancellation of the substation AMR works also contributed to this reduction.

Furthermore, the Eastern and Western Regions experienced fewer cable and

overhead line faults, and a significant increase in their numbers of customers.

8 ADDC, Technical Assessment , op. cit.

9 Ibid.

02006

184.6

2007

157.6

2008

173.7

2009

185.9

20112010

107.0

205.3

20

40

60

80

100

120

140

160

200

180

220

240

SAIDI

02006

1.77

2007

1.58

2008

1.65

2009

1.74

20112010

1.71

1.99

0.5

1.0

1.5

2.5

2.0SAIFI



AADC performance

Figures 10 and 11 show AADCs SAIDI and SAIFI KPIs.

Figure 10:AADC System Average Interruption Duration Index (SAIDI)10

Figure 11:AADC System Average Interruption Frequency Index (SAIFI)11

The improvement in AADCs SAIDI/SAIFI values in 2011 was mainly due to the

installation of overhead line auto-reclosers and sectionalisers in 20082009,

new primary 33/11 kV substations being added in the City Region, and the

undergrounding of a number of overhead lines.

Both companies are introducing the capability to control their systems remotely and

restore power during severe weather events, and the Bureau has recommended

targeted investment programmes for regions that have suffered consistently poor

performance.

Related events

10 AADC Technical Assessment op. cit .

11 Ibid.

02006

265.8

2007

165

2008

220.7

2009

261.34

20112010

134.65

186.86

20

40

60

80

100

120

140

160

200

180

220

240

260

280

300

SAIDI

02006

3.6

2007

2.63

2008

2.76

2009

2.78

20112010

1.45

1.92

0.5

1.0

1.5

4.0

2.5

3.0

3.5

2.0SAIFI



Related events

Electricity wiring regulations training

Two nominated companies continue to provide regular training courses on electricity wiring

regulations for private contractors. The five-day course, based on a programme developed by

the Bureau, includes both theoretical and practical elements, as well as a final examination.

The Bureau maintains a list of registered engineers who have successfully completed the

course (169 passed in 2011), which is available on its website. The aim of this training initiative

is to improve the skill levels of electrical contractors in Abu Dhabi, as well as to streamline

procedures for the approval and testing of wiring in new buildings.

Asset risk management review

The rapid development and associated demand growth within Abu Dhabi Emirate in recent years has led

the network companies to invest heavily in network assets. In order to maximise the benefits of this activity,

and to avoid future acute operation and maintenance issues, it is vital that assets and associated risks are

managed effectively.

An important aspect of this is the process of determining and assessing the network companies

current asset risk management performance against international best practice in order to identify

any areas for improvement.

Towards the end of 2011, the Bureau appointed an external consultant to review the companies and

assess their asset risk management performance. The review will be complete by Q3 2012 and a

programme developed to implement the resulting recommendations.

AADC and ADDC five-year planning statement reviews

Each year the Bureau reviews and comments on the five-year planning statements

produced by each of the distribution companies. The parties then discuss the observations

of the Bureau in order to improve the quality and format of their statements.

Connection process improvements

During Q3 of 2011, the Bureau collaborated with ADDC to review the companys

existing electricity connection process, with the aim of reducing the overall time required

for connection.

KPIs were selected at various stages of the process, and their results monitored by both

parties. Wherever a KPI highlighted a significant delay, ADDC and the Bureau worked

together to understand the cause and develop appropriate action plans.

Emergency load reduction plans

During 2011, the Bureau set up a working group and carried out a review of

TRANSCO, AADC and ADDC emergency planning.



The review led to significant developments in the AADC and ADDC emergency load reductionplans, which will improve the management of emergencies in which load shedding is a requirement.

As a result, measures are now in place to determine demand prioritisation and minimise the

effects of load reduction on consumers, whilst maintaining the security of the power system.

Reem Island mega development

At the request of the Government, the Bureau cooperated with Bunya and ADDC to facilitate

the asset transfer of electricity and water network infrastructure to Reem Island.

Reem Island is considered a mega development, in which the developer builds the infrastructure to the

Distribution Companys standards and specifications, and the assets are transferred upon completion.

3. Health and safety (H&S)

H&S performance: electricity and waterThe table below summarises the health and safety performance of the electricity and water networks

operated by TRANSCO, AADC and ADDC during 2011.

During Q3 of 2011, a review of AADC and ADDC H&S management and operational

systems and processes was completed. The review was conducted by an external consultant

at the request of the Bureau, and follows the successful completion of a similar appraisal of

TRANSCO in 2010.

The Bureau will use the data from these reviews to achieve significant improvements in

H&S performance, working with network companies to implement action plans for thispurpose. The Bureau also organised best practice workshops for the beginning of 2012

to share the lessons learnt from the process with the rest of the sector.

Following on from the work carried out in 2010 to establish the Bureaus internal

Environment, Health and Safety Management System (EHSMS), the AD EHSMS

Centre completed its review of the system and gave its approval during Q1 of

2011; the Bureau began to implement the system thereafter.

During the latter part of 2011, the Bureau was appointed Sector Regulatory

Authority (SRA) for the Wastewater Sector, and began working closely with the

AD EHSMS Centre and other entities to develop codes of practice for the sector.

LICENSEE Total man hours

worked Fatalities

Lost time

injuries (LTI) Minor injuries

AADC 22,397,728 0 2 0

ADDC 13,278,754 0 4 6

TRANSCO 17,497,060 0 4 156

Total 53,173,542 0 10 162

Figure 12:Health and safety performance, 2011


14/14

Abbreviations and Acronyms:

AADC Al Ain Distribution Company

ADDC Abu Dhabi Distribution Company

ADWEC Abu Dhabi Water and Electricity Company

BST bulk supply tariff

CML customer minutes lost

CI customer interruption

EHSMS Environment, Health & Safety Management System

FAPCO Fujairah Asia Power Company

GCC Gulf Cooperation Council

GCCIA GCC Interconnection Authority

H&S health and safety

KPI key performance indicator

HV high voltage

kV kilovolt

MVA megavolt ampere

MWh megawatt hour

SAIDI System Average Interruption Duration Index

SAIFI System Average Interruption Frequency Index

TRANSCO Transmission and Despatch Company

TUoS transmission use-of-system

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