Cameron Parrote - AEMO

SLIDE 1

TRANSITION OF ELECTRICITY SYSTEMS

TO LOWER CARBON FOOTPRINT

March 2017

PRESENTED BY CAMERON PARROTTE

SLIDE 2

KEY POINTS

• AEMO is accountable for overseeing power system security of the National

Electricity Market in the South and Eastern states of Australia and the

Wholesale Electricity Market in Western Australia.

• The electricity landscape is rapidly transforming: generation technology is

changing; customers are becoming more engaged in the way they manage

their energy supply and consumption. As a result AEMO is reviewing how to

maintain power system security into the future.

• This presentation will give some insights into observable trends, the impacts

of these changes and how AEMO is responding to these challenges.

SLIDE 3

FUTURE POWER SYSTEM SECURITY

1. AEMO Power System Security Accountability

2. Emerging Trends

3. Future Power System Security Program

4. Immediate challenges

1. Frequency control

2. Management of extreme power system conditions

3. System strength

4. Visibility of the power system

5. Opportunities

6. Questions

SLIDE 4

AEMO POWER SYSTEM SECURITY

SLIDE 5

WHAT IS POWER SYSTEM SECURITY

• Power System Security: The ability of the system to withstand sudden disturbances, including the failure of generation, transmission and distribution equipment and secondary equipment.

• Power System Reliability: The ability of the system to deliver energy within reliability standards.

• In more simple terms: getting customers the power that they need when they need it while maintaining the system within specified limits, including allowing for credible contingency events.

o For safety, to avoid equipment damage and to avoid widespread disruptions to consumers.

• Second-by-second function relating to the physical operation of the power system.

SLIDE 6


• AEMOs vision is Energy Security for All Australians.

• AEMO is responsible for overseeing power system security of the National Electricity Market (NEM) and the Wholesale Electricity Market (WEM).

• The electricity landscape is rapidly transforming.

o Generation technology is changing.

o Consumers are becoming more engaged in the way they manage their energy supply and consumption.

• AEMO does not own the physical plant - like power stations or transmission lines.

• AEMO monitors electrical properties around the system and sends instructions to generators and network businesses to control plant to keep these electrical properties within specified limits.

SLIDE 7

POWER SYSTEM SECURITY

– EMERGING TRENDS

SLIDE 8

HOW DOES A POWER SYSTEM WORK

SLIDE 9

SOME OBSERVABLE TRENDS

• Non-registered

• Presence / characteristics could be unknown

Registered Generation

• Distributed / embedded

• Not individually monitored

• Not centrally dispatched

Centrally Monitored Dispatched

• Intermittent generation • Reduction in frequency control capability

under normal and extreme circumstancesControllable

• Inverter connected and asynchronous generation

• Low inertia and weak AC system

Synchronous Generation

SLIDE 10

Synchronous

generationNon-synchronous

variable generation

Dispatchability

Inertia

Frequency

regulation

Fault level

contribution

Dynamic frequency

response

Energy

Voltage

control

Semi-dispatch

No minimum

generation level

(can be more flexible)

No start-up lead

time or costs

LARGE SCALE GENERATION –

SOME IMPACTS OF THE CHANGES

SLIDE 11

Concentration of renewables

PV continuing to grow

Excellent wind resource

Gas availability / Rising gas price

Most SA thermal generation is gas

Flat energy and peak demandVIC – SA interconnection

upgrade

Competition from VIC coal

Squeeze on conventional generation

SOME KEY TRENDS IN SOUTH AUSTRALIA

“TEST” STATE

SOME KEY TRENDS IN SOUTH AUSTRALIA

SLIDE 12

THE CHANGES IN SA DEMAND

Solar PV output is offsetting

Operational Demand in

Summer 2015

SLIDE 13

SOME COMPARISONS

Balancing Area Peak Demand Annual Energy Installed Wind

(% peak)

Installed PV

(% peak)

Texas 68,000 MW 340 TWh 12,400 MW (18%) 300 MW (0.4%)

NEM 35,000 MW 194 TWh 3,800 MW (11%) 4,200 MW (12%)

Ireland (all island) 6,600 MW 35.4 TWh 2,325 MW (35%) 1 MW (0%)

South Australia 3,400 MW 13.2 TWh 1,475 MW (43%) 671 MW (20%)

Hawaii (Oahu) 1,140 MW 7.0 TWh 99 MW (9%) 221 MW (19%)

Source: ERCOT, EirGrid, SONI, HECO

Western Australia 4,013MW 18.6 TWh 490 MW (12.2%) 650 MW (16.2%)

SLIDE 14

SOUTH AUSTRALIA – MINIMUM DEMAND

FYEActual (MW) Date / Time

2011 1,107 26/12/10 06:30

2012 1,073 26/12/11 05:00

2013 1,041 25/12/12 13:30

2014 981 07/10/13 12:30

2015 790 26/12/14 13:30

-400

-200

0

200

400

600

800

1,000

1,200

1,400

2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025

Dem

and

(M

W)

FYE

90% POE forecast

Industrial Residential/Commercial Auxiliary loadsTransmission losses SNSG PVEnergy Efficiency Operational MD

SLIDE 15

WESTERN AUSTRALIA – MINIMUM DEMAND

Overnight

Minimum Daytime

Minimum

SLIDE 16


PROGRAM

SLIDE 17


• AEMO has a strategic program of work underway to manage the challenges

associated with these changes.

• In this we are reviewing how we will maintain power system security into the

future.

• Initial focus has been on understanding the nature of potential challenges.

• It was critical to identify the right challenges and their relative priority before

seeking to find solutions.

SLIDE 18

FUTURE POWER SYSTEM SECURITY PROGRAM

OBJECTIVES

Short-termTo be transparent and

clear in how AEMO

intends to meet its

obligations for system

security and reliability as

the generation mix

changes.

Long-termTo identify, rank and

promote resolution of

long-term technical

challenges of operating

the power system to

inform the potential

need for policy,

procedural or regulatory

changes.

Adapt AEMO’s functions and processes to deliver ongoing

power system security and reliability

SLIDE 19

CHALLENGES NOT PROBLEMS

• We have identified challenges in maintaining system security:

o Under some operating conditions.

o Potential technical solutions abound.

• Delivery mechanisms for the solutions need to:

o Be forward looking.

o Provide a flexible market and regulatory environment.

o Be fuel and technology neutral.

o Use efficient markets or incentive regulation to drive optimal outcomes.

o Incorporate regulatory arrangements that support innovation.

o Be tested against National Electricity Objective.

SLIDE 20

FPSS PROGRAM PROCESS

2017 →Dec 2016May 2016→ Dec 2015

Identify challengesAnalysis to define operational bounds

and risks

Identify technical solutions

Develop solution

frameworks

Analysis of other

technical challenges

Address short-term challenges using existing market and regulatory

frameworks

SLIDE 21

OVERALL FINDINGS TO DATE

• Clear that there are technical challenges under some

conditions.

• Generally not expected when the NEM is intact – except

some local issues that cannot be managed globally.

• Some technical challenges can arise at the same time.

• Need for visibility of widespread embedded devices.

SLIDE 22

IMMEDIATE CHALLENGES

SLIDE 23

THE CHALLENGES

Information to market

Cyber-security

Under-frequency and

over-frequency

schemes

Frequency regulationHigher rates of

change of frequency

Higher variability of

supply and demandFrequency control

System restart with

less synchronous

plant

Voltage and power

flow management

Management of

power flows with less

scheduled plant

Security assessments

with lower visibility of

generation

Weakening system

(lower fault levels)

Reduction in transfer

(stability) limits

Veracity of models

and tools

Understanding

technical performance

and potential

Representation of

distributed energy

sources

Modelling and

operational tools

System restart

Market information

Cyber-security

Real time operational

data requirements

SLIDE 24

WHAT ARE THE IMMEDIATE CHALLENGES?

Frequency control

Management of extreme power system

conditions

Visibility of the power system

(information, data and models)

System strength

SLIDE 25

Frequency control


conditions



System strength

SLIDE 26

FREQUENCY CONTROL

• Frequency is the signal for supply/demand balance

• Frequency needs to be balanced in real time and needs to be resilient to system events

• Aspects of our market design have put us in a good position

50.0

DE

M

GE

N

Despite this, low inertia on the one hand and less

controlled and responsive plant on the other provides

challenges especially in some circumstances

SLIDE 27

FREQUENCY CONTROL

Challenges: • Managing high RoCoF when inertia is low.

• Reducing FCAS supply as synchronous generation withdraws.

• Possible increasing FCAS requirements from variability of supply and demand.

• Can under-frequency load shedding (UFLS) schemes react fast enough?

• Are over-frequency generation shedding (OFGS) schemes needed?

Where challenges might arise: • Not expected to be NEM-wide challenges in the near term.

• May be challenges in regions that can separate from the NEM.

SLIDE 28

Frequency control


conditions



System strength

SLIDE 29

MANAGING EXTREME POWER SYSTEM CONDITIONS

Challenges:

• We have limited powers to act pre-emptively to manage a non-credible contingency event.

Where will the challenges arise:

• Initial challenge is to manage risks of non-credible loss of Heywood Interconnector (SA-NSW).

Interim solutions:

• We are:o Redesigning the current UFLS.

o Designing an OFGS.

o Reviewing procedures to operate SA as an island.

o Assessing the need to clarify expectations, roles and responsibilities in relation to particular system events.

SLIDE 30

Frequency control


conditions



System strength

SLIDE 31

SYSTEM STRENGTH

Challenges:

• System strength is reducing.

• Can be challenging to model.

• Impacting on new connections.

• Can compromise:

o Effectiveness of protection systems to detect and clear electrical faults.

o Ability of non-synchronous generation to operate as required in performance standards.

o Voltages stability leading to potential voltage collapse.

Where challenges might arise:

• Can arise in even in an intact NEM

• In areas remote from synchronous generation.

SLIDE 32

REDUCING LEVELS OF SYSTEM INERTIA

• Modelling is based on least cost dispatch, which delivers conservative

inertia estimates

• Trend is important

South Australia inertia for Rapid Transformation scenarios

Source: AEMO NTNDP

SLIDE 33

Frequency control


conditions



System strength

SLIDE 34

VISIBILITY OF THE POWER SYSTEM

(INFORMATION, DATA AND MODELS)

Challenges:

• Visibility of distributed energy resources (DER).

• Dynamic load behaviour is not effectively modelled.

• In the future, models of physical plant and modelling tools currently used may not be capable of providing accurate system state information.

Where challenges might arise:

• The challenges will arise in all NEM regions.

• There will be greater uncertainty in operational demand forecasts.

• Future limitations in determining system security limitations.

• The process of assessing and reviewing models and modelling tools is expected to be a longer-term challenge.

SLIDE 35

DISTRIBUTED ENERGY RESOURCES

A MAJOR BLIND SPOT

• Over 4 GW of rooftop PV systems are installed in NEM, 0.55GW in WEM

• Individually small but in aggregate LARGE• What If the Clean Energy Regulator didn’t collect details?

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

50%

2009-10 2010-11 2011-12 2012-13 2013-14 2014-15

Pe

rce

nta

ge

of

de

ma

nd

me

t b

y r

oo

fto

p P

V

NSW QLD VIC TAS SA

• DER displaces

scheduled generation.

• We lose some levers

to maintain system

security.

• Visibility becomes

even more important

at these times to

maintain normal

operating conditions.

SLIDE 36

CASE STUDY:

MARCH 2015 EUROPEAN SOLAR ECLIPSE

• 6 months planning across 23 countries with 89 GW solar.

• Decrease in forecast PV output of 20 GW at start of eclipse.

• Increase by ~40 GW at end.

• Power system remained secure because operators had:

“A clear description of

the installed PV

capacity and their

capabilities… [and] real

time measurement of

the dispersed PV

generation… key for

adapting the

operational strategy in

real-time*”

*ENTSOE, Solar Eclipse: The successful

stress test of Europe’s power grid, 2015.

https://docs.entsoe.eu/dataset/solar-eclipse-

the-successful-stress-test-of-europe-s-

power-grid-more-ahead

SLIDE 37

NOT JUST ABOUT DER

• DER is biggest gap but not the only one.

• Generator performance standards changed in 2007 to include information of

RoCoF settings, etc.

o Settings for older generating units are not all known.

• As the generation mix changes, system strength is changing.

o Can affect the performance of some generating units and other network

elements.

o Need greater level of information about generating units to understand

performance under changing system.

SLIDE 38

2016 SA BLACKOUT (AND OTHER RECENT NEM EVENTS)

SLIDE 39

SYSTEM BLACK PRE-EVENT:

AEMO DECISIONS

At 8:30am on 28 September 2016 in accordance with normal operating

procedure, AEMO assessed:

o Forecast wind speed against SA powerlines capability - OK

o Vulnerability to lightning of SA transmission powerlines - OK

o Possibility of wind farm overspeed trips – may be some risk, so monitor it

o Vulnerability of Heywood interconnector to the storm - OK

o Advice from SA network owners and generators of extra risk - OK

AEMO found no basis to justify application of extra network constraints to

restrict power flows or change generation dispatch.

Peak wind speeds were forecast at 120 km/h at the time of decision, then

raised to 140 km/h later in the day. AEMO decisions were not reviewed or

changed during the day.

Interconnector flow was set to allow up to 600MW to SA on Heywood

(AC), and maintain 140MW to SA on Murraylink (DC). The actual pre-

event flow was 505MW to SA on Heywood, 140MW to SA on Murraylink.

SLIDE 40

WHAT HAVE WE LEARNT FROM SA BLACKOUT

Cause Effect Potential disruptor

Tornadoes Tower collapse line faults Stronger towers

Tower collapse line faults Grid voltage dips Increased SA system strength

Grid voltage dips Wind farm ride-throughs -

Pre-set ride-through limits Wind farm output reduction Changes to wind farm control settings

Wind farm output reduction Increase in Heywood flow Very fast response local reserve supply

Increase in Heywood flow Loss of VIC-SA synchronism Lower pre-event flow (more headroom)

Loss of VIC-SA synchronism Heywood interconnector trip Back-to-back DC link at Heywood

Heywood interconnector trip SA supply deficit (50%) New concept fast load shedding scheme

SA supply deficit (50%) SA frequency fall -

Low SA system inertia Very fast SA frequency fall Increased SA system inertia

Very fast SA frequency fall Ineffective UFLS Faster smarter frequency control scheme

Ineffective UFLS Fast system collapse Smart grid islanding scheme

Fast system collapse Black system – all supply lost -

SLIDE 41

WHAT HAVE WE LEARNT FROM SA BLACKOUT

Potential disruptor Feasibility factors

Stronger towers Prohibitive cost, uncertain incremental value X

Increased SA system strength Moderate cost, uncertain (moderate) value ?

Changes to wind farm control settings High value, low cost, practical in short term √ (done)

Very fast response local reserve supply Possible long term new technology, cost uncertain (FPSS) ?

Lower pre-event flow (more headroom) Potentially high cost to SA customers, uncertain value ?

Back-to-back DC link at Heywood High cost, uncertain incremental value X

New concept fast load shedding scheme Possible long term new technology, cost uncertain

Increased SA system inertia Moderate cost, possible longer term (FPSS) ?

Faster smarter frequency control scheme Moderate cost, moderate value, medium term ?

Smart grid islanding scheme Moderate cost, uncertain incremental value X

• Given the action already taken, if the same sequence of tornado related events happened today, VIC-SA

separation is unlikely to occur. The only load lost from the transmission grid might be the Eyre Peninsula

(Port Lincoln and surrounds) due to damage to its single line.

• On 3 March 2017, a voltage transformer failure resulted in 3 separate SA faults causing the loss of

600MW of gas fired SA generation (260MW expected given the faults) and flow on interconnector to go

from 500MW to 963MW, however lower voltage dip so interconnector protection did not operate. No

sustained reduction in wind farms

SLIDE 42

WHAT HAVE WE LEARNT FROM INSTRUCTED LOAD

SHEDING

7-12 February 2017 heatwave resulted in very high electricity loads across the Eastern

States.

1) 8 February 2017 SA Directed Load Shedding due to demand/supply changing

rapidly just prior to the 6pm peak:

o Actual load higher than forecast (4pm temperature 2 degrees C more than forecast;

~150MW)

o Wind generation lower than forecast (90MW less than forecast at 4pm)

o Thermal generation failures (~150MW)

o Due to reserve shortfall, AEMO directed 100MW of load shedding at 6:03pm.

o All load restored 27min later as peak subsides.

• Learning: Are Loss of Reserve (LOR) levels which cover various contingencies

adequate; forecasting improvements; day ahead market?

2) 10 February 2017 NSW Directed Load Shedding due to loss of generation just prior

to peak:

o Load less than forecast (voluntary/contracted reductions, temperature higher than forecast)

o Thermal generation failures / reduced output (2GW unavailable, 720MW failed)

o Due to reserve shortfall, AEMO directed 290MW of block load shedding at 4:58pm,

restored 6:07pm.

• Learning: Voluntary reductions do assist; block load shedding preferential

SLIDE 43

OPPORTUNITIES TO ADDRESS THE CHALLENGES

SLIDE 44

CHALLENGES NOT PROBLEMS

While we see there are challenges in maintaining the

security of the power system in the future under some

operating conditions, we are confident that potential

solutions abound.

Solutions need to:

• be forward looking

• provide a flexible market and regulatory environment

which is technology neutral

• use efficient markets or incentive regulation to drive

optimal outcomes

• incorporate regulatory arrangements that support

innovation.

SLIDE 45

OPPORTUNITIES – CONSUMER SIDE

• Enhanced retail market offerings and rollout of advanced meters.

• Home automation and the Internet of everything.

• Smart, controlled loads and embedded generation.

• Smart, controlled embedded storage.

• Frequency controlled loads.

SLIDE 46

OPPORTUNITIES – LARGE SCALE

• Large generators

o Synchronous generators

o Non-synchronous generators

with augmented performance

• Specialist connected plant

o Synchronous condensers

o Statcoms and SVCs

o Flywheels

o Storage

SLIDE 47

OPPORTUNITIES – NETWORKS

• New AC interconnectors and upgraded interconnectors

• New DC interconnectors

• Advanced protection systems and dynamic UFLS

Photo: Scoobay. Creative Commons BY-NC-SA (cropped)

https://www.flickr.com/photos/scoobay/5750035274/

https://creativecommons.org/licenses/by-nc-sa/2.0/

SLIDE 48

OPPORTUNITIES – DELIVERY FRAMEWORKS

• Revised markets to encourage the economic delivery of required services.

• Revised technical standards requiring new plant to provide additional

services.

• Changed Australian standards for appliances, embedded generation and

storage.

• New regulatory arrangements.

SLIDE 49

NEXT STEPS

SLIDE 50


• With challenges identified, our focus is now on:

o Specifying the technical parameters required by the system, and

o Assessing the technical capability of various potential technology

solutions.

SLIDE 51

QUESTIONS

Thank you!

Presentations & Public Speaking

Cameron Parrote - AEMO