Does a Smarter Power Grid Really Matter Anyway?

… A Reflection of Challenges Experienced in the UK

Professor William Hung MBA, PhD, BSc, CEng FIET

Director/WH Power Systems Consultant LtdHonorary Professor/ University of WarwickTechnical Director/ Cardiff University

University of Warwick School of Engineer Seminar - 29 January 2016

Presentation Overview

• Development of Electricity Supply Industry in the UK and its implications on Key Stakeholder relationships

• Review of frequency control issues

• Collaborative effort between stakeholders since privatization

• Future Challenges in a Low Carbon Economy

• Contributions not only from a smarter grid but smarter demands

• Extension of Stakeholder Engagement Activities

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Generating

Companies

Distributors

Transmission

Companies

Suppliers

Electricity Supply Industry – Key Stakeholders

Changes in the UK Electricity Supply Industry

• Privatization – 1990

• Dash for Gas – around 1993

• Liberalization of electricity market - 1999

• NETA- March 2001

• Dash for Wind – ROC payment -2002

• BETTA- April 2005

• EU Large Combustion Plant Directive

• Renewable Obligations

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Implications on Key Stakeholders Relationship

• Change of industry structure and generation mix - significant implications on system security from a frequency control perspective.

• From separation of Generation and Transmission businesses after privatization, to dash for gas then for wind and finally the renewable obligations challenges, National Grid in the UK has worked closely with key stakeholders to ensure the transmission Licence obligations are met.

• Be transparent and share concerns with relevant stakeholders in a timely manner to seek collective resolution options

• Developing financial incentives to reward service providers

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Frequency Control Issues

• Frequency control requirements• Nominal level: 50Hz

• Statutory limits: +/- 0.5 Hz

• Operational limits: +/- 0.2 Hz (standard deviations 0.07 Hz)

• Cover instant generation loss was up to 1320MW

• Avoid automatic load disconnections • Above 48.8 Hz

• If triggered - could be up to 9 stages and 60% load disconnection

• System needs responsive and flexible plant

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Typical Frequency Incidents

49.20

49.30

49.40

49.50

49.60

49.70

49.80

49.90

50.00

50.10

12

:24

:00

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:25

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:26

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:27

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:28

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12

:29

:00

Note:

On this occasion

Gas Turbines started

at 12:29:20

Primary Response 0 - 30 secs

Secondary Response 30 secs - 30 mins

freqcont.ppt 009 24/02/99

Frequency Control Analogy

Frequency Control/ Wheel Pulling Analogy

Generators Vehicles

Frequency Wheel speed

Demand level Slope gradient

Load variations Bumpy road

TV pickup Big rock

Largest generation loss Largest truck stalled

Blackout Wheel run away

Improve Frequency Service Provision after Privatization

• Define frequency services• Primary, Secondary and High Frequency Response services

• Establish payment mechanism

• Establish contract format

• Validate plant capability through dynamic plant testing

• On-line monitoring – gain confidence on service delivery

• Enhance Grid Code minimum technical requirements

• Liaise with main plant suppliers to improve plant/control design

• Collaborate with Generators to improve plant performance

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Primary & Secondary Responses

10s 30s 30 mintime

Fre

qu

ency

Ch

an

ge

(Hz)

Pla

nt

Res

po

nse

(M

W)

P S

-0.5 Hz

High Frequency Response

Fre

qu

ency

Ch

an

ge

(Hz)

Pla

nt

Res

po

nse

(M

W)

+0.5 Hz

H

10s time

Frequency Response Contract Format

On-line Monitoring

• Feedback to System Operator

Confirm contracted level of delivery

Improve confidence level in service despatch

Optimise frequency response service cost

• Feedback to Generators

Improve plant performance, if required

Increase incentive for plant control improvement

Gain confidence level in service delivery

• Evidence to support frequency incident investigations

On-line Monitoring - Example 1

On-line Monitoring - Example 2Coal Station 4, 28-Aug-2003

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TIME (GMT)

GE

NS

ET

AC

TIV

E P

OW

ER

OU

TP

UT

(M

W)

49.6

49.7

49.8

49.9

50

50.1

50.2

50.3

FR

EQ

UE

NC

Y (

Hz)

GENSET OUTPUT CAPPED COMMITTED LEVEL (MW) EXPECTED RESPONSE (MW) FREQUENCY TARGET FREQ

Low Frequency Automatic Demand Disconnection Incident - 27th May 2008

England ‘v’ Sweden (20th June 2006, 8pm)

TV Pick-up – Football World Cup

TV Pick Ups met using combination of coal plant,

French Interconnector & pump storage hydro

Half Time

1800MW

Full Time

1600MW

Demand 20 June 2006

England vs Sweden

36000

36500

37000

37500

38000

38500

39000

39500

19:5

0:00

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2:00

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4:00

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6:00

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8:00

20:0

0:00

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2:00

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4:00

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6:00

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8:00

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0:00

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2:00

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4:00

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6:00

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0:00

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2:00

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4:00

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6:00

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8:00

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0:00

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2:00

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4:00

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6:00

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8:00

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0:00

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2:00

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4:00

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6:00

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6:00

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6:00

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0:00

Time (Local)

De

ma

nd

MW

20th June 2006 30th May 2006

Half time1800MW Full-time

1600MW

TV Pick-up – TV Soaps 25th April 2005

The more popular the TV programme, the larger the MW pick up

Dash for Gas

• CCGT were traditional designed for full load operation not for flexible operation

• The perception was CCGT could not provide frequency response… it would rack the turbine

• Offered service price were 8 times higher than conventional plant

• Falling power/ falling frequency issues

• Could CCGT be exempted for frequency response service? No but Why?

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Impact of poor response and inflexible plant on Grid operation

a) For responsive generators, five are required to cover the loss of one generator

60 60 60 6060

Generator Rating 5 x 100MW

Primary Response 4 x 15MW = 60MW

300 MW Load

Generator Rating 5 x 100MW

Primary Response 4 x 15MW = 60MW

Plant Response Capability/Flexibility - 15% Response Capability

Impact of poor response and inflexible plant on Grid operation

b) For less responsive generators, six are required to cover the loss of one generator

Generator Rating 6 x 100MW

Primary Response 5 x 10MW = 50MW

300 MWLoad

50 50 50 5050 50

Plant Response Capability/Flexibility - 10% Response Capability

Dash for Wind

• Traditionally wind turbines were distribution connected• Generally smaller size units

• Not designed for ridding through system fault disturbances

• ‘If in doubt, trip it out’ were the design concept

• The successful integration of large volume of wind farm connections to the Grid will require the review of wind turbine design by the manufacturers, eg• Fault ride through capability

• Frequency and voltage control capability

• DNO will have to strengthen the minimum technical requirement of their connected plants

10/15/2015WH PSCL 23

Stakeholders’ collaborations

• Visited major wind turbine manufacturers to clarify the minimum technical requirements for wind turbine connection to the system

• Made aware of the issues to the Industry in particular the Generation community

• Worked with DNOs to enhance their Technical Codes for connection of the smaller plant

• Campaign for minimizing the impact of small embedded generation on Transmission System performance had been a long and steady process

• First wake up call - The UCTE incident of splitting the European Network into 3 islands and pre-mature tripping of large volume of embedded plant had helped the campaign to drive home the message

• Second wake up call was in the UK where the frequency went down to 48.8 Hz leading to automatic demand disconnections. Large volume of embedded generation was lost due to weakness in the Distribution Code.

• The above had helped in strengthening the Distribution Code to ensure small embedded plants are resilience to system disturbances

10/15/2015WH PSCL 24

Drivers for Renewable Obligations

Greenhouse gas emissions - reduce by at least 80% below an agreed 1990 baseline by 2050

UK Energy Landscape is Changing

A balance of energy trilemma of security of supply, affordability and sustainability

The Network Challenge: Electricity Transmission

Gas CCGT Coal CCS

Nuclear Wind Renewable

Interconnector CHP Other

2010

2020

~75GW

~110GW

The Changing Generation Mix

0

5

10

15

20

25

30

35

40

GW

Gas

Coal

CCS

Wind

Other R

enewable

Nuclear

Interconnectors

Total Connected Generation (GW)

2010 2020 2030 2050

2020:

28GW of wind plus 9GW of

hydro, tidal, biomass

11GW nuclear available post

2.5GW of closures and 3GW

new build

Demand remains flat - growth is

offset by energy efficiency and

smart metering

15 GW of embedded generation

2050:

30GW of nuclear now provides

majority of baseload generation

Increased demand with

electrification of

Transport (mainly during

2030s)

Heat (growth from 2020)

Further Frequency Control Challenges

• Closure of flexible and responsive plant (eg conventional coal, gas and oil stations)

• New plants are less flexibility and less responsive (eg clean coal, supercritical boiler, IGCC, CCS, new nuclear)

• Domination of wind farms – intermittency issues

• Reduction of system inertia and increase of ROCOF risks – significant cost implications

• Secured generation loss – increased to 1800 from 1320 MW

• Significant increase of small embedded generation – less robust and invisible to System Operators

10/15/2015WH PSCL 29

Forecast of RoCoF up to 2020

GCRP WG

Traditional RoCoF protection setting of 0.125 Hz/s but proposed to change to 0.5 then 1 Hz/s

Transmission reinforcement alone is not sufficient …

..Meters

An informative

display showing

energy utilisation

and cost

Increases consumers’

sensitivity to energy prices

and thus reduces demand.

..Grids

Automation and

efficient use of

network systems

Facilitates network flexibility

in a complex generation

pattern

..Demand

Automation of loads in

industrial plants,

commercial buildings,

superstores and home

Facilitates demand side

response in a world of more

inflexible generation

Flexing generation to

meet demand

Flexing demand to

meet generation

Maximising capacity with smart..

Smart Demand meets Smart Grid Objectives

Dynamic Demand and Active Demand Side Management

Smart Grid = Paradigm shift in providing flexibility

From redundancy in assets

to more intelligent operation

through incorporation of

demand side and advanced

network technologies in

support of real time grid

management

Source-HiDEF

Electrification of Transport and Heat Pump Sectors

Value of Smart Demand – equivalent to a saving of almost 40GW of installed generation capacity

Source-HiDEF

Smart Fridges/Freezers – Displacing Power Stations

Wind penetration

Cost savings £/FF/10yr

CO2 savings kg/FF/yr

Low High

10-30

30-5015-30

40-90

Source-HiDEF

…Smart Fridges/Freezers – could help to limit frequency fall

Source-RLTec

Active Demand Side Management –Offset Wind Intermittency

Water

HeaterHVAC

Generation flexibility

Cost savings £/kW/10yr

CO2 savings kg/kW/yr

High Low

3-15

100-250<50

75-100

Source-HiDEF

Widen Downstream Stakeholder Engagement

• The growth of Demand Side Response (DSR) has been slow for years and potential service providers were not forthcoming

• The recent campaign led by the Grid Company is to provide greater clarity

• Hopefully, the raise of profile in the DSR communities will ensure DSR is a long term investment proposition

10/15/2015WH PSCL 37

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Generating

Companies

Distributors

Transmission

Companies

Suppliers

Future Electricity Supply Industry

How to meet these challenges in the most economic and

sustainable way whilst maintaining security of supply?

Active Distribution

Networks

Smart Grids

& meters

GenerationDemand

Variable generation

Variable generation

Synthetic inertia

Distributed generation

ROCOF &

Robustness

issues

Active Demand

30

35

40

45

50

55

60

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:00

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Time of Day

Ele

ctr

icit

y D

em

an

d (

GW

)

2020 Demand ~ 15GWh (daily) - 1.5million vehicles

Typical winter dailydemand

Pe

ak

Co

mm

uti

ng

Tim

e

12,000 miles p.a.

Pe

ak

Co

mm

uti

ng

Tim

e

Optimal Charging

Period

Time of use

tariffs

Inflexible generation

Variable generation

Large generation

1800MW loss risk

Operating the System in 2020

New Technology - to Make It Happen

All this has been used elsewhere, but not together in a densely meshed network

New technology is required to evolve the Transmission network and enable

renewable generation

VSC Technology is still developing

2-3 year lead times for the larger cables

Multi terminal HVDC has very limited operational

experience

Control system optimisation

Sub-synchronous torsional interaction (SSTI)

HVDC

Wide area monitoring to control power flows

Dynamic circuit rating to manage constraints

Special protection schemes to facilitate additional

generation

Automated control to manage complex networks

Congestion management control

Opportunities to implement demand side

management

Smart Tools

Review of protection settings

Sub-synchronous resonance (SSR)

Employed to control stability

Series capacitors

What is a Smart Grid?

Two way communication - Sensing, automation and control

Self Healing and resilient

Asset optimisation

Active power flow management

Integration of renewable and distributed energy

More reliable, more efficient networks

Customer Focused

Tools to engage consumers

with energy efficiency

Network Focused

Integration of new sources

of supply & demand

Smart meters

Improved information and awareness

New energy services and tariffs

Home automation & Demand response solutions

More engaged, more efficient consumption

Taking Stock

• The Grid Company has been successful in providing leadership to the industry to improve frequency response services from all generating plant types including HVDC interconnectors

• The success has been the effective communications with developer and their plant suppliers to ensure their early understanding of system needs and their potential market opportunities.

• Future successes will rely on continual close collaboration within the industry to seek resolution to any identified problems within the legal, regulatory and commercial framework

The Way Forward

• Future of energy for the UK has never been so important and exciting

• The Electricity Market Reform (ERM), environmental legislation, energy costs and developments in the economy will have a major impact on the future energy landscape

• Future Energy Scenarios (FES) forum led by the Grid Company represent transparent, holistic paths through that uncertain landscape to help the Government, the customers and other stakeholders make informed decisions

• Base upon the energy trilemma of security of supply, affordability and sustainability, FES helps to identify system performance requirements and operational challenges and agree operational solutions and opportunities with key stakeholders via the System Operability Framework (SOF) forum.