BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT:...

20
EQUINOX ENERGY 2030 BLUEPRINT A technological roadmap for a low-carbon, electrified future Lead Authors: Jatin Nathwani and Jason Blackstock Chapter Authors: Esther Adedeji,Will Catton, Zhewen Chen, Kerry Cheung, Felipe De Leon, Aaron A. Leopold, Marc McArthur, Nigel Moore, Jakob Nygard, Lauren Riga,Vagish Sharma,Ted Sherk, Gita Syahrani, Miles Avery Ten Brinke, José Maria Valenzuela, Arthur Yip Contributors: Jay Apt, Alán Aspuru-Guzik, Robin Batterham, Barry Brook, Jillian Buriak, Zoë Caron, Lia Helena Demange, Jian hua Ding, Craig Dunn, Cathy Foley,Yacine Kadi,Velma McColl, Greg Naterer, Linda Nazar, Nicholas Parker,Walt Patterson,Tom Rand, Marlo Raynolds, William D. Rosehart, David Runnalls,Ted Sargent, Maria Skyllas-Kazacos,Wei Wei Lead Writer and Editor: Stephen Pincock Editor-in-Chief: Wilson da Silva A report on the outcomes of the Equinox Summit: Energy 2030, convened by the Waterloo Global Science Initiative and held in Waterloo, Ontario, Canada on 5-9 June 2011 FEBRUARY 2012

Transcript of BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT:...

Page 1: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

E Q U I N O X

E N E R G Y 2 0 3 0

B LU E P R I N T

A t e c h n o l o g i c a l ro a d m ap fo r a

l ow - c a r b o n , e l e c t r i f i e d f u t u re

Lead Authors: Jatin Nathwani and Jason Blackstock

Chapter Authors: Esther Adedeji, Will Catton, Zhewen Chen, Kerry Cheung, Felipe De Leon, Aaron A. Leopold, Marc McArthur,

Nigel Moore, Jakob Nygard, Lauren Riga, Vagish Sharma, Ted Sherk, Gita Syahrani, Miles Avery Ten Brinke, José Maria Valenzuela, Arthur Yip

Contributors: Jay Apt, Alán Aspuru-Guzik, Robin Batterham, Barry Brook, Jillian Buriak, Zoë Caron, Lia Helena Demange, Jian hua Ding,

Craig Dunn, Cathy Foley, Yacine Kadi, Velma McColl, Greg Naterer, Linda Nazar, Nicholas Parker, Walt Patterson, Tom Rand, Marlo Raynolds,

William D. Rosehart, David Runnalls, Ted Sargent, Maria Skyllas-Kazacos, Wei Wei

Lead Writer and Editor: Stephen Pincock

Editor-in-Chief: Wilson da Silva

A report on the outcomes of the Equinox Summit: Energy 2030, convened by the Waterloo Global Science Initiative and held in Waterloo, Ontario, Canada on 5-9 June 2011

FEBRUARY 2012

rtaylor
Text Box
. EXCERPT: LARGE-SCALE STORAGE WITH RENEWABLES This document is an excerpt of the Equinox Blueprint: Energy 2030. It only contains two of ten chapters. The entire document is available for download at WGSI.org. .
Page 2: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

E Q U I N O X B L U E P R I N T : E N E R G Y 2 0 3 0

2 PAGE

Publisher: Waterloo Global Science InitiativeEditor-in-Chief: Wilson da SilvaLead Writer and Editor: Stephen PincockLead Authors: Jatin Nathwani, Jason BlackstockChapter Authors: Esther Adedeji, Will Catton, Zhewen Chen, Kerry Cheung, Felipe De Leon, Aaron A. Leopold, Marc McArthur, Nigel Moore, Jakob Nygard, Lauren Riga, Vagish Sharma, Ted Sherk, Gita Syahrani, Miles Avery Ten Brinke, José Maria Valenzuela, Arthur YipContributors: Jay Apt, Alán Aspuru-Guzik, Robin Batterham, Barry Brook, Jillian Buriak, Zoë Caron, Lia Helena Demange, Jian hua Ding, Craig Dunn, Cathy Foley, Yacine Kadi, Velma McColl, Nigel Moore, Greg Naterer, Linda Nazar, Nicholas Parker, Walt Patterson, Tom Rand, Marlo Raynolds, William D. Rosehart, David Runnalls, Ted Sargent, Maria Skyllas-Kazacos, Wei WeiArt Director: Lucy GloverDeputy Editor: Kate ArnemanCopy Editor: Dominic CaddenIllustrator: Fern Bale Picture Editor: Tara Francis Research Assistants: Zhewen Chen, Ganesh Doluweera, Miriel KoProofreaders: Heather Catchpole, Renae Soppe, Becky Crew, Fiona MacDonald

EQUINOX SUMMIT: ENERGY 2030 PATRON His Excellency The Right Honourable David Lloyd Johnston, CC, CMM, COM, CD, FRSC (Hon)Summit Moderator and Content Team Leader: Wilson da SilvaContent Team: Ivan Semeniuk, Lee SmolinScientific Advisor: Jatin Nathwani Forum Peer Advisor: Jason BlackstockFacilitator: Dan Normandeau Rapporteur: Stephen PincockStrategic Advisors: Jason Blackstock, Blair Feltmate, Thomas Homer-Dixon, David Keith, David Layzell, Kevin Lynch, Jatin NathwaniEvent Producers: Sean Kiely and Frank Taylor, Title Entertainment Inc.Presenting Media Partner: TVO

WATERLOO GLOBAL SCIENCE INITIATIVEBOARDDr Neil Turok (Chair)Director, Perimeter Institute for Theoretical Physics

Dr Feridun Hamdullahpur (Vice-Chair)President and Vice-Chancellor, University of Waterloo

Dr Arthur Carty (Secretary & Treasurer)Executive Director, Waterloo Institute for Nanotechnology

Dr Tom Brzustowski, RBC Professor, Telfer School of Management, University of Ottawa; and Chair, Institute of Quantum Computing (IQC), University of Waterloo

Michael Duschenes, Chief Operating Officer, Perimeter Institute for Theoretical Physics

ADVISORY COUNCILMike Lazaridis (Chair)Founder & Chair of the Board, Perimeter Institute for Theoretical Physics; and Founder and Vice Chair of the Board, Research In Motion

Dr Tom Brzustowski (Vice-Chair)RBC Professor, Telfer School of Management, University of Ottawa; and Chair, Institute of Quantum Computing (IQC), University of Waterloo

Dr David Dodge Chancellor, Queen’s University; and Sr. Advisory, Bennett Jones

Dr Suzanne Fortier President, Natural Sciences and Engineering Research Council of Canada

Peter HarderSenior Policy Advisor, Fraser Milner Casgrain

Dr Chaviva Hošek President & CEO, Canadian Institute for Advanced Research (CIFAR)

Dr Huguette LabelleChancellor Emeritus, University of Ottawa

John PollockCEO, Electrohome; and Chancellor Emeritus, Wilfrid Laurier University

Dr Cal Stiller Chair, Ontario Institute for Cancer Research; and Former Chair, Ontario Innovation Trust and Genome Canada

John M. Thompson Chancellor, University of Western Ontario; and Chairman of the Board, TD Bank Financial Group

The Hon. Pamela Wallin Senator, Government of Canada; and Chancellor Emeritus, University of Guelph

Lynton Ronald (Red) Wilson Chancellor, McMaster University; former CEO, Redpath; Chairman of the Board of BCE; and Former Deputy Minister

MANAGEMENT TEAM John Matlock Director, External Relations and Public Affairs, Perimeter Institute for Theoretical Physics

Tim Jackson Vice-President, External Relations, University of Waterloo

Ellen RéthoréAssociate Vice-President, Communications and Public Affairs, University of Waterloo

Martin Van NieropSenior Director of Government Relations and Strategic Initiatives, University of Waterloo

Stefan PregeljSenior Analyst, Financial Operations, Perimeter Institute for Theoretical Physics

STAFFWGSI Coordinator: Julie Wright WGSI Communications Liaison: RJ TaylorOperations Support: Jake Berkowitz, Lisa Lambert, Mike Leffering, Peter McMahon, Cassandra Sheppard, Graeme Stemp-Morlock, and the staff of the Perimeter Institute for Theoretical Physics

February 2012 Waterloo Global Science Initiative. This work is published under a Creative Commons license requiring Attribution and Noncommercial usage. Licensees may copy, distribute, display and perform the work and make derivative works based only for noncommercial purposes, and only where the source is credited as follows: “produced by the Waterloo Global Science Initiative, a partnership between Canada’s Perimeter Institute for Theoretical Physics and the University of Waterloo”.

Waterloo Global Science Initiative 31 Caroline Street North Waterloo, ON, N2L 2Y5, Canada Tel: +1 (519) 569 7600 Ext. 5170 Fax: +1 (519) 569 7611 Email: [email protected] URL: www.wgsi.org

Produced for the Waterloo Global Science Initiative by Cosmos Media Pty Ltd, a publishing company in Sydney, Australia. PO Box 302, Strawberry Hills NSW 2012, Sydney, Australia. Tel: +61 2 9310 8500, Fax: +61 2 9698 4899. Email: [email protected] URL: www.cosmosmedia.com.au

A technolog ica l roadmap for low-carbon e lectr ic i ty product ion

Page 3: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

E Q U I N O X B L U E P R I N T : E N E R G Y 2 0 3 0

8 PAGE INTRODUCTION

Quorum members during the working sessions. In the foreground, Cathy Foley, Chief of the

Division of Materials Science and Engineering at Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO).

NA

TASH

A W

AX

MA

N

A LOW CARBON ELECTRICITY ECOSYSTEM During Equinox Summit: Energy 2030, participants evolved their discussions

of technologies for generation, transport and storage of electricity into a

detailed exploration of the societal contexts into which such technologies

must be integrated.

From this emerged the concept of a Low Carbon Electricity Ecosystem. It

highlights how a series of technological, economic and social innovations

in different contexts can contribute to transforming how we, as individuals

and societies, think about and use energy. It also allows us to more clearly

consider how we might alter the future direction of our varied electricity

systems in a more sustainable direction.

Three of the Pathways focus on technologies that could help replace our

reliance on the burning of fossil fuels for the generation of constant, reliable

‘baseload’ power in long-established electrical systems: the deployment

of grid-scale battery storage to support renewable energy expansion; the

development of Enhanced Geothermal power potential; and the accelerated

development of Advanced Nuclear Power technologies.

A fourth Pathway focusses on opportunities for innovation in rapidly

expanding urban environments, which are already among the largest

contributors to greenhouse gas emissions. Taking advantage of ever-

improving information and communication technologies, coupled with

emerging battery technologies, could allow the simultaneous improvement

of urban transport systems and our cities’ electric grids. In addition,

emerging superconductor technology may allow a substantial increase in the

efficiency of electricity provision, allowing more energy to be delivered per

square metre of densely packed, power-hungry city cores. These together are

described as elements that could contribute to green urbanisation.

Finally, an important Exemplar Pathway developed by participants

focusses on the billions of people who currently live without adequate access

to electricity. This Pathway proposes routes for encouraging the development

of affordable, ‘off-grid’ power solutions for energy-poor regions.

Baseload arge scale storage

for rene able energy Geothermal dvanced nuclear

Smart urbanisation Enhanced grid lexible solar Superconductors

Electrified transport Storage

Off-grid lexible solar and

storage icro grids

INNOVATION AND

WEALTH CREATION

Figure 3: As discussions progressed, a new model for the global electricity landscape emerged: the Low-Carbon Electricity Ecosystem. It allowed participants to better conceptualise the enormous changes required, and how they could be integrated.

Page 4: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

E Q U I N O X B L U E P R I N T : E N E R G Y 2 0 3 0

9PAGEINTRODUCTION

BLUEPRINT STRUCTURE The Equinox Blueprint contains two parts:

Part One details the Exemplar Pathways developed by participants of the Equinox Summit: Energy 2030, and incorporates specific proposals for addressing important aspects of the global energy problem. Each of these Exemplar Pathways identifies specific opportunities for action – aspects of the energy problem that are amenable to improvement with science or technology. They describe existing barriers to that improvement, and describe a series of steps to overcoming those barriers. Each Pathway includes interventions and action points for generating change, as proposed by participants.

Part Two is a more detailed discussion of the scientific and technical context of each of these Exemplar Pathways. It describes the science, technology and societal underpinnings of each proposed Pathway. The focus in this section is on clarifying the scale and nature of specific facets of the energy problem, and on identifying the technological or societal developments needed to address those problems.

Part One is aimed at policy makers, the media and the general public, and provides a detailed discussion of the proposals. Part Two delves deeper into the technical and scientific challenges and opportunities of each proposal, and is aimed at the scientific, engineering and academic community.

Within each of these two major sections, chapters have a similar structure: they each detail the Opportunities and Challenges of each proposal, and the suggested Pathway to Innovation. These are followed by proposed Actions, or other suggested initiatives to help make the recommendations a reality.

The chapters are built around the five Exemplar Pathways, which are the core pillars of the proposals contained herein. In Part One, they are:

REPLACING COAL FOR BASELOAD POWER Chapter 1: Large-scale Storage with Renewables 12 Chapter 2: Enhanced Geothermal 18 Chapter 3: Advanced Nuclear 24

REENGINEERING ELECTRICITY USE Chapter 4: Off-grid Electricity Access 30 Chapter 5: Smart Urbanisation 36

In Part Two, which focuses on the scientific and technical discussion of each of the five Exemplar Pathways, the chapters follow a similar structure:

REPLACING COAL FOR BASELOAD POWER Chapter 6: Large-scale Storage with Renewables 54 Chapter 7: Enhanced Geothermal 64 Chapter 8: Advanced Nuclear 72

REENGINEERING ELECTRICITY USE Chapter 9: Off-grid Electricity Access 80 Chapter 10: Smart Urbanisation 90

Page 5: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

C H A P T E R 1 : LARGE-SCALE STORAGE FOR RENEWABLE ENERGYE Q U I N O X B L U E P R I N T : E N E R G Y 2 0 3 0

12 PAGE

LARGE-SCALE STORAGE FOR RENEWABLE

ENERGY

ISTO

CK

Wind farm for electric power production and an electrical substation.

Page 6: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

C H A P T E R 1 : LARGE-SCALE STORAGE FOR RENEWABLE ENERGYE Q U I N O X B L U E P R I N T : E N E R G Y 2 0 3 0

13PAGE

THE FIRST EXEMPLAR Pathway is the one with the

shortest time-frame for implementation: the development

of large-scale storage facilities coupled to renewable energy

facilities such as wind or solar. It relies on existing storage

technologies currently deployed at the small scale or in

pilot plants at various sites. The goal would be to upscale, de-risk and

commercialise the technologies for widespread deployment.

OPPORTUNITIES The enormous potential of renewable energy sources is limited by their

intermittency and variability of supply. Large-scale storage technologies

will be critical to facilitate the integration of variable and dispersed

sources of renewable energy into the grid.

Among innovations in storage technologies, electrochemical batteries

offer several advantages. They can be sited anywhere, they are modular,

their rapid response times may be used concurrently with advanced

energy management applications and they can be placed near residential

areas due to their low environmental impact.

Within electrochemical batteries, flow batteries are among the

most advanced. Of these, the Vanadium Redox Battery — a type

of rechargeable, large-scale battery that employs vanadium ions in

different oxidation states to store chemical potential energy — has seen

important advances in development. Over the past 25 years, a design

based on vanadium and utilising sulfuric acid electrolytes has been under

investigation with testing and evaluations at several institutions in

Australia, Europe, Japan and North America.

The main advantages of the Vanadium Redox Battery are that it can offer

almost unlimited capacity simply by using larger and larger storage tanks;

it can be left completely discharged for long periods with no ill effects; it

can be recharged simply by replacing the electrolyte if no power source is

available to charge it; and, if the electrolytes are accidentally mixed, the

battery suffers no permanent damage.

CHALLENGES There a number of barriers to full commercialisation of flow batteries.

One priority is the reduction of manufacturing costs per kilowatt (kW)

by achieving higher electric current density and increasing stack

module sizes.

Another important research and development priority is to evolve

inexpensive, chemically stable ion exchange membranes not subject to

fouling by impurities in the electrolyte medium, thereby allowing lower

purity vanadium sources to be used for further cost reduction.

Page 7: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

C H A P T E R 1 : LARGE-SCALE STORAGE FOR RENEWABLE ENERGYE Q U I N O X B L U E P R I N T : E N E R G Y 2 0 3 0

14 PAGE

There are also issues that need to be investigated around scale-up,

capital and cycle-life costs and optimisation; the volatility in the price of

vanadium pentoxide itself; and the low energy density of the electrolyte

presents a limiting factor on system portability.

In electric bus applications of Vanadium Redox Batteries, safety and

environmental concerns need to be addressed, particularly with regard to

electrolyte refuelling at public refuelling stations and potential electrolyte

spills in accidents.

Renewable energy spilling — where energy that is generated but not used

is discarded — is a problem that loses large amounts of current renewable

capacity because there is no adequate storage capacity. This challenge

must be overcome to bring renewable energies into baseload calculations

and developed at scale.

PATHWAY TO INNOVATIONResearch efforts and grid-scale battery demonstration projects should be

expanded and prioritised to profile the reliability and scope of renewable

energy combined with storage.

Larger-scale demonstration projects to establish the economic viability of

storage technologies specifically targeting promising options such as flow

batteries are needed.

Effective partnerships between existing utilities and technology developers

are one path towards commercialisation and wider implementation.

Incentives for storage implemented on a large scale would be effective

for better utilisation of renewable energy resources to prevent the poor

practices of ‘spilling’ the resource.

STORAGE: THE MISSING INGREDIENTEnergy from the wind and sunlight has great potential to provide us

with low-emissions electricity. Storage technologies that account for the

variability and intermittency of these energy sources could allow them to be

integrated into our power systems.

In the near future, large-scale batteries installed close to the source of

electricity generation, or close to the end user, can also play a part in turning

clean and abundant, yet intermittent, energy sources into reliable, steady

forms of baseload power for our cities and industry.

To make this a reality, the Pathway to this goal developed by the Equinox

Process includes four key priorities:

A focus on reliability requirements, in concert with renewable energy

deployment, to ensure the effective and efficient integration of new,

cleaner sources of energy into the grid which maximally replace existing

fossil fuel production.

A series of demonstration projects for grid-scale storage techniques, with

an emphasis on battery storage in general and flow batteries in particular.

Page 8: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

C H A P T E R 1 : LARGE-SCALE STORAGE FOR RENEWABLE ENERGYE Q U I N O X B L U E P R I N T : E N E R G Y 2 0 3 0

15PAGE

Dynamic pricing and other demand management mechanisms that act to

alter energy consumption patterns in order to better balance the demand

and supply of electricity.

Penalising renewable energy ‘spilling’ through legislative action, with

promotion of battery storage as an incentivised alternative to spilling.

Demonstration projects

Demonstration projects of the grid-scale use of flow batteries (i.e. Vanadium

Redox) are best located in jurisdictions with a regulatory environment that

includes some of the policy actions outlined above, and where there is already

a high level of penetration of renewable energy within the overall supply mix.

Markets with limited capacity to sell excess power are also excellent locations

for energy storage demonstration projects.

The overall strategy for developing storage technologies to the point of

rapid commercialisation would require the innovation timeline to mirror

overall renewable penetration into global energy markets, so that production

and storage are deployed in tandem, especially in greenfield sites.

Domestically and internationally supported research efforts and small

grid-scale battery demonstration projects exist today, but these need to be

expanded geographically and given a higher priority. Bringing larger-scale

demonstration projects that specifically target flow batteries – and are

supported by an enabling regulatory environment – will be needed to

ensure widespread adoption. Examples include Japan’s experience with

Vanadium Redox Battery demonstration projects such as the JPower unit

at Tomamae, where such demonstration projects could be expanded in

the near term.

Potential players in demonstration projects

Changing the global energy system to the degree envisioned herein requires

political action, which could be encouraged by cooperation between

coalitions of stakeholder groups.

The involvement of electrical utilities – whose function is to provide reliable,

low-cost electricity to consumers – is also important. Renewable electricity

generation provides an important opportunity for enhancing supply and

greening the electricity sector. Utilities are at the functional core of the

deployment of large-scale storage and understand the necessary coupling of

renewable energy production with supply and demand management techniques

of which energy storage is an important part. If utilities are to make good

on their responsibilities for providing reliable electricity to consumers at an

appropriate cost – while also accommodating the larger and larger supply of

intermittent production – they will need to invest heavily in these techniques,

effectively building the energy delivery infrastructure of tomorrow. This in

some cases departs significantly from the state of affairs today.

However, utilities cannot be expected to deliver on all of their responsibilities

without the support of other stakeholders. With the appropriate policy and

legislative settings, the expertise and capital resources available to private

enterprise could help accelerate progress on technologies such as flow

batteries. If the private sector is encouraged to recognise the market

opportunities within this new energy system, they could be of enormous

help in the upscaling and commercialisation of storage.

High voltage equipment at an electricity generating station.

ISTO

CK

Page 9: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

C H A P T E R 1 : LARGE-SCALE STORAGE FOR RENEWABLE ENERGYE Q U I N O X B L U E P R I N T : E N E R G Y 2 0 3 0

16 PAGE

A public awareness campaign is needed so that electricity consumers and civil

society groups can become more engaged. Such a campaign would enable these

players to more assertively make the case for investment in energy storage as

a critical enabler of intelligent renewable energy production that will deliver

reliable, cleaner energy, and provide domestic employment opportunities.

Ultimately all of these groups must support policy changes and public

investments required to lay the foundations for the kind of smart energy

infrastructure this proposal envisages.

Certain regions exist where these partnerships and coalitions are

especially important in the near term. One obvious example is areas with

already high intermittent energy penetration (about 10-20% of total

electricity production). Utilities and energy policymakers in these areas

are beginning to face the challenge of intermittency head-on. However, it

is also in these areas that intermittency is often resolved by contracting

suppliers of natural gas and coal to supplement supply, because these same

utilities often need more rapid solutions to increasingly problematic supply

variability. Rather than pursue inefficient short-term solutions such as

these (known as ‘firming agreements’) or allow renewable energy spilling

without penalty, these regions should be encouraged to forge partnerships

that utilise the necessary public and private resources to build a sustainable

renewable energy infrastructure that includes large-scale storage and

demand management. In other words, future development of the capacity

for generating electricity from renewable and intermittent sources must go

hand-in-hand with the development of adequate storage capacity.

Fast-growth cities are another opportunity for constructive partnerships

in large-scale storage. These regions are building their energy infrastructure

regardless, and are increasingly looking to bring on renewable supply

while making good on commitments to source supply close to home. If

resources are spent effectively to nudge their emerging energy infrastructure

toward long-term sustainability, the investment of human and financial

resources will be much less costly when compared with regions that have

long-established energy infrastructure, which may or may not be slated for

reinvestment. Fast-growth cities are ideal sites for large-scale energy storage

demonstration projects immediately.

End-of-line and remote areas are also good locations for energy storage to

provide large benefits to the reliability of supply. Large-scale storage could

be a very attractive option for increasing energy security in such regions, and

can bring wealth creation through storing and selling energy produced rather

than spilling it. Since they stand to gain so much from the development

of storage technologies, they too are ideal sites for the next wave of

demonstration projects that accelerates technological and policy progress in

energy supply and demand management.

Large-scale storage that accounts for variability and intermittency of wind and solar energy will enable better integration into power systems.

ISTO

CK

Page 10: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

C H A P T E R 1 : LARGE-SCALE STORAGE FOR RENEWABLE ENERGYE Q U I N O X B L U E P R I N T : E N E R G Y 2 0 3 0

17PAGE

TIMELINE ACTIONS PARTICIPANTS

2012-2020 Expand large-scale storage demonstration projects, especially battery storage Penalise renewable energy spilling through legislative action and offer storage (through demonstration projects, etc.) as an incentivised alternative to wasting renewable energy Further deployment of smart-grid technology. Implement dynamic pricing initiatives to balance demand and supply of electricity.

Coalitions of stakeholders in regions with already high (or mandated) increases in intermittent renewable energy penetration.

2020-2030 Establish a thriving market in energy storage through deployment of large-scale energy storage technologies on a global scale Increase penalties for energy spilling and discourage firming agreements with fossil fuel power plants (alternative energy storage methods must be available at reasonable cost in these circumstances).

Policymakers and electrical utilities in regions with expanding intermittent renewable energy penetration, where energy spilling is commonplace, or where supply and demand for energy is difficult or expensive to balance Private groups involved in building the energy storage infrastructure.

2030-2050 Encourage and make ubiquitous large-scale energy storage and intelligent supply and demand management as integral parts of domestic, as well as global energy systems Accelerate intermittent renewable energy deployment enabled by large-scale storage to the point of outpacing fossil energy production.

Energy policymakers in all regions, particularly in global energy governance forums Private groups involved in building renewable energy production capacities at an accelerated rate in all regions.

ACTIONS

Page 11: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

E Q U I N O X B L U E P R I N T : E N E R G Y 2 0 3 0

C H A P T E R 6 : LARGE-SCALE STORAGE FOR RENEWABLE ENERGYPAGE54

LARGE-SCALE STORAGE FOR RENEWABLE

ENERGY

ISTO

CK

Page 12: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

C H A P T E R 6 : LARGE-SCALE STORAGE FOR RENEWABLE ENERGYE Q U I N O X B L U E P R I N T : E N E R G Y 2 0 3 0

55PAGEALE STORAGE FOR RENEWABLE ENERGYU E P R I N T : E N E R G Y 2 0 3 0

55PAGE

1 InterAcademy Council. Lighting the Way: Towards a Sustainable Energy Future 2007.

RENEWABLE ENERGY SOURCES offer a great potential

for producing energy on a large scale with low greenhouse gas

emissions. The resource adequacy of renewables is generally

not an issue, although some parts of the world have more

geographical limitations than others. Even when practical

limitations are factored in, the remaining resource base remains enormous.

The challenges are how to capture these dilute, low energy-density,

intermittent, variable and geographically dispersed energy resources where

they are needed and when they are needed, at reasonable cost.

The variable and intermittent nature of renewable sources such as solar

power or wind means that they are currently only partially dispatchable

– making it difficult to integrate them into electricity supply grids. Large-

scale storage is therefore the critical technology required to enable solar and

wind to ‘mimic’ the characteristics of baseload generation, and subsequently

assume a greater role within the global energy supply mix.

Modern electrical grid systems have been designed primarily to

accommodate constant, baseload energy from sources such as natural gas

and coal-fired power plants, hydroelectric dams and nuclear power. At

current levels of penetration, the intermittency of renewables such as wind

and solar is generally manageable.

As renewables penetration expands in the long-term to significantly higher

levels, however, the intermittency issue may become more salient and may

require some combination of innovative grid management techniques,

improved grid integration, dispatchable back-up resources, and cost-effective

energy storage technologies.1

Over the next 30-70 years, sustained efforts will be needed to realise the

potential of renewable energy as part of a comprehensive strategy that

supports a diversity of resources options for energy over the next century.

OPPORTUNITIESA range of options exists for managing the variability of renewable resources,

each with strengths and weaknesses that differ across scale and situation.

These include the use of natural gas generation as a complement to wind

output generation, demand management or storage.

Here, we focus particularly on renewables coupled with large-scale storage,

because it has the potential to turn renewables into a serious contender for

providing energy on large-scale with characteristics that nearly match those

of baseload power. Increased storage in concert with the development of

Smart Grids could also reduce transmission costs and decrease transmission

system load. Ancillary services such as regulation, spinning reserve,

supplemental reserve, replacement reserve, voltage control and black start

services are also needed to intelligently smooth the integration of storage

into the system. iSTO

CK

Page 13: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

C H A P T E R 6 : LARGE-SCALE STORAGE FOR RENEWABLE ENERGYE Q U I N O X B L U E P R I N T : E N E R G Y 2 0 3 0

56 PAGE

2 Science 18 November 2011. Dunn, Bruce et al. “Electrical Energy Storage for the Grid: A Battery of Choices”. Derived from the Electric Power Research Institute (EPRI), Electrical Energy Storage Technology Options 2010, Palo Alto, California, USA. 3 Journal of Power Sources, September 1989: Bartolozzi, M. “Development of Redox Flow Batteries: A Historical Bibliography”. Science 18 November 2011: Dunn, Bruce. “Electrical Energy Storage for the Grid: A Battery of Choices”. Journal of the Electrochemical Society 1986. Skyllas-Kazacos, Maria et al. “New All-Vanadium Redox Flow Cell”.

UPSPOWER QUALITY

Dis

char

ge ti

me

at r

ated

pow

er

System power ratings, module size

T & D GRID SUPPORTLOAD SHIFTING

BULK POWERMANAGEMENT

Sec

onds

Min

utes

Hou

rs

1 kW 10 kW 100 kW 1 MW 10 MW 100 MW 1 GW

Pumpedhydro

Compressed airenergy storage

Flow batteries: Zn-Cl, Zn-BrVanadium redox New chemistries

NaS battery

Advanced lead-acid batteryHigh-energy

supercapacitors

Li-ion battery

Lead-acid battery

NiCd

NiMH

High-power flywheels

High-power supercapacitors

NaNiCl2 battery

FLOW BATTERIES AND ELECTROCHEMICAL STORAGE SYSTEMSFour main types of energy storage technology for large-scale grid applications

are available: mechanical, electrical, chemical and electrochemical (see Figure 1

for a comparison of discharge time and power ratings).

In the ecosystem of energy storage technologies, discussions at the

Equinox Summit focused on electrochemical batteries and flow batteries

in particular – a storage technology that has the potential to address the

intermittency and variability characteristics of renewables.

Flow batteries have been receiving significant attention of late, and

several concepts are at advanced stages of research and development.

Since the 1970s, numerous types of flow battery systems have been

investigated, including iron/chromium, vanadium/bromine, bromine/

polysulfide, zinc-cerium, zinc/bromine and all-vanadium.

The all-vanadium (1.26 V) and zinc/bromine (1.85 V) systems are the most

advanced, and have reached the demonstration stage for stationary energy

storage. Interest in the all-vanadium system is based on having a single cationic

element so that the crossover of vanadium ions through the membrane upon

long-term cycling is less deleterious than with other chemistries.3

Flow batteries work by storing energy as charged ions in two separate tanks

Figure 1: Comparison of discharge time and power rating for various EES technologies. The comparisons are of a general nature because several of the technologies have broader power ratings and longer discharge times than illustrated.2

Figure 2: A 1-10 kWh VRB installed by UNSW in a Solar Demonstration House in Thailand in the mid- 1990s (top) and 5kWh VRB lab test battery (bottom).

SOU

RC

E: M

AR

IA S

KY

LLA

S-K

AZ

AC

OS

AD

APT

ED F

RO

M: E

LEC

TR

IC P

OW

ER R

ESEA

RC

H IN

STIT

UT

E, 2

010

Page 14: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

C H A P T E R 6 : LARGE-SCALE STORAGE FOR RENEWABLE ENERGYE Q U I N O X B L U E P R I N T : E N E R G Y 2 0 3 0

57PAGE

4 Electric Power Research Institute 2003. EPRI-DOE Handbook of Energy Storage for Transmission & Distribution Applications. 5 Electric Power Research Institute 2010, “Energy Storage Technology Options” white paper. 6 The Electrochemical Society Interface 2010: Doughty, D. H. et al. “Batteries for Large-scale Stationary Electrical Energy Storage”. Science 18 November 2011. Dunn, Bruce et al. “Electrical Energy Storage for the Grid: A Battery of Choices” The Electrochemical Society Interface Fall 2010: Nguyen, T et al. “Flow Batteries”.

Ion-selectivemembrane

Electrolytetank

Electrode

CatholyteV4+/V5+

Electrolytetank

+ –AnolyteV2+/V3+

PumpPump

e

Powersource-load

V2+

V2+

V3+

O2+O2+

O2+

O2+

H+

H+H+

H+

e

V4+

V4+

O2+H+

V5+

e

e

of solutions, one to store the electrolyte for the positive electrode reaction

and the other to store electrolyte for negative electrode reaction – all using

one common electrolyte. To discharge, the electrolyte flows to a redox cell

where the electron transfer reactions take place at inert electrodes, producing

electric current; and all this with only two moving parts.5

The simplicity of the electrode reactions contrasts with those of many

conventional batteries that involve, for example, phase transformations,

electrolyte degradation, or electrode morphology changes. Perhaps their most

attractive feature is that power and energy are uncoupled, a characteristic that

many other electrochemical energy storage approaches do not have.

This gives considerable design flexibility for stationary energy storage

applications. The capacity can be increased by simply increasing either the

size of the reservoirs holding the reactants or increasing the concentration of

the electrolyte. In addition, the power of the system can be tuned by either:

1) modifying the numbers of cells in the stacks;

2) using bipolar electrodes, or

3) connecting stacks in either parallel or series configurations. This

provides modularity and flexible operation to the system.6

Moreover, since the electrodes themselves do not undergo any reaction,

they do not suffer from any changes that can lead to deterioration. This is

important because it means that these batteries could have significantly

longer cycle lives than conventional batteries such as lead-acid and lithium.

Figure 3: Schematic of the various components for a redox-flow battery. The cell consists of

two electrolyte flow compartments separated by an ion-selective membrane. The electrolyte

solutions, which are pumped continuously from external tanks, contain soluble redox couples.

The energy in redox-flow batteries is stored in the electrolyte, which is charged or discharged

accordingly. In practice, individual cells are arranged in stacks by using bipolar electrodes.

The power of the system is determined by the number of cells in the stack, whereas the energy is determined by the concentration and volume of electrolyte. In the vanadium

redox-flow battery shown here, the V(II)/V(III) redox couple circulates through the negative

compartment (anolyte), whereas the V(IV)/V(V) redox couple circulates through the positive

compartment (catholyte).7

AD

APT

ED F

RO

M: E

LEC

TR

OC

HEM

ICA

L EN

ERG

Y ST

OR

AG

E FO

R G

REE

N G

rid,

4 M

arch

201

1

Page 15: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

C H A P T E R 6 : LARGE-SCALE STORAGE FOR RENEWABLE ENERGYE Q U I N O X B L U E P R I N T : E N E R G Y 2 0 3 0

58 PAGE

7 Science 18 November 2011. Dunn, Bruce et al. “Electrical Energy Storage for the Grid: A Battery of Choices”. Chemical Reviews 2011: Yang, Z. et al “Electrochemical Energy Storage for Green Grid”. 8 SEI Technical Review, June 2000: Tokuda, N. et al. “Development of a Redox Flow Battery System”. 9 Environmental Health Perspective 2007: Holzman, D.C. “The Vanadium Advantage: Flow Batteries Put Wind Energy in the Bank”. 10 Ibid. 11 EPRI 2003 - see 4. 12 See 3.

The use of solutions to store energy also makes the batteries relatively easy

to recharge by conventional charging methods, or even by replacing the

electrolytes in use, like refilling a fuel tank – discharged electrolyte can just be

replaced with freshly charged electrolyte.

In the case of Vanadium Redox Batteries, not only can the vanadium

electrolyte be recycled (it may be used semi-permanently) but it can operate

at room temperature, significantly increasing life cycle.8 Uniquely, simply

raising the volume of electrolytes in the external storage tanks can increase

the storage capacity of flow batteries – allowing very low incremental costs

for increased storage capacity. Capital costs per kWh of installed capacity

therefore drop significantly as a function of storage time, while the long cycle

life means replacement costs are also very low compared with other types of

batteries. Vanadium Redox Batteries produce very little waste, particularly

when compared to other technologies. Additionally, the most acidic component

of a Vanadium Redox Battery is the sulfuric acid in the electrolyte, meaning

these batteries contain one-third the acidity of a lead–acid battery.9

An important consideration – considering recent controversies over rare

earth minerals supplies on which many technologies rely (including wind

turbines and other advanced battery technologies) – is the global supply of a

resource such as vanadium. It’s worth noting that the U.S. Geological Survey

has estimated the world’s vanadium supply is far more than what would be

necessary to supply storage for total global electricity production.10

Over the past two decades, demonstration projects using Vanadium Redox

Batteries have been developed around the world. In Denmark there is a

15 kW/120 kWh unit operating in a Smart Grid configuration. Australia’s

Hydro Tasmania has developed a 200 kW/800 kWh unit on King Island, and

JPower is operating a 4 MW/6 MWh unit in Tomamae, Hokkaido in Japan.11

By far the largest projects are concentrated in the USA, Japan, Europe, China

and Australia. It is valuable to note the range of applications for Vanadium

Redox Batteries, from smaller

scale off-grid applications to

the potential of megawatt-

scale integration into the grid.

To date there are more than

20 multi-kW to MW scale

demonstration projects in

place around the world.12

ELECTROCHEMICAL BATTERIES AND OTHER ENERGY STORAGE SYSTEMSBesides flow batteries,

various electrochemical

storage technologies abound.

In general, they possess a

number of desirable features,

including pollution-free

operation, high round-trip

efficiency, flexible power

and energy characteristics to

Figure 4: 200 kW/800 kWh Vanadium Redox Battery installation at the Kashima-Kita Electric Power station in Japan (installed in the mid-1990s).

SOU

RC

E: M

AR

IA S

KY

LLA

S-K

AZ

AC

OS

High powerE.C. capacitors

Ni-Cd

Li-ion Long durationfly wheels

Zinc-airbattery

Rechargeable

NaSbattery

Flow batteries

Pumpedhydro

Metal-airbatteries

CAES

Long durationE.C. capacitors

Lead-acidbatteries

Better forenergy

managementapplications

Better for UPS and powerquality applications

100 300 1 000 3 000 10 000

Capital cost per unit power ($/kW)

Cap

ital c

ost p

er u

nit e

nerg

y ($

/kW

h-ou

tput

)C

ost/c

apac

ity/e

ffici

ency

10

100

1 000

10 000

High powerfly wheels

Figure 5: Commercial characteristics of different battery technologies.

AD

APT

ED F

RO

M: E

LEC

TR

ICIT

Y ST

OR

AG

E A

SSO

CIA

TIO

N

Page 16: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

C H A P T E R 6 : LARGE-SCALE STORAGE FOR RENEWABLE ENERGYE Q U I N O X B L U E P R I N T : E N E R G Y 2 0 3 0

59PAGE

13 See 2. 14 Electricity Storage Association, USA. See http://www.electricitystorage.org/technology/storage_technologies/technology_comparison 15 Developed by the Waterloo Institute for Sustainable Energy, 2011. Data from The Electricity Journal 2010: Culver, W. J. “High-Value Energy Storage for the Grid: A Multi-Dimensional Look”.

meet different grid functions, long cycle life, and low maintenance. Batteries

represent an excellent energy storage technology for the integration of

renewable resources. Their compact size makes them well-suited to use

at distributed locations, and they can provide frequency control to reduce

variations in local solar output and to mitigate output fluctuations at wind

farms. Although high cost limits market penetration, the modularity and

scalability of different battery systems provide the promise of a drop in costs

in the coming years.13 See Figure 5 for commercial characteristics of different

battery technologies.14

Electrochemical battery technologies provide direct conversion between

chemical and electrical energy, allowing for storage of any source of electricity.

While they promise considerable commercial value and an effective mitigation

of intermittency they are, however, less commercially advanced than other

storage systems such as lead-acid batteries or pumped-storage hydroelectricity.

ENERGY STORAGE FOR GRID APPLICATIONSFigure 6 captures the commercial viability requirements and cost effective

aspects of different storage solutions for grid applications.

Besides electrochemical batteries, there are many different types of energy

storage, each suited to specific types of application. Historically, however, they

have all shared a common trait: a very high price due to the low production

volumes of each technology. This is beginning to change. Advances in battery,

flywheel, compressed-air and fuel cell technologies, as well as new and creative

approaches to pumped storage, are lowering the cost of energy storage. More

importantly, thanks to renewables, a market for storage has now emerged and

this is attracting investment that is allowing more widespread field-testing

and a scale-up in production that will lead to significant cost reductions.

Innovation around

‘process’ storage – a way

of intelligently managing

loads in the commercial

and industrial sectors to

mimic the functions of

storage – presents another

Time scale 3.6 ms 1 hr 10 hrs 100 hrs 1 000 hrs

Cost $/kW

Super capacitors

SMES

Flywheels

Batteries

CAES

Pumped hydro

1 cycle 1 sec 1 min

Current $250–350/kW

$350 Current $500/kW Advanced

$3 000/kW–$5 000/kWCurrent Advanced

$1 500/kW–$3 000/kWLead acid $1 750–2 500/kW

Sodium sulphur $1 850–2 100/kWFlow battery $1 545–3 100/kW

Current Advanced

$600

$1 000

Current

Current

$750/kW

$4 000/kW

Power qualityapplications

Stabilityapplications

Enhanced loadfollowing

Load levellingPeak reduction

Spinning reserve

Reliability,investment,

deferral,renewable energy

Seasonalstorage

Benefit breakeven$/kW

$400–1 000/kW

$400/kW

$600–1 000/kW

$800–2 000/kW

$400–1 100/kW

$400–700/kW

Figure 6: Characteristic times for energy storage and cost benefit data.15

AD

APT

ED F

RO

M: W

AT

ERLO

O IN

STIT

UT

E FO

R SU

STA

INA

BLE

ENER

GY,

201

1

Page 17: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

C H A P T E R 6 : LARGE-SCALE STORAGE FOR RENEWABLE ENERGYE Q U I N O X B L U E P R I N T : E N E R G Y 2 0 3 0

60 PAGE

16 Independent Electricity System Operator, Ontario, Canada, 2011: Modernizing Ontario’s Electricity System: Next Steps: Second Report of the Ontario Smart Grid Forum. 17 Electricity Storage Association, at: http://www.electricitystorage.org/technology/storage_technologies/technology_comparison

promising option. At the same time, forecast higher electricity prices will

improve the economics of these technologies and approaches.17

Not all storage systems can be applied to electric power utility that integrates

scalable renewables generation. When considering baseload integration, there

are several critical storage metrics that need to be considered. A comparison of

how capable each storage system is for grid application is shown in Figure 8.

Vanadium Redox Battery technology, as described earlier, favours applications

with a high energy to power ratio (kWh/KW), namely applications requiring

several hours of storage. They are capable of discharging at maximum design

power for a period of 4-10 hr. In terms of footprint and space requirements,

they scale with system ratings with relatively large footprint. For typical grid

applications, the Vanadium Redox Battery (VRB) systems are best suited to

load-shifting applications involving shifting 10 hours of stored energy from

periods of low value to periods of high value. They are generally not suited to

applications such as grid angular stability, grid voltage stability, grid frequency

excursion suppression, and regulation control.

As shown in Figure 7, no single energy storage system can match the multiple

device requirements for large-scale grid applications. We describe briefly an

alternative storage system, the Superconducting Magnetic Energy Storage

(SMES), to illustrate how its capabilities complement those of the VRB system.

10 kW 100 kW 1 MW 10 MW 100 MW

Storage power requirements for electric power utility applications

Sto

rage

tim

e (m

in)

10

100

1 000

1

0.1

0.01

0.001

Commoditystorage

Rapid reserve

T&D facility deferral

Customer energymanagement

T voltageregulation

Renewable energymanagement

Power qualityand reliability

Transmissionsystemstability

10 h

1 h

1 m

1 s

100 ms

Area controland frequency

Responsive reserve

Figure 7: Storage power requirements for electricity power utility applications.16

AD

APT

ED F

RO

M: E

LEC

TR

ICIT

Y ST

OR

AG

E A

SSO

CIA

TIO

N

Page 18: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

C H A P T E R 6 : LARGE-SCALE STORAGE FOR RENEWABLE ENERGYE Q U I N O X B L U E P R I N T : E N E R G Y 2 0 3 0

61PAGE

18 Ibid.

STORAGE TECHNOLOGIES MAIN ADVANTAGES (RELATIVE)DISADVANTAGES

(RELATIVE)POWER

APPLICATIONENERGY

APPLICATION

PUMPED STORAGE High capacity, low cost Special site requirement

CAES High capacity, low cost Special site requirement, need gas fuel

FLOW BATTERIES:PSB, VRB, ZNBR

High capacity, independent power and energy ratings

Low energy density

METAL-AIR Very high energy density Electrical charging is difficult

NAS High power and energy densities, high efficiency

Production cost, safety concerns (addressed in design)

LI-ION High power and energy densities, high efficiency

High production cost, requires special charging circuit

NI-CD High power and energy densities, high efficiency

OTHER ADVANCED BATTERIES High power and energy densities, high efficiency

High production cost

LEAD-ACID Low capital cost Limited cycle life when deeply discharged

FLYWHEELS High power Low energy density

SMES, DSMES High power Low energy density, high production cost

E.C. CAPACITORS Long cycle life, high efficiency Low energy density

Legend: Fully capable and reasonable

reasonable for the application feasible but not practicable or economic

not feasible

AD

APT

ED F

RO

M: E

LEC

TR

ICIT

Y ST

OR

AG

E A

SSO

CIA

TIO

N

Figure 8: Storage power requirements for electricity power utility applications.18

Page 19: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

C H A P T E R 6 : LARGE-SCALE STORAGE FOR RENEWABLE ENERGYE Q U I N O X B L U E P R I N T : E N E R G Y 2 0 3 0

62 PAGE

19 IEEE Transactions on Sustainable Energy 2010: Ali, M. H. et al “An Overview of SMES Applications in Power and Energy Systems”. 20 Ibid. 21 Ibid. 22 See 6. 23 See 8.

SMES SYSTEMSSuperconducting Magnetic Energy Storage (SMES) systems store energy in

the magnetic field created by the flow of direct current in a superconducting

coil which has been cryogenically cooled to a temperature below its

superconducting critical temperature. Since energy is stored as circulating

current, energy can be drawn from an SMES unit with almost instantaneous

response, with energy stored or delivered over periods ranging from a fraction

of a second to several hours.19

SMES was originally envisaged for large-scale load levelling. However,

its rapid discharge capabilities allowed its implementation in electric power

systems for pulsed-power and system-stability applications. SMES systems

have attracted the attention of both electric utilities and the military due

to their fast response and high efficiency (a charge-discharge efficiency in

excess of 95%).20

This fast response makes SMES suitable to provide benefits to many

potential utility applications. Some of the core applications include energy

storage of up to 5 000 MWh, instantaneous load following, stabilisation of

system oscillations, spinning reserve capacity and so on. As with VRB, the

power utility integration characteristics of SMES denote constraints and

limitations if they are deployed as stand-alone solutions; yet the combination

of VRB with SMES has the potential to complement the comparative

disadvantage of each technology.

CHALLENGESThere a number of barriers to full commercialisation of flow batteries like VRB

systems, particularly in scale-up, capital and cycle-life costs and optimisation.

Despite the apparent advantages for redox-flow batteries, application of this

technology to stationary energy storage is still uncertain.

One principal reason is that redox-flow systems have been limited to

relatively few field trials. In contrast, other battery technologies have

benefitted from extensive experience in the development of products for

portable electronics and automotive applications. A related disadvantage of

flow batteries is the system requirements of pumps, sensors, reservoirs and

flow management.21

A priority for the expansion of like VRB systems is the reduction of

manufacturing costs per kW by using low-cost materials or by achieving

a higher electric current density (current or power output per unit area of

electrode in the cell stack).22 Increasing current density means more power can

be generated per unit area of membrane and electrode material, so the cost per

kW can be reduced. This requires the development of low-cost membranes,

and electrodes with lower electrical resistance and good electrochemical

performance –research areas already receiving considerable attention around

the world. Manufacturing costs can, however, also be reduced by automation

and increased production volume, but this can only happen when the energy

storage market is fully developed.

Another important research and development priority is in the ionic

exchange membrane, which is the most expensive component of the entire

apparatus. Developing inexpensive, chemically stable membranes not subject

to fouling by impurities in the electrolyte medium will not only lower the cost

of the batteries, but also allow for lower purity – and less expensive –vanadium

oxide materials to be used in producing the electrolyte.23

Wind turbines can produce energy on a large scale with low greenhouse gas emissions.

Page 20: BLUEPRINT - WGSI.orgwgsi.org/sites/.../files/Equinox_Blueprint_Energy... · EQUINOX BLUEPRINT: ENERGY 2030. INTRODUCTION. PAGE 9. BLUEPRINT STRUCTURE . The Equinox Blueprint contains

C H A P T E R 6 : LARGE-SCALE STORAGE FOR RENEWABLE ENERGYE Q U I N O X B L U E P R I N T : E N E R G Y 2 0 3 0

63PAGE

24 Journal of The Electrochemical Society, 27 June 2011: Skyllas-Kazacos, Maria et al. “Progress in flow battery research and development”.

A further challenge is volatility in the price of vanadium pentoxide. While

historical prices have been acceptable, fluctuations in recent years have created

uncertainty for prospective investors and customers. Current vanadium

production is linked to demand from the steel industry, and any spikes in this

demand have impacted global vanadium supply and prices. Recent investment

in new vanadium mines in Canada, the USA, Australia and elsewhere is

expected to stabilise both the supply and price of vanadium globally.

For full-vanadium systems, the low energy density of the electrolyte

presents a limiting factor on system portability. Without significant advances,

applications in transportation are minimal. Though this is not the only type of

flow battery – vanadium-halide and mixed acid systems for instance have been

proposed for use in buses or vans.24

CONCLUDING REMARKSFlow batteries are among many storage solutions that can enhance and

amplify the value of intermittent and variable renewable resources for

baseload integration. They are illustrative examples of what niche they

can fulfil in terms of power and energy requirements for grid applications.

Electricity energy storage alone does not solve all the problems

associated with the grid integration characteristics of renewables.

Transmission and distribution systems, and ancillary services, are

responsible for managing the flow of electricity. However, storage

provides a well-established time dimension solution, critically

strengthening power quality and reliability from renewable generation.

STORAGEFOR

RENEWABLE ENERGY

Workers set up an electrical substation in Santiago, Chile.