《IEC：2023以新能源為主體的零碳電力系統（英文版）（90頁）.pdf》由會員分享，可在線閱讀，更多相關《IEC：2023以新能源為主體的零碳電力系統（英文版）（90頁）.pdf（90頁珍藏版）》請在三個皮匠報告上搜索。

1、Zero carbon power system based primarily on renewable energyWhite PaperWe support the Sustainable Development Goals3Executive summaryThe Intergovernmental Panel on Climate Change has stated that“it is unequivocal that human influence has warmed the atmosphere,ocean and land”,and that“the stabilizati

2、on of greenhouse gas concentrationsrequires a fundamental transformation of the energy supply system”.Decarbonizing,or reducing the carbon intensity of,the electricity sector is a key component of reducing these greenhouse gas emissions.This white paper considers the challenge of decarbonizing the p

3、ower system,the resulting required transition ahead,and what this may mean for the IEC,its members and the standards it produces,which guide the worlds electrotechnology sector.Exposure to a variety of pressures means power systems around the world are already changing and have been doing so for som

4、e years.Power system operators,users and other stakeholders are facing a once-in-a-lifetime level of profound challenges,ranging from the need to significantly increase capacity to support the global replacement of fossil fuels sources with electricity,to the uptake of new generation devices such as

5、 solar,wind and marine energy generation,to dramatically shifting generation and load profiles,and significant changes in the control and communications equipment used in the network itself.Commitments towards net zeroOver 130 countries around the world have committed to a goal of carbon neutrality

6、or net zero carbon emissions,and many more have committed to significant reductions in their energy intensity.These commitments,to be met over the coming decades,will only accelerate the changes already seen in power systems.The challenge of net zeroFundamentally,a commitment to net zero carbon emis

7、sions has profound implications for the electrical power system of a nation.The electricity sector is one of the highest sources of emissions in most nations and is also often considered the sector most readily decarbonized.Thus,a national countrys net zero carbon goal can be taken to also mean a go

8、al of net zero carbon for the electricity or power sector.Furthermore,the transition of other economic sectors such as transport,towards lower carbon goals will have a significant flow-on impact on the power sector.Realization of a net zero carbon power system is an incredible challenge.At the time

9、of writing,carbon-emitting generation sources make up over 60%of electricity supply around the world.The removal of these emissions,and the need to add carbon-free capacity to meet new electrical demands,will require an immense amount of work across a very broad range of topics.Effort will be requir

10、ed in policy and law,regulation,standardization,and technology development.The implications of net zeroA net zero power system will look very different to the power system of today.A net zero power system will rely on large amounts of wind and solar generation,perhaps nuclear,hydro or marine generat

11、ion,and will involve much more energy storage capacities,from pumped-hydro to batteries.Fossil fuel generators will either be phased out or converted to zero carbon operation.The broader requirement of net zero carbon emissions will likely see many new loads appearing on the power system.Industries

12、from transport 4Executive summaryto manufacturing will convert from fossil-fuelled equipment,such as boilers or combustion engines,to electrically-driven processes.Space heating for homes and buildings will transition away from fossil fuels to electrical heating including the use of heat pump techno

13、logy.These new loads will dramatically increase demand on the power system some estimates have countries such as Canada needing to more than double system capacity by 2050.If managed carefully,the increase in demand may also assist with power system operation and the integration of variable renewabl

14、e energy generation.Generation and load profiles in the power system will be much more dynamic,with significant swings from very low consumption to high consumption throughout a day,and seasonally.This will require generation to be much more flexible in order to match supply with rapidly changing de

15、mand,and it is likely some loads will be dynamically managed to match supply.A net zero power system will have far less rotating inertia than the traditional power system that relied on large rotating machines with significant mechanical inertia.In order to maintain system security and ensure the re

16、liable operation of protection devices across the power system,generators and storage devices that rely on power electronic interconnection(such as solar and wind generators,or batteries)will need to emulate the operational characteristics of rotating machines.This will require new operational appro

17、aches and regulatory or other incentives to see these operational modes built into the machines and systems deployed.These changes mean the transition to a net zero power system will require the power system to change in multiple dimensions.Generation will need to move to zero carbon operation.The c

18、ontrol of electricity generation will be much more closely integrated with the control of loads and storage.Lastly,the power system control technologies will need to become more sophisticated,taking advantage of the latest digital technologies to manage a power system that is much more complex than

19、those before it.The technologies of a zero carbon power systemMultiple studies have shown that in many nations,hydro,wind and solar are the cheapest forms of carbon-free generation.These technologies are generally well understood.The key challenge ahead is not so much the operation of wind and solar

20、 generation,but rather their integration into the power system,and the reliable operation of a power system with very large portions of supply coming from wind and solar generators.Wind and solar generation need to be located where the wind and solar resource is available.In some cases,this will be

21、at greater distances from electricity load centres,requiring significant transmission infrastructure to carry energy to where it is used.In other cases,solar and wind may be available close to load centres,and this will reduce the need for significant long distance transmission infrastructure.The el

22、ectricity distribution system will need to absorb massive amounts of distributed renewable generation,electric vehicles,heat pumps and local energy storage.This has significant repercussions on the design of the power system,which will now need to enable significantly varying and bi-directional powe

23、r flows.Meeting this challenge will require new sensing and control schemes and the provision of very large amounts(ranging from seconds to seasons)of energy storage.A variety of other generation technologies have potential to assist in the transition to zero carbon.These include nuclear energy(incl

24、uding small modular nuclear reactors),and highly efficient and flexible coal or gas generators partnered with carbon capture utilization and storage.These technologies remain in their infancy,and many challenges still exist to their widespread uptake,not the least of which is the cost involved.5Exec

25、utive summaryWhile much analysis of the path to zero carbon power systems focuses on the energy generation and storage technologies on the“supply side”of the system,consideration of the“demand”side of the power system will become increasingly important.In simply reducing the amount of energy needed

26、to be generated,energy efficiency measures will have a key role in the transition to zero carbon and have been legislated by most countries around the world.Demand-side integration technologies,which seek to actively and dynamically manage the load on the power system,will also have an increasing ro

27、le,helping to reduce emissions,avoid infrastructure upgrades,enable end customers to make choices in their energy usage and investment,and ensure power system reliability.Power systems will become more“digitalized”,with new information and communication technologies being introduced across all reach

28、es of the power system.Similarly,this digitalization will impact all operational processes within the system.Technologies such as edge computing,data analytics and the industrial Internet of Things will allow for better monitoring and control,improved energy provisioning and faster response to fault

29、s.The benefits provided will help accelerate the transition to net zero carbon operation.Standards implications of the transition to zero carbonTo ensure that energy systems,platforms,devices and markets can transition and work effectively in a zero carbon power system,standards have a critical role

30、 to play,ensuring interoperability,maintaining a minimum level of performance and safety,and helping guide the transition towards new technologies and operating regimes.While a range of standards exist today that are relevant to the zero carbon vision,a zero carbon power system will require a broad

31、range of new standards to ensure reliable,efficient and resilient system operation.The standards required cover a broad spectrum,ranging from standards for new technologies,such as offshore wind generation,to standards for facilitating the much tighter integration between generation and demand that

32、will occur in the power system of the future.These standards must not only support integration within the power system itself,but also interactions between the power system and both consumers of energy and external providers of energy services to the power system.Given the massive complexity of a ze

33、ro carbon power system,a systems approach will need to be taken.System standards are likely to be needed considering requirements such as the environment,safety and health.To meet climate targets,the transition to a zero carbon power system needs to happen very rapidly,much faster in fact than many

34、of the changes seen in the power system over recent decades.If standards and regulation lag the rollout of new technologies in the power system,there is a significant risk of delayed implementation,inefficiency,misapplication,major outage,technical failures or other harm.Standards and regulatory cha

35、nge often happen at a pace significantly slower than some of the changes occurring in the journey to zero carbon power systems.Thus,in this journey,as well as a need for new standards,there is also a need to consider the processes of creating new standards and regulation,so that these processes can(

36、at the very least)keep up with the pace of change of technology and the short timeframes involved in the transition of the power system to net zero.The abundance of new technologies in a zero carbon power system,and the convergence of distributed resources and non-power system technologies with larg

37、e-scale power system infrastructure,will require a more top-down approach to standardization.This should be based on a systems approach that starts at the overall system architecture level,rather than the traditional bottom-up approach that focuses on individual components.6Executive summaryThis whi

38、te paper is structured as follows:Section 1 introduces the massive changes occurring in the worlds power systems,the white paper and its aim.Section 2 considers the forces that are driving power systems to transition to net zero.Section 3 reviews what a zero carbon power system may look like.Section

39、 4 considers the various pathways to a zero carbon power system.Section 5 introduces the technologies that will underpin the realization of a reliable,economic net zero power system.Section 6 considers what the changes discussed in the previous section mean for the IEC,its stakeholders and standards

40、 work.Section 7 concludes the paper and provides some key recommendations.Net zero carbon power systems are no longer a remote possibility of some distant future.Many countries around the world have committed to net zero carbon emissions targets,and a variety of pressures mean that power systems aro

41、und the world are changing dramatically.These changes have profound implications for all IEC stakeholders from system operators to equipment manufacturers and service providers,or power system end-users.Understanding the changes detailed in this paper,the new technologies,operating principles and st

42、andards requirements involved,will ensure that the IEC remains at the forefront of the evolution now underway.7Executive summaryAcknowledgmentsThis white paper has been prepared by a project team representing a variety of organizations,working under the IEC Market Strategy Board.The project team inc

43、luded representatives from electrical power network businesses,standards organizations,and equipment vendors from around the world.The project sponsor was Dr Jianbin Fan,from the State Grid Corporation of China and an IEC Market Strategy Board member.Project coordination was by Peter J Lanctot,Secre

44、tary of the IEC Market Strategy Board.Coordinating author and project partner was Dr Glenn Platt from N.OGEE consulting.The project team members were(in alphabetical order):Mr Carlos Alvarez-Ortega,HuaweiProf Zhaohong Bie,Xian Jiaotong University,ChinaMr George Borlase,ULMr Jonathan Colby,Streamwise

45、 DevelopmentMr Qixiang Fan,China Huaneng GroupDr Qi Guo,China Southern Power GridDr Hao Hu,State Grid Corporation of ChinaMr Yun Chao Hu,HuaweiMr Hua Huang,State Grid Shanghai Research InstituteMr Hirokazu Ito,Tokyo Electric Power CompanyMr Qun Li,State Grid Jiangsu Research InstituteMr Gang Lin,Hua

46、neng Yangtze Environmental Technology CompanyMr Tianyang Liu,China Huaneng Group Carbon Neutrality Research InstituteMr Zhong Liu,China Southern Power GridMr Geert Maes,HuaweiMr Andrew McConnell,CitiPower,Powercor and United EnergyDr Luc Meysenc,Schneider ElectricMr Jedong Noh,EnSTAR Ltd.Mr Ju-Myon

47、Park,ZeroEN Ltd.Mr Salvatore Pugliese,Italian Electrotechnical Committee(CEI)Mr Hai Qian,China Southern Power GridMr Ke Sun,Economic Research Institute of State Grid Zhejiang Electric Power CompanyMr Jon Sojo,Tratos Ltd.Mr Pascal Terrien,EDFMr Sebastiaan Van Dort,British Standards InstitutionProf Di

48、rk Van Hertem,KU LeuvenMr Ivano Visintainer,Italian Electrotechnical Committee(CEI)Mr Di(Andy)Wang,HuaweiMr Ziwei Wang,Huaneng Lancang River Hydropower IncMr Hee-Jeong Yim,Korean Agency for Technology and StandardsMs Ellen Yin,HuaweiDr Wedian Youssef,Schneider ElectricMr Guoxin Yu,HaierMr Liang Zhao

49、,China Huaneng Group Carbon Neutrality Research InstituteMr Dehua Zheng,Goldwind9Table of contentsExecutive summary 3List of abbreviations 13Glossary 17Section 1 Introduction 191.1 Background 191.2 Scope and definitions 211.3 Structure 22Section 2 The zero carbon power system:driving factors and mar

50、ket needs 232.1 Climate change 232.2 Achieving net zero 232.3 Government policy 242.3.1 Africa 252.3.2 Australia 252.3.3 China 262.3.4 France 262.3.5 Italy 272.3.6 Japan 272.3.7 Republic of Korea 282.3.8 The United States 282.4 Market changes 292.5 Reliable power supply 302.6 Affordable and economic

51、ally competitive energy 302.7 Changing energy consumption 312.7.1 Changing load profiles 312.7.2 New loads 32Section 3 Characteristics of a zero carbon power system 343.1 Large scale deployment of zero carbon energy generation 343.2 High penetration power electronics and decreasing inertia 343.3 Dig

52、italization of the power system 363.4 Decentralization of the power system 363.5 Bulk power transfer 3710Table of contentsSection 4 Alternative pathways to a zero carbon power system 384.1 Centralized vs decentralized 384.2 Energy efficiency 384.2.1 Electrification makes energy efficiency easier 394

53、.2.2 Standards are essential to help realize energy efficiency outcomes 394.3 Load/demand integration 394.4 Electrical vs chemical energy transfer and storage 404.5 Comparing technology options:evaluating emissions 404.6 Evaluating zero carbon systems 41Section 5 Key new technologies and their chall

54、enges 435.1 New generation technologies 435.1.1 Efficient coal generation technology 435.1.2 Carbon capture,utilization and storage 445.1.3 Nuclear power 455.1.4 Solar 465.1.5 Wind 465.1.6 Smart hydropower 475.2 Energy storage 485.2.1 Uses of energy storage 495.2.2 Energy storage technology 495.3 Tr

55、ansmission and distribution system technology 505.3.1 Control 505.3.2 Congestion management 515.3.3 High voltage direct current 525.3.4 Protection 535.3.5 Demand-side response and energy management 535.3.6 Virtual power stations 545.3.7 Vehicle-to-grid technology 555.4 Hydrogen 565.5 Digitalization

56、of the power system 575.5.1 IoT/smart sensing 585.5.2 Big data and AI 605.5.3 Blockchain 6111Table of contents5.5.4 Cyber security 615.5.5 Simulation 655.6 Alternative technologies 65Section 6 Standardization and conformity assessment analysis 676.1 Standards to facilitate interconnection,integratio

57、n and interoperability 686.1.1 Bidirectional vehicle-to-grid interaction in the distribution network 686.1.2 Interaction between natural gas and electricity systems 696.2 Standards for power generation technology 696.2.1 Offshore wind power 696.2.2 Fault ride-through 706.2.3 Case study:European Mari

58、ne Energy Centre hydrogen testing 706.3 Standards for power transmission technology 706.3.1 Low frequency power transmission 706.3.2 High voltage DC power systems with direct generator connection 706.3.3 Superconducting cable 716.4 Pervasive digitalization of power technology 716.5 Standards for cyb

59、er security 716.6 Standards for hydrogen-based power systems 726.7 Power system carbon management/life cycle assessment 726.7.1 Power system carbon footprint calculation 726.7.2 Green power markets 726.7.3 Carbon structure,utilization and storage 726.8 Conformity Assessment 726.9 Simulation and test

60、ing procedures 736.10 The standardization process 736.11 A systems approach 74Section 7 Conclusions and recommendations 757.1 Recommendations to government,industry and broader stakeholders 767.2 Recommendations regarding new standards 767.3 Recommendations regarding standardization practices and pr

61、ocesses 76Annex A 78Bibliography 8013List of abbreviations 6LoWPAN IPv6 over Low-Power Wireless Personal Area Networks AC alternating current AI artificial intelligence AMQP Advanced Message Queuing Protocol BLE Bluetooth Low Energy CCS carbon capture and storage CCUS carbon capture,utilization and

62、storage CO2 carbon dioxide CoAP Constrained Application Protocol DC direct current DDS data distribution service DLMS Device Language Messaging Specification DSR demand-side response EES electrical energy storage EV electric vehicle GDP gross domestic product GHG greenhouse gas GW gigawatt GWh gigaw

63、att-hour HIL hardware-in-the-loop HVDC high voltage direct current ICT information and communication technology IEV international electrotechnical vocabulary(IEC)IoT Internet of Things IPv6 Internet Protocol version 6 JTC joint technical committee(ISO/IEC)kW kilowatt kWh kilowatt-hourTechnical andsc

64、ientific terms14List of abbreviations LCA life cycle assessment LCOE levelized cost of electricity LFAC low frequency AC LoRaWAN Long Range Wide Area Network LTE-M Long-Term Evolution for Machine-Type Communications LVDC low voltage direct current MW megawatt MWe megawatt-electrical MWh megawatt-hou

65、r NB-IoT narrowband IoT OneM2M one machine-to-machine P2G power-to-gas P2H power-to-heat PLC Power Line Communication PV photovoltaic RETL renewable energy test laboratory SC subcommittee SMR small modular reactor SRD systems reference deliverable(IEC)SyC systems committee(IEC)TC technical committee

66、 tce tonne of coal equivalent TS technical specification(IEC)TW terawatt TWh terawatt-hour UHV ultra high voltage V2G vehicle-to-grid V2H vehicule-to-home VPP virtual power plant VPS virtual power station WG working group WTE waste-to-energy ZB zettabyte15List of abbreviations AEMO Australian Energy

67、 Market Operator AREI Africa Renewable Energy Initiative BSI British Standards Institute BNEF Bloomberg New Energy Finance CEI Italian Electrotechnical Committee COP26 26th United Nations Climate Change Conference of the Parties ECOWAS Economic Community of West African States EDF lectricit de Franc

68、e EMEC European Marine Energy Center EU European Union EU-ETS European Union Emission Trading Scheme G7 Group of Seven IAEA International Atomic Energy Agency IEA International Energy Agency IPCC Intergovernmental Panel on Climate Change IRENA International Renewable Energy Agency ISO International

69、Organization for Standardization ITU International Telecommunication Union MSB Market Strategy Board(IEC)NDC Nationally Determined Contribution(Republic of Korea)NEM National Energy Market(Australia)OCCTO Organization for Cross-regional Coordination of Transmission Operators(Japan)PNIEC National Int

70、egrated Energy and Climate Plan(Italy)PNRR National Recovery and Resilience Plan(Italy)RETL Renewable Energy Test Laboratory(United Kingdom)RITE Roosevelt Island Tidal Energy Project UL(formerly)Underwriters Laboratories UNCTAD United Nations Conference on Trade and Development UNDP United Nations D

71、evelopment Programme UNESCO United Nations Educational,Scientific and Cultural Organization UNFCCC United Nations Framework Convention on Climate ChangeOrganizations,institutions and companies17distributed generationelectricity generation,often relatively small,located close to the particular load t

72、o which it supplies powerduck curvetypically a pattern of net demand on a transmission or distribution system with very low demand in the middle of the day,and peaks in morning and late afternoonintermittentnon-continuousNOTE An intermittent generation source in and of itself cannot provide a consta

73、nt non-zero power output over the long-term.megawatt(MW)a measurement unit of power equal to one million wattsmegawatt electrical(MWe)a measurement unit of power equal to one million watts referring specifically to the electrical power output capacity of a plantmegawatt hour(MWh)a measurement unit o

74、f energy equal to 1 000 kilowatts of electricity used continuously for one hournet zero carbonrefers to a system in which the total carbon emissions produced are balanced by the total carbon emissions taken out of the atmosphere NOTE In this paper,“net zero carbon”is taken as synonymous with“net zer

75、o emissions”.net zero emissionsrefers to a system where the greenhouse gas emissions produced are balanced by the total greenhouse gas emissions taken out of the atmospherepower systemframework of electricity generation,transmission,distribution,storage and utilization,as well as associated effortss

76、ynchronizationin the context of power system operations,the matching of phase or instantaneous voltagetonne of coal equivalent(tce)unit of energy comparable to the energy in one tonne of coaltransientrelating to a momentary event NOTE Transient analysis looks at fine-grained temporary changes in sta

77、te.terawatt hour(TWh)a measurement unit of energy equal to outputting one trillion watts for one hourvariablechanging significantly over time NOTE The output of a variable generation source(such as wind or solar)changes over time and is not completely controllable.zero carbona system that produces z

78、ero carbon emissions NOTE In this paper,“zero carbon”is taken as synonymous with“net zero emissions”.Glossary191.1 BackgroundAround the world,electricity systems are undergoing incredible transition and upheaval.This shift is profound,affecting electricity generation,transmission,distribution,even b

79、usiness models.Gas,diesel or coal electricity generators that have been in place for decades are being replaced by technologies such as solar,wind,hydropower or marine generation and batteries,whose operating principles are very different.The way electricity systems are planned and laid out is also

80、changing dramatically.Traditionally,electricity systems have operated under a relatively centralized structure,with a small number of larger generation stations sending electricity a long distance to where it is used.The arrival of renewable energies such as solar and wind generation means energy sy

81、stems are being“decentralized”:instead of relying on a few large generation plants,energy systems may be made up of large numbers of much smaller plants,geographically distributed and closer to loads.This changes the topology of the electricity distribution system significantly.As shown in Figure 1-

82、1,traditional power systems were based on unidirectional power flow,and generators were all closely synchronized.The power system of the future is likely to look quite different than those of today.As shown in Figure 1-2,power flow is likely to be bidirectional in many parts of the power system;gene

83、rators will be smaller and more distributed,and not inherently synchronized.These changes can bring benefits for example,a more decentralized power system is likely to be more resilient to natural disasters but in many other ways they pose significant challenges to power system operation.The transit

84、ion from large fossil fuel-based electricity systems to more decentralized systems based on renewable generation and storage(such as batteries)is occurring worldwide,in nations large and small.While the transition is well recognized and considered profound in its impact,in many ways it is not happen

85、ing fast enough.The Intergovernmental Panel on Climate Change(IPCC)2021 report states that“it is unequivocal that human influence has warmed the atmosphere,ocean and land”,and that this is”.already affecting many weather and climate extremes in every region across the globe 11”.Referencing this repo

86、rt,United Nations Secretary General Antnio Guterres said“This is a code red for humanity.If we combine forces now,we can avert climate catastrophe.Butthere is no time for delay and no room for excuses”2.1 Numbers in square brackets refer to the Bibliography.Section 1 Introduction20IntroductionFigure

87、 1-1|A typical traditional power system topologyFigure 1-2|A typical zero carbon power system topology21IntroductionTo avoid the worst effects of climate change,the world needs to reduce its greenhouse gas(GHG)emissions.The energy supply sector is the largest contributor to global GHG emissions,and

88、the IPCC has said“The stabilization of GHG concentrationsrequires a fundamental transformation of the energy supply system”.The electricity sector makes up approximately 40%of the worlds energy-related emissions 3,and thus decarbonizing,or reducing the carbon intensity of,the electricity sector is a

89、 key component of reducing greenhouse gas emissions 4.The massive shifts already seen show that the world has started the journey of decarbonizing its power sector.Yet there is a long way to go.Today,approximately 60%of the worlds electricity generation comes from greenhouse-emitting fossil fuel gen

90、eration 5.The International Energy Agency(IEA),in considering the challenge of decarbonizing the energy sector,found that the entire global electricity system will need to produce net zero emissions by 2040,and that realizing this goal will involve“.nothing short of the complete transformation of th

91、e global energy system”6.As the transition of the energy system accelerates,it will have a significant impact on every facet of the power sector.This paper considers the transition ahead and what it may mean for the International Electrotechnical Commission(IEC),its members,and the standards it prod

92、uces that guide the worlds electrotechnology sector.1.2 Scope and definitionsThis white paper is part of a series whose purpose is to ensure that the IEC can continue to contribute through its standards and conformity assessment services to solving global challenges in electrotechnology.The white pa

93、pers are developed by the IEC Market Strategy Board(MSB),which is responsible for analyzing and understanding changes in the market in which the IEC operates,so as to help prepare the IEC strategy for the future.The transition to a fully net zero power system is one of the most significant challenge

94、s facing the IEC and the electrical power industry.This paper is an initial step in the journey of understanding,adapting and addressing this challenge.The paper considers why a net zero carbon power system is needed,how such a system will be different than todays power system,and how such a system

95、could be realized.Realization of a net zero carbon power system is an incredible challenge,requiring an immense amount of work across a very broad range of topics.Effort will be required in policy and law,regulation,standardization,finance and technology development,while ensuring that societal need

96、s continue to be met.This paper pays particular attention to the technologies likely to be part of a net zero carbon power system,and what these might mean for the IEC and its standardization work.The project team included representatives from utilities(lectricit de France(EDF),State Grid Corporatio

97、n of China,Tokyo Electric Power Company,United Energy),electrical equipment manufacturers(Haier,Huawei,Schneider,Tratos),consultancies(EnSTAR,ZeroEN),and standardization organizations(IEC,British Standards Institute(BSI),Italian Electrotechnical Committee(CEI),UL,Korean Agency for Technology and Sta

98、ndards).Almost all of society is a stakeholder in the goal of a net zero carbon power system.The transition needed will affect energy consumers,generation and distribution organizations,energy service organizations,markets,governments and financiers.Consequently,this paper is targeted at a wide-rang

99、ing audience:from those with a simple interest in how the power system is going to change,to the organizations charged with developing and following the standards necessary to facilitate the move to a net zero carbon power system while maintaining the supply reliability and performance to which we a

100、re accustomed.22IntroductionThe paper is focused on the supply and utilization of electrical energy.Thus,“power system”is taken to refer to electricity generation,transmission,distribution,storage and utilization technologies and associated efforts.For the purposes of readability,this paper will use

101、 the terms“zero carbon”,or“net zero”synonymously with“net zero carbon”.Similarly,while the vast majority of GHG emissions associated with the power system are from the combustion of carbon-based fossil fuels,for the purposes of brevity,in this paper a“zero carbon”goal will be taken to refer also to

102、the removal of non-carbon GHG emissions associated with the power system.1.3 StructureThis white paper aims to review the background of the massive transition facing power systems around the world,introduce the changes that will take place,and then review what this means for the work of the IEC and

103、its stakeholders.Following the introduction,Section 2 considers the forces that are driving power systems to transition towards net zero and reviews the different positions around the world on this topic.Section 3 reviews what a zero carbon power system may look like,and Section 4 considers the path

104、 to a zero carbon power system,and how to evaluate the carbon emissions of alternative paths.Section 5 introduces the technologies that will underpin the realization of a reliable,economic net zero power system.Having detailed what a zero carbon power system is expected to look like,and the changes

105、this will involve,Section 6 considers what this may all mean for the IEC,its stakeholders and standards work.Section 7 presents conclusions and recommendations to IEC and broader stakeholders based on the reviews and research that underpin this paper.232.1 Climate changeAwareness of climate change a

106、nd,subsequently,concern regarding its impact on humanity,has grown across the entire world over a number of decades.In 1992,the United Nations Framework Convention on Climate Change(UNFCCC)recognized for the first time that climate change and its adverse impacts are of common concern to mankind.In 1

107、997,37 developed countries set specific emission reduction targets for the first time,under the Kyoto Protocol.In 2005,the European Union established the European Union Emission Trading Scheme(EU-ETS)as the first in the world involving the engagement of multiple member states,and in 2008,the UK beca

108、me the first country in the world to formulate a long-term legally binding framework on climate change.In 2015 the United Nations published its Sustainable Development Goals 7,which include specific goals on climate change and energy,and are strongly supported by the IEC standardization and conformi

109、ty assessment efforts.In 2015,186 countries and regions signed up to the Paris Agreement,which specifies a“hard target”of temperature control,holding the increase in the global average temperature to no more than 2 degrees Celsius by the end of the century.At the time of writing,124 countries have p

110、ledged to achieve net zero carbon emissions(or carbon neutrality)by 2050 8.The goal of“net zero”means that a country will balance the GHG emissions it releases into the atmosphere through its everyday activities with the amount it absorbs or removes from the atmosphere.In November 2021,the UN Climat

111、e Change Conference in Glasgow(COP26)brought together signatory countries to review and assess the current climate governance and make a further commitment to increase and accelerate emissions reduction.In short,recognizing our climate change challenge,today net zero is a goal that has been committe

112、d to by many nations around the world.2.2 Achieving net zeroThe realization of net zero carbon emissions will have a far-reaching impact on countries energy systems,financial systems and the development of enterprises.Emissions will need to be significantly reduced across all sectors,including energ

113、y,manufacturing,agriculture,transportation and construction,and key industries including steel,construction materials,non-ferrous metals and petrochemical.For many,the task of emission reduction is both daunting and urgent.The energy industry,including fossil energy production and use,is the worlds

114、largest source of carbon emissions,accounting for 76%of the worlds total GHG emissions in 2021 9,and thus it is a key focus for nations striving towards net zero carbon emissions.Furthermore,the low carbon transition of a broad range of other industries is likely to depend on the transition of the e

115、nergy industry.As an example,reduction of carbon emissions from the transport industry is likely to depend heavily on a move to electric vehicles,which will have a flow-on profound impact on all aspects of the electrical power system,from Section 2 The zero carbon power system:driving factors and ma

116、rket needs24The zero carbon power system:driving factors and market needsgeneration to transmission and distribution.The changes required here are immense:today,fossil fuel generation,which emits large amounts of GHG,makes up over 60%of worldwide electricity supply 10.Ultimately,the faster the power

117、 system can achieve net zero emissions,or zero carbon,the sooner the entire world starts to meet its climate challenge.2.3 Government policyAs mentioned previously,many countries and regions across the world have committed to a goal of net zero carbon emissions.A total of 124 countries have committe

118、d to reach net zero by 2050,with another 13 countries aiming to achieve this goal sometime after 2050 8.Countries including the United States,the European Union,the UK and Japan have made the commitment to reach net zero by 2050.Several countries have committed to a“predominantly”decarbonized electr

119、icity grid by 2035 11.With these goals in mind,governments around the world are considering how to meet their climate commitments,what this means for their incumbent industries and economies,and how a zero carbon power system may look given their particular domestic situation.Ultimately,government p

120、olicy is a key enabler for the rapid transition to a zero carbon system.Government policy can also constitute a key barrier to the transition of the power system,with regulatory hurdles,organizational inertia or political forces delaying the rollout of already successful technologies.Broadly,measure

121、s being adopted around the world to decarbonize the power system can be grouped into the following categories:1)Phasing out of carbon-intensive generation assets.Countries around the world are phasing out carbon-intensive coal and gas generation assets and replacing these with low carbon assets.For

122、example,the G7 countries have committed to a phaseout of all carbon-intensive generation by 2035 11.2)Electrification of other sectors of the economy.Replacing assets powered by fossil fuels with electricity-driven alternatives can reduce the emissions of a range of other sectors of the economy,prov

123、iding that electricity comes from zero carbon sources.For example,the use of electric vehicles(EVs)can dramatically reduce the emissions associated with the transport sector,and nations around the world are looking to significant growth in the uptake of EVs.Similarly,replacing space and industrial h

124、eating with heat pump alternatives can help decarbonize the consumer,manufacturing and building sectors.3)Encouraging new zero carbon technologies.A range of new technologies will be required to address the fundamental challenges of operating a reliable zero carbon power system or to decarbonize ind

125、ustries that can not rely on electrification for their carbon reduction.A wide range of new energy technologies are being developed and trialled around the world,from electricity generation or energy storage to energy efficiency and management technologies.As an example,further development of low-co

126、st affordable energy storage(including but not limited to,batteries and pumped-hydro)will be needed for the operation of a zero carbon power system.Similarly,development of low-cost and safe hydrogen technologies can assist with the energy storage challenge as well as help reduce the carbon emission

127、s of industries such as cement or steel manufacture.Lastly,some countries have made the choice to build new nuclear power plants and to invest in the development of innovative new nuclear technologies,as a source of zero carbon generation.4)Provision of financial assistance to encourage the uptake o

128、f zero carbon technologies.Financial support through mandates,rebates and the issuance of 25The zero carbon power system:driving factors and market needsgreen bonds or loans can provide a financial advantage to zero carbon technologies as compared to their alternatives,and thus accelerate the transi

129、tion.For example,in 2019,the energy sector witnessed the issuance of USD 190 billion worth of green bonds,and green loans have been issued by a wide range of companies,including companies from ExxonMobil to Tokyo Electric Power Company and Edison International 12.With the aim of demonstrating the br

130、oad range of regulatory and policy mechanisms available for realizing a zero carbon power system,subsections 2.3.1 to 2.3.8 provide a few examples of government approaches to net zero from IEC member countries around the world.Further details can be found in Annex A.2.3.1 AfricaAfrican countries are

131、 especially vulnerable to the impacts of climate change due to the nature of their economies,which often depend primarily on rain-fed agriculture,and their geography 13.Thus,countries across Africa are collectively,and unilaterally,devising policies and making economic changes towards a carbon-free

132、future.One of the collective policy tools that is expected to play a critical role is the Africa Renewable Energy Initiative(AREI),which was established in 2015 14.The AREI shows how Africa intends to achieve low-to-zero carbon development through climate finance and implementation methods based on

133、the principles of the UNFCCC 15.The AREI initiative anticipates African countries will be able to generate more than 300 GW of zero carbon electricity by 2030.There are also subcontinental frameworks such as the Renewable Energy Policy adopted by the Economic Community of West African States(ECOWAS)

134、in July 2013.The policy aims at ensuring increased use of renewable energy and the provision of access to energy services in rural areas.A target of increasing the share of renewable energy in the regions overall electricity mix to 19%(48%including large hydro)in 2030 has been set.Microgrids and sta

135、nd-alone power systems are expected to be integral to Africas plans going forward,as they are predicted to supply power to around 25%of the rural ECOWAS population by 2030 16.Sub-Saharan Africa is expected to implement policies that encourage renewable energy uptake,with the portion of renewable ele

136、ctricity generation in the region predicted by the IEA to increase by 76%during 2021-2026,doubling the capacity of the previous half-decade 17.2.3.2 AustraliaAustralia is a world leader in the decentralization of the energy system,with one in three households having rooftop solar 18 and the expectat

137、ion that the National Energy Market(NEM)will operate at 100%renewable energy for short periods of time by 2025 19.South Australia,a state with a peak load of approximately 3 GW is already operating at certain times with zero operational demand.That is,that the states load is being met by generation

138、on the distribution network that is not seen by the national system operator.Over the years,uptake of renewable energy(particularly solar)in Australia has trended,or exceeded,the most aggressive forecasts of the Australian power system operator.While in part this has been driven by government policy

139、,it has been largely led by consumers exercising their choice to purchase solar for either economic,social or energy independence reasons.This has led to Australia being one of the cheapest countries in the world to install rooftop solar 20.Australia has not yet seen a high uptake of EVs,but this is

140、 expected to change rapidly as markets provide suitable products and infrastructure meets demand.26The zero carbon power system:driving factors and market needsIt is not just on rooftops that renewable energy is being produced in Australia.Australia is abundant with wind and solar resources.The chal

141、lenge to the growth of centralized wind and solar generation in Australia is that the countrys existing transmission infrastructure was built to support centralized coal generation,and this coal generation was often located in areas other than where the best wind and solar resources are found.Thus,n

142、ew transmission and large-scale storage assets are required to support the large,centralized wind and solar generation being added to the Australian energy system.Providing the necessary investment signals and gaining social license for the construction of the new transmission assets are key enabler

143、s for this new storage and transmission to be realized.The challenges that exist in Australia to meeting zero carbon goals include:A need to support market driven choices.Operating a power system with very low minimum system demand.The highly decentralized power system in Australia,with long distanc

144、es between load centres.Gaining social license for some technologies.Federal government policy has changed regularly and has been unclear concerning the preferred path to take.2.3.3 ChinaChina has announced that it aims to reach peak carbon dioxide emissions before 2030 and to achieve net zero carbo

145、n emissions before 2060.By 2030,the proportion of non-fossil fuels used in primary energy consumption is expected to reach around 25%,and the total installed capacity of wind and solar power will exceed 1 200 GW 21.By the end of 2020,Chinas total installed capacity of renewable energy generation rea

146、ched 930 GW,accounting for 42%of the total installed capacity,an increase of 14,6%compared with 2012.Of this,hydropower represents approximately 40%of renewable generation capacity,wind power 30%,and solar photovoltaics 30%22.2.3.4 FranceFrances electricity system is already relatively low carbon,th

147、anks to a generation mix mainly composed of nuclear power,together with wind,solar and hydro generation.Frances energy-climate law includes the objective of net zero carbon emissions by 2050.The text sets the framework,ambitions and target for Frances energy and climate policy 23.Some of the more di

148、stinctive approaches incorporated in Frances plan include:A gradual withdrawal from fossil fuels and the development of renewable energies,reducing fossil fuel consumption by 40%by 2030 and terminating coal-fired electricity generation by 2022.It introduces a cap on GHG emissions for existing fossil

149、 fuel-fired electricity generation facilities(0,55 tonnes of carbon dioxide equivalent per megawatt hour).The law also states solar panels or other renewable energy production or greening processes will have to be installed for new warehouses and commercial buildings containing over 1 000 square met

150、ers of floor space.Establishment of the concept of“renewable energy communities”:this is a legal entity controlled by shareholders or members in the vicinity of the renewable energy projects it has subscribed to and developed.A renewable energy community is allowed to produce,consume,store and sell

151、renewable energy,including through renewable electricity purchase agreements,and to share,within the community,the renewable energy produced by the generation units owned by the community,accessing all relevant energy markets directly or through an aggregator.27The zero carbon power system:driving f

152、actors and market needs Measures to assist low income consumers to improve the energy efficiency of their houses.The aim is to renovate houses currently served by technologies such as oil heaters within 10 years.A plan to revive nuclear power in France,with the construction of six new large nuclear

153、reactors,the first by 2035,and to launch studies on the construction of eight additional large nuclear reactors,supported by small modular reactors 24.The French government anticipates that by 2050,nuclear energy will be second to photovoltaics(PV)as the cheapest form of generation in France,and it

154、has the ultimate goal of 25 GW of nuclear capacity by 2050 24.2.3.5 ItalyItalys vision of decarbonization focuses not just on emissions,but also on the need to guarantee all citizens accessible energy of similar quality across the country.Italy is also considering the full breadth of environmental s

155、ustainability,including the principles of a circular economy,or dealing with waste.Italys plans are encapsulated in the Italian Governments National Integrated Energy and Climate Plan(PNIEC)25.A related plan,the National Recovery and Resilience Plan(PNRR)26 provides a package of investments and refo

156、rms,divided into six missions.Mission#2 of the plan(approximately EUR 60 billion)focuses on the“Green revolution and ecological transition”and contains a strong emphasis on measures such as hydrogen and the circular economy.Additional goals include energy efficiency(particularly in metropolitan buil

157、dings)and recertification,which includes the structural recertification of buildings,with particular reference to schools and hospitals.Mission#3 of Italys PNRR(approximately EUR 25 billion)covers“Infrastructure for sustainable mobility”and aims to build a more modern,digital and sustainable infrast

158、ructure system by 2026.It includes the goal of decarbonization and reduction of emissions through the transfer of passenger and freight traffic from road to rail and the development of an integrated logistics chain.2.3.6 JapanJapan has announced an aim of net zero carbon emissions by 2050.Its Basic

159、Energy Plan contains a goal that by 2030 the proportion of renewable energy generation will have increased to 36-38%,and nuclear power generation to 20-22%,making decarbonized power generation 60%of the total electricity output 27.At present,Japans total annual electricity consumption is approximate

160、ly 987 TWh,where fossil fuel generation makes up approximately 70%of total capacity 28.A unique challenge faced by Japan is that in recent years,the country has become more reliant on fossil fuel generation.Between 2010 and 2016,the proportion of nuclear power generation in total electricity output

161、decreased from 26%to 1,7%,due to the publics concerns regarding nuclear power following the Fukushima Daiichi Nuclear Power Plant disaster in 2011.More recently,the carbon intensity of Japans power industry dropped by 4,3%in 2019,which was the largest decline since 2009,as nuclear power has started

162、to return and take a greater role in the power sector.The transition of Japans power sector is not just limited to the technologies in use.The sector is being completely disaggregated,new market mechanisms are being introduced,and mechanisms such as the Organization for Cross-regional Coordination o

163、f Transmission Operators(OCCTO)are being established to foster a free power market and competitive pricing mechanisms for generation and retail businesses 29.28The zero carbon power system:driving factors and market needs2.3.7 Republic of KoreaThe Republic of Koreas approach to a zero carbon power s

164、ystem has started with the design of detailed investment plans that include the prioritization needed in order to realize the transition.These investment plans are currently focused on strengthening the electricity system,considering the maximum demand in a geographical region,predicting available r

165、enewable energy capacity,and adding decentralized generation to meet any gaps.As such,the Korean approach is to strengthen and optimize the power network as soon as possible at province level,and then deploy additional zero carbon generation capacity on demand.The Republic of Koreas 2030 Nationally

166、Determined Contribution(NDC)Plan 30 includes over KRW 78 trillion of investment for strengthening of the power grid by 2030.Of this,KRW 30 trillion is dedicated to power system strengthening efforts associated with the expansion of renewable energy generation 31.The Republic of Koreas approach to th

167、e power system transition focuses on a broad range of stakeholder impacts or benefits from the transition.Articles such as the Electric Power Source Development Promotion Act 32 include consideration of resident support projects in regions adjacent to new transmission infrastructures,and the provisi

168、on of free space available to residents neighbouring new power system infrastructures.They seek resident and local government involvement in system planning,and construction design that particularly considers nearby residents.The technologies being planned to strengthen the Republic of Koreas power

169、system are similar to those of many other jurisdictions,with 1,4 GW of large-scale battery storage,and 1,8 GW of pumped-hydro planned 32.New laws and incentive mechanisms to encourage various hydrogen power technologies have also been added.Supporting this new power system are measures such as exist

170、ing pumped-hydro plants,district heating systems,and additional distributed battery storage uptake.The Republic of Korea is taking a“connect and manage”approach to the hardware rollout of its new power system and real-time control of these is expected by 2025.The Republic of Koreas transition effort

171、 also includes regulation and standards changes.Multiple market mechanisms are being considered to incentivize dynamic participation of generators and storage.Standards for renewable energy equipment will be revised to improve the strength of the power system.The role and responsibility of power sys

172、tem organizations is also being revised,and local government has actively participated in power system planning activities.Empirical and trial projects on sector coupling technologies have been conducted including power-to-gas(P2G),power-to-heat(P2H),and vehicle-to-grid(V2G).2.3.8 The United StatesT

173、he US has set goals of a shift to zero carbon power generation by 2035 and realization of countrywide net zero carbon emissions by 2050.In 2020 fossil fuel made up 79%of energy production in the US 33.In 2020,coal power generation in the US decreased by 20%compared to 2019,while renewable energy pow

174、er generation,including small-scale solar farms,increased by 9%33.Wind power was the most common type of renewable energy power source in the US,an increase of 14%compared to 2019.Large solar farms(with an installed capacity of over 1 MW)increased by 26%,while distributed solar(such as grid-connecte

175、d solar roofs)increased by 19%34.The US is unique in that much of the energy transition has been led by private companies,using options from power purchase agreements and purchase of renewable energy credits,to on-site solar or wind generation.Companies 29The zero carbon power system:driving factors

176、 and market needssuch as IBM,AT&T,Amazon and General Motors have announced carbon-neutrality goals,and these targets are having ripple effects across the economy.Utilities are following suit,with the five largest utilities in the US having pledged to realize zero carbon emissions.2.4 Market changesI

177、n many parts of the world today the cost of energy generated by renewable sources such as wind and solar is cheaper than the cost of energy from coal or gas generation.Bloomberg New Energy Finance(BNEF)found that in China,India and most of Europe,solar generation is cheaper than coal-based electrici

178、ty 34.It noted that the lowest“levelized cost of electricity”(LCOE)was USD 22/MWh for wind in Brazil and Texas,USA,while a similar price was seen for utility-scale solar in Chile and India.BNEF also found that the cost of constructing and operating a solar plant in China now realizes an electricity

179、price of USD 34/MWh,which they state is below the cost of running a typical coal-fired power plant at USD 35/MWh 35.Critics of the levelized cost of energy approach state that it does not factor in the additional costs incurred to operate a reliable power system with large amounts of variable wind a

180、nd solar generation,namely the costs of storage,additional transmission infrastructure,and devices to add rotating inertia.However,today,even when such additional costs are included,the final cost of wind and solar can be cheaper than coal or gas generation.Figure 2-1 is from the Australian Energy M

181、arket Operator(AEMO),and shows that even with 2-6 hours of storage added,based on AEMOs estimates,wind and solar PV generation are cheaper than new-build coal and gas generation in Australia.400350300250200150100500Gas turbine smallGas turbine largeGas reciprocatingBlack coalBrown coalGasBlack coalB

182、rown coalGasBlack coal with CCSBrown coal with CCSGas with CCSSolar thermal 8hrsBiomass(small scale)WindSolar PVPeaking 20%loadFlexible 40-80%load,high emissionFlexible 40-80%load,low emissionVariableClimate policy risk premiumStandalone2020-21 A$/MWhFigure 2-1|Australian 2020 generation costs,with

183、grid-firming included 3630The zero carbon power system:driving factors and market needs2.5 Reliable power supplyIn a modern economy,a power system must not just provide electrical energy to end-users,it must also supply this power with very high reliability,be resilient to failure,and facilitate the

184、 rapid restoration of supply if there is an outage.As a critical service,any outage in the power system will cause significant impact and loss.Some selected examples of this include:On 14 August 2003,a tree touching a power line in Ohio,USA triggered the most widespread power outage in North America

185、n history,impacting 50 million people across many cities in the east of Canada and the US,and causing an economic loss of USD 25-30 billion 37.In 2011,several cities including Seoul in the Republic of Korea were hit by a sudden power outage,affecting 2,12 million households and plunging the whole co

186、untry into chaos.A grid collapse in India in 2012 impacted 600 million people and induced traffic paralysis 38.In 2019,a power outage in Venezuela paralyzed the country,disrupting water and communication services and social order 39.These outages were triggered by a variety of causes,from major equi

187、pment failures and human error to natural disasters,but in all of them,the failure of the power system resulted in further collapse of other systems,with wide-ranging impact and significant losses.Even without the changes occurring during the transition towards zero carbon,the challenges to power sy

188、stem reliability and resilience are multiplying.Increasing extreme weather events due to climate change pose a significant risk to power system infrastructure.The growth of equipment automation and networked equipment bring the new risk of cyber attacks,in which remote actors can compromise system o

189、peration.These risks mean that,even without considering the move to zero carbon,power system resiliency needs to increase around the world.As the transition towards zero carbon occurs in the worlds power systems,it will bring a mixture of outcomes related to system stability and security.As detailed

190、 later in this paper,a move towards more distributed generation based on power-electronic converters will result in less system inertia,which is a challenge for traditional modes of power system operation.A more distributed power system is more difficult to control,and power quality can suffer.On th

191、e other hand,a move towards more distributed generation removes central-point-of-failure risks in the power system,may help avoid widespread outages after a local failure,and can be more resilient overall.Ultimately,the key message here is that the path to a zero carbon power system is not one of si

192、mply replacing carbon-intense technologies with zero carbon technologies.The transition to zero carbon is enough of a challenge in itself,but this challenge is exacerbated by the overarching need to actually improve system resilience and reliability.In order to continue the reliability and affordabi

193、lity of system operation that modern economies are used to,the transition to a truly zero carbon power system will completely disrupt every aspect of system design,operation and maintenance.Ultimately,the power system of the future will be based on zero carbon technologies,with control systems that

194、can sense the operation of the grid in a rapid and accurate manner,adapt to risks,coordinate internal and external resources,automatically reconfigure around outages,and do all this while adjusting to the rapid changes in output from renewable generation.2.6 Affordable and economically competitive e

195、nergyThe amount of investment in power system infrastructure and operations,and the costs to the end-user of electricity provided by the power system,have a profound impact around the world.Broadly,end-use electricity costs are a core element of the economic competitiveness of a 31The zero carbon po

196、wer system:driving factors and market needsparticular country or jurisdiction.Electricity costs can also have a significant impact on the lifestyle,health and wellbeing of end-users.Thus,the amount of investment required in power system assets,and the price of electricity to the end-user,are key con

197、siderations during the transition of the power system towards net zero emissions.Energy prices have been a particularly acute consideration in recent years.The soaring price of primary energy all over the world in 2021 led to a surge in electricity prices in major countries.For example,in September

198、2021,the wholesale price of electricity in the UK,Germany,and France was 4,3 times,2,9 times and 2,9 times respectively that of the same period in 2020 40.Some provinces in China witnessed an increase of nearly 20%in wholesale electricity prices during the same timeframe,but government regulation me

199、ant end-user prices remained unchanged 41.The war in Ukraine has significantly increased the price of fossil fuel in many countries.The impact on electricity costs from the move to a zero carbon power system will vary depending on geography,regulatory arrangements,technology choices and market press

200、ures.Thus,no simple statement can be made regarding the effect on costs from the move to net zero,except that this must remain an important consideration.Ultimately,though,as described earlier,as the price of renewable generation continues to decrease below the price of fossil fuel generation,this i

201、s likely to mean a move towards lower-cost electricity supply.2.7 Changing energy consumptionAmidst all the other changes facing power systems,the loads they are built to supply are also changing significantly.The consumption profile of traditional loads is changing,and major new loads are also appe

202、aring.The changes outlined in subsections 2.7.1 to 2.7.2 have significant implications for the transition to a net zero power system.2.7.1 Changing load profilesIn many developed nations,the profile of electricity consumption is changing very significantly,particularly in the electricity distributio

203、n network.There are multiple factors at play here:The consumption profiles of buildings are changing,with new appliances appearing or different living practices.For example,the uptake of air conditioning has increased significantly over recent years,and in some networks it is not uncommon for a sing

204、le home to have multiple air conditioners that are only turned on a small percentage of the year.This results in very“peaky”load profiles,where the total demand from the building increases very significantly on the few occasions the air conditioner is active.The uptake of rooftop solar systems is ch

205、anging the net load profile seen by the electricity network.As more and more buildings have solar panels installed on their roof,the total demand seen by the network changes.Today,there are many distribution systems in which the total load on a particular network segment may approach zero(or even be

206、 negative)in the middle of the day,as rooftop solar meets(or exceeds)the local demand in that segment.The arrival of major new electricity loads,as detailed in the following subsection.Broadly,these changes mean that in many parts of the world,the net load profile seen by the electricity network is

207、becoming very“peaky”,with total demand changing quite dramatically multiple times in a 24-hour period.An example of how load profiles have changed over time is shown in Figure 2-2,where the most recent load profile,with a significant drop in the middle of the day,is often referred to as the“duck cur

208、ve”,due to the general shape presented.32The zero carbon power system:driving factors and market needsIn addition to seeing dramatic ramp-ups/ramp-downs in demand,power systems are starting to wrestle with“minimum demand”issues,where the net demand on the system is very low(approaching zero),and the

209、 bulk energy flow needed to meet this demand is thus also so low that system reliability is threatened.This minimum demand is typically caused by the growing uptake of solar systems:solar generation in the middle of the day may meet instantaneous demand but may be insufficient at a later time.The ch

210、anges in net load profile pose many challenges for power system operation.Generation needs to be highly flexible,able to adapt its output quickly to match the highly variable demand.Even with flexible generation,ensuring that supply matches demand at every instant,when both may be changing significa

211、ntly,is difficult,suggesting a need for more energy storage on the system and more flexible load that is controlled,so load itself can be varied to match available generation.Additionally,sizing of infrastructure is difficult,given the trade-off between maximizing equipment utilization versus ensuri

212、ng sufficient capacity to meet peak demand.2.7.2 New loadsA growing trend in energy systems around the world is electrification of devices that may have traditionally used fossil fuels as their primary energy supply.By switching boilers,heating systems and similar loads to electricity as their prima

213、ry source of energy,a facility may be able to reduce its GHG emissions or operating costs.Research has shown that the economic value of electric power is 3 times that of oil,and 17 times that of coal2,Figure 2-2|Changing load profiles over an 8-year period,by California Independent System Operator 4

214、22 The overall benefit to society created by 1 tonne of coal equivalent(tce)of electricity is the same as the benefit created by 3,2 tce of oil or 17,27 tce of coal 43.33The zero carbon power system:driving factors and market needsand every 1%increase of the proportion of electric power in end-user

215、energy consumption will lead to a 2-4%reduction of per-capita GDP energy consumption 44.Thus,electrification of loads that traditionally operated on fossil fuels has many benefits and is likely to be a trend that continues for many years.Over the long term,another example of new-load for the electri

216、city system may be the use of electricity to store energy in materials,produce new energy carriers or energy-intensive chemical products.Examples here may include the production of hydrogen,synthesis gas,or plastics.This“power-to-X”concept 45 has been proposed as a way of absorbing low-cost or exces

217、s renewable energy and helps add a large flexible load to the electricity system.2.7.2.1 Heat pumps and induction cookingIn the residential sector,a significant change in load is the electrification of heating technologies that were traditionally fuelled by gas or liquid fuels.There is a rapid growt

218、h in heat pump-based air conditioning systems that provide both heating and cooling to a house.Similarly,domestic hot water units based on increasingly efficient heat pump technologies are growing rapidly around the world.More broadly,a variety of jurisdictions are mandating gas-free buildings,where

219、,on top of heating and hot water appliances,gas cooking appliances are being replaced by electric ones.Electric induction cooktops have similar cooking characteristics to their gas counterparts yet offer a number of emissions and cost benefits.This change in electrical loads in a residential setting

220、 adds significant demand on the power system,but also adds“discretionary”load electric storage hot water systems,and to some extent air conditioning systems,have some flexibility as to the exact time they consume energy from the grid.2.7.2.2 Electric vehiclesThe transport sector is another example w

221、here electrification will significantly reduce the GHG emissions associated with the sector.EVs are significantly more efficient than fossil fuelled vehicles,and if the electrical energy they use is sourced from zero carbon generation,they offer a means of zero carbon transport.However,such a move w

222、ill add a significant extra load on the power system,potentially increasing peak demand and exacerbating the load profile challenges described in the previous subsection.The potential exists for this demand to be managed by technologies that control the time that an EV charges and the rate at which

223、it draws energy from the power system.If managed well,EVs could actually be considered an asset to the power system.Two examples of such behaviour are:EV charging being managed to match available renewable energy generation,and thus reduce the rapid swings in power system net demand.The energy store

224、d in an EV battery being exported into the power system,supporting local demand.Such“vehicle-to-grid”(V2G)or“vehicle-to-home”(V2H)technologies are being trialled around the world.34A zero carbon power system is likely to look quite different than the power system seen in many developed nations today

225、.Some features will certainly remain:gas turbine generators,as a flexible and reliable source of power generation are likely to remain in use for some time,potentially with technologies such as carbon capture used to turn them into a zero carbon generation source.Hydro power,a flexible and zero carb

226、on generation source,will continue,as will fundamental approaches to electricity transmission and distribution.However,many other aspects of system operation will change.These differences are explored in the following subsections.3.1 Large scale deployment of zero carbon energy generationAny zero ca

227、rbon power system will rely on the vast majority of electricity coming from zero carbon generation sources.As described earlier in this paper,today,in most regions,wind and solar-based generators are the cheapest form of new-build zero carbon generation.Thus,it follows that any zero carbon power sys

228、tem is likely to have a very significant amount of wind and solar generation,so long as sufficient wind and solar resources are available.Wind and solar generators have quite different operating characteristics than traditional power system generators.Wind and solar generation can be found at a vari

229、ety of scales,from less than a kW generation capacity to tens of GW.Large(tens of MW or greater)wind and solar generators typically connect to a high voltage transmission system,whereas smaller wind and solar generators connect at low voltage to the distribution network.When wind and solar generator

230、s connect“lower”in the power system,where the carrying capacity is more constrained,they can cause issues with voltage management,affecting the quality of supply of the power system.A zero carbon power system may also use nuclear generation(which is typically considered carbon-free),hydropower or fo

231、ssil fuel generators,in which the carbon emissions from the generator are absorbed and prevented from entering the atmosphere.Such generators can offer benefits to the power system,compensating for some of the challenges introduced by more variable generation.A zero carbon power system may also impo

232、se new operational requirements on traditional generators,such as more flexible operation or speed of response.The focus of subsections 3.2 to 3.5 is on the significant differences between a traditional power system and a zero carbon system,which tend to follow from the extensive use of wind and sol

233、ar generation and storage devices such as batteries.3.2 High penetration power electronics and decreasing inertiaTodays power systems require significant“inertia”to cope with sudden shifts in generation or load.This inertia serves as temporary energy storage,providing time for supply and demand to b

234、e rebalanced.Traditionally,this inertia was provided by large,synchronized generators and,to a lesser extent,industrial motors,the significant rotating Section 3Characteristics of a zero carbon power system35Characteristics of a zero carbon power systemmass of these synchronous machines giving them

235、the tendency to resist frequency changes when power imbalances occur.Furthermore,conventional synchronous machines are connected by electromagnetic forces,meaning their rotating masses are aggregated and contribute to grid inertia together.Traditional synchronous generators also provide very high sh

236、ort-circuit currents,which has been a fundamental principle of power system fault detection.A zero carbon power system is likely to have far fewer large rotating synchronous machines.Wind turbines,solar photovoltaics and battery storage devices are“asynchronous”devices that connect to the power syst

237、em through power electronics.As such generators proliferate,the total amount of inertia in the power system will decrease.This loss of inertia challenges the basic principles of traditional power system operation.Frequency swings are likely to become deeper and with a faster rate of change,fault det

238、ection will be more difficult,and there is a risk of reduced system strength.With the amount of synchronous generation decreasing as power systems move towards net zero,some power system operators are installing technology not seen for many years,in an“old is new”approach to power system security.Sy

239、nchronous condensers are a technology historically used to help manage reactive power flow in power systems,but they faded from operation as alternative ways of managing reactive power flow arrived that were cheaper and required less maintenance.An advantage of synchronous condensers is that they op

240、erate based on a large rotating mass,so their inclusion in a power system adds to system inertia.Thus,synchronous condensers are making a modern comeback in some power systems,with their primary purpose not being to manage reactive power,but to improve system inertia and strength.For example,the Sou

241、th Australian transmission system operator Electranet has recently installed four synchronous condensers,to improve power system security with the rapid uptake of renewable energy generation in South Australia.These synchronous condensers have allowed the minimum operational system demand to be lowe

242、red,and synchronous generators to be turned off 46.One way of managing the loss of inertia in the power system would be to completely redesign the system and its operating principles,for example,to redesign the system to accept varying system frequency,and/or shift to much greater use of direct curr

243、ent(DC)energy transfer.Such changes would be profound and would affect almost all aspects of system operation and very many devices across the system.Given that the path to a zero carbon power system needs to be a managed transition,rather than a complete upheaval,such approaches are generally consi

244、dered unviable by most system operators.Rather,the transition to a low-inertia zero carbon power system is being managed by requiring power-electronic based assets such as wind,solar and batteries to emulate the behaviour of more traditional rotating machines 47.A variety of ways exist to provide th

245、is“synthetic inertia”,including:Provision of frequency support through the kinetic energy in large wind turbines.This requires new control system approaches that mean the wind turbine blades(which have significant rotating inertia but are not directly coupled to the power system frequency)can provid

246、e frequency support,replicating the behaviour of a synchronous machine.Having inverter-based resources change their behaviour based on the local power supply frequency.While battery-and solar-based inverter systems do not have the rotating inertia of a large wind turbine blade,they can ramp up or do

247、wn their output in response to system frequency.These output variations can occur much faster and over a larger range than conventional generators.36Characteristics of a zero carbon power system The implementation of“grid forming”inverters that have the potential to function akin to a synchronous ge

248、nerator.Such inverters may operate on current-source principles,rather than on the voltage-source operation typically seen in a grid connected inverter,and are already available at the+100 kW scale.Regulation of load.Certain loads,such as EVs,some industrial processes,heat pumps,pool pumps and elect

249、ric boilers,can vary their energy consumption over time,with little effect to end-user amenity or productivity.In doing so,these loads have the potential to respond to power system events,and thus support grid operations.Such loads could,for example,vary their consumption in response to the local fr

250、equency or voltage.All behaviours listed above require changes in the control system of the devices mentioned.Often,new regulation or incentives are needed to realize such changes,to encourage device manufacturers to implement the new control approach and end-users to take up the new devices and ena

251、ble their grid-interactive behaviour.Furthermore,the behaviours listed above are not a“natural”outcome of the physical properties of the power electronics,they derive entirely from the control system implemented by the equipment vendor.Given this,the dynamic behaviour of a large number of power-elec

252、tronic based devices can be difficult to determine,which could result in interoperability or system stability issues.Standardized behaviour and(partially)open control structures set in grid codes can reduce these risks.3.3 Digitalization of the power systemPower systems have relied on digital sensin

253、g and control technologies for decades,but typically such functionality was restricted to major power system assets.Even today,most power systems do not have much remote sensing or automatic control capability at the lower-voltage levels of the distribution network.Managing the changes in power syst

254、em operation described in the subsections above will require much finer-grained sensing and control at all levels of power system operation.This“digitalization”of the power system brings its own profound changes.The volume of data needing to be collected and acted upon by power system operators is i

255、ncreasing exponentially:power system controllers now need to consider tens of thousands of very small devices,and the issues to consider when making control decisions are dramatically more complicated.These issues are further considered in Section 5.3.4 Decentralization of the power systemAs they tr

256、ansition towards zero carbon,power systems are becoming more decentralized.Very large-scale generation plants are being replaced by greater numbers of smaller generators,geographically distributed.There exists a range of“decentralization”of the power system that is possible.In some countries,the pow

257、er system may be predominantly made up of relatively large(hundreds of MW or more)generation plants such as large solar or wind farms.In other countries,the power system will be more decentralized and will be made up of much larger numbers of smaller generation,such as rooftop solar,small wind gener

258、ators,or diesel or gas generators located close to load.There are trade-offs involved in selecting fewer numbers of large plants over more distributed smaller plants.For example,larger plants may offer economies of scale,but smaller plants can reduce the load on the local distribution system and may

259、 be funded by the end-user directly.A different version of decentralization is the microgrid,which is a combination of distributed energy devices,linked to provide reliable power 37Characteristics of a zero carbon power systemin a network that resembles a smaller version of the electricity grid.A mi

260、crogrid may be installed to supply a village,a university or commercial campus,or an outlying island.It may operate connected to the main power system,or be completely separate,“islanded”from the broader grid.A more decentralized power system represents a significant change in business practices,reg

261、ulatory approach and technical operation for the traditional power system operator.It can also represent a significant threat to their business model.For example utilities whose revenue depends on selling power,or maintaining a regulated asset base,may face the threat of less revenue if customers st

262、art supplying themselves locally from rooftop solar or similar technologies.3.5 Bulk power transferRenewable energy,such as solar and wind generation,has significant geographical diversity.In one place,at a particular instant,it may not be sunny or windy,but in some other place at that same instant

263、it may be very windy.In large areas,the variable nature of wind and solar generation can be at least partly managed by increasing the amount of bulk power transfer,or energy transmission,to enable the transfer of renewable energy from the places it is available to the places it is needed.Thus,the mo

264、ve to a net zero power system is likely to see a significant increase in transmission capacity in many areas around the world.This trend is already visible in Europe and China,where significant long distance transmission capacity has been added over the last decade.This increase is likely to include

265、 additional long-distance transmission,as well as more“intermeshing”of electricity transmission networks,to allow greater diversity in how and where electrical energy can be transferred across a particular area.38Section 4Alternative pathways to a zero carbon power systemIt is clear that any zero ca

266、rbon power system will rely heavily on zero carbon energy generation and energy storage,will involve the electrification of services,and will have quite different net load profiles to many power systems operating today.These changes alone mean significant modifications to standards and regulation as

267、sociated with all aspects of the power system.Many different options remain that can be taken in realizing a zero carbon power system.What choices are made will depend on a very wide range of factors:regulatory and political preferences,the wind,solar,or other natural resources available in a geogra

268、phical area,whether the challenge is to build a new power system in a relatively undeveloped area or transition an already-built mature power system,and so on.Subsections 4.1 to 4.6 review the key power system characteristics that will vary depending on the transition path chosen.4.1 Centralized vs

269、decentralizedAs described earlier,traditional power systems tended to have a relatively“centralized”nature,where energy flowed in one direction,from a relatively small number of very large generators.Very large transmission and distribution systems were constructed to transfer that energy from the l

270、arge generation plant to the loads where the energy was consumed.While it is likely that all zero carbon power systems will be more decentralized than their forebears,how much to centralize the power system remains a choice.For countries that already have large,mature centralized power systems,the t

271、ransition to a net zero future is likely to continue to rely on relatively centralized approaches.Such power systems will continue to feature relatively large zero carbon generation plants and take advantage of their existing transmission and distribution systems for the carriage of energy.This is n

272、ot to say that such countries will not feature distributed energy solutions.Rooftop solar,battery storage and similar technologies will certainly feature,but bulk energy is likely to come from centralized generators and transmission and distribution infrastructure.In places where there is not alread

273、y a mature,extensive power system,the path to net zero may be based on much more decentralized approaches.Such approaches may replace centralized generation plants with large numbers of smaller net zero generators,located much closer to load centres,and thus reduce the need for costly high-voltage t

274、ransmission infrastructure.Similarly,large energy storage infrastructures such as pumped-hydro plants may be replaced with much smaller distributed storage technologies,again located close to load centres.Such approaches may also improve system reliability,reducing the number of failure points in th

275、e network.4.2 Energy efficiencyA key decision in the path to net zero is how much to include the demand or load side of the system in transition plans.In a fossil fuel-based power system,one seemingly straightforward way to reduce emissions is simply to use less energy.Energy efficiency efforts aim

276、to use less energy,but without a reduction in output or amenity.Another way of framing energy efficiency is to“waste less”.As such,energy efficiency is a relatively 39Alternative pathways to a zero carbon power systemeasy political choice,and is thus high on many zero carbon plans across the globe.M

277、oreover,while over 130 countries around the world have committed to net zero targets,many more,in fact most countries worldwide have the goal of being less energy-intensive 48.Broadly,energy efficiency can be considered a“no regrets”option to realizing the net zero goal,as it offers many benefits:En

278、ergy efficiency helps to reduce costs.As just one example,the UK government found savings of 39%were achievable through energy efficiency improvements across all non-domestic buildings in England and Wales in 2014.This is equivalent to GBP 3,7 billion that businesses could have saved on their energy

279、 bills 49.Reducing energy usage reduces emissions.Currently a large part of the worlds energy comes from fossil fuel,and so reducing energy use means emitting less GHG and other pollutants into the atmosphere,soil,and water.Energy efficiency provides other system benefits.By reducing consumption,pow

280、er system operators are able to manage peak loads in a reliable,predictable,and measurable way.This optimizes the grid and delays,reduces,or eliminates the need for new infrastructure investments,which can contribute to a more reliable and resilient grid.4.2.1 Electrification makes energy efficiency

281、 easierThe electrification of loads traditionally supplied by gas,oil,or other fossil fuels,as described in Section 2,generally makes energy efficiency easier.It also adds more controllable load to the electricity system,which can bring benefits as described in subsection 4.3.The IEA expects the ele

282、ctrification of other fuel sources to contribute to electricity generation rising 40%by 2030 in the Net Zero Emissions by 2050 Scenario 50.However,while generation output rises,this is amidst increased efficiency and lower total emissions.Equipment driven by electricity is often much more efficient

283、than the equivalents powered directly by fossil fuels,with electric heat pumps,for example,being three to four times more efficient than burning fossil fuels for heat.How much to electrify loads traditionally outside the electricity sector will remain a choice for regulators,operators and end-users.

284、4.2.2 Standards are essential to help realize energy efficiency outcomesThe UK government recognized that the built environment massively contributes to the carbon emissions produced by a country,and that if the countrys housing stock is more energy-efficient it will better be able to reach its carb

285、on reduction targets.The UK recognized that while building regulations ensured that new properties met minimum energy efficiency standards,there was a gap when considering existing buildings.As such,the government set minimum energy efficiency standards for domestic privately rented properties,ensur

286、ing that such properties will become more energy-efficient,and reducing their energy use.In addition to buildings,standards have helped halve the energy consumption of key electrical appliances 50.Over 120 countries have implemented or are developing mandatory standards and labels for electrical app

287、liances.Typical appliances that have minimum efficiency standards applied to them include air conditioners,refrigerators,lighting,televisions,washing machines and cooking appliances 50.4.3 Load/demand integrationIn considering how much the“demand side”of the power system should feature in the path t

288、o net zero,in addition to energy efficiency measures,40Alternative pathways to a zero carbon power systemload integration or demand-side management is another option available.Traditionally,power system operators considered the demand side of the system relatively uncontrolled,and so supply had to b

289、e managed in order to match the varying demand.As described in Section 5,today many technologies are available that facilitate careful control of loads in the power system.So the challenge of ensuring that supply and demand are carefully matched can be considered two-ended:one end involves matching

290、generation to the current load,while the other involves matching the load to the available generation.Power system operators have a choice regarding how much to rely on demand-side management.At one extreme,they can effectively ignore demand-side measures and simply focus on the supply side of the p

291、ower system.This may result in lower asset utilization,but it is a well-known and understood method of power system operation.Alternatively,they may rely heavily on demand-side management,which can bring benefits such as improved utilization of infrastructure,but also brings added complexity to syst

292、em operation.Standards are key to enabling load integration or demand-side management.They are critical to the interoperability required when a power system operator seeks to manage individual loads located relatively low in the power system.Standards take time to be realized,so even if the choice i

293、s made to have a relatively small amount of demand-side integration in the short term,it is likely standards and interoperability efforts will need to start in earnest,to enable greater demand-side participation at a later date.4.4 Electrical vs chemical energy transfer and storageElectricity system

294、s are fundamentally a way of transferring energy from where it is produced,to where it is needed.They also include a means of storing energy for use at a later time.While electricity-based energy storage and transfer mechanisms are pervasive,there is a growing interest in the use of alternative ener

295、gy storage and transfer mechanisms that may provide advantages over electricity in certain situations.Hydrogen is seen as one potential alternative to electricity for the transfer and storage of zero carbon energy.Hydrogen can be produced,stored,and then transferred close to loads.It may be used its

296、elf(for example,to provide heat)or be converted to electricity for end use.Hydrogen proponents suggest that hydrogen,or related chemical energy carriers,may be cheaper or more appropriate than electricity for very long-distance energy transfer,long-term energy storage or some uses such as aviation t

297、ransport.Hydrogen-based technologies are further described in Section 5.Ultimately,if hydrogen technologies meet the technical and commercial goals their proponents suggest,then in the future organizations may have a choice whether to follow an electrical-or a chemical-based approach to bulk energy

298、transfer and storage.4.5 Comparing technology options:evaluating emissionsIn striving towards a zero carbon power system,it is important to be able to compare the greenhouse or carbon emissions associated with various technology options.Various ways exist to count the emissions of a particular techn

299、ology.Generally,these are categorized into three scopes according to the World Resources Institute Greenhouse Gas Protocol 51:Scope 1 includes emissions released into the atmosphere as a direct result of an activity at a facility level.Examples include emissions produced from the burning of fossil f

300、uels or the fugitive emissions produced from leaking gas pipes in a gas generation facility.41Alternative pathways to a zero carbon power system Scope 2 includes emissions released into the atmosphere from the indirect consumption of an energy commodity.Scope 2 emissions in one facility would usuall

301、y be considered scope 1 emissions in a different facility.For example,the scope 2 emissions of a data centre would be the scope 1 emissions of the electricity generator that produces the electricity used by the data centre.Scope 3 includes all other indirect emissions and can be identified as the em

302、issions from the“corporate value chain”.Scope 3 emissions occur as a consequence of the activities of a facility,but from sources not owned or controlled by that facilitys business.Thus,for an electricity generation facility,scope 3 emissions would include the emissions associated with the extractio

303、n,production and transport of fuels for the facility.They would also include the emissions associated with the manufacture of the equipment used in that facility,and the extraction and transport of raw materials used to produce that equipment.Scope 3 emissions also typically include emissions associ

304、ated with waste from the facility,its inputs and outputs.Electricity systems contain a variety of potential emissions,particularly the emissions associated with burning fossil fuels.But emissions can also be inherent to particular equipment or materials,for example,common electrical insulation mater

305、ials such as sulphur hexafluoride can have a very significant greenhouse potential.Often,“zero carbon”is taken as referring solely to the scope 1 emissions associated with a technology or facility.However,ideally all emissions associated with the facility and produced over its lifetime would be meas

306、ured.This is a very complex process.Among the methods of measurement available for this purpose,the life cycle assessment(LCA)methodology is most common.An LCA of the emissions from a technology or facility can assist in:Providing industry,government or other stakeholders a like-for-like comparison

307、of the total emissions produced by various technologies,as defined by a comprehensive list of measurements.Identifying opportunities to improve the environmental performance of products at various points in their life cycle.Identifying the most important indicators of environmental performance for a

308、 particular technology or business approach.For example,while“distance travelled”has often been taken as a proxy for a products carbon impact,an LCA might show that,if carried efficiently,a product that travels a long distance may actually have a relatively low carbon impact.Marketing a product,serv

309、ice or technology.The LCA methodology is standardized in the ISO 14040,ISO 14041 and ISO 14044 standards.In the IEC,technical committee(TC)111 on environmental standardization oversees work relevant to this topic.There is a significant opportunity to develop further standards for applying these gene

310、ral methods to the specific needs and features of the power sector.4.6 Evaluating zero carbon systemsWhen considering the goal of a zero carbon energy system,it is critical to determine how to actually measure if the system is truly zero carbon.Two common goal-oriented approaches associated with ren

311、ewable energy or zero carbon include:Goal of carbon neutral,in which a company,government or other organization offsets its emissions by purchasing carbon offsets that reduce or prevent future global emissions.42Alternative pathways to a zero carbon power system Goal of 100%renewable energy,in which

312、 a company,government or other organization purchases enough renewable energy to match its annual energy use.A more ambitious goal considered by the United Nations 52 and supported by a range of commercial organizations is the concept of 24/7 carbon-free energy,where rather than emitting and subsequ

313、ently compensating for carbon emissions,organizations do not emit carbon in the first place.This requires every unit of electricity consumption to be supplied by zero carbon sources,at every instant in time.Such a goal is significantly more challenging than measurement approaches that operate based

314、on averaging measurements over a long period of time and is considered a“transformative approach to energy procurement,supply and policy design.”52.Overall,whether a 24/7 carbon-free goal or more traditional time-averaged goals are adopted,further effort is needed to standardize the approaches taken

315、 to measuring the progress and success of such targets.Possible issues to be addressed include the specific geography a goal applies to,what types of data are measured and how,adequate means to ensure traceability,and so on.43The transition to zero carbon operation brings many new technologies to po

316、wer system stakeholders.While well-known technologies such as hydropower,gas,and other forms of generation will continue in the zero carbon power system,many other new technologies,or significant evolutions of older technologies,are appearing.From generators to end-users,the technologies that source

317、,distribute and manage electrical energy are changing significantly.The following subsections introduce some of the new technologies that will feature in a zero carbon power system,their benefits,and the challenges to their operation.5.1 New generation technologies5.1.1 Efficient coal generation tec

318、hnologyDue to the variable nature of generation technologies such as solar and wind power,and the current limitations of storage technology,coal power will continue to feature in our power systems,albeit in a decreasing amount,for years to come.As a result,industry needs to find new ways to make the

319、 utilization of coal as efficient as possible.Modern coal plants that will remain in the power system in the coming years are likely to have new features,such as:The highest thermal efficiency possible.A variety of programmes around the world are targeting net power generation efficiencies that appr

320、oach 50%for a coal generator.The Huaneng RuiJin Power Plant in China achieved a supply efficiency of 49,25%in 2021,using 620C ultra-supercritical double-reheat turbine technology 53.The path to higher thermal efficiencies includes operation at higher temperatures.Plants today operate at up to 600C,a

321、nd system developers have a goal of 650C-700C,which will require new high-temperature materials.Another option is to move away from traditional steam turbine cycles for coal-based generation to new cycles such as integrated gasification combined cycles,integrated gasification fuel cells,supercritica

322、l CO2 or chemical looping cycles.High thermal efficiency under low-load conditions.It is not sufficient to achieve high thermal efficiency at full-load operation.Given the variability in power system demand,a modern coal generator is likely to operate at low or partial load for significant periods o

323、f time,and thus needs to maintain its efficiency in these usage regimes.The Chinese Huaibei Pingshan project used technologies such as broad reheat,flexible reheat and concentrated frequency conversion to maintain efficiency at low loads 54.Flexible operation.Given the variability of demand in a net

324、 zero power system,a coal generator needs to be very flexible,changing its operation to match changing demand.Here,flexibility includes the ability to start and shut down the machine,the rate of change of output power,and having a wide safe load range.As an example of such performance,China has rece

325、ntly regulated in-service generators to have a range of operation of 20%-100%of rated load.This target presents Section 5Key new technologies and their challenges44Key new technologies and their challengesan enormous challenge to the operation of the coal generator.Fast cut back ability,which means

326、the generator can swiftly cease output in case of a grid contingency,and then come online quickly thereafter.Biomass mixed combustion.Biomass is considered a low-carbon energy source.If biomass can be used in a coal generator,replacing some if not all of the coal,this provides a low-carbon path for

327、coal generation assets.While trials have been run throughout the world for 20 years(for example,the Drax plant in the UK,with four units running purely on biomass in 2018),a key issue for such plants is the availability of biomass(for example,the Drax plant imports almost all its biomass from overse

328、as 55).Another challenge is that existing coal generators often require an upgrade of their furnaces,fuel transportation and storage systems in order to handle biomass.New units can have such changes already incorporated in their design,even if they start operation based on coal.5.1.2 Carbon capture

329、,utilization and storageCarbon capture,utilization and storage(CCUS)technologies,although not a form of“generation”are relatively new technologies that can help with the transition to a zero carbon power system by reducing the emissions from fossil-fuelled generation,and/or compensating for the carb

330、on emissions from other sectors of the economy.CCUS refers to a range of technologies that fundamentally are designed to capture carbon dioxide emissions,preventing them from going into the atmosphere and exacerbating the greenhouse effect.Broadly,CCUS consists of the following stages:1)Carbon captu

331、re.All CCUS approaches have carbon capture as their first step.Carbon dioxide must be captured from the source(for example,after combustion),or captured from the atmosphere.This carbon dioxide then needs to be concentrated for use in the latter stages of the CCUS system.2)Transport.The carbon dioxid

332、e needs to be transported by pipeline,tanker,ship or other means to where it is subsequently handled.3)Storage.In a carbon capture and storage system,captured carbon dioxide is stored,usually underground or in an aquifer,hopefully permanently,rather than allowing it to escape into the atmosphere.4)U

333、tilization.In a carbon capture and utilization system,captured carbon dioxide is used in a follow-on industrial process.Some examples of how the carbon dioxide could be used include:Enhanced oil recovery,in which the carbon oxide is injected into an oil or gas reservoir,where hopefully it stays,but in doing so assists the extraction of oil or gas from the well.Utilization in industrial processes.T