1、European Marine Board IVZW Belgian Enterprise Number:0650.608.890Jacobsenstraat 1 I 8400 Ostend I BelgiumTel:+32(0)59 33 69 24 E-mail:infomarineboard.euwww.marineboard.euEuropean offshore renewable energyTowards a sustainable futureN 9 April 2023Future Science BriefEuropean offshore renewable energy

2、 Towards a sustainable futureN 9 April 2023Future Science BriefEMB FUTURE SCIENCE BRIEF2The European Marine Board provides a pan-European platform for its member organisations to develop common priorities,to advance marine research,and to bridge the gap between science and policy in order to meet fu

3、ture marine science challenges and opportunities.The European Marine Board is an independent and self-sustaining science policy interface organisation that currently represents 35 Member organisations from 18 European countries.It was established in 1995 to facilitate enhanced cooperation between Eu

4、ropean marine science organisations towards the development of a common vision on the strategic research priorities for marine science in Europe.The EMB promotes and supports knowledge transfer for improved leadership in European marine research.Its membership includes major national marine or ocean

5、ographic institutes,research funding agencies and national consortia of universities with a strong marine research focus.Adopting a strategic role,the European Marine Board serves its Member organisations by providing a forum within which marine research policy advice is developed and conveyed to na

6、tional agencies and to the European Commission,with the objective of promoting the need for,and quality of,European marine research.www.marineboard.euEuropean Marine Board Member OrganisationsEuropean Marine Board IVZWNational Research Council of ItalyUNIVERSITS MARINESIrish Marine Universities Cons

7、ortium N 9 20233This Future Science Brief is a result of the work of the European Marine Board Expert Working Group on Offshore Renewable Energy.See Annex 1 for the list and affiliations of the Working Group members.Working Group ChairsTakvor Soukissian,Anne Marie OHaganContributing Authors Arianna

8、Azzellino,Ferdinando Boero,Ana Brito e Melo,Patricia Comiskey,Zhen Gao,Dickon Howell,Marc Le Boulluec,Christophe Maisondieu,Beth E.Scott,Elisabetta TedeschiAdditional ContributionAlireza Maheri,Shona PennockSeries EditorSheila J.J.HeymansPublication Editors Paula Kellett,Britt Alexander,ngel Muiz Pi

9、niella,Ana Rodriguez Perez,Jana Van Elslander,Sheila J.J.HeymansExternal Reviewers Alistair Borthwick,Andrea Copping,Margaret Mutschler,Eugen RusuInternal review process The content of this document has been subject to internal review,editorial support and approval by the European Marine Board Membe

10、r Organisations.Suggested reference Soukissian,T.,OHagan,A.M.,Azzellino,A.,Boero,F.,Brito e Melo,A.,Comiskey,P.,Gao,Z.,Howell,D.,Le Boulluec,M.,Maisondieu,C.,Scott,B.E.,Tedeschi,E.,Maheri,A.,Pennock,S.(2023)European offshore renewable energy:Towards a sustainable future.Heymans,J.J.,Kellett,P.,Alexa

11、nder,B.,Muiz Piniella,.,Rodriguez Perez,A.,Van Elslander,J.Eds.Future Science Brief No.9 of the European Marine Board,Ostend,Belgium.ISSN:2593-5232.ISBN:9789464206173.DOI:10.5281/zenodo.7561906 www.marineboard.eu infomarineboard.euDesign&cover picture ZoeckFirst edition,April 2023European Marine Boa

12、rd IVZW Future Science Brief 9EMB FUTURE SCIENCE BRIEF4ForewordAs I write this foreword,the 27th Conference of the Parties(COP27)is coming to an end in Sharm el-Sheikh(Egypt),with unfortunately no progress on how greenhouse gas emissions will be reduced,although the dedicated fund to repair the loss

13、 and damage already suffered by the countries of the South is a good start.As confirmed by the Secretary-General of the United Nations,Antonio Guterres,in his final address to COP negotiators:Clearly,this fund is not enough,but it is an essential political signal to rebuild the broken trust.Indeed,p

14、eople are starting to understand that the climate crisis is real,and science is urging action to achieve the Paris Agreement to limit global warming to well below 2C above pre-industrial levels and the more ambitious target to limit temperature increase to below 1.5C.In December 2019,to respond to t

15、his challenge,the European Union launched its Green Deal aiming to transition to a fairer,healthier,and more prosperous society,whilst guaranteeing a healthy planet for future generations.According to the 2019 EU Climate Law,the EU aims to reduce its emissions by 2030 and become climate neutral by 2

16、050,with significant ambition for the expansion of offshore renewable energy.The solutions outlined in the EU Green Deal can only succeed if people,communities,and organisations are all involved and take action.There is an urgent and immediate need to significantly reduce carbon emissions and move t

17、owards a carbon neutral society.Renewable energy can potentially supply the energy needed to support an ever-growing population and increasing industrialisation.There are many different offshore renewable energy resources including wind,waves,currents,tides,and thermal(the temperature gradient betwe

18、en warm surface waters and cold waters at depth).The extraction of these resources is at different levels of development,ranging from the research stage to that of commercial exploitation,particularly for offshore wind.While offshore renewable energy resource extraction is less mature than that on l

19、and,it is an attractive area for growth.To achieve the EU Green Deal vision,European offshore renewable energy capacity must increase 30-fold.However,there is a lot of competition for maritime space,and offshore renewable energy development must be conducted in line with EU nature conservation and r

20、estoration requirements.It is therefore imperative that the development of the European offshore renewable energy sector is conducted in a responsible,equitable and sustainable manner,and in collaboration with relevant parties.In 2010 the Marine Board ESF published a Vision Document on Marine Renewa

21、ble Energy that made recommendations for the development of marine renewable energy in Europe.In 2020 the European Marine Board felt it was timely to revisit the topic,and a new EMB Working Group on Offshore Renewable Energy kicked off in June 2021 and have worked with efficiency and enthusiasm to d

22、eliver this informative Future Science Brief.On behalf of the Members of the EMB,I would like to thank the Chairs and Members of the Working Group(Annex 1)for their hard work and dedication in producing this Future Science Brief.I would also like to thank the external reviewers for their valuable in

23、put.I thank the EMB Secretariat for supporting the Working Group and coordinating the production of this document,namely Paula Kellett,Britt Alexander,ngel Muiz Piniella,Ana Rodriguez,Sheila Heymans,and Jana Van Elslander.Gilles Lericolais Chair,European Marine BoardApril 2023N 9 20235Table of Conte

24、nts Foreword 4Executive Summary 7 Terminology used in this document 71.Climate change:The need for clean energy 9 1.1 How bad is climate change for the Ocean?9 1.2 What is the role of offshore renewable energy in addressing climate change?11 1.3 What are the main effects of climate change on offshor

25、e renewable energy?11 1.4 What are the interactions between climate change and offshore renewable energy?112.State of global offshore renewable energy 13 2.1 Offshore renewable energy resource review 13 2.1.1 Wind 13 2.1.2 Waves 15 2.1.3 Tides and currents 15 2.1.4 Solar 16 2.1.5 Other resources 17

26、2.1.6 Comparing different offshore renewable energy resources 19 2.2 Offshore renewable energy technology review 19 2.2.1 Offshore wind turbines 20 2.2.2 Wave energy converters 21 2.2.3 Marine turbines 24 2.2.4 Floating solar energy platforms 26 2.3 Integrated use of offshore renewable energy 273.Re

27、view of European offshore renewable energy status 28 3.1 European policies and aims 28 3.1.1 Marine Strategy Framework Directive 29 3.1.2 Biodiversity Strategy and Nature Restoration Law 29 3.1.3 Maritime Spatial Planning 29 3.1.4 European Green Deal and Offshore Renewable Energy Strategy 29 3.1.5 E

28、uropean governance initiatives 31 3.2 Overview of offshore renewable energy implementation and capacity in Europe 31 3.2.1 Mature technologies 31 3.2.2 Technologies in pilot/demonstration phase 33 3.3 Barriers 33 3.4 Expansion to key markets 344.Environmental impacts from offshore renewable energy:L

29、essons learnt 36 4.1 Positive and adverse impacts 36 4.2 Short-term and long-term effects 38 4.3 Physical agents of adverse impact 39 4.3.1 Underwater noise 39 4.3.2 Electromagnetic fields 39EMB FUTURE SCIENCE BRIEF6 4.4 Mitigation measures 40 4.5 Environmental assessment and monitoring 415.Socioeco

30、nomic impacts from offshore renewable energy:Lessons learnt 42 5.1 Why are socioeconomic aspects important?42 5.2 Socioeconomic benefits 43 5.2.1 Direct economic benefits 43 5.2.2 Job creation,training and skills 44 5.2.3 Community benefits and ownership 46 5.3 Social impacts 47 5.4 How are socioeco

31、nomics currently included in decision-making processes?48 5.4.1 Social Impact Assessment 48 5.4.2 Social Licence to Operate 48 5.5 Consenting and governance 49 5.5.1 Spatial conflicts 506.Knowledge and capacity gaps 52 6.1 Effect of climate change on offshore renewable energy 52 6.2 Technology and i

32、nfrastructure 53 6.2.1 Strategic grid 53 6.2.2 Energy storage 54 6.2.3 Materials and related challenges 54 6.2.4 Full Life Cycle Assessment 56 6.3 Environmental impacts of offshore renewable energy 57 6.3.1 Cumulative impacts 57 6.3.2 Environmental monitoring 58 6.4 Maritime Spatial Planning 59 6.5

33、Data sharing 597.Policy,governance,and research recommendations 60 7.1 Policy 60 7.2 Research and technology 60 7.3 Data and capacity 61References 62List of Abbreviations and acronyms 77Annex 1:Members of the European Marine Board Working Group on offshore renewable energy 80Annex 2:European policie

34、s,strategies and directives relevant to ORE 81Annex 3:Comparing units of power 82Annex 4:Examples of references supporting positive and negative environmental impacts of ORE 83 as outlined in Section 4.1 N 9 20237Executive summaryConsidering the Ocean environment as a potential source of energy is n

35、ot new.Renewable energy research and technological development have been looking at the Ocean for some time.The first offshore wind farm in Europe was installed by Denmark in 1991 in the Baltic Sea and decommissioned in 20171.The 2010 EMB Vision Document 2 on Marine Renewable Energy(Le Boulluec et a

36、l.,2010)presented the research challenges and opportunities for a new energy era in Europe.It offered an overview of how renewable energy from the Ocean can provide innovative solutions to tackle future energy challenges and to fully contribute to the EU 2020 vision2.It provided a baseline of inform

37、ation representing progress in marine renewable energy development at that time.The signing of the Paris Agreement3 in 2015 brought significant public and political attention to the wider issues of climate change,and solutions such as offshore renewable energy that could support the achievement of t

38、he Paris Agreement.In 2019 the European Green Deal4 outlined Europes vision to become the first climate-neutral continent with no net emissions of greenhouse gases by 2050.There is also an interim aim to“reduce net greenhouse gas emissions by at least 55%by 2030 compared to 1990 levels”.The related

39、2020 EU Strategy to harness the potential of offshore renewable energy for a climate neutral future presented the key role for offshore renewable energy in achieving this vision.The global economic and geopolitical situations in 2022,including the recovery from the COVID-19 pandemic,increasing fuel

40、prices,and the war in Ukraine leading to questions of energy security,have further increased the impetus on governments to accelerate the move away from a reliance on oil and gas as energy sources.Offshore renewable energy sources should play a key role in that move.In light of these geo-political,e

41、conomic,and environmental drivers,this Future Science Brief outlines the state-of-the-art in knowledge on offshore renewable energy(ORE).It also highlights key research needs to help us fully understand the implications of such an energy transition.The main recommendations are to:Address misalignmen

42、t in policy,and the approaches and practices used in different EU Member States that hinder efficient and sustainable ORE development and deployment;Support measures to increase the availability of open and high-resolution data,to understand ORE resource availability,environmental impact,and the imp

43、act of climate change;Further develop the research capability to holistically investigate the ecological and socioeconomic benefits and impacts of ORE;Conduct further research into the technical,environmental and socioeconomic aspects of ORE devices and their full lifetime from design to operation t

44、hrough to decommissioning,to improve sustainability and viability;Ensure that offers for training and skills development match industry requirements.1 https:/www.power- http:/ec.europa.eu/europe2020/index_en.htm 3 https:/unfccc.int/process-and-meetings/the-paris-agreement/the-paris-agreement 4 https

45、:/ec.europa.eu/info/strategy/priorities-2019-2024/european-green-deal_enEMB FUTURE SCIENCE BRIEF8EMB acknowledges that while the Working Group members writing this document and its recommendations represent some diversity in terms of European geographical location(see Annex 1),professional backgroun

46、d,and career level,their views do not represent ideas from all forms of diversity.This document has a European focus,but its messages and recommendations are relevant to offshore renewable energy stakeholders globally.This Future Science Brief and its recommendations support the UN Decade of Ocean S

47、cience for Sustainable Development(Ocean Decade)in a number of ways.The Future Science Brief highlights knowledge to indirectly support Societal Outcome 1(A clean Ocean where sources of pollution are identified and reduced or removed)and Challenge 1(Understand and map land and sea-based sources of p

48、ollutants and contaminants and their potential impacts on human health and Ocean ecosystems and develop solutions to remove or mitigate them),presenting a state-of-the-art on cleaner energy production approaches,which would support the removal of fossil fuel-related pollutants.It also provides knowl

49、edge to support Societal Outcome 3(A productive Ocean supporting sustainable food supply and a sustainable Ocean economy)and Challenge 4(Generate knowledge,support innovation,and develop solutions for equitable and sustainable development of the Ocean economy under changing environmental,social and

50、climate conditions),by providing recommendations on the further development of offshore renewable energy as a key component of a sustainable Ocean economy,and discussing how the development of renewable energy can consider environmental,social and climate factors.Finally,it supports Challenge 5(Enha

51、nce understanding of the Ocean-climate nexus and generate knowledge and solutions to mitigate,adapt and build resilience to the effects of climate change across all geographies and at all scales,and to improve services including predictions for the Ocean,climate,and weather)by providing recommendati

52、ons for the development of renewable energy as direct mitigation to climate change.This Future Science Brief and its recommendations support the EU Mission:Restore our Ocean and Waters and its objectives and enablers in several ways.It addresses Objective 2(Prevent and eliminate pollution of our Oce

53、an,seas,and waters)by providing recommendations on how renewable energy can be sustainably developed,as a direct measure for reducing fossil fuel-related pollutants.It also addresses Objective 3(Make the sustainable blue economy carbon-neutral and circular)by making recommendations on how to develop

54、 the renewable energy sector to not only support Europes climate-neutral vision,but to also consider its own circularity.Wavy conditions on the north coast of Madeira,Portugal.Credit:Dzintra GrinbergsN 9 202391Climate change:The need for clean energy1.1 How bad is climate change for the Ocean?We are

55、 all aware that the planet is warming,but not everyone is aware of the role our Ocean plays in counteracting this.The Ocean has greatly slowed the rate of climate change by taking up more than 90%of the extra heat stored on the planet.This extra heat has arisen from increased greenhouse gas(GHG)emis

56、sions,including carbon dioxide(CO2),methane(CH4),nitrous oxide(N2O),water vapour and fluorinated gases.The Ocean is taking up around 25%of the excess carbon emitted by human activities(IPCC,2019).But this comes at a cost.The Ocean has warmed at all depths,with the greatest increases occurring in sur

57、face and shallow coastal waters(IPCC,2019).The Ocean is also acidifying as increased CO2 uptake decreases seawater pH.This acidifying effect reduces the future ability of the Ocean to take up more carbon(Goodwin et al.,2009),and affects the physiology of many marine species.The global Ocean has lost

58、 around 2%of its dissolved oxygen in the past 50 years,caused directly by lower solubility in warmer water 5 https:/eur-lex.europa.eu/legal-content/EN/TXT/?uri=COM:2020:741:FIN&qid=66 6 https:/research-and-innovation.ec.europa.eu/research-area/energy/ocean-energy_enThe world has changed p

59、rofoundly in recent years with a global recognition that we are in a climate emergency and must rapidly reduce our use of fossil fuels.Therefore,it is imperative to fully understand the role that offshore renewable energy will play in meeting the worlds energy needs(European Commission,2020b).There

60、needs to be a clear understanding of the positive and negative environmental and social implications of large-scale development of 100s to 1000s of gigawatts of offshore renewable energy worldwide in the next few decades(IRENA,2019).This chapter highlights the urgent need to switch to using our Ocea

61、n for large-scale energy extraction in the fight against climate change and outlines how the use of offshore renewable energy can help to reduce fossil fuel reliance and harmful emissions.It also outlines the aspects of climate change that can directly influence the production of offshore renewable

62、energy.Terminology used in this documentThere are a number of terms that are used when discussing marine-related energy extraction.The term offshore energy refers to all sources of energy that can be extracted from the Ocean,including both fossil-based(e.g.oil and gas)and renewable sources.The term

63、offshore renewable energy5 refers to all sources of renewable energy that can be extracted from the Ocean,including wind,wave,tidal,Ocean/marine current,thermal and salinity gradient,floating solar and algae-based biofuels.The term marine renewable energy refers to a subset of offshore renewable ene

64、rgies including waves,tides and Ocean currents,thermal and salinity gradient,floating solar and algae-based biofuels.The term Ocean energy refers to a different subset of offshore renewable energies,specifically waves and tides(range and current),Ocean circulation currents,and thermal and salinity g

65、radients6.Throughout this document and in line with terminology used by the European Commission,we will use the all-encompassing term offshore renewable energy,abbreviated to ORE,unless a distinction is appropriate.EMB FUTURE SCIENCE BRIEF1020212025No new sales offossil fuel boilersUniversal energy

66、accessAll new buildings arezero-carbon-ready60%of global carsales are electric50%of heavy trucksales are electricNo new ICEcar salesNet zero emissionselectricity globally50%of heating demandmet by heat pumps150 Mt low-carbon hydrogen850 GW electrolysers435 Mt low-carbon hydrogen3000 GW electrolysers

67、4 Gt CO2 captured7,6 Gt CO2 captured1020 GW annual solarand wind additionsMost new cleantechnologies in heavy industry demonstratedat scale50%of existingbuildings retrofttedto zero-carbon-readylevels Almost 70%of electricity generationglobally from solarPV and windMore than 90%of heavy industrial pr

68、oduction is low-emissionsMore than 85%of buildings arezero-carbon-readyNo new unabatedcoal plants approved for developmentPhase-out ofunabated coal inadvanced economiesOverall net-zeroemissions electricity in advanced economiesAll industrialelectric motor salesare best in classPhase-out of allunabat

69、ed coal and oilpower plantsMost appliances andcooling systems soldare best in class50%of fuels usedin aviation arelow-emissionsNo new oil and gas feld approved fordevelopment;no new coal mines or mine extensionsAround 90%of existing capacity in heavy industries reaches end of investment cycle-505101

70、520253035402020202520302035204020452050GtCO2BuildingsTransportIndustryIndustry and heatOther20452030203520402050Figure 1.1 Global net anthropogenic greenhouse gas emissions 1990-2019.Credit:Figure SPM.1 in(IPCC,2022b)Global net anthropogenic emissions have continued to rise across all major groups o

71、f greenhouse gasesKey milestones in the pathway to net zeroFigure 1.2 Key milestones in the pathway to net zero.Credit:(IEA,2021a),Net Zero by 2050:A Roadmap for the Global Energy Sector,https:/www.iea.org/reports/net-zero-by-2050,CC-BY-4.0N 9 202311Table 1.1 Comparison of GHG emissions for differen

72、t electricity generation approaches over their lifetime.Credit:Based on(Barthelmie&Pryor,2021;UNECE,2021)and indirectly via reduced mixing between surface layers and deeper waters(Stramma&Schmidtko,2019).There is emerging evidence for climate change impacting the strength and direction of Ocean curr

73、ents(Halo&Raj,2020),which could impact heat exchange in the Ocean and lead to the shutdown of the Atlantic Meridional Overturning Circulation(AMOC),a key part of the global Ocean circulation system(MetOffice,2019).Many fish stocks depend on Ocean currents for transport between spawning and feeding a

74、reas.This could eventually affect commercial fish stock recruitment success(Prtner&Peck,2010).Finally,global sea levels are rising and will continue to rise due to melting land-ice and the thermal expansion of water with rising temperatures(Oppenheimer et al.,2019).1.2 What is the role of offshore r

75、enewable energy in addressing climate change?Renewable energy is an important climate mitigation and adaptation measure.Given the continuous rise in anthropogenic GHG emissions(see Figure 1.1),it is imperative to increase the pace of renewable energy penetration in countries energy mix.According to

76、the International Energy Agencys7(IEA)scenario for Net Zero GHG emissions by 2050(IEA,2021a,Table 2.6),the anticipated required capacity additions of renewable energy from onshore and offshore solar and wind by 2030 is 1,020 Gigawatts(GW)per year,which is significant given that in 2022,Europes total

77、 installed wind capacity was 236GW8.By 2050,it is foreseen by the International Energy Agency(IEA)that 70%of electricity production globally should come from solar and wind energy(see Figure 1.2).The most recent Intergovernmental Panel on Climate Change(IPCC)report also foresees a high potential for

78、 wind and solar energy to support emission reductions by 2050(IPCC,2022,Figure SPM 7).The International Renewable Energy Agency9(IRENA)estimates that to keep global temperature rise at 1.5oC,25%of the emissions reductions must be provided using renewable energy(IRENA,2022).Offshore renewable energy(

79、ORE)still produces GHG emissions,but these are much lower than those of fossil fuels,as is shown for the example of wind and solar energy in Table 1.1.Hoegh-Guldberg et al.,(2019)suggest that ORE can mitigate the production of up to 5.4 gigatons(Gt)of CO2 equivalent per year by 2050,representing app

80、roximately 10%of global efforts to keep temperature increase under 1.5C.From an economic perspective,the global climate value10 of offshore wind energy only(considering the value from reduced emissions and on reductions in the cost of abatement)is estimated to be$US 100 in a scenario with no climate

81、 policy,$US 120 where a limit is set on permissible carbon emissions(carbon caps),and$US 450 billion with significant carbon taxes respectively(Cranmer&Baker,2020).This is the case even with the highest offshore wind energy cost assumptions and lowest damage severity of climate change factors used.1

82、.3 What are the main effects of climate change on offshore renewable energy?ORE systems are sensitive to structural risk from weather and climate variability,which can reduce the efficiency of their energy production.The impact of climate change on the available offshore energy resources is uncertai

83、n and is the subject of a growing body of scientific research.The magnitude and direction of the predicted changes depends on the region and climate change scenario considered.Reviews summarising the existing(and often contradictory)literature on this subject are presented by Solaun&Cerd(2019)and mo

84、re recently by Gernaat et al.,(2021).The expected climate change impacts vary by region however Weiss et al.,(2020)suggest that the areas expected to be most suitable for ORE deployment are not likely to be significantly affected by climate change.Climate change also affects meteorological and ocean

85、ographic parameters such as wind speed,wave height and period,Ocean current speed and sea level.These meteorological and oceanographic variables and their extremes impact the design of offshore and coastal structures and operations,and their ability to withstand environmental loads.A more detailed d

86、iscussion on the future needs regarding understanding the effects of climate change on ORE is presented in Section 6.1.1.4 What are the interactions between climate change and offshore renewable energy?Large-scale energy extraction from offshore renewable resources will lower the likelihood of marin

87、e ecosystems experiencing the more extreme effects of climate change.However,the effects of these installations and of extracting energy can have impacts that are synergistic with climate change and have similar consequences(de Dominicis et al.,2018;Sadykova et al.,2020).Large-scale offshore energy

88、extraction is not the free energy proclaimed in some economic evaluations,and the cost of its effects must also be considered(Dasgupta,2021).The extracted 7 https:/www.iea.org/8 https:/windeurope.org/intelligence-platform/product/wind-energy-in-europe-2021-statistics-and-the-outlook-for-2022-2026/9

89、https:/www.irena.org/10 Global climate value is a valuation of the financial return considering climate-related risks and opportunities.Electricity generation approachEquivalent grams of CO2 emitted per kWhFossil fuel360 1259Onshore wind energy14.5 28.5Offshore wind energy11Solar energy from solar p

90、anels/photovoltaics8 83EMB FUTURE SCIENCE BRIEF12Oil rigs in waters off Santa Cruz,Tenerife,Spain.Credit:European Marine Boardenergy would otherwise have served another purpose within the Ocean ecosystem e.g.by providing heat to marine surface waters(Dorrell et al.,2022).The ecological effects of OR

91、E are covered in Chapter 4 and in published reviews(e.g.Copping&Hemery,2020)but they should be understood in the context of climate change rather than against a non-shifting current baseline(Wolf et al.,2021).We need to understand the compromises we are making between the positive impacts of using O

92、RE to reduce the impacts of climate change on the environment and humanity,against potential negative impacts of installing offshore renewable energy extraction devices in maritime space.For example,as discussed in more detail in Section 6.2.3,deep-sea mining for energy transition minerals used in c

93、omponents of turbines and batteries is critical for the creation of renewable energy devices but causes irreversible impacts to deep-sea ecosystems.According to the IEA(2021b),by 2040,the demand for minerals needed for clean energy technologies will be four times the present demand,increasing by up

94、to six-fold by 2050.This issue is not limited to ORE but could also have serious implications for its development.N 9 2023132State of global offshore renewable energy The marine environment contains abundant renewable energy,arising from wind,waves,tides,the sun,and thermal and salinity differences.

95、Technologies and devices to extract these energies efficiently and sufficiently,either by converting them into electricity or energy storage media for future use,are being,and need to be,further developed.This chapter provides brief reviews of the characterisation and global distribution of offshore

96、 renewable energy resources,and of existing and emerging offshore renewable energy technologies up to 200km from the shore.In the context presented in this document,the basic unit of power,a watt(W),is a measure of the rate of energy transfer,e.g.from an offshore renewable energy source to electrici

97、ty.A watt-hour(Wh)is a unit of energy which describes the amount of power generated in an hour.Annex 3 presents a comparison of the different units of power.2.1 Offshore renewable energy resource review This section outlines the estimated global energy resources of different offshore renewable energ

98、y(ORE)sources.It is important to note that the use of theoretical power is debatable because not all theoretically estimated power can be extracted due to technical and economic efficiencies encountered when installing devices offshore,the efficiency of the extraction method,and natural factors such

99、 as variations in wind and wave direction(see e.g.Guo&Ringwood,2021).Chapter 3 provides more detail on the availability of ORE resources in European waters,and its implications.2.1.1 Wind Compared to onshore wind,offshore wind is stronger and less turbulent,and thus more energetic and stable.The est

100、imated global energy demand in 2019 was 65,000 Terawatt Hours(TWh),while onshore and offshore wind energy could,in an ideal/theoretical situation,provide 900,000TWh per year11.Due to the technological maturity of wind turbines and the expertise of onshore developers,offshore wind energy is the most

101、advanced offshore renewable energy option.Energy extraction from wind depends on wind speed and density of the air and is usually quantified in terms of either wind power density or the amount of power available per year at a given location.Wind speed varies in time and space,and therefore the mean

102、wind speed at a certain height(e.g.100m above sea level which approximately corresponds to the wind turbine hub height)is often used to characterise offshore wind energy resources.Figure 2.1 shows the global distribution of mean wind speed(top)and available power density(bottom)at sites up to 200km

103、offshore,taken from the Global Wind Atlas12.This figure clearly shows a significant difference in mean wind speed and wind power resource in different areas,with the most notable difference being about twice the wind speed(and therefore eight times the wind power)towards the North or South Poles com

104、pared to the Equator.The global offshore wind resource is mainly assessed by combining satellite remote sensing data with hindcast datasets generated using numerical atmospheric models(Bosch et al.,2018;Karagali et al.,2013).Atmospheric models provide estimates of wind speed every one to three hours

105、 at different heights above the ground(or sea level),and at different geospatial locations.The models provide estimates of wind speed and direction(at different heights above a ground datum or mean sea level).To get wind speed estimates closer to the turbine hub height,the European Centre for Medium

106、-Range Weather Forecasts13(ECMWF)also provides estimates of wind speed and direction at 10m and 100m above sea level.However,since the tips of the blades of the wind turbine are at different heights as they rotate,the rotor(i.e.the rotating part of the turbine comprising of the hub and blades)equiva

107、lent wind speed(instead of the wind speed at the hub height)is used for the estimation of the annual energy production.In addition,the rotor diameters of modern offshore wind turbines have increased from 112m(in 2010)to 157m(in 2019)(IRENA,2021).Long-term(three to five years or more)atmospheric data

108、 based on simulations from hindcast models and satellite observations are used for resource assessment,i.e.these data are used to 11 https:/carbontracker.org/solar-and-wind-can-meet-world-energy-demand-100-times-over-renewables/12 https:/globalwindatlas.info/13 https:/www.ecmwf.int/EMB FUTURE SCIENC

109、E BRIEF14Mean Wind Speed 100m-(m/s)9.75Wind Power Density 100m-(W/m2)1300plan where offshore wind farms should be situated.Numerical atmospheric models have multiple types of uncertainties(such as uncertainties in initial conditions,uncertainties caused by errors in the model formulation/parameteris

110、ation schemes or numerical integration methods),thus measurements are very important to evaluate and validate their results(Olafsson&Bao,2020).Moreover,the available spatial resolution of these models is not currently fine enough to assess wind variability(instability,eddies and turbulence)at the sc

111、ale of a single turbine.This is needed to support the design and dynamic analysis of offshore wind turbines.To make an accurate assessment of the flow at this scale additional long-term datasets combining in situ monitoring with high sampling frequency(e.g.a sample taken every second),fine recording

112、 period(e.g.a recording duration of ten minutes),and short recording interval(e.g.one hour between ten-minute recordings)and very fine resolution atmospheric models or,usually,computational fluid dynamics techniques14,are necessary.New monitoring solutions that can provide vertical wind profiles are

113、 also necessary,such as floating LIDAR(Light Detection and Ranging).Such technology still needs further development.14 Computational fluid dynamics techniques use continuity and momentum equations,within software packages,to predict how gases and liquids flow and interact with different objects.Figu

114、re 2.1 A.Global distribution of mean wind speed,and B.wind power density potential at a reference height of 100m for offshore areas up to 200km offshore.Source:Maps obtained from the Global Wind Atlas 3.0,a free,web-based application developed,owned,and operated by the Technical University of Denmar

115、k(DTU).The Global Wind Atlas 3.0 is released in partnership with the World Bank Group,utilising data provided by Vortex,using funding provided by the Energy Sector Management Assistance Program(ESMAP).For additional information:https:/globalwindatlas.info.AWind power density potentialCredit:Global W

116、ind Altas,CC BY 4.0BN 9 20231515 https:/www.oceanenergy-europe.eu/ocean-energy/wave-energy/16 Numerical spectral wave models mathematically provide a description of how a wave energy field changes over time and in coastal areas can be used for forecasting.17 https:/www.oceanenergy-europe.eu/industry

117、-news/sustainable-marine-powers-up-tidal-energy-in-nova-scotia/Figure 2.2 Global mean value of wave power,P(kW/m).2.1.2 Waves Wave energy has great potential as an offshore renewable energy resource.It is unevenly distributed globally,and is most available between 40-60 N,e.g.in the North Atlantic,a

118、nd 40-60 S.Wave power is a function of wave height,wave period(i.e.the time between two consecutive wave peaks passing a given point)and seawater density.Figure 2.2 shows the global mean offshore wave power.Wave power density is highest in the open Ocean,while in more sheltered,coastal areas,where i

119、t is more realistic to deploy Wave Energy Converters(WECs),it is typically around a quarter to half of the wave power density of the open Ocean.Similar to wind,wave energy is highly variable seasonally and inter-annually,and location dependent.Closer to the Equator the mean wave power is lowest,howe

120、ver there is permanent and relatively constant wave action.In the higher latitudes where the mean wave power is high,the operation of a WEC requires high installation and maintenance costs to survive those conditions.Consequently,areas of highest wave energy resource are not necessarily optimal for

121、energy extraction(Portilla et al.,2013).The theoretical potential annual global wave energy production is estimated to be 29,500TWh15.Sea state data(i.e.wave height,wave period,wave direction)used to estimate the available wave resource in a given area are obtained by in situ monitoring,numerical sp

122、ectral wave models16,and remote sensing techniques.For coastal areas where WECs are usually deployed,high spatio-temporal resolution wave models combined with in situ wave measurements are required to evaluate and calibrate numerical model results.The directional distribution of wave energy is also

123、important as this plays a major role in some WEC technologies(Soukissian&Karathanasi,2021).2.1.3 Tides and currents Energy can be extracted from tidal currents(the horizontal movement of water),tidal range(the vertical change in water level)and Ocean circulation currents(such as the Gulf Stream).Flo

124、w speed is a key factor in assessment of the available energy:median current speeds greater than 1.1m/s(3.96km/h)are economically favourable for energy extraction(Khare et al.,2019).Since tides are very predictable(at locations where long-term tidal gauge measurements are available),tidal range is o

125、ften used to characterise the global distribution of tidal energy,as shown in Figure 2.3(IRENA,2014a).Tidal range is often enhanced in coastal areas or channels and displays considerable variation around the globe.The funnelling effects of bays,estuaries and inlets,or areas where flow is constrained

126、 by the presence of islands or headlands,can provide a viable tidal energy resource(Vila-Concejo et al.,2020).The morphology of some bays may also create large tidal ranges at the head of the bay and consequently strong tidal currents.Locations such as the Bay of Fundy in Canada17,Cook Strait in New

127、 Zealand(Walters et al.,2010),and the Pentland Firth in the UK(Coles et al.,2021)are good examples that have been targeted for development.Tidal energy was harnessed in early commercial ventures through the construction of barrages,such as the 240MW La Rance tidal energy station in France and the 25

128、4MW Sihwa Lake Tidal Power Station in the Republic of Korea(Neill et al.,2021).Credit:(Martinez et al.,2020,Figure 3)CC BY 4.0EMB FUTURE SCIENCE BRIEF16The estimated global tidal energy available for extraction per year ranges between 150 and 800TWh18,with potential estimates up to 1200TWh(IRENA,202

129、0a).Data on tidal energy properties such as current speed and direction and tidal range are obtained from in situ measurements,drifters,and numerical oceanographic models.In situ measurements are obtained from oceanographic buoys,or Acoustic Doppler Current Profilers(ADCP)that are deployed on the se

130、a bottom or placed on the bottom of ships.Tidal ranges are usually measured at coastal locations,harbours,bays,ports,etc.through tidal gauges.Free floating devices called drifters can submerge and measure marine current characteristics at different depths.It is noted that sea level rise due to globa

131、l warming should also be included in all projections for tidal resources(Sobey,2005).The number of coastal locations with strong enough tidal currents or high enough tidal ranges to make energy extraction economically viable is limited(Figure 2.3,highlighted in red).In highly energetic sites where c

132、urrent velocities can regularly reach values higher than 2.5m/s(or 9km/h)the flow is invariably turbulent,which creates high resource variability in space and time.The characterisation of this variability is necessary to properly access the potential of the resource.Further development and design of

133、 high-resolution in situ monitoring devices,tools and procedures are necessary to quantify the current profiles and turbulence.Ocean circulation currents are generated by factors including Earths rotation,wind,gravity,temperature and salinity in the Ocean,and their location,width,depth,and flow are

134、determined by the shape of the Ocean basin in question and the Coriolis Force(caused by Earths rotation acting on both air and water).Their flow is typically considered to be continuous and almost unidirectional,and they are characterised by low variability and high predictability.However,early indi

135、cations of weakening and instability of these currents due to climate change are being observed(Boers,2021).It is also not clear from the literature how much potential energy could be extracted from Ocean currents,although the US Department of the Interior(2006)estimate global power in Ocean current

136、s to be around 5000GW.Energy extraction from Ocean currents is at present only considered for the Gulf Stream in the Atlantic Ocean,and the Kuroshio Current in the Pacific Ocean,and no commercial installations have yet been deployed.This energy resource will not be considered further in this documen

137、t.2.1.4 Solar Solar energy is created by the power from the sun as electromagnetic radiation,called solar irradiance.The intensity of solar irradiance is variable and depends on latitude,season,time of day,weather conditions,solar cycle,etc.In the Ocean,solar energy could be extracted using solar pa

138、nels(photovoltaic(PV)systems)fitted to dedicated floating platforms or to existing offshore structures.Data on solar irradiance in the Ocean are mainly obtained using dedicated sensors called pyranometers(mounted on buoys or on-board ships),numerical atmospheric models and satellite imagery(Trolliet

139、 et al.,2018).18 https:/ec.europa.eu/research-and-innovation/en/projects/success-stories/all/tidal-flows-generate-huge-potential-clean-electricityFigure 2.3 Global tidal range distribution.Credit:(IRENA,2014a)N 9 20231719 https:/argo.ucsd.edu/20 http:/ https:/ http:/www.ocean-thermal.org/mw-scale-ot

140、ec-for-kiribati/23 https:/www.ccreee.org/news/2022-un-oceans-conference-prime-minister-of-tonga-oversees-historic-signing-of-development-of-worlds-first-ocean-energy-power-purchase-agreement-for-sao-tome-and-principe/24 https:/plotec.eu/2.1.5 Other resources In addition to the more mature and/or wel

141、l-known ORE technologies presented above,there are also several other resources under consideration.These are not the focus of this document but are briefly introduced here.It is also noted that the process of sea water air conditioning(or geo-exchange of heat and cooling),where the temperate of sea

142、 water is used directly in installations rather than being converted to energy,is outside the scope of this document.Thermal GradientOcean Thermal Energy Conversion(OTEC)uses the thermal gradient between deeper cold seawater and warmer surface water to generate electricity using a heat engine.Areas

143、of largest temperature gradient between deep and surface water(above 20C,which is the lower threshold for OTEC applications)occur in a belt around the Equator,especially in the western part of the Pacific Ocean.This energy is continuously available and offers a significant resource potential,and a v

144、ery high capacity to produce energy.This capacity factor is the ratio of the actual electrical energy produced for a specific time-period compared to the theoretical maximum electrical energy produced in the same period.The data needed to calculate OTEC include seawater temperature at different dept

145、hs,which are obtained using buoys,oceanographic model results,CTD casts(which measure Conductivity(or salinity),Temperature,and Depth)from research vessels,and more recently,by autonomous underwater vehicles and the ARGO profiling floats19.Many possible configurations for OTEC plants have been propo

146、sed,ranging from floating to land-based plants.There have been some relevant international OTEC developments in recent years:In Japan,a 100 kilowatt(kW)OTEC demonstration facility was established by Okinawa Prefecture in 2013,with technical assistance from Saga University20;An OTEC plant set up by t

147、he Natural Energy Laboratory of Hawaii Authority in the 1970s and taken over by Makai Ocean Engineering21 in August 2015;The Korea Research Institute of Ships and Ocean Engineering(KRISO)developed a 1 Megawatt(MW)OTEC plant in 2019,and recently transported it for installation as an onshore OTEC faci

148、lity in South Tarawa,Republic of Kiribati,in the South Pacific Ocean22.Completion of the installation was expected in 2022.In 2022,So Tom and Prncipe,in cooperation with the Global OTEC company and the Small Island Developing States(SIDS)Sustainable Energy and Climate Resilience Organisation,signed

149、a Memorandum of Understanding for the development of a 1.5MW floating Ocean OTEC platform offshore So Tom Island.The deployment of the platform is anticipated for 202423.A map with potential future OTEC developments is provided by OES(2021c)and a review of OTEC has recently been provided by Herrera

150、et al.,(2021).Even though European waters are in mid-and high-latitudes(i.e.areas that are not favourable for thermal gradient energy exploitation because the temperature differences are not large enough)some European countries still support the development of OTEC R&D programmes for application in

151、their overseas territories as well as in tropical Small Island Developing States(SIDS).Apart from electricity generation,OTEC power can be also used for desalination and freshwater production that is of utmost importance in tropical areas.In 2022,a consortium called PLOTEC24 from Austria,Italy,Portu

152、gal,Spain,and the UK received funding in the context of the Horizon Europe Framework Programme for the design and simulation of an OTEC platform capable of withstanding the extreme conditions associated with tropical weather.A scaled demonstrator model will be tested at the Oceanic Platform of the C

153、anary Islands(PLOCAN)facility in Gran Canaria in 2024.The consortium will engage with SIDS leaders and policymakers for future capacity-building.These advances should help to overcome technical and economic challenges and achieve a multi-MW full-scale demonstration plant which would make a significa

154、nt step towards commercialisation.Salinity gradientSalinity gradient energy(SGE)can be produced from the salinity difference between seawater and fresh-water.This energy is typically generated using either:a)pressure-retarded osmosis(PRO),where salt-and fresh-water are separated by a membrane and mi

155、xed via osmosis,with the energy of the physical flow being extracted,or b)Reverse Electro Dialysis(RED),where salt ions are transported through membranes to generate a charge(Han et al.,2021).Plants can be located either at naturally occurring gradient sites such as where rivers flow into the sea,or

156、 alongside other infrastructure such as desalination plants.A comprehensive review of SGE is provided by Cipollina&Micale(2016).SGE is both highly available and predictable,and salinity data is obtained by the same means as seawater temperature,although salinity data at depth is not as critical give

157、n that salinity plants are located in shallow coastal and nearshore waters or estuaries.Reasons that the use of salinity gradient energy extraction is not more mature include a lack of research on the environmental and legal implications of these installations,the high cost of components,especially

158、the membranes,and a lack of realistic operative cost estimates and real-world experience with these devices which act as a barrier for policymakers and investors(IRENA,2014b).BiomassMarine biomass in the form of algae is a renewable resource for biofuel production.The algae(which are usually cultiva

159、ted)can be EMB FUTURE SCIENCE BRIEF1825 https:/eklipse.eu/request-macroalgae/26 https:/www.nweurope.eu/projects/project-search/alg-ad-creating-value-from-waste-nutrients-by-integrating-algal-and-anaerobic-digestion-technology/%C2%A0%C2%A027 https:/www.surfnturf.org.uk/index.phpCredit:Jose Gayo Pelae

160、zA team of researchers at Swansea University are using food and farm waste to cultivate microalgae as part of the Interreg North-West Europe project ALG-AD26.converted into biofuel by extracting their fatty acids(called lipids).Biofuels can be produced from both macroalgae(e.g.seaweeds)and microalga

161、e(e.g.phytoplankton),and have the advantage that agricultural land is not taken up displacing other biofuel crops(e.g.corn,soy,grasses).However,it is important to note that while macroalgae can be cultivated at sea(either open sea or shallower coastal waters),microalgae can only be cultivated in con

162、trolled systems on land(in artificial ponds or tanks,or in closed bioreactors).Supported by EU funding,an expert working group of Eklipse25 recently reported on the“State of knowledge regarding the potential of macroalgae cultivation in providing climate-related and other ecosystem service”(Bermejo

163、et al.,2022).A review of progress and further needs towards a biorefinery for microalgae is presented by Wood et al.,(2022).Biofuels are particularly useful in the transport and heating sectors.Algae have the potential to yield significantly more energy than current biofuels,are able to produce the

164、longer-chain lipids needed for e.g.aviation fuel,and,in biodiesel form,they also emit lower levels of greenhouse gases than conventional diesel fuel.The sustainability and costs associated with biofuel generation from algae are variable and are strongly linked to the way they are cultivated and extr

165、acted(Darda et al.,2019).A technological challenge for large-scale development is that currently more energy is required to extract the lipids than gained back from the resulting biofuel,and so more efficient extraction methods are being explored(Sarwer et al.,2022).Power-to-X and hydrogenThe Power-

166、to-X concept is defined as conversion of surplus electricity produced by ORE sources into hydrogen or other products for energy storage purposes,offering a means to address imbalances between resource availability and demand,especially for intermittent ORE sources such as wind(see Section 6.2.2.for

167、more discussion).It is not intended as a replacement for renewable energy.Hydrogen can be generated using the process of electrolysis,where an electric current is used to split water into its components,hydrogen and oxygen.Where the required electricity for the electrolyser is supplied by renewable

168、energy sources,the hydrogen is sometimes called green hydrogen.Power-to-X systems offer direct ways to decarbonise various industrial processes and to provide an energy source for transportation(e.g.shipping,aviation)because the ORE-generated hydrogen can be used as a fuel instead of fossil fuels.Po

169、wer-to-X systems also allow stored energy to be transported.Hydrogen is therefore considered“essential to support the EUs commitment to reach carbon neutrality by 2050”(European Commission,2020a).The possibility of using wind power for hydrogen production and avoiding the need for grid infrastructur

170、e upgrades to manage resource variability is very relevant for the ORE sector.A further advantage is that the cost of hydrogen production can potentially be cut by 60%-80%(IEA,2021a;Wilson,2020).An example of this is the community-led Surf N Turf project27 in Orkney,UK,where excess wind and tidal cu

171、rrent power generated on the island is used to produce hydrogen,N 9 20231928 Based on the ideas presented here,where 14,000GW would equate to around 18,000TWh depending on location,and the assumption of 50%of overall global solar energy production taking place at sea(rather than on land):https:/ aut

172、hors are not aware of an equivalent estimate in the published literature.29 Estimate based on examples in sheltered waters only,as no commercial-scale applications exist in open seas.30 https:/ec.europa.eu/research/participants/data/ref/h2020/wp/2014_2015/annexes/h2020-wp1415-annex-g-trl_en.pdf 31 h

173、ttps:/www.etipocean.eu/which is then used to power harbour and local ferry operations in Orkneys capital,Kirkwall.The generated hydrogen can also be used in other applications,such as the production of methane or ammonia for use in natural gas systems or in fertiliser(Power-to-gas)and methanol for u

174、se in fuel cells(Power-to-liquid).The hydrogen can also be used to power fuel cells,converting the stored power back to electricity(Power-to-Power).Given that not all industries(e.g.mining,aviation)will be easy to electrify,there will be an increasing role for ORE in the generation of green hydrogen

175、 and other green fuels to support further decarbonisation.2.1.6 Comparing different offshore renewable energy resources Wave and tidal power have a much larger power density than wind and solar power,i.e.they have larger power availability per unit volume.However,the utilisation of ORE also depends

176、on the efficiency,maturity and cost-effectiveness of the corresponding technologies.At present,offshore wind energy systems are much more mature than other ORE technologies.If a certain technology,such as a wind turbine,wave energy converter(WEC),tidal turbine,or solar PV,is used,the actual energy c

177、onverted to electricity also depends on the device,which typically varies for different environmental conditions.The average energy a device can produce is a function of the efficiency of the device and the long-term distribution of the energy resource(i.e.wind speed distribution or joint distributi

178、on of wave parameters),which varies with time.Table 2.1 below shows a general comparison in capacity factor,energy production and cost between the different resources for which information is readily available in the literature.There is significant variation in the estimations provided in different

179、sources,therefore this information should be taken as indicative only.These values are also estimated global values that vary depending on geographic,technological and economic variables.As offshore wind has already been commercialised,one could expect that other technologies would be much more cost

180、ly.2.2 Offshore renewable energy technology review This section reviews different ORE technologies and their maturity in terms of commercial development,with a focus on offshore wind,wave,tidal current and range and solar energy technologies.The European Commission defines the maturity of a technolo

181、gy in terms of Technology Readiness Level(TRL),where TRL 1 has basic principles outlined,and TRL 9 represents an actual system proven to work in an operational environment and therefore ready for commercialisation30.For each of these stages,the Strategic Research&Innovation Agenda(SRIA)published wit

182、hin the scope of the ETIPOcean31 platform(ETIPOcean,2020)has identified technological challenges and priority topics for the next four to five years that will increase the reliability,availability,maintainability and survivability of ORE devices(see Section 3.1.5).ENERGY TYPECAPACITY FACTOR ESTIMATE

183、D ANNUAL ENERGY PRODUCTION TECHNICAL POTENTIALESTIMATED LEVELISED COST OF ELECTRICITY (The average absorbed power(or electricity)divided by the maximum power(or electricity)that a device can produce)(TWh/year)(Average cost of generating electricity over the generation lifetime,$US/kWh)Offshore wind0

184、.3-0.64,000-37,0000.08Wave energy0.25-0.325,5601.46Tidal current0.5-0.7150-1,2000.2-0.9Floating solar0.1-0.39,00028 0.06-0.1129 Thermal gradient0.9-0.9583,4000.03-0.38Salinity gradient0.8-0.841,6500.11-2.37Table 2.1 Indicative comparison of different ORE resources.Sources:(Bhuiyan et al.,2022;IPCC,2

185、011;IRENA,2020a;Langer et al.,2020;Newby et al.,2021;Oliveira-Pinto&Stokkermans,2020;Yang et al.,2022)EMB FUTURE SCIENCE BRIEF20ORE technologies have reached different stages in their development:Offshore wind energy is mature and in commercial operation(TRL 9),with floating wind in a pre-commercial

186、 phase(TRL 8);Wave energy is at full-scale prototype phase(TRL 7);Tidal current energy is in the demonstration phase with pilot projects(TRL 6);Tidal range energy is mature and in commercial operation(TRL 9);Offshore or floating solar energy is in early demonstration phase(TRL 5).2.2.1 Offshore wind

187、 turbines Wind turbines convert wind energy to kinetic energy via a rotating turbine,and then to electricity directly or via a drivetrain(i.e.the components that transfer the power from the moving blades to the generator)and a generator.Offshore wind development has significantly benefitted from the

188、 experience gained from onshore wind turbine technologies and operations.In particular,the standardisation of commercial systems towards a design with three-bladed horizontal axis turbines which face the wind(upwind)that can change the angle of the blade to the wind(pitch-controlled)and operate at d

189、ifferent rotation speeds(variable-speed)has been an important offshore wind development during the past 20 years.Wind turbines are designed to operate in different wind speeds,such that maximum power efficiency is achieved by adjusting the rotation speed for wind speeds lower than predicted average

190、speed.A controlled power output is obtained by pitching the blades for wind speeds higher than the rated value,i.e.the wind speeds at which it is designed to operate.Turbine technology is very mature,and modern turbines feature aerodynamically efficient blades,cost-effective blade and tower structur

191、al designs and robust turbine control systems.Traditionally offshore wind turbines and electrical blades are made of composite materials(e.g.fibreglass and polyester,or fibreglass and carbon),whereas bottom-fixed and floating support structures,towers,moorings,and anchors are made of metal(steel,alu

192、minium)or concrete.Drivetrains,generators,and power cable components also include critical minerals and rare earth metals.Moving from land to offshore shallow water areas(with water depth of 0-20m),then into intermediate water depths(20-60m),and finally towards deep water areas(with water depth grea

193、ter than 60m),has required the development of different foundations to support the wind turbines.As shown in Figure 2.4,foundations for shallow or intermediate waters are typically bottom-fixed,and include designs such as monopiles,tripods,jackets,foundations with suction buckets and gravity-based s

194、tructures.Such technologies are mature and have been widely developed,especially monopile foundations,which are the most used foundations in current offshore wind farms because they are simple to design and install.Factors such as water depth,seabed type and possible environmental impacts influence

195、the choice of foundation.Gravity base foundations are used for depths up to 10m,monopiles are economic for water depths of 2040m,and jacket foundations are considered competitive for water depths up to 70m.For deeper offshore areas,bottom-fixed foundations become too large and expensive(Jiang,2021),

196、and floating wind turbines become more economically feasible.These floating turbines are anchored to the seabed via mooring lines and have spar,semi-submersible or tension leg platform designs,as shown in Figure 2.4.In recent years,floating wind turbines have gained significant interest not only fro

197、m a research perspective,but also in pre-commercial development.Pilot demonstrators of spar and semi-submersible floating wind turbines already deployed at sea include Hywind Scotland32 and WindFloat33 as shown in Figure 2.5.However,no tension leg platform floating wind turbine prototypes have yet b

198、een tested at sea,because of the complexity and the high cost for transport and installation.A list of existing and planned prototypes of floating wind turbines can be found in the Carbon Trust Joint Industry Project report(Strivens et al.,2021).Credit:Left:(Puruncajas et al.,2020),CC BY 4.0;Right:(

199、Manzano-Agugliaro et al.,2020)CC BY 4.0.Figure 2.4 Left A:Illustrations of bottom-fixed foundations for offshore wind turbines.Right B-D:Floating foundations for offshore wind turbines,B:Spar;C:Semi-submersible;D:Tension leg Platform.CBD32 https:/ 33 https:/ 9 202321Credit:A:Equinor;B:Photo courtesy

200、 of Principle PowerBoth bottom-fixed and floating structures have been extensively deployed at commercial scale by the oil and gas sector,leading to the availability of relevant experience and expertise.However,offshore wind turbine foundation and support structure designs have different requirement

201、s to those of oil and gas installations,and therefore new skills need to be developed.Moreover,design analysis methodologies for offshore oil and gas installations may not translate directly to ORE.In the recent Scotwind34 offshore wind leasing process,60%of the 24GW of projects for which bids were

202、submitted related to floating as opposed to fixed offshore wind.Floating offshore wind is expected to account for between 100-150GW of the targeted 450GW offshore wind capacity for 2050(WindEurope,2020).Although most wind turbines in commercial offshore wind farms today are Horizontal Axis Wind Turb

203、ines,proposals have also been made for Vertical Axis Wind Turbines(VAWTs)(Arredondo-Galeana&Brennan,2021)(Figure 2.6).VAWTs can lower the centre of gravity of the turbine,which is beneficial for the stability of floating wind turbines.Two contra-rotating VAWTs are currently under investigation at th

204、e IFREMER test site(Matoug et al.,2020).However,further development of VAWT designs to maximise efficiency and address issues with reliability is needed before they can be commercialised.According to IRENA(2020a),the global offshore wind sector received$US 25.7 billion in investment in 2018(i.e.20%o

205、f the total for wind energy).In the same year,China led the way with offshore projects worth$US 11.4 billion,with European projects valued at$US 3.3 billion.Cost reduction is the major driver for the further development of the offshore wind industry and is particularly sensitive to the choice of fou

206、ndations for a given water depth.Recently power delivery by offshore turbines have been scaled up through improvements in design,efficiency and adaptation to the available resource.Typical modern turbines have a power rating of eight to ten MW,up to 14MW.Offshore development facilitates the deployme

207、nt of increasingly larger turbines because of the feasibility to transport such turbines by ship(as opposed to road for onshore development).However,the operation and maintenance(O&M)costs for offshore wind installations are much higher than on land:23%of total investment cost over the project lifet

208、ime vs 5%on land(Ren et al.,2021).One of the bottlenecks for future development lies in the design and manufacture of cost-effective ultra-large turbines(rated power exceeding 20MW):further research and development are needed on new blade materials and design optimisation.2.2.2 Wave energy converter

209、s A wave energy converter(WEC)is a device that converts energy from surface waves to electricity.As shown in Figure 2.7,there are three basic WEC types(Falco,2010)which can be sub-classified into:Oscillating water column(OWC)devices which utilise the air pressure difference caused by the wave-induce

210、d water surface up-down movement.The advantage of this type of device is that the air turbine is located above sea level,which reduces damage from corrosion and fouling.However,these devices need to be able to operate in two directions to account for the up-down movement,making them less efficient t

211、han one-directional devices;Overtopping devices which collect the water that spills into a device as the waves pass and then passes in through a turbine to generate energy;and Oscillating bodies which utilise the relative motions between a floating structure and a reference body to drive a generator

212、 and produce energy.34 https:/ 2.5 A:Hywind Scotland spar floating wind turbine;B:WindFloat Atlantic semi-submersible floating wind turbine.ABEMB FUTURE SCIENCE BRIEF22Credit:Sandia National LaboratoriesFigure 2.6 Comparing horizontal-and vertical-axis wind turbines.Credit:(Syarif Arief et al.,2020)

213、CC BY 4.0Figure 2.7 Types of wave energy converters.BuoyWells turbineand generatorCementstructuredirectionPrincipal waveLineTranslatorSpringsStatorSea Water InWaterImpoudmentEnd stopAir flowAir columnLow HeadA.Oscillating Water Column(OWC)C.Oscillating Bodies(OB)B.OvertoppingN 9 202323Since the 1980

214、s,there have been many different types of WEC concepts that have been studied theoretically,numerically and experimentally at model and even prototype scale.WECs have not yet been developed at commercial farm scale,although there are ongoing developments of several concepts towards commercialisation

215、,notably the oscillating body CorPower device35(see Figure 2.8)and Oscilla Powers Triton-C wave energy system36.Unlike the wind energy industry,which has converged on a small number of turbine designs,the wave energy industry is still exploring a wider range of approaches to both absorb the energy f

216、rom the waves and transform this energy into electricity.Theories,numerical methods/models,and model-scale experimental studies to quantify the hydrodynamics,power efficiency and to some extent the survivability of proposed WECs have been very well developed for conceptual studies.However,up to 2017

217、,most of the WEC prototypes had short testing periods or failed due to survivability issues(European Commission,2017a).The challenge to develop pre-commercial prototypes is not unique to wave energy and is faced by all other types of ORE development,except offshore wind.The industry is aware of this

218、 barrier,and is developing technology for high efficiency energy capture,reliability and survivability in extreme weather conditions and advanced control technologies.In recent years,large-scale WEC prototypes of 100-500kW have been developed and tested at sea(OES,2021b).Experiences from testing the

219、se prototypes are invaluable to better understand power performance(helping to validate simulations),fabrication,operation,technological optimisation and potential areas for cost reduction.As noted by ETIPOcean(2020),it is important to extensively test these devices,their foundations and moorings,in

220、 real sea conditions to learn more and eventually advance their TRL.Some representative examples are listed below and shown in Figure 2.8:In 2020,Chinas Guangzhou Institute of Energy Conversion(GIEC)installed a 500kW WEC,a variant of the oscillating body type,called Sharp Eagle,which consists of a s

221、emi-submersible floater and a hinged double floating body37;In 2019,Finlands AW-Energy Ltd installed the 350kW WaveRoller,a bottom-hinged surface-piercing flap-type WEC and a variant of the oscillating body type,in Portugal38;In 2021,Wave Swell Energy installed a 200kW WEC oscillating water column d

222、evice,the UniWave200,in Tasmania,Australia39;In 2021,Mocean Energy installed a 10kW prototype WEC(Blue X)at the European Marine Energy Centre(EMEC)test site in Orkney,UK40;In 2021,Oscilla Power tested the 100kW Triton-C point absorber WEC,at the US Navy Wave Energy Test Site in Hawaii41;In 2022,Swed

223、ens CorPower Ocean began testing a full-scale 300kW oscillating body type WEC C4 point absorber device,which has a unique wave spring design that allows the WEC to be more efficient in different wave frequencies42;and In 2022,the Waveswing WEC,a 16kW submerged wave power buoy using a direct-drive ge

224、nerator,was deployed at the EMEC test site.The trials will be repeated in early 202343.35 https:/ https:/ https:/ 38 http:/aw- 39 https:/ https:/www.mocean.energy/blue-x-device-removal/41 https:/ 42 https:/ https:/ Swell Energy;C:CorPower Ocean Figure 2.8 Wave energy converter prototypes.A:AW-Energy

225、s WaveRoller;B:Wave Swell Energys UniWave device;C:An artists impression of a CorPower C4 wave farm.BCAEMB FUTURE SCIENCE BRIEF242.2.3 Marine turbines Marine turbines are devices that are used to extract energy from tidal currents(tidal current turbines)and tidal ranges(where turbines form part of t

226、he system with a tidal barrage or tidal lagoon)as shown in Figure 2.9.Marine turbines are completely submerged in seawater,giving rise to challenges in material selection and design of blades,corrosion,installation and O&M.These challenges arise due to the large current speeds,as well as the waves i

227、n these locations and the large forces that these will exert on the turbines,low visibility underwater affecting maintenance,the inherently damaging nature of salt water and biofouling effects(Stringer&Polagye,2020).Tidal current turbines operate in seawater but have similarities to wind turbines in

228、 that they possess blades,drivetrains and support structures.Marine turbines require far smaller rotor diameters than wind turbines to achieve the same power output,as seawater is much denser than air.Different configurations and prototypes of tidal turbine designs have been developed and MW-size tu

229、rbines have been tested at sea recently(OES,2021a),representing a significant step towards commercialisation.Credit:Zoeck,based on original by The Asean PostFigure 2.9 Methods for generating electricity from the tides:A:tidal current,B:tidal barrage,C:tidal lagoon.Low tideOcean floorTidal flowGenera

230、torTurbine bladesWater flowStored waterACBN 9 202325Several examples of devices are listed below and shown in Figure 2.10:In 2016,Nova Innovation installed the worlds first offshore tidal energy array,the Shetland Tidal Array,at Bluemull Sound in Shetland(see Section 3.1.1);In 2018,SIMEC Atlantis En

231、ergy44 developed and installed four 1.5MW three-blade bottom-mounted tidal turbines in the MeyGen array in Pentland Firth,UK.This is the largest planned multi-phase tidal current project in the world,and the only commercial multi-turbine array currently in construction;In 2019,HydroQuest45 installed

232、 a 1MW tidal current turbine with a dual vertical contra-rotating axis in France,which was in operation for testing for two years until October 2021;In 2019,Magallanes Renovables46 tested a 45m long floating platform equipped with two 1.5MW rotors at the European Marine Energy Centre(EMEC)in Orkney,

233、UK;In 2021,Orbital Marine Power47 installed and tested a 72m long floating tidal turbine platform with two 1MW turbines at the same site in Orkney;In 2022,Sustainable Marine tested the grid-connected 420kW PLAT-I 6.40,equipped with six 70kW instream turbines at the Grand Passage/Bay of Fundy,Canada4

234、8;and In 2022,Sabella installed and connected its D10 turbine to the Ushant Island grid in Brittany,France.The turbine has been providing electricity since then.Assessment of the production over the first eight months showed that the turbine has a capacity to cover up to 49%of the islands electricit

235、y consumption49.44 https:/ https:/www.hydroquest.fr/en/tidal-turbines-services/46 https:/ https:/ https:/ 49 https:/www.sabella.bzh/sites/default/files/upload/communiquePresse/20221201_-_pr_d10_power_curve_certified_en.pdfCredit:A:Nova Innovation;B:SIMEC Atlantis Energy;C:Magallanes Revovables;D:Orb

236、ital Marine PowerFigure 2.10 MW-size tidal turbine prototypes.A:Shetland Tidal Array device;B:MeyGen Array device;C:Assembling the main structure of the Magallanes Renovables device;D:Orbital Marine Power device.ACBDEMB FUTURE SCIENCE BRIEF26A detailed review of energy storage solutions suitable for

237、 tidal currents is given by Zhou et al.,(2013).Tidal barrages are dam-like structures that are built across the mouth of a bay or river.However,unlike a dam,they allow water to flow in and out through the structure.The water flows into the bay or river at high tide,via turbines located within the ba

238、rrage structure,and flows back out at low tide,again via the turbines,generating electricity in both directions.Tidal barrages are still the most powerful ORE systems,with notable examples being the La Rance tidal plant50 in France(240MW)and the Sihwa Lake tidal plant51 in Korea(254MW).Some smaller

239、multi-MW tidal plants also exist in China and Russia,and smaller systems are also being considered for local needs in Small Island Developing States(SIDS)(OES,2020).However,the construction of tidal barrages can have significant environmental impacts in the wider area on benthic habitats,fish and ma

240、mmal passage and migration,phytoplankton dynamics and bird communities(Frid et al.,2012;Retiere,1994).Due to the variable nature of the water height during a tidal cycle,there are different configurations of the turbine at the various stages.Also,energy must be extracted from flows in both direction

241、s.Both of these factors drastically decreases the efficiency(or increases the cost)of the turbine and overall system.Tidal lagoons are an alternative means of extracting energy from tidal ranges.Tidal lagoons are complete enclosures within highly tidal areas and are artificially created(rather than

242、a straight structure across an existing bay or river).As with tidal barrages,they use a dam-like structure,a small section of which contains turbines,and extract energy both while the tide is rising and falling.An example is the proposed Swansea Bay Tidal Lagoon in the UK(Petley&Aggidis,2016)52,whic

243、h has yet to be permitted because of concerns regarding its potential environmental impacts(Elliott et al.,2018).2.2.4 Floating solar energy platforms Soler energy is extracted using solar panels,or photovoltaics(PV).Onshore solar energy is one of the cheapest renewable energy resources.Floating sol

244、ar PV have been implemented on lakes and reservoirs,where wave action is very limited.In such applications,plastic floating structures are connected to steel frames that support the solar PV panels.An example is the worlds first floating solar PV farm in Singapore,developed by Sembcorp Tengeh53(see

245、Figure 2.11).Other concepts have been proposed and prototypes developed for deployment in sheltered coastal areas with a mild wave climate,such as OceanSun54 developed in Norway.In seas with relatively high waves,the previously mentioned systems struggle with survivability due to their flexibility a

246、nd the large forces exerted by waves.More solid floating platforms,made of steel or concrete,are needed to support the PV panel deck,such as the concept developed by Equinor and Moss Maritime for sea trials in 202255.However,to make these systems commercially viable,a very large Ocean surface area n

247、eeds to be covered with solar panels to produce sufficient power,which presents considerable design and spatial planning challenges.Moreover,there is limited experience in other offshore sectors of designing,mooring,and operating such large floating structures,and doing so in a cost-effective way.Th

248、ese challenges,along with technological challenges linked to e.g.clouds and other coverage issues,the cost of movable panels(for permanent optimal orientation),and the deterioration of the materials in the marine environment,will need to be overcome to develop floating coastal and offshore solar PV

249、commercially.A review of projects related to onshore and offshore solar energy up to 2013 is provided by Trapani&Santaf(2014),with more recent overviews of offshore solar installations presented by Vo et al.,(2021)and Yousuf et al.,(2020).Credit A:Ocean Sun Floating PV,patented;B:moss maritimeFigure

250、 2.11 Floating solar PVs.A:OceanSun floating solar PV;B:Offshore floating solar concept by Equinor and moss maritime.AB50 https:/tethys.pnnl.gov/project-sites/la-rance-tidal-barrage 51 https:/tethys.pnnl.gov/project-sites/sihwa-tidal-power-plant 52 http:/ https:/.sg/business/energy-solutions/solar/f

251、loating-solar/54 https:/oceansun.no/55 https:/ 9 202327Credit:Floating Power Plant A/SFigure 2.12 Hybrid wind-wave energy system,Floating Power Plant P37 system.56 https:/www.pelagicpower.no/57 https:/ https:/ https:/webgate.ec.europa.eu/maritimeforum/en/node/547260 https:/euscores.eu/2.3 Integrated

252、 use of offshore renewable energy Most ORE devices will require a large Ocean area for commercial development and therefore it is natural to investigate the synergy of different devices,co-located at the same site,in terms of efficient Ocean space and infrastructure use and complimentary power produ

253、ction.Combined systems are typically divided into two main types:co-located and hybrid.Co-location consists of deploying independent systems(e.g.separate wind and wave devices,or floating wind and solar devices)at the same site,while hybrid systems combine different ORE technologies on the same plat

254、form.Different combinations of ORE technologies have been proposed and designed:wind-wave,wind-solar,wind-tidal,wave-solar as well as wind-solar-tidal-wave.An analysis by Soukissian et al.,(2021)regarding the hybrid exploitation of offshore wind and solar energy in the Mediterranean Sea identified t

255、he Aegean and Alboran Seas as areas with high potential and low variability for both resources,with the Gulfs of Lion,Gabes and Sidra,the Aegean Sea,and Northern Cyprus also appearing feasible.Overall,the hybrid exploitation of offshore wind and solar energy in the Mediterranean Sea seems promising.

256、There are also investigations looking at placing electrolysers for hydrogen production in situ with the different ORE devices,as it may be more efficient to transport hydrogen back to land than electricity.However,no commercial concepts have been developed for any of these systems yet.Hybrid platfor

257、ms are only as mature as their least mature components(e.g.those with the lowest TRL),which poses a challenge in terms of the viability of the systems,meaning that extensive prototyping and demonstration at sea is required to increase TRL.There are limited examples of hybrid platform developments.Pe

258、lagic Power in Norway56 developed the W2Power hybrid wind-wave energy system as a semi-submersible platform,combining two wind turbines and multiple oscillating body WECs.The platform has so far achieved TRL 6 through deployment in open sea58.The company Floating Power Plant58 developed the Poseidon

259、 Wave and Wind system,and a 37m scale model(called P37,see Figure 2.12)equipped with ten 3kW oscillating body and oscillating water column WECs and three 11kW wind turbines.It was tested off the Danish coast between 2008 2013,and using findings from the tests,work is now ongoing to develop and deplo

260、y an improved commercial level(TRL 7)design59.The company also expects to launch a platform combining wind and wave energy with hydrogen storage in 2025.The EU-SCORES project60,funded under Horizon 2020,will consider co-located devices,and present the benefits of continuous energy production with sm

261、all space requirements via complementary energy sources(wind,sun and waves).The project will organise two demonstrations in Europe:An offshore PV system co-located with a bottom-fixed wind farm in Belgium,and a wave energy array co-located with a floating wind farm in Portugal.The project runs from

262、2021-2025.EMB FUTURE SCIENCE BRIEF283.1 European policies and aims Policy for offshore renewable technology in the European Union is driven by the European Green Deal and its objective to reach carbon neutrality by 2050.Non-EU countries,such as Norway61,the UK62 and Switzerland63,have different appr

263、oaches on the extent to which they abide by the requirements and/or sentiments of the Green Deal.However,to ensure sustainable development,the development of the sector will need to be in accordance with both carbon and biodiversity targets,and will also be influenced and shaped by policies which ma

264、nage maritime spatial planning,grid connectivity and other sectors.The European Union has several policy instruments that specifically concern the impact of human activities on the state of coastal and marine environments.Relevant EU Directives and legislation for offshore renewable energy(ORE)are p

265、resented in Figure 3.1.A full list of EU policy instruments that relate to ORE are presented in Annex 2.Credit:Updated from(Benedetti-Cecchi et al.,2018)Figure 3.1 Key EU Directives regarding the seas and Ocean,where GES=Good Environmental Status,MPAs=Marine Protected Areas,QS=Quality Status,RFMO=Re

266、gional Fisheries Management Organisation,IUU=Illegal,Unreported and Unregulated fishing,SPAs=Special Protection Areas,SAC=Special Areas of Conservation,SCI=Sites of Community Importance.3Review of European offshore renewable energy status In recent years,Europe has maintained its pledge to become a

267、world leader in renewable energy,through policy instruments and by promoting technology development,especially in light of the 2015 Paris Agreement.This chapter presents the European Unions vision regarding offshore renewable energy,as well as the current and planned status of different offshore ren

268、ewable energy installations in European waters.GESDescriptorsEcosystem approachMPAsMarineStrategyFrameworkDirective(2008)ProtectionBiodiversityRestorationNaturerestorationlaw(2022)European environmentalDirectives andlegislationCharacterizationClassifcationReview of QSWaterFrameworkDirective(2000)Pro

269、tectionSPAs500 Wild SpeciesBiodiversityHabitat and SpeciesConservationSCI/SACHabitatsDirective(1992)Natura 2000(1992)BirdsDirective(1979)DecarbonisationHydrogenOREGreanDeal(2019)SustainabilityFisheriesAquacultureCommnonFisheriesPolicy(2014)Ocean governanceRFMOIUUInternational roleBlue growthSea spac

270、e useInteractionssea-landMaritimeSpatialPlanning(2014)61 https:/www.regjeringen.no/contentassets/38453d5f5f5d42779aaa3059b200a25f/a-european-green-deal-norwegian-perspectives-and-contributions-20.04.2021.pdf 62 https:/www.chathamhouse.org/2020/02/what-european-green-deal-means-uk 63 https:/www.eda.a

271、dmin.ch/missions/mission-eu-brussels/en/home/key-issues/enviroment-climate.htmlN 9 20232964 https:/www.europarc.org/european-policy/eu-biodiversity-strategy-protected-areas/eu-2030-biodiversity-strategy/65 https:/environment.ec.europa.eu/topics/nature-and-biodiversity/nature-restoration-law_en66 htt

272、ps:/www.msp-platform.eu/msp-eu/introduction-msp3.1.1 Marine Strategy Framework Directive The most comprehensive European Ocean-related Directive is the Marine Strategy Framework Directive(MSFD)(European Parliament and the Council of the European Union,2008).The MSFD lists eleven Descriptors of Good

273、Environmental Status(GES),and embraces the ecosystem approach,recognising the paramount importance of biodiversity and ecosystem functioning.Descriptor 1 prescribes that biodiversity is maintained.Descriptors 2-11 consider a series of impacts arising from human activities and require that they do no

274、t cause significant harm to ecosystem functioning.The installation and operation of ORE must thus respect these prescriptions.3.1.2 Biodiversity Strategy and Nature Restoration Law In May 2020,the European Commission(EC)published a Communication on the Biodiversity Strategy to 2030(European Commissi

275、on,2020c).The strategy outlines the need to address the significant biodiversity loss that has been witnessed over the last four decades.The Communication recognises that“more sustainably sourced renewable energy will be essential to fight climate change and biodiversity loss”.It also states that th

276、e“EU will prioritise solutions such as ocean energy,offshore wind,which also allows for fish stock regeneration”.However,the Communication also calls for 30%of the sea to be protected and at least 10%of EU seas to be strictly protected.Currently 19%of EU waters are protected,and only 1%strictly prot

277、ected64.Member States have until the end of 2023 to demonstrate significant progress in legally designating new protected areas and integrating ecological corridors.Member States should also effectively manage all protected areas,defining clear conservation objectives and measures,and monitor them a

278、ppropriately.These requirements will add to competition for Ocean space and impact the selection of viable locations for ORE installations.There are,however,potential opportunities to be considered e.g.in relation to co-location of Marine Protected Areas(MPAs)and ORE sites.In 2022,the EC proposed a

279、new Nature Restoration Law65 aiming to restore ecosystems,as a key component of the Biodiversity Strategy.This Law,if approved,would require Member States to develop nature restoration plans to“cover at least 20%of the EUs land and sea areas by 2030,and ultimately all ecosystems in need of restorati

280、on by 2050.”In relation to ORE,the EC highlights the importance of considering the aims and requirements,including for Ocean space,of other relevant Directives(outlined in this Section),and recommends mapping areas ideal for ORE installations,while ensuring that their impact would be low and that ar

281、eas assigned for protection or restoration are avoided.3.1.3 Maritime Spatial Planning Spatial planning has been introduced as a tool to manage the use of marine space,creating synergies between different activities.There are two differing terminologies that are often used:Marine Spatial Planning an

282、d Maritime Spatial Planning(both abbreviated as MSP).Based on the UNESCO approach,Marine Spatial Planning mainly considers the development,conservation and promotion of marine biodiversity and ecosystem functioning.Maritime Spatial Planning,as used by the European Commission,involves all human use o

283、f the Ocean and seas,e.g.fishing,aquaculture,mining,transportation(from ships to pipelines),tourism and leisure and the installation of infrastructure such as ORE platforms(Ehler et al.,2019).We use the EC approach,which considers marine and maritime as synonyms66 since Maritime Spatial Planning sen

284、su EC merges the natural aspects with human uses.This should result in a holistic approach that nests maritime activities into the natural world,and the term MSP in this case is used to cover both aspects.The EU MSP Directive(European Parliament and Council,2014)was adopted in 2014 in response to th

285、e high and rapidly increasing demand for Ocean space for different purposes,including ORE installations.Member States are supported in producing national plans for their waters(e.g.via an expert group who provides advice,and in cross-border cooperation),which should include the placement of all OREs

286、 and other spatial uses of the marine environment and must be reviewed at least once every 10 years.3.1.4 European Green Deal and Offshore Renewable Energy Strategy The production and use of energy accounts for more than 75%of the EUs greenhouse gas emissions(European Commission,2019).Decarbonising

287、the EUs energy system is therefore critical.The EU Green Deal focuses on three key principles for the clean energy transition:1.Ensuring a secure and affordable EU energy supply;2.Developing a fully integrated,interconnected and digitalised EU energy market;and3.Prioritising energy efficiency,improv

288、ing the energy performance of buildings and developing a power sector based largely on renewable sources.In 2021,the installed offshore wind capacity of Europe was 28.33GW(see Figure 3.2),of which 15.59GW was in EU Member State waters(WindEurope,2022b).Installed Ocean energy capacity in European wat

289、ers was 11.5MW for wave and 1.4MW for tidal current(OEE,2022).The Offshore Renewable Energy Strategy(European Commission,2020b),which is part of the Green Deal,outlines what the EU considers to be realistic and achievable objectives to contribute to its climate neutrality vision.This includes a requ

290、irement to increase capacity in European waters to:At least 60GW of installed offshore wind and 1GW of installed Ocean energy in 2030;and At least 300GW of installed offshore wind and 40GW of installed Ocean energy in 2050.EMB FUTURE SCIENCE BRIEF30This requires an approximate 30-fold increase in OR

291、E capacity by 2050,divided into a 25-fold increase in wind energy capacity,and over 3000-fold increase in Ocean energy capacity.The current national targets as expressed in the Member States National Energy and Climate Plans(NECPs)suggest that this can be achieved.However,as discussed in Chapter 2,t

292、he renewable energy resource is not equally distributed,and therefore a regional approach will be needed,considering the available potential and specific capacities of each European sea basin.Individual technologies will also need to be adapted for different regions and support infrastructure consid

293、ered(e.g.in terms of grid connections).In its Offshore Renewable Energy Strategy,the EC also addresses broader issues,such as:Access to sea-space;Industrial and employment dimensions;Regional and international cooperation;and The technological transfer of research projects from the laboratory into p

294、ractice.National governments and authorities must plan for this long-term European evolution,assessing Member States environmental,social and economic sustainability,and ensuring coexistence with other maritime activities,while remaining compatible with other EU policies,strategies and Directives.To

295、 ensure progress towards EU climate neutrality in 2050,negotiations are ongoing around a proposed intermediate Fit for 55 package67 of measures,first published in 2021,which intend to reduce emissions by at least 55%by 2030.This package includes plans to further boost the share of European renewable

296、 energy by 203068.It also revises climate and energy legislation to reduce the reliance on fossil fuels and to expand the use of renewable energy sources(among others).In this respect,the EC is proposing a more ambitious target for the renewable energy share of 40%by 2030 instead of 32%.In response

297、to the economic and geopolitical challenges in Europe,the EC adopted the REPowerEU Plan69 in 2022.This plan aims to both reduce European reliance on Russian fossil fuels and address climate change.For renewable energy,this plan calls for increased acceleration of the energy transition,further increa

298、sing the ambitions set out in the Fit for 55 Package.In September 2022,the European Parliament voted to increase the renewable energy share target to 45%and added a sub-target requiring that 5%of all new renewable energy capacity installed in Europe should be from innovative sources,including Ocean

299、energy70.At the time of writing,negotiations on these targets are ongoing between European bodies.Credit:WindEuropeFigure 3.2 European offshore wind farms map71.67 https:/www.consilium.europa.eu/en/policies/green-deal/fit-for-55-the-eu-plan-for-a-green-transition/68 https:/www.consilium.europa.eu/en

300、/infographics/fit-for-55-how-the-eu-plans-to-boost-renewable-energy/69 https:/ec.europa.eu/commission/presscorner/detail/en/IP_22_3131 70 https:/www.oceanenergy-europe.eu/strong-support-for-innovative-renewables-must-continue-into-next-stage-of-red-iii-negotiations/71 https:/windeurope.org/intellige

301、nce-platform/product/european-offshore-wind-farms-map-public/N 9 20233172 https:/energy.ec.europa.eu/topics/research-and-technology/strategic-energy-technology-plan_en 73 https:/setis.ec.europa.eu/set-plan-progress-report-2021_en 74 https:/www.eera-set.eu/75 https:/etipwind.eu/76 https:/www.etipocea

302、n.eu/3.1.5 European governance initiatives There are several additional European governance initiatives which relate to the development of ORE.The 2007 European Strategic Energy Technology Plan72(SET Plan)is a European initiative to accelerate the development and deployment of low-carbon technologie

303、s,through cooperation amongst EU countries,companies,research institutions,and the EC.In relation to ORE,implementation plans have been developed for offshore wind,Ocean energy,integrated energy systems and High Voltage Direct Current(HVDC).Annual reports have been published on the progress of the i

304、mplementation plans since 2019,with the most recent report being from 202173.In parallel to the launch of the SET Plan,the European Energy Research Alliance74(EERA)was created to align the research and development activities of individual research organisations with the SET Plan priorities and to es

305、tablish a joint programming framework at EU level.EERA operates using joint programmes on technologies and cross-cutting issues including Ocean and wind energy,as well as energy storage.European Technology Innovations Platforms(ETIPs)are industry-led stakeholder Platforms recognised by the EC as key

306、 actors for driving innovation,knowledge transfer and European competitiveness in their sector.ETIPs develop research and innovation agendas,and roadmaps for action at EU and national levels to be supported by both private and public funding.They mobilise stakeholders to actively contribute to the a

307、greed priorities and share information across the EU.There are ETIPs dedicated to both wind75 and Ocean energy76,which have worked to support the SET Plan and have identified research priorities and roadmaps for these technologies.3.2 Overview of offshore renewable energy implementation and capacity

308、 in Europe This section will present an overview of the present and planned capacity of ORE in European waters.Related enablers and infrastructure(e.g.grid connectivity)are discussed in Chapter 6.3.2.1 Mature technologies Mature ORE technology installations are those at TRL 6-9,including offshore wi

309、nd,tidal current and range,and wave energy.Offshore wind According to WindEurope(2022a),by mid-2022 there was 28,363MW installed offshore wind capacity in Europe(with 30MW installed in early 2022),corresponding to 123 offshore wind farms with 5,795 grid-connected wind turbines.Only 103MW(0.36%)of th

310、is total installed capacity involved floating offshore wind farms.However,this represents 83%of floating wind capacity globally,indicating the relative immaturity of this sector and the ongoing dominance of Europe in offshore renewable energy installation,including for floating wind installations.Cr

311、edit:European Marine BoardSea Installer vessel loaded with offshore wind turbine towers and blades in Ostend,Belgium.EMB FUTURE SCIENCE BRIEF32In Europe as of June 2022(WindEurope,2022a),the UK lead in offshore wind production,with a cumulative capacity of 12,739MW(i.e.the total of all the capacity

312、that has at some point been installed,including some devices that have since been removed from the water),and 2,542 grid connected wind turbines.The UK is followed by Germany(7,713MW and 1,501 turbines),the Netherlands(2,986MW and 599 turbines),Denmark(2,308MW and 631 turbines)and Belgium(2,261MW an

313、d 399 turbines).These countries represent 99%of the total installed capacity in Europe.The North Sea hosts almost 20GW(79%of the total offshore wind capacity in Europe),followed by the Irish Sea(12%),the Baltic Sea(9%),and the Atlantic Ocean(1%).The dominance of northern European seas in offshore wi

314、nd energy production is due to a combination of factors including wind resource availability,and the fact that these regions have shallower waters which enable easier installation.Although the oceanographic and atmospheric conditions and the seafloor geomorphology in the Mediterranean Sea are quite

315、different from the northern European seas,the available wind potential is significant.The first operational(since April 2022)offshore wind farm in the Mediterranean Sea is located off the Italian Puglia coast.It comprises 10 wind turbines each with a nominal capacity(in optimal wind conditions)of 3M

316、W,giving a total capacity of 30MW77.However,ORE developments in the Mediterranean Sea are experiencing opposition on both environmental and social-economic grounds(see e.g.Lloret et al.,2022).Over the next three years,several floating offshore wind projects are expected to be commissioned including

317、four projects in France(with a total capacity 113.5MW),one in Norway(88MW)and one in the UK(50MW).Three of the floating projects in France will be in the Mediterranean Sea with a total capacity of 85MW.Tidal current and range,and wave energy According to Ocean Energy Europe(OEE,2021),the cumulative

318、tidal current energy potential(i.e.the total capacity of all tidal current devices that have been installed,even if some of them have now been removed,operating at their maximum in ideal conditions)installed in Europe since 2010 is 27.9MW,which is nearly 77%of the global cumulative installed potenti

319、al of 36.3MW,showing European leadership.By the end of 2020,10.1MW was still deployed in European waters,with other installations having been decommissioned.The corresponding figures for wave energy are 12MW cumulative energy potential in Europe(51%of the global cumulative installed potential of 23.

320、3MW)and 1.1MW of capacity still installed in 2020.These figures indicate the lower maturity of tidal current and wave energy,with most devices being installed for limited durations to facilitate testing and prototyping,rather than in permanent commercial farms.In 2021,a major advance in tidal curren

321、t energy was achieved through the deployment of O278:the worlds largest tidal turbine(2MW capacity),by Orbital Marine Power in the Orkney Islands,UK.Another Orbital turbine is scheduled to be deployed in the same area in combination with a hydrogen production facility and a battery system within the

322、 scope of the EUs Horizon 2020-funded FORWARD2030 project79.In another relevant Horizon 2020-funded project,EnFAIT80(Enabling Future Arrays in Tidal),Nova Innovation has installed a commercial turbine as part of the tidal array deployed in Shetland,as noted in Section 2.2.3.At present there are only

323、 two operational tidal range energy plants in Europe:La Rance tidal barrage in France,and a smaller scale tidal range power plant(of 1.2MW capacity)installed in Oosterschelde in the Netherlands(see Figure 3.3).Credit:European Marine BoardFigure 3.3 Oosterschelde tidal range power plant in the Nether

324、lands.77 https:/www.offshorewind.biz/2022/04/22/first-mediterranean-offshore-wind-farm-up-and-running-in-italy/78 https:/ https:/forward2030.tech 80 https:/www.enfait.eu/N 9 202333Regarding wave energy,two pioneering oscillating water column(OWC,see Section 2.2.2)power plants in Europe were the 400k

325、W Pico in the Azores that was constructed in 1999 as part of a pilot project and closed in 201881,and the Mutriku 296kW plant constructed in 2011 in the Basque country which is still operational82.In 2018,a 200kW Wavepiston wave energy converter(WEC)oscillating body device was also installed in Gran

326、 Canaria,Spain as a demonstrator.This latter device will be in the water until 2023 and a second device is expected to be installed in the same area for desalination and power production purposes83.However,except for a 600kW oscillating body WEC that was deployed by Wello at the Biscay Marine Energy

327、 Platform in July 2021 and was connected to the grid84,most deployed devices are of limited capacity,many of them being sub-scale prototypes under development.The Wello device is undergoing two years of testing in real conditions to better assess its reliability and robustness.3.2.2 Technologies in

328、pilot/demonstration phaseLess mature ORE technology installations,considered at TRL 1-5,include floating solar,salinity gradient,marine biomass and hydrogen production.Floating solar energy Although floating solar parks have been installed and are operating in artificial lakes etc.in Europe,especial

329、ly in the Netherlands85,no solar park has yet been installed offshore.In 2019,the Dutch company,Oceans of Energy86,installed a pilot floating solar module in the North Sea.The system survived the harsh environmental conditions in the installation area for 18 months87.This was followed in 2022 by the

330、 installation of a 1MW system of 200 floaters 12km offshore in the North Sea88.Salinity gradient At present,European activities utilising salinity gradients are very limited.The first pilot osmotic power plant was developed by the Norwegian company,Statkraft,in 2009 but ceased operations in 2014 due

331、 to viability issues89.The first Reverse Electro Dialysis(RED)power plant(50kW)was installed in 2014 in the Afsluitdijk dam in the Netherlands(Wadden Sea)and is still operational90.Within the context of the EUs FP7 REAPower project91,a pilot-scale plant was installed in 2014 at Trapani(Italy),with 4

332、8m2 of total membrane area and one RED unit(Tedesco et al.,2016).A further scale-up(of 1kW power capacity)of the original pilot plant resulted in three RED units and 400m2 of total membrane area(Tedesco et al.,2017).The pilot plant is no longer in operation.The EU Horizon 2020 project INTELWATT92 ai

333、ms inter alia to develop an integrated pilot unit in Castellgal near Barcelona,Spain.This unit will comprise of RED and solar powered membrane distillation systems and should demonstrate a TRL of 7.Marine biomass In Europe,there are 13 countries developing macroalgae production(Arajo et al.,2021),with the top three producers being France,Ireland and Spain.Macroalgae is mostly wild harvested and us