The Future of Marine Technologies: Technology developments, key costs and the future outlook

• Publication date: January 2010

Many of the world's potential renewable energy resources are being exploited today to generate electricity. The main exception is marine energy, the energy contained in various forms in the world's seas and oceans. This situation looks set to change as the challenge of combating global warming inspires a renewed search for methods to extract marine energy from our seas. Wave power and systems that can exploit the movement of water generated by th...

Many of the world's potential renewable energy resources are being exploited today to generate electricity. The main exception is marine energy, the energy contained in various forms in the world's seas and oceans. This situation looks set to change as the challenge of combating global warming inspires a renewed search for methods to extract marine energy from our seas. Wave power and systems that can exploit the movement of water generated by the tides are attracting the most attention but methods for using the warm seas in the tropics to produce electricity and even the attempts to extract energy released when salt and fresh water mix are now coming under the gaze of scientists and technicians too. Some of the resulting technologies remain far from commercial implementation but several are now close to commercialization.
With all but tidal barrage power plants still in an early stage of development and no commercial plants of any other type in operation, assessing the economics of marine power generation technologies today depends on projections based on early prototypes of early demonstration units. Today these are generally more costly than alternative forms of power generation, both conventional and renewable. However the example of the wind power market shows that costs can fall dramatically as both technology improves and economies of scale are realized. Some early predictions suggest that some marine technologies might be cheaper than wind power but the level of uncertainty in such predictions is high.


Key features of this report


• Analysis of marine technologies concepts and components.
• Assessment of marine technologies power plant market.
• Insight relating to the most innovative technologies and potential areas of opportunity for manufacturers.
• Examination of the key technology introductions and innovations.


Scope of this report


• Realize up to date competitive intelligence through a comprehensive review of marine technologies concepts in electricity power generation markets.
• Assess the emerging trends in marine technologies – including ocean thermal energy conversion, wave power generation and tidal stream technologies, tidal barrage power plants, salinity gradient power generation.
• Identify which key trends will offer the greatest growth potential and learn which technology trends are likely to allow greater market impact.
• Compare how manufacturers are developing new marine technologies


Key Market Issues


• Environmental requirements:- The volume of fossil fuels burnt for power and heat generation have continually grown in line with economic, infrastructure and population growth. The resulting growth of carbon dioxide emissions globally has been linked to global warming and thereon climate change. Political, environmentalist and consumer pressures to lower carbon emissions is creating a path for lower carbon emitting power generation technologies.
• Ocean energy resources:- The energy that can be derived from the world's oceans and converted into electrical power comes from a number of different sources. These include daily tidal motions, the energy contained in waves, a variety of ocean and sea currents and by exploitation of both thermal and salinity gradients where these exist. Estimates for the amount of power that can be extracted from the oceans depend on assumptions about the energy content of the particular source being exploited as well as the efficiency of extraction of energy that can be achieved by an energy converter.
• Economics of clean thermal technologies:- With all but tidal barrage power plants still in an early stage of development and no commercial plants of any other type in operation, assessing the economics of marine power generation technologies today depends on projections based on early prototypes of early demonstration units.

Key findings from this report


• New types of marine power generation technologies are evolving that are designed to use freely available resources and collect energy outputting low level pollutant emissions.
• Wave power is again potentially the largest resource, with the potential to provide between 1,000GW and 10,000GW of generating capacity.
• The strongest winds and the largest waves are generally found between 30º and 60º of latitude.
• Ocean Thermal Energy Conversion technologies have among the lowest of all life cycle carbon emissions.
• Certain forms of marine technology generation are already cost competitive with alternative forms of energy generation.

Key questions answered


• What are the drivers shaping and influencing marine technology development in the electricity industry?
• What are the life cycle carbon emissions of the various marine technologies?
• What is marine technology power generation going to cost?
• Which marine technology types will be the winners and which the losers in terms power generated, cost and viability?


Companies mentioned

Global Electric Power Energy Industry

Table of Contents
The Future of Marine Technologies
Executive summary 10
Introduction 10
Ocean energy resources 10
Ocean thermal energy conversion 11
Wave power generation 11
Tidal stream technologies 12
Tidal barrage power plants 12
Salinity gradient power generation 13
The economics of marine power generation 13
The prospects for marine power generation technologies 13
Chapter 1 Introduction 16
Summary 16
Marine energy resources 17
Energy capture technologies 18
The structure of the report 20
Chapter 2 Ocean energy resources 22
Introduction 22
Global resource levels 23
Wave energy 27
Tidal power 30
Thermal gradient 32
Salinity gradient 33
Mapping marine resources 33
Chapter 3 Ocean thermal energy conversion 36
Introduction 36
Background 37
Heat engine efficiency 39
OTEC configurations 41
Open cycle OTEC 43
OTEC projects 44
Major challenges and developments 46
Environmental considerations 47
Economics 49
Chapter 4 Wave power generation 54
Introduction 54
History of wave energy capture 56
Types of wave energy capture device 57
Shore line and near shore devices 58
Oscillating water columns 58
Tapered channels and overtopping devices 59
Oscillating flaps 60
Offshore wave energy converters 61
Floats, wave pumps and swings 61
Snakes, ducks and pontoons 62
Piezo-electric converters 63
Intermittency and wave energy 63
Wave energy pilot projects 64
Environmental impact 67
Economics 68
Chapter 5 Tidal stream technologies 74
Introduction 74
Tidal stream energy 75
Tidal stream technology 78
Horizontal axis tidal stream turbines 80
Vertical axis tidal stream turbines 83
Cross flow turbines 84
Hydrofoils 84
Other tidal current systems 85
Tidal stream pilot projects 86
Environmental considerations 88
The economics of tidal stream power generation 89
Chapter 6 Tidal barrage power plants 94
Introduction 94
Tidal barrage principles 98
Bunded reservoirs and tidal lagoons 100
Tidal turbines 101
Tidal barrages 102
Seawater pumped storage 103
Tidal barrage projects 104
Environmental considerations 105
The economics of tidal barrages 107
Chapter 7 Salinity gradient power generation 110
Introduction 110
Extracting power from a salinity gradient 111
Osmotic power 111
Vapor compression 112
Hydrocratic generation 113
Reversed electrodialysis 113
Environmental considerations 114
Costs 115
Chapter 8 The economics of marine power generation 118
Introduction 118
Comparisons with wind energy 119
Installed cost of marine technologies 121
Cost of electricity from marine power generation technologies 122
Chapter 9 The prospects for marine power generation technologies 128
Introduction 128
Comparative costs of power generation 129
Wave and tidal stream power 136
Tidal barrage power plants 139
Ocean thermal energy technology 140
Salinity gradient power generation 143
Conclusions 143
Index 145

List of Figures
Figure 2.1: Ocean energy resources, (TWh/y) 24
Figure 2.2: Ocean energy potential generating capacity, (GW) 26
Figure 2.3: US wave energy potential, (TWh/y) 29
Figure 2.4: US tidal current potential, (TWh/y) 31
Figure 3.5: Theoretical OTEC efficiencies 40
Figure 3.6: Life cycle carbon dioxide emissions from OTEC plants 48
Figure 3.7: Costs for a 100MW floating OTEC plant 51
Figure 4.8: Annual wave energy content for different regions, (kW/m) 55
Figure 4.9: Estimated installation costs for wave energy converters 69
Figure 4.10: Estimated cost of electricity from wave energy plants 70
Figure 5.11: Tidal current turbine size required to sweep out a power density of 1MW at different current speeds 76
Figure 5.12: Water current power swept out by a 10m diameter turbine at different current speeds 78
Figure 5.13: Estimated installed cost ($/kW) of tidal stream generation in North America 92
Figure 6.14: Tidal reach at best global sites, (m) 95
Figure 6.15: Global tidal sites with largest energy potential 97
Figure 8.16: Cost estimates for generation in the UK (£/kW) 124
Figure 9.17: Comparative installed cost of generating technologies (£/kW), UK 131
Figure 9.18: Cost of electricity from competing technologies (£/MWh), UK 132
Figure 9.19: Levelized cost of electricity from competing technologies ($/MWh), California 134
Figure 9.20: Island states with potential OTEC 142

List of Tables
Table 2.1: Ocean energy resources, (TWh/y) 23
Table 2.2: Ocean energy potential generating capacity, (GW) 25
Table 2.3: US wave energy potential, (TWh/y) 28
Table 2.4: US tidal current potential, (TWh/y) 31
Table 3.5: Theoretical OTEC efficiencies 40
Table 3.6: OTEC plant configurations 42
Table 3.7: Life cycle carbon dioxide emissions from OTEC plants 48
Table 3.8: Costs for a 100MW floating OTEC plant 50
Table 4.9: Annual wave energy content for different regions, (kW/m) 55
Table 4.10: Types of wave energy converter 57
Table 4.11: Estimated installation costs for wave energy converters 68
Table 4.12: Estimated cost of electricity from wave energy plants 70
Table 5.13: Tidal current turbine size required to sweep out a power density of 1MW at different current speeds 76
Table 5.14: Water current power swept out by a 10m diameter turbine at different current speeds 77
Table 5.15: Types of tidal stream power generation devices 81
Table 5.16: Cost estimates for tidal stream power generation 90
Table 5.17: Economics of tidal stream generation in North America 91
Table 6.18: Tidal reach at best global sites, (m) 95
Table 6.19: Global tidal sites with largest energy potential 96
Table 6.20: Major tidal barrage power plants 104
Table 7.21: Types of salinity gradient power generation 113
Table 8.22: Marine power generation costs 121
Table 8.23: Cost estimates for generation in the UK 123
Table 9.24: Comparative installed cost of generating technologies (£/kW), UK 130
Table 9.25: Cost of electricity from competing technologies (£/MWh), UK 132
Table 9.26: Levelized cost of electricity from competing technologies ($/MWh), California 134
Table 9.27: European growth prospects for wave and tidal stream technologies 137
Table 9.28: Island states with potential OTEC 141