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

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?

The Future of Marine Technologies

Executive summary

Introduction

Ocean energy resources

Ocean thermal energy conversion

Wave power generation

Tidal stream technologies

Tidal barrage power plants

Salinity gradient power generation

The economics of marine power generation

The prospects for marine power generation technologies

Chapter 1 Introduction

Summary

Marine energy resources

Energy capture technologies

The structure of the report

Chapter 2 Ocean energy resources

Introduction

Global resource levels

Wave energy

Tidal power

Thermal gradient

Salinity gradient

Mapping marine resources

Chapter 3 Ocean thermal energy conversion

Introduction

Background

Heat engine efficiency

OTEC configurations

Open cycle OTEC

OTEC projects

Major challenges and developments

Environmental considerations

Economics

Chapter 4 Wave power generation

Introduction

History of wave energy capture

Types of wave energy capture device

Shore line and near shore devices

Oscillating water columns

Tapered channels and overtopping devices

Oscillating flaps

Offshore wave energy converters

Floats, wave pumps and swings

Snakes, ducks and pontoons

Piezo-electric converters

Intermittency and wave energy

Wave energy pilot projects

Environmental impact

Economics

Chapter 5 Tidal stream technologies

Introduction

Tidal stream energy

Tidal stream technology

Horizontal axis tidal stream turbines

Vertical axis tidal stream turbines

Cross flow turbines

Hydrofoils

Other tidal current systems

Tidal stream pilot projects

Environmental considerations

The economics of tidal stream power generation

Chapter 6 Tidal barrage power plants

Introduction

Tidal barrage principles

Bunded reservoirs and tidal lagoons

Tidal turbines

Tidal barrages

Seawater pumped storage

Tidal barrage projects

Environmental considerations

The economics of tidal barrages

Chapter 7 Salinity gradient power generation

Introduction

Extracting power from a salinity gradient

Osmotic power

Vapor compression

Hydrocratic generation

Reversed electrodialysis

Environmental considerations

Costs

Chapter 8 The economics of marine power generation

Introduction

Comparisons with wind energy

Installed cost of marine technologies

Cost of electricity from marine power generation technologies

Chapter 9 The prospects for marine power generation technologies

Introduction

Comparative costs of power generation

Wave and tidal stream power

Tidal barrage power plants

Ocean thermal energy technology

Salinity gradient power generation

Conclusions

Index

List of Figures

Figure 2.1: Ocean energy resources, (TWh/y)

Figure 2.2: Ocean energy potential generating capacity, (GW)

Figure 2.3: US wave energy potential, (TWh/y)

Figure 2.4: US tidal current potential, (TWh/y)

Figure 3.5: Theoretical OTEC efficiencies

Figure 3.6: Life cycle carbon dioxide emissions from OTEC plants

Figure 3.7: Costs for a 100MW floating OTEC plant

Figure 4.8: Annual wave energy content for different regions, (kW/m)

Figure 4.9: Estimated installation costs for wave energy converters

Figure 4.10: Estimated cost of electricity from wave energy plants

Figure 5.11: Tidal current turbine size required to sweep out a power density of 1MW at different current speeds

Figure 5.12: Water current power swept out by a 10m diameter turbine at different current speeds

Figure 5.13: Estimated installed cost ($/kW) of tidal stream generation in North America

Figure 6.14: Tidal reach at best global sites, (m)

Figure 6.15: Global tidal sites with largest energy potential

Figure 8.16: Cost estimates for generation in the UK (£/kW)

Figure 9.17: Comparative installed cost of generating technologies (£/kW), UK

Figure 9.18: Cost of electricity from competing technologies (£/MWh), UK

Figure 9.19: Levelized cost of electricity from competing technologies ($/MWh), California

Figure 9.20: Island states with potential OTEC

List of Tables

Table 2.1: Ocean energy resources, (TWh/y)

Table 2.2: Ocean energy potential generating capacity, (GW)

Table 2.3: US wave energy potential, (TWh/y)

Table 2.4: US tidal current potential, (TWh/y)

Table 3.5: Theoretical OTEC efficiencies

Table 3.6: OTEC plant configurations

Table 3.7: Life cycle carbon dioxide emissions from OTEC plants

Table 3.8: Costs for a 100MW floating OTEC plant

Table 4.9: Annual wave energy content for different regions, (kW/m)

Table 4.10: Types of wave energy converter

Table 4.11: Estimated installation costs for wave energy converters

Table 4.12: Estimated cost of electricity from wave energy plants

Table 5.13: Tidal current turbine size required to sweep out a power density of 1MW at different current speeds

Table 5.14: Water current power swept out by a 10m diameter turbine at different current speeds

Table 5.15: Types of tidal stream power generation devices

Table 5.16: Cost estimates for tidal stream power generation

Table 5.17: Economics of tidal stream generation in North America

Table 6.18: Tidal reach at best global sites, (m)

Table 6.19: Global tidal sites with largest energy potential

Table 6.20: Major tidal barrage power plants

Table 7.21: Types of salinity gradient power generation

Table 8.22: Marine power generation costs

Table 8.23: Cost estimates for generation in the UK

Table 9.24: Comparative installed cost of generating technologies (£/kW), UK

Table 9.25: Cost of electricity from competing technologies (£/MWh), UK

Table 9.26: Levelized cost of electricity from competing technologies ($/MWh), California

Table 9.27: European growth prospects for wave and tidal stream technologies

Table 9.28: Island states with potential OTEC