© IRENA 2020

Unless otherwise stated, material in this publication may be freely used, shared, copied, reproduced, printed and/or stored, provided that appropriate acknowledgement is given of IRENA as the source and copyright holder. Material in this publication that is attributed to third parties may be subject to separate terms of use and restrictions, and appropriate permissions from these third parties may need to be secured before any use of such material.

ISBN 978-92-9260-288-8

Citation: IRENA (2020), Fostering a blue economy: Offshore renewable energy, International Renewable Energy Agency, Abu Dhabi.

About IRENA

The International Renewable Energy Agency (IRENA) is an intergovernmental organisation that supports countries in their transition to a sustainable energy future and serves as the principal platform for international co-operation, a centre of excellence, and a repository of policy, technology, resource and financial knowledge on renewable energy. IRENA promotes the widespread adoption and sustainable use of all forms of renewable energy, including bioenergy, geothermal, hydropower, ocean, solar and wind energy in the pursuit of sustainable development, energy access, energy security and low-carbon economic growth and prosperity. www.irena.org

ACKNOWLEDGEMENTS

This report was prepared by the Innovation team at IRENA’s Innovation and Technology Centre (IITC), under the guidance of Roland Roesch and developed by Francisco Boshell, Elena Ocenic, Alessandra Salgado, Judit Hecke and Gabriel Castellanos, with additional contributions and support from Dolf Gielen, Mustafa Abunofal, Sean Ratka and Ahmed Abdel-Latif.

IRENA is grateful for the support of the Ministry of Foreign Affairs of Denmark in producing this publication.

This report forms part of the “SIDS Lighthouses Initiative 2.0” project, which is supported by the Ministry of Foreign Affairs of Denmark.

DISCLAIMER

This publication and the material herein are provided “as is”. All reasonable precautions have been taken by IRENA to verify the reliability of the material in this publication. However, neither IRENA nor any of its officials, agents, data or other third-party content providers provides a warranty of any kind, either expressed or implied, and they accept no responsibility or liability for any consequence of use of the publication or material herein.

The information contained herein does not necessarily represent the views of all Members of IRENA. The mention of specific companies or certain projects or products does not imply that they are endorsed or recommended by IRENA in preference to others of a similar nature that are not mentioned. The designations employed and the presentation of material herein do not imply the expression of any opinion on the part of IRENA concerning the legal status of any region, country, territory, city or area or of its authorities, or concerning the delimitation of frontiers or boundaries.

Photographs are from Shutterstock unless otherwise indicated. Cover illustration is based on Ling Ling Federhen.

Figures

Figure 1 Ocean energy resource potential (TWh)

Figure 2 Active and projected tidal stream and wave capacity beyond 2020

Figure 3 Global active cumulative installed capacity by ocean energy technology in 2020 (MW) (excluding tidal range technology)

Figure 4 Examples of tidal energy technologies

Figure 5 Examples of wave energy technologies

Figure 6 Filed patents in ocean energy technologies (cumulative, 2000-2017)

Figure 7 Total filed ocean energy patents by country per year (2000-2017)

Figure 8 Annual offshore wind capacity additions (2000-2050)

Figure 9 Offshore wind turbine foundation technologies

Figure 10 Summary of offshore wind projections and progress level

Figure 11 Annual CO₂ emissions associated with international shipping (1970-2017)

Figure 12 Share of ships worldwide, by ship size (2017)

Figure 13 Gross tonnage of ships worldwide, by ship size (2017)

Figure 14 Biofuel product cost projections (2018-2050)

Figure 15 Hydrogen product cost projections (2018-2050)

Figure 16 Trends in global desalination by (a) number and capacity of total and operational desalination facilities and (b) operational capacity by desalination technology (1960-2020)

Figure 17 Capacity and global share of operational desalination plants by region, country income level and sector use

Figure 18 Summary of recommended actions for the offshore renewables sector to move forward

Abbreviations

CO₂ carbon dioxide

EUR euro

GBP British pound

GW gigawatt

H₂ hydrogen

IMO International Maritime Organization

IRENA International Renewable Energy Agency

kW kilowatt

kWh kilowatt-hour

LCOE levelised cost of electricity

LHI Lighthouses Initiative

m³ cubic metre

MENA Middle East and North Africa

MW megawatt

MWh megawatt-hour

NDC Nationally Determined Contribution

OTEC ocean thermal energy conversion

PV photovoltaic

R&D research and development

RD&D research, development and deployment

SDG Sustainable Development Goal

SIDS Small Island Developing State

TWh terawatt-hour

UK United Kingdom

UN United Nations

US United States

USD US dollar

01

INTRODUCTION

“Oceans, seas and marine resources are critical to sustainable development, including sustainable ocean-based economies and to the 2030 Agenda for Sustainable Development as a whole.
They underpin poverty eradication and food security, are a source of employment and livelihoods and support the well-being of humans and the planet.”

– ANTÓNIO GUTERRES,
UNITED NATIONS SECRETARY-GENERAL¹

Oceans are a source of abundant renewable energy potential, capable of driving a “blue economy” based on sustainable use of ocean resources. Energy harnessed from the oceans, through offshore renewables, can contribute to the decarbonisation of the power sector and to other end-use applications that are relevant for a blue economy (for example, shipping, cooling and water desalination). Nascent ocean energy technologies – including wave, tidal, ocean thermal energy conversion and salinity gradient energy – can make use of this enormous potential in line with overall sustainable energy and economic development.

Along with their own intrinsic renewable energy potential, the world’s oceans provide a crucial venue for the expansion of other renewable energy sources. Offshore renewables include offshore wind (fixed and floating foundations) and floating solar photovoltaic (PV) technologies, as well as various forms of ocean energy technologies. Offshore renewables can also provide significant socio-economic opportunities to countries with coastal areas and island territories, such as job creation, improved livelihoods, local value chains and enhanced synergies among blue economy actors.

Small Island Developing States (SIDS) are positioned to become the main beneficiaries of a blue economy driven by offshore renewables, helping to address some of SIDS’ most pressing needs, including:

• AFFORDABLE AND RELIABLE ACCESS TO ELECTRICITY: Renewables can replace costly power generation systems dependent on imported diesel and, with offshore variants, reduce the use of scarce land for energy facilities; and

• FRESH, POTABLE WATER SUPPLIES: Renewable energy technologies can support sustainable local desalination.

To ensure the sustainability of renewables sourced from oceans, benefits must be maximised while addressing potential negative impacts on ocean ecosystems. How the ocean energy technologies, including tidal, are affecting the environment, including marine life, is not clear. Negative impacts could arise in the form of habitat loss, animal-turbine interactions, noise and electromagnetic fields produced by sea cables, which may impact aquatic species. However, research to address these risks is being conducted. Some studies indicate that ocean energy may actually support biodiversity through artificial reefs, fish aggregation devices and marine protected areas.

As for any infrastructure project, detailed impact assessment studies and best practices must apply. As understanding of these technologies deepens, we must continue to mitigate any potential risks while maximising the socio-economic and environmental benefits of the various technologies.

This brief from the International Renewable Energy Agency (IRENA) discusses the potential of offshore renewables to contribute to achieving the United Nations (UN) Sustainable Development Goals (SDGs), particularly in the ongoing development of islands and coastal territories. This applies particularly to SDG 7 (ensure access to affordable, reliable, sustainable and modern energy for all) and SDG 14 (conserve and sustainably use the oceans, seas and marine resources for sustainable development).

This work – initially envisaged as a contribution to the UN Ocean Conference 2020² – aims to support the SIDS Lighthouses Initiative and to provide input to global discussions on the potential for sustainable ocean and offshore renewable energy development.

The brief draws on insights from various IRENA analyses and studies, including: Future of wind (IRENA, 2019a), Future of solar photovoltaic (IRENA, 2019b) and Navigating the way to a renewable future: Solutions to decarbonise shipping (IRENA, 2019c).

02

INNOVATION IN OFFSHORE RENEWABLES

02.1

Ocean energy

The theoretical resource potential of ocean energy³ is sufficient to meet present and projected global electricity demand well into the future. Ocean energy is highly predictable and is well suited to provide baseload power. The theoretical potential for electricity generation differs among technologies, with the aggregated potential for all ocean energy technologies combined ranging from 45 000 terawatt-hours (TWh) to well above 130 000 TWh per year (Figure 1). This means that ocean energy could cover more than twice the current global demand for electricity.⁴

At present, ocean energy technologies are still in developmental stages, with most technologies in the prototype phase and some just reaching commercialisation (IRENA, 2018a). The current global cumulative installed capacity across all ocean energy technologies is 535 megawatts (MW). Substantial growth in the deployment and installed capacity of ocean energy is expected in the coming years. The cumulative tidal stream and wave projects in the pipeline (excluding tidal range technology) account for nearly 3 gigawatts (GW). IRENA projects that ocean energy could reach 10 GW of installed capacity by 2030 (Figure 2).

Ocean energy technologies are commonly categorised based on the resource utilised to generate energy. Tidal stream and wave energy converters are the most widely developed technologies across geographies apart from tidal range, which is suitable only in limited locations. Other ocean energy technologies that harness energy from the differences in temperature (for example, ocean thermal energy conversion, OTEC) or from the differences in salinity may become increasingly relevant over longer time horizons. The cumulative installed capacity in 2020 is shown in Figure 3.

Tidal technology

The theoretical electricity generation potential of tidal energy is the lowest of all ocean energy technologies, at around 1 200 TWh per year (OES, 2017). This is due to its location-specific nature, as only a few dozen countries can really harness this resource. Interestingly, a sub- category of tidal technology, tidal range, dominates the current cumulative global installed capacity for ocean energy technologies. Tidal range (see Figure 4) has a 98% share of global installed capacity at present, thanks to just two large installations: a 240 MW plant deployed in France in 1966, and a 254 MW plant deployed in the Republic of Korea in 2011.

Expansion beyond these plants, however, has been slow, due to significant challenges associated with deployment of the technology, including limited site availability, high capital investment and high environmental impact. For these reasons tidal range has seen limited growth, and other tidal technologies – particularly tidal current technologies, such as those with horizontal-axis turbines – are expected to come to the fore.

Whereas a few years ago single tidal turbines boasted capacities of only 100 kilowatts (kW), turbines of 1.5 MW have now been successfully deployed, and many developers are scaling them up further. Currently, projects totalling 10 MW are installed and running, with several installations representing the first phase of larger tidal current farm projects, the most advanced of which is the MeyGen project in Scotland. Another roughly 20 MW of tidal current technologies is scheduled for deployment in the next two years, and this number is expected to exceed 1 GW by 2025.

Wave technology

The theoretical potential of wave energy is 29 500 TWh per year (Mørk et al., 2010) and can mainly be found between 30 degrees and 60 degrees latitude and in deep-water (> 40 metres) locations. Wave energy technologies have not seen a convergence towards one type of design, as has happened for other technologies such as wind energy. Many different technologies are being pursued, some of which are presented in Figure 5. In recent years, despite the absence of a clear technology convergence for wave technologies, many deployments are of the “point absorber” type. Energy is generated from the movement of a buoy caused by waves coming from all directions, relative to the base connection.

The technology readiness level of wave energy is lower than that of tidal, and its deployment is currently restricted to demonstration and pilot projects. Therefore, only around 2.5 MW is installed globally. However, like tidal turbines, wave energy devices are rapidly increasing in size and power output, and around 100 MW of new instalments can be expected in the coming years.

Ocean thermal energy conversion (OTEC)

OTEC generation is based on the temperature difference between the surface and deeper layers of the ocean. At locations where this difference is around 20 degrees Celsius, energy can be produced using cycles with heat exchangers and turbines. The global technical potential of OTEC is the largest of all ocean energy sources at 44 000 TWh per year (Nihous, 2007). The technology is still in the research and development (R&D) phase, but demonstration plants rated at 100 kW have been successful in Hawaii and Japan. The Republic of Korea is currently installing a 1 MW plant in Kiribati in the Pacific Ocean. This will be the largest of its kind and is expected to demonstrate OTEC’s high potential in island applications, as these locations enable using the water flows for purposes other than energy generation, such as desalination, aquaculture and cooling.

Salinity gradient

Through pressure-retarded osmosis or reverse electrodialysis, energy can be generated from the difference in salt concentration between two fluids. Riverbeds where freshwater flows into the sea are ideally suited for this because the amount of energy that can be generated is proportional to the difference in salt concentration. Due to geographical limitations, this technology has the least potential of all ocean energy technologies with only 1 650 TWh per year. As of 2020, only one such plant in the Netherlands (of 50 kW) was generating electricity, but many countries are intensively researching the technology and collecting data through small-scale testing.

Innovation paving the way towards ocean energy technology uptake

Among all types of ocean energy technology today, tidal technologies show the highest level of readiness and are the closest to approaching commercialisation. Next to tidal technologies, wave energy technologies have medium technology readiness levels, between laboratory to full-scale prototypes. In the last two decades both technologies have traversed various technology readiness levels, accompanied by an increasing invention activity trend. Tidal and wave hold the majority of filed patents worldwide in ocean energy technologies (Figure 6), with top country applicants spread across different geographies. Leaders include Australia, Canada, China, Germany, Japan, the Republic of Korea, the United Kingdom (UK) and the United States of America (US) (Figure 7).

In general, invention activity in ocean energy technologies has witnessed a surge since the early 2000s, reaching more than 24 000 filed patents by local intellectual property authorities. These technology breakthroughs were accompanied by an annual compound growth rate of 15% between 2007 and 2017. While the fastest growth was driven by wave and tidal technologies, other technologies, such as OTEC and salinity gradient, also achieved rapid progress.

02.2

Offshore wind

Offshore wind⁵ technology allows countries to open new sites with high wind resources, building farms at gigawatt-scale close to densely populated coastal areas. This makes offshore wind an important addition to the portfolio of technologies used to decarbonise the energy sector. The first commercial-scale offshore wind farm was commissioned in 2002 in Denmark with an installed capacity of 160 MW.

By the end of 2019, the world’s installed offshore wind capacity accounted for close to 29 GW. Around 90% of global installed offshore wind capacity is commissioned and operated in the North Sea and nearby the Atlantic Ocean.

According to IRENA’s Paris-compliant scenarios, offshore wind capacity could reach 228 GW by 2030, as innovation continues and the industry evolves. By 2050, offshore wind would increase substantially, with total offshore installations nearing 1 000 GW globally (Figure 8). Asia would take the lead in the coming decades with more than 60% of global installations by 2050, followed by Europe (22%) and North America (16%).

A main driver of this accelerated market growth and deployment is the sharp decrease in technology costs, with offshore wind currently being cost competitive with all other energy generation technologies. From 2010 to 2018, the global weighted average levelised cost of electricity (LCOE) of offshore wind decreased from USD 0.16 per kilowatt-hour (kWh) to USD 0.13/kWh. IRENA expects LCOEs to continue to fall to an average between USD 0.05/kWh and 0.09/kWh by 2030 and between USD 0.03/kWh and 0.07/kWh by 2050. In 2018, average installed costs were USD 4 353/kW and are expected to fall to between USD 1 700/kW and 3 200/kW by 2030 and between USD 1 400/kW and 2 800/kW by 2050.

R&D together with technology-driven innovation will likely lead to turbine sizes reaching between 15 MW and 20 MW in a decade or two, from around 9.5 MW today. The combination of improved wind turbine technologies, deployment of higher hub heights and longer blades with larger swept areas leads to increased capacity factors. For offshore wind farms, enhanced capacity factors are expected in the range of 36% to 58% by 2030 and 43% to 60% by 2050, compared to an average of 43% in 2018.

Developments in wind turbine technologies as well as in foundations, installation, access, operation and system integration have enabled moves into deeper waters, farther from shore, to reach sites with better wind resources. These turbines, rooted in the seabed by monopile or jacket foundations, are still restricted to waters less than 50-60 metres deep.

This is a major limitation, as some of the largest potential markets for offshore wind, such as Japan and the US, have few shallow-water sites. Scaling up offshore wind markets undoubtedly requires offshore wind turbines to move into deeper waters (> 50 metres) with higher wind resources. Therefore, floating foundations are potentially a game-changing technology for offshore wind generation.

Floating foundations offer the offshore wind industry two important opportunities: they allow access to sites with deeper water (below 50 metres) and as far as 80 kilometres from shore. The first full-scale prototypes for floating wind turbines have been in operation for several years, with three main designs being tested: spar buoys, spar submersible and tension-leg platforms (Figure 9).

Significant and encouraging developments in floating foundations have been seen in recent years. The Norwegian energy company Equinor is planning a floating offshore wind farm called Hywind Tampen, located 140 kilometres offshore with water depths ranging between 260 metres and 300 metres. It is an 88 MW floating wind power project designed to supply electricity for offshore oil and gas operations in the Norwegian North Sea, due to start operations in 2022.

Tampen will be the world’s largest floating offshore wind farm, with 11 large wind turbines with Hywind floating foundations, with each turbine having a rotor diameter of 167 metres and 81.5 metre-long blades. It promises to explore the use of new installation methods, simplified moorings, concrete substructures and integration between natural gas and wind power generation systems.

Previously, the first offshore wind farm to deploy floating foundations began operations in October 2017 in Scotland. The Hywind wind farm in Scotland has a nominal power capacity of 30 MW, consists of five turbines of 6 MW each and uses a spar buoy design (Hirtenstein, 2017). Based on progress seen in the market, three to five additional foundation designs are expected to be demonstrated at full scale by 2020, and the commercialisation of floating offshore wind could be expected between 2020 and 2025.

Globally, there are 13 announced floating offshore wind projects: 9 in Europe (France, Portugal and the UK), 3 in Asia (Japan and the Republic of Korea) and 1 in the US (Power Technology, 2019). By 2030, industry experts estimate that around 5 GW to 30 GW of floating offshore capacity could be installed worldwide and that, based on the pace of development across various regions, floating wind farms could account for up to 15% of global offshore wind installed capacity, around 150 GW by 2050.

The oil and gas industries, which have operated offshore for over half a century, could leverage synergies by transferring the knowledge acquired to the offshore wind industry.

For example, several projects are being conducted in the Netherlands:

• INTEGRATION OF WIND, GAS AND HYDROGEN (POSHYDON PROJECT): The pilot aims to integrate three energy systems – offshore wind, offshore gas and offshore hydrogen – by producing hydrogen from seawater on a platform in the Dutch North Sea (Neptune Energy, 2020).

• NORTH SEA ENERGY PROGRAMME: Over 30 national and international parties collaborate in the Dutch North Sea Energy programme, which researches how an integrated approach can best utilise the North Sea’s energy potential for a climate-neutral energy system (including the creation of energy hubs with offshore energy islands, roadmaps, resource mapping for offshore wind potential, etc.) (North Sea Energy, 2020).

• ARTIFICIAL ISLAND IN THE NORTH SEA (IJVER): A multipurpose island with 4 GW of installed capacity and 80 kilometres away from shore, it is the largest planned offshore farm in the Netherlands (Offshore Service Facilities, 2020).

The offshore wind levels needed to limit greenhouse gas emissions in line with the Paris Agreement would be difficult to reach at the current pace of technological progress. Innovation, technological breakthroughs, and policy and regulatory support can help to catalyse fast deployment (Figure 10). To achieve this aim, concrete recommendations are provided in section 5.

02.3

Floating solar photovoltaic (PV)

Floating solar PV⁶ is an emerging technology with the potential for rapid growth. As of the end of September 2018, the global cumulative installed capacity of floating solar PV plants totalled 1.1 GW (World Bank, 2018). Demand for floating solar PV is expanding, especially on islands (and other land-constrained territories), as the cost of the water surface is generally lower than the cost of land (GlobalData, 2018).

The world’s top ten plants are located in Asia, namely in China, Japan and the Republic of Korea. In particular, the Republic of Korea has announced a 2.7 GW floating solar plant in the Yellow Sea (Radowitz, 2019). Other Asian countries, namely India, Singapore, Thailand and Viet Nam, are also actively pursuing floating solar project development.

Most activity on floating PV at present relates to freshwater artificial reservoirs. For instance, a plant in eastern China (in Panji District, Huainan City) is one of the world’s largest operational floating solar plants with a capacity of 150 MW, which is expected to generate almost 78 000 megawatt-hours (MWh) in its first year. Hydropower reservoirs and other artificial bodies of water also have enormous potential for floating PV settings.

Islands are also interested in this application – such as Seychelles, which plans to build 5.8 MW of floating PV (Publicover, 2020). French developer Qair planned to start building the floating solar array on a lagoon on the East African nation’s main island in late 2020, and claims that, upon completion, the installation will be the world’s largest floating PV project to be built on salt water.

An offshore floating PV plant on seawater also recently began operation in the North Sea. This 8.5 kW project is expected to be scaled up in stages, up to 50 kW after one year and eventually to 100 MW, although the time frame is not known. The combined use of space with offshore wind is possible, because the solar panels can float between the wind turbines at sea, resulting in a hybrid system that can provide more stable power for the grid (Bellini, 2019).

03

INNOVATIVE RENEWABLE APPLICATIONS FOR A BLUE ECONOMY

03.1

Shipping fuelled by renewables

In January 2020, the International Monetary Fund projected that global economic growth would increase from an estimated 2.9% in 2019 to 3.3% in 2020 and 3.4% in 2021 (IMF, 2020). However, the COVID-19 pandemic might lead to a revision of this projection. Within this context, in the absence of suitable mitigation policies, the International Maritime Organization (IMO) estimates that greenhouse gas emissions associated with the shipping sector could grow by 50-250% by 2050. Overall, around 80-90% of internationally traded goods, totalling 8.7 gigatonnes, are transported by ship, representing 9.3% of carbon dioxide (CO₂) emissions linked to the transport sector. The Third IMO greenhouse gas study found that, between 2007 and 2012, shipping was responsible for an average of 2.8% of annual greenhouse gases on a CO₂-equivalent basis (IMO, 2015). Figure 11 shows the historical CO₂ emissions associated with international shipping.

Bulk and container carriers, as well as oil and chemical tankers, represent 20% of the global shipping fleet; together these vessels are responsible for 85% of the net greenhouse gas emissions associated with the shipping sector. Simultaneously, seven ports are responsible for nearly 60% of the bunker fuel sales around the world, with Singapore delivering as much as 22% of today’s total bunkering. Accordingly, any shift towards the use of cleaner fuels should consider the need for infrastructure adjustment at main bunkering ports. Figures 12 and 13 show the total number of ships worldwide and the gross tonnage of ships by ship size, respectively.

Fuel price and availability will likely be the decisive factors in the choice of fuel/propulsion technology. Given its energy-intensive nature, bunker fuel costs can account for 24-41% of total shipping costs. Therefore, competitive fuel prices are a highly important factor. Low-carbon fuel options are currently not competitive, with costs ranging from double to five times those of heavy fuel oil. However, this is expected to change in the medium to long term as the adoption of clean technologies grows across sectors, technology improves, costs fall, and regulations become more favourable.

The most prominent renewable options to fuel the shipping sector are discussed in the following paragraphs.

Biofuels

From a technological perspective, biofuels are mature, require few adjustments to the existing engines of ships and port infrastructure, and can have considerable emissions reduction benefits, even as blends. Cleaned biogas holds potential as a transitional fuel that could gradually replace fossil liquefied natural gas (LNG) that is currently being introduced in the sector.

Yet three main barriers limit biofuel potential in the shipping sector: economics, availability and sustainability concerns. Advanced biofuels from residues and lignocellulosic crops can minimise sustainability issues, but these require further development. Presently, the cost of biofuels is roughly twice the price of their fossil counterparts; however, the cost of biofuels is expected to drop considerably, becoming competitive by 2040 (Figure 14).

Hydrogen

Hydrogen is a clean energy carrier that can play an important role in the transition to zero-emission shipping. One option is the production of hydrogen from fossil fuels with CO₂ capture and storage – sometimes referred to as blue hydrogen. Some consider this a transitional solution, given the current high costs of producing hydrogen from renewable power. The better solution, however, is green hydrogen, produced through electrolysis using renewable power, as this is the only source of zero-carbon hydrogen (IRENA, 2019d). Current hydrogen costs are not competitive with those of the fossil fuels in use today. However, hydrogen costs are expected to decrease and to become competitive by 2030 (Figure 15).

Synthetic fuels

Other synthetic fuels being considered include methanol and ammonia. These fuels can effectively decrease and even eliminate emissions if they are produced from green hydrogen. This hydrogen is combined with CO₂ or nitrogen to yield liquid and gaseous energy commodities. IRENA’s study, Hydrogen: A renewable energy perspective (IRENA, 2019d), shows the rapid scale-up and falling costs of green hydrogen production worldwide, driven by falling renewable power generation costs. Hydrogen can be used directly as a shipping fuel, but its storage poses challenges. Liquids derived from hydrogen (so-called e-fuels or power fuels) do not face such problems, but their production incurs additional cost and efficiency losses.

Electric propulsion

At present, for full electric propulsion to be economically viable, the weight of the battery should be comparable to that of a conventional fossil fuel system. With the current state of technology, therefore, fully electric vessels are generally unable to travel more than around 95 kilometres, with such solutions viable only for relatively small vessels. As battery technology progresses, however, the energy density and the cycle life of batteries should increase, whereas the cost of battery storage technologies, including lithium-ion, should gradually fall. IRENA’s report, Electricity storage and renewables: Costs and markets to 2030 (IRENA, 2017), shows that the expected drop in costs of stationary battery technologies by 2030 will be significant. Considering that vehicle batteries cost a fraction of what stationary batteries cost, in a shipping context the decline in battery technology costs may be even greater. Therefore, in the long term, full electrical propulsion is likely to become more attractive for larger vessels engaged in services that require longer-distance travel.

Under the existing regulatory framework – and given current carbon prices – clean fuels are not economically competitive. Thus, fuel price and availability will likely be the decisive factors in the choice of renewable fuel/propulsion technology. Other key, decisive factors will include the infrastructural adaptation costs of ships and ports, technological maturity and sustainability issues (for example, food security). The willingness and ability of shipping companies to pay a premium price for low-carbon products is another decisive factor.

As the adoption of clean technologies grows across sectors, technology improves, renewable fuel costs fall and regulation becomes more favourable, carbon-neutral options are expected to become more competitive in the medium to long term. All these developments will require a global effort, however, involving the co-operation of both private and public stakeholders.

03.2

Desalination of water with renewables

Over the past ten years, the global population has grown substantially at an average annual rate of 1.14%, reaching a total of around 7.79 billion people in 2020 (UN DESA, 2019). This has resulted in increasing demand for fresh water for industrial, agricultural (irrigation), power generation and domestic (human consumption) uses, with the latter sector consuming around 60% of desalinated water (Antonyan, 2019).

As freshwater reservoirs continue to come under stress, seawater desalination is becoming the primary source of potable water for several countries, particularly in the Middle East and North Africa (MENA) region and in various SIDS. However, given the energy-intensive nature of this process, desalination is often linked to high monetary costs and accounts for significant greenhouse gas emissions. As of 2015, desalination was responsible for an estimated 76 million tonnes of annual CO₂ emissions (GCWDA, 2015). The need to decarbonise this activity is emphasised by the fact that between 2010 and 2016, global desalination capacity grew 54%. As a consequence, energy use for this purpose grew 70% over this same period (Jia et al., 2019).

Currently nearly 20 000 water desalination facilities are spread across the world (Jones et al., 2019). MENA countries – specifically Saudi Arabia and the United Arab Emirates – register the highest installed desalination capacities, at 17% and 12% respectively, followed by Spain, the US and China. Given that most desalination plants are in high-income countries, and considering that 66% of the global population faces severe water scarcity, desalination technology is not easily affordable for low- and lower middle-income countries.

While the precise emissions linked to desalination depend greatly on the energy mix of the country where the desalination plant is located, desalination currently is driven mostly by fossil fuels. The specific emissions linked to the desalination process will depend on the selected technology – either thermal desalination, which has higher energy requirements, or membrane desalination, which requires less energy. Prioritising membrane desalination (via reverse osmosis) over thermal technologies could result in a significant reduction of CO₂ emissions.

As the global need for fresh water increases rapidly, new desalination plants are being developed, and the associated increases in energy demand threaten to further drive up carbon emissions. Developing desalination infrastructure based on renewable energy is of utmost importance. The deployment of renewables in a centralised manner would result in a lower carbon footprint of desalination plants connected to the national power network. However, the direct coupling of distributed renewable systems to desalination plants would result in a higher positive impact.

Overall, the right combination of renewable energy and desalination technologies can lead to the production of fresh water in an effective, economic and environmental manner. Linking desalination with solar energy promises the highest potential to reduce carbon emissions.

Emerging options for water desalination using renewables are discussed in the following paragraphs.

Solar PV

Given that solar PV systems can be directly connected to membrane-based desalination plants, this approach appears to be one of the most promising paths towards carbon- free desalination – especially for medium and large systems – by reducing or eliminating consumption of electricity from the local grid, depending on the size of the desalination plant. For instance, in the Mediterranean Sea, the production of one cubic metre (m³) per day of clean water has been shown to require the installation of 0.71 kW of solar PV. Considering a daily consumption of 0.20 m³ per person and a fluctuating number of people between 100 million and 200 million, then 14.2 GW to 28.4 GW of capacity could power enough reverse osmosis plants to satisfy freshwater needs in the Mediterranean region (Ganora et al., 2019).

Wind

Coastal areas with high wind potential are ideal sites for coupling wind technology with desalination, which is particularly suitable for meeting the electricity needs of reverse osmosis and electrodialysis desalination plants. Wind-powered solar water reverse osmosis desalination can be found mostly in small-scale applications, for example on the Canary Islands (wind reverse osmosis; 5-50 m³/day) and Fuerteventura Island (diesel-wind reverse osmosis 56 m³/day) in Spain. Further examples have been demonstrated in the UK through a wind power plant with a capacity of 12 m³/day where wind mechanical energy could also be directly harnessed in mechanical vapour compression plants during the vapour compression phase (IRENA and IEA-ETSAP, 2012). An alternative route, given the intermittent nature of wind generation, is to capitalise on desalination as an excellent storage opportunity, particularly when wind power generation exceeds demand.

Solar thermal

Across thermal desalination methods, multi-stage flash distillation and multiple-effect distillation are the preferred technologies for the desalination of feedwater that is high in total dissolved solids. The inclusion of solar thermal is best suited for multiple-effect distillation, multi-stage flash distillation, membrane desalination and humidification- dehumidification desalination plants where, depending on whether the solar collectors are integrated in the desalination system, the process is referred to as direct or indirect. One consists of a solar collector system combined with a distillation unit.

Although the operating principle is well understood, recent research (Zheng and Hatzell, 2019; Huang et al., 2019) indicates that large potential exists for improving the design and overall engineering of solar desalination systems, thus increasing the system efficiency and reducing desalination costs. However, direct solar desalination, specifically concentrated solar power coupled with either membrane or thermal desalination, is a promising approach towards the development of large-scale low-carbon desalination by providing high-temperature heat and electricity, hence it can be used for membrane and thermal desalination plants.

Geothermal

The uninterrupted nature of geothermal resources represents a clear advantage over solar and wind alternatives, where geothermal wells deeper than 100 metres can already support desalination processes. For instance, high-pressure sources can be used as shaft power to drive mechanical desalination processes, while high-temperature fluids can be used to generate electricity to drive reverse osmosis or electrodialysis (Antonyan, 2019). A small- scale geothermal dual desalination system is being considered for Milos Island in Greece with a capacity of 1 920 m³/day. This project uses a geothermal well to run an organic Rankine cycle 470 kWe turbine as well as a multiple-effect distillation desalination unit.

The growing demand for fresh water highlights the importance of the water–energy nexus. Accordingly, sector coupling is vital for the integration of variable renewable energy and the expansion of water desalination capacity, particularly in regions with scarce freshwater resources, such as the MENA region and the Mediterranean Sea, as well as SIDS across the globe. Water desalination plants that use reverse osmosis technology, coupled with water storage, have the potential to become flexibility agents of the power system. This could result in more affordable electricity and fresh water, while increasing the profitability of renewable energy projects by reducing curtailment.

04

SOCIO-ECONOMIC BENEFITS: JOBS IN OFFSHORE WIND

Renewable energy supports a wide range of socio-economic benefits, including new opportunities for economic activity, job creation, local value creation, improved livelihoods, gender equity and other benefits.

In terms of jobs, while wind power is an established and maturing industry, ocean energy is still in the early stages of development. Consequently, deployments and jobs are still minor in ocean energy for the time being. The wind energy sector provides employment for about 1.2 million people worldwide (IRENA, 2019e), but the bulk of this presently relates to onshore installations, reflecting the fact that wind farms on land were installed for many years before the offshore segment was developed. However, the offshore wind segment is gaining traction and received USD 25.7 billion of investments in 2018, or 20% of the total for wind energy. For the first time, China led the way with offshore projects worth USD 11.4 billion. European projects attracted spending of USD 3.3 billion (Efstathiou, 2019).

Given that much offshore wind deployment is taking place in Europe, the continent has been the first to benefit from this development, with most supply chain activity in the UK and Germany, as well as in Denmark, the Netherlands and Belgium. However, China is now leading the pace on new offshore installations, a development that will lead to growing jobs and benefits domestically. Canada is also supporting the funding of its first floating tidal energy array of 9 MW, which is planned to be connected to Nova Scotia’s power grid, with a total investment estimated at USD 21.7 million (Renews, 2020).

Europe aims to retain its leadership in this renewable technology area, maximising the benefits for the region. In this context, the European Commission is giving offshore renewables a prominent role within its plans to realise the European Green Deal as part of the COVID-19 recovery package. The offshore renewable energy strategy of the European Commission released on 19 November 2020 (European Commission, 2020) sets ambitious plans.

These include:

• 60 GW of offshore wind by 2030 (from 12 GW today);

• 300 GW offshore wind by 2050;

• At least 1 GW of wave and tidal energy by 2030; and

• 40 GW of wave and tidal energy by 2050.

Offshore wind projects are helping to revitalise coastal communities in the UK’s Humber and East Yorkshire regions, the Isle of Wight and other areas. A GBP 310 million (USD 411 million) investment by Siemens Gamesa and ABP in turbine assembly and blade manufacturing has created around 1 000 direct and indirect jobs in Hull. The more than 300 jobs in blade manufacturing at an MHI Vestas Offshore Wind facility on the Isle of Wight are to expand to 380, plus 720 indirect and induced jobs (MHI Vestas Offshore Wind, 2018). A former oil-fired power plant has been converted into a paint and logistics facility for wind blades (Whitmarsh, 2019).

Offshore wind farms tend to require more labour inputs than onshore projects. In addition to the construction, assembly and deployment of new equipment such as platforms, they can leverage existing technical capacities and skills from the onshore wind segment (IRENA, 2018b). They can also use converted and upgraded existing infrastructure from the offshore oil and gas and shipping industries (Froese, 2018). Offshore wind development in northern Europe, for example, utilises the expertise of workboats that provide surveying, lifting and other services, and draws on the know-how of companies that build foundations for production platforms (O’Connell, 2018).

IRENA’s energy transition modelling suggests that the wind industry, both onshore and offshore, may employ 3.74 million people by 2030 and more than 6 million people by 2050. Where these jobs will be created depends not only on the level of deployment in individual countries, but also on the degree to which the domestic industrial and services bases can be built and leveraged.

IRENA’s “Leveraging local capacity” report series, which includes a study of the offshore wind industry entitled Renewable energy benefits: Leveraging local capacity for offshore wind (IRENA, 2018b), provides valuable information for policy makers on the occupational and skill structure along the value chain. For a 500 MW offshore wind farm, the human requirements from planning to decommission account for up to 2.1 million person-days. The vast majority of these are concentrated in the manufacturing and procurement segments.

05

RECOMMENDED ACTIONS TO MOVE OFFSHORE RENEWABLES FORWARD

05.1

Capacity building in renewables for a blue economy

• BOLSTER AND ENHANCE SKILLS IN THE WORKFORCE: There is a growing need for professionals with knowledge and skills in offshore renewables technology development and deployment. Methods to clarify future needs can include: 1) exchanging knowledge between offshore renewables (for example, in terms of materials, technology installation in waters, turbine design, port and vessel logistics, etc.), 2) facilitating the reskilling of the workforce from fossil fuel industries to renewables, and 3) working closely with academia and youth to align curricula with sector jobs.

• EARLY EDUCATION PROGRAMMES: Sufficient training and programmes from an early stage of education are essential to improve renewable energy knowledge and understanding. This calls for a strong focus on education in science, technology, engineering and mathematics (STEM) that can help increase technical capacity and technological learning.

05.2

Ocean energy

• DE-RISK PROJECTS AND UNLOCK RESEARCH, DEVELOPMENT AND DEPLOYMENT (RD&D) FUNDING: Ocean energy project risk assessment should create awareness on the technology reliability and raise trust among investors, who may be reluctant to provide financing in this sector. Ocean energy technologies are in major need of funds to push technologies towards the commercial stage.

Mechanisms that can help to address this include:

Fund projects based on the technology readiness level: Establish funding programmes that consider the different technology readiness level stages and remunerate projects based on stage completion (for example, components testing, successful design and efficient operational levels). Technologies close to commercialisation with a functional full-scale prototype face a lack of financial support when trying to deploy the technology in the water and generate electricity.

Emphasise stakeholder partnerships and build international co-operation: Emerging continental economies and islands may be in need of financial resources and business development analysis, both of which could be spurred by cross-water partnerships. Equally important is to strengthen international technology co-operation; policy makers, industry, academia and users of ocean energy technologies should share existing information and collaborate in a more organised manner. Front- runner countries can encourage knowledge transfer to locations where ocean energy is still at early stages of development.

Provide access to finance in SIDS: Innovative financing schemes are key to promoting ocean energy in SIDS, as risks are still perceived around the technology, hindering access to financing. Islands could be considered as new ocean energy “small” markets, which can be used as testing hubs before moving to larger markets.

• COUPLE BLUE ECONOMY SECTORS WITH OCEAN ENERGY: The blue economy is expected to grow, and in doing so, ocean energy is well placed as a potential solution to decarbonise sectors such as desalination, space cooling, shipping, and tourism, as well as emerging sectors such as aquaculture, green hydrogen generation, ocean observation (to power environmental equipment for monitoring) and underwater vehicle charging.

• BOOST REGULATORY SCHEMES FOR OCEAN ENERGY: Offshore renewables solutions must be included in the decarbonisation discussion, and countries should plan for an offshore renewables roadmap and establish clear policies that can help in the achievement of national offshore renewable targets. For a sector scale-up, different regulatory and tariff schemes that can propel ocean energy are needed. Countries should adopt different mechanisms, and their expansion and replicability in other locations could promote ocean energy deployment. Some potential solutions include providing feed-in tariffs for at least 100 MW projects or defining ocean energy tender criteria; the latter is a measure used in the Netherlands.

• DEVELOP INNOVATIVE HYBRID RENEWABLE ENERGY SYSTEMS: Promoting systemic approaches for ocean energy is crucial to decrease the LCOE of ocean energy technologies. Due to their predictability, ocean energy technologies can provide baseload power and stabilise the grid and are therefore ideally suited to be developed in harmony with other renewables, offshore as well as onshore. This is particularly interesting in coastal regions and islands where a mix of energy sources is needed due to land limitations and where high shares of renewables are present. Furthermore, technologies can even be complemented to create hybrid devices (for example, wave and wind on a single floating platform).

• BUILD MARINE SPATIAL KNOWLEDGE AND EVALUATE ITS IMPACT: Countries must consider adequate and comprehensive marine spatial planning to enable a successful roll-out of ocean energy technologies. Governments should plan the spatial requirements for the blue economy in advance, reserving a space for R&D and commercialisation purposes of ocean energy technologies. In addition, marine spatial planning should go hand in hand with social, economic and environmental impact assessments.

05.3

Offshore wind⁷

• ADOPT A SYSTEMIC APPROACH, DRAWING TOGETHER INNOVATIONS IN ENABLING TECHNOLOGIES, MARKET DESIGN, BUSINESS MODELS AND SYSTEM OPERATION: The implementation of innovations to unlock flexibility across the whole power sector would result in lower costs to integrate variable renewable energy and thus support the energy transformation (IRENA, 2019f).

• PROMOTE R&D ROADMAPS AND STRATEGIES: Facilitate an offshore wind roadmap for national research and industry development institutions to advance offshore wind uptake in the public and private sectors.

• PROVIDE LONG-TERM STABILITY OF POLICY INSTRUMENTS: Policy making needs to minimise swings from strong supportive measures to aggressive curbs. Likewise, prolonged periods of policy uncertainty can greatly impact the future of the wind industry.

• STREAMLINE THE PERMITTING PROCESS TO AVOID LONGER CONSTRUCTION PERIODS: Streamlining the processes around applying for grid and construction permitting can reduce long lead times and construction periods. This is also linked to the need to reduce the uncertainties of regulatory and policy frameworks in countries where offshore wind is being deployed, as this could severely impact the permitting process, investor confidence and overall project risk, which feeds down to project costs.

• IMPROVE EXISTING INFRASTRUCTURE ALONG WITH BUILDING A HIGH-VOLTAGE GRID, OR SUPER GRID: This will help to transport electricity to other regions and avoid renewable energy curtailment.

• DEPLOY SUSTAINABLE FINANCE INITIATIVES AND PROGRAMMES: This aims to enlarge the fiscal space and to foster sector diversification to finance the energy transition process in the medium and long terms.

• STRENGTHEN AND MAXIMISE VALUE CREATION FROM THE DEVELOPMENT OF A DOMESTIC WIND INDUSTRY: To reinforce the industrial capability of domestic firms, policy measures and interventions are needed that contribute to increased competitiveness. These measures could include industrial upgrading programmes, supplier development programmes, promotion of joint ventures, development of industrial clusters and investment promotion schemes.

05.4

Floating solar PV⁸

• PROMOTE R&D STRATEGIES AND BUILD OFFSHORE KNOWLEDGE: Plan R&D roadmaps in harmony with the marine sector. Essential topics needed to advance the sector include further environmental assessment and impact, electrical safety, mooring and anchoring systems, and project development knowledge for offshore conditions (World Bank, 2018). Establish institutions that can help to advance the uptake of learnings from R&D in the public and private sectors.

• PUSH INNOVATION INTO CO-LOCATION OF RENEWABLE OFFSHORE TECHNOLOGIES: Floating PV can benefit from spatial co-location with other marine technologies. This could enhance water space use and at the same time enable a more stable power generation in the grid.

• NURTURE TECHNOLOGY BREAKTHROUGHS: As with any new technology, several engineering challenges need to be overcome. For instance, mooring (or anchoring) systems must be designed to withstand the dynamic forces of waves and strong winds and, due to the novelty of the technology, mooring specialists have limited experience in applying such systems to floating PV plants. As a result, floating PV installations are always moving to some extent, which increases with wind load.

• BENCHMARK AND EXPAND “ONSHORE” PV FINANCIAL MECHANISMS: Current successful financial practices from onshore solar PV can be used as a baseline and incorporated for floating PV technologies. In particular, the inland PV sector has built experience in feed-in tariffs, renewable energy certificates, carbon pricing and green bonds.

05.5

Shipping

• SUPPLY OF ZERO EMISSION FUELS: Upstream dynamics need to be better understood, including not only greenhouse gas life-cycle analysis of the different fuels but also the potential and production limits of clean fuels. This includes biofuels, hydrogen and ammonia. The sector needs to be sure that clean fuel supply will be constant in the long term.

• DE-RISKING FIRST MOVERS: Participants across the entire value chain need to be well engaged and capable of supplying a variety of clean fuels without interruptions. Simultaneously, first movers need incentives, including funding with special, attractive conditions, as well as other types of economic incentives.

• CARBON LEVY: For clean fuels to become viable in the near term, a carbon price of USD 250-300 per tonne would be necessary. However, the industry is only willing to pay up to USD 75 per tonne of carbon. Hence, policy makers, cargo operators and ship owners must be brought together to agree on suitable mechanisms to fund the transition towards zero carbon emissions.

• STAKEHOLDER ENGAGEMENT: The engagement of stakeholders needs to go beyond the shipping industry and energy-related stakeholders. Routes for engaging end-use consumers need to be identified and put in place.

• AWARENESS OF END USERS: Shifting to clean fuels will likely result in an increase in the final price of the transported goods, hence the final consumer needs to be made aware of which goods were transported by vessels using clean fuels.

05.6

Desalination

• DESALINATION WITH VARIABLE RENEWABLE ENERGY RESOURCES: Combining variable renewable technologies, such as solar and wind, with desalination processes – which require a constant energy supply – involves technical, economic and organisational challenges. This knowledge and understanding is lacking in developing countries with scarce freshwater resources (for example, on small islands). Hence, platforms are needed for developed countries to share their technical knowledge and experiences with least-developed countries and SIDS.

• IDENTIFICATION OF NICHE MARKETS: The identification of niche markets for renewable desalination and the establishment of proper enabling frameworks would help attract private investors.

• MULTI-STAKEHOLDER COLLABORATION: More collaboration and integration is needed between energy and water sector companies.

• FUNDING MECHANISMS: An estimated 66% of the global population faces severe water scarcity, yet more than 70% of desalination infrastructure sits in high-income countries. Mechanisms are needed urgently to enable affordable funding to low- and lower middle-income countries.

Figure 18 provides a summary of the recommended actions to move the offshore renewables sector forward.

05.7

Framework for action

As the leading global intergovernmental organisation dedicated to energy transformation, IRENA aims to help countries gain access to the latest knowledge on offshore renewables, particularly to strengthen national strategies to achieve SDG 7 and SDG 14. It also aims to support capacity building and international co-operation to foster a global blue economy.

Collaborative Framework on Ocean Energy / Offshore Renewables

In response to a call by its global membership, IRENA has created collaborative frameworks that serve as an effective platform for increased dialogue and co-ordinated action among its Members. A new Collaborative Framework on Ocean Energy / Offshore Renewables brings countries together to identify priority areas and actions and to foster international collaboration to understand the role of ocean and offshore renewables in the energy transition and ensure its widespread deployment in the future.

The collaborative framework has been endorsed by several IRENA member countries and is now operational. This platform for collaboration aims to foster advancements in areas relevant to offshore renewables including technology development, research and innovation, market incentives, regulatory frameworks and sustainability. It shows IRENA’s continued commitment as a leading global platform to share knowledge and support governments in pursuit of the deployment of renewable energy.

IRENA stands ready to:

• Provide a common vision on offshore renewables potential and expected changes in the market;

• Disseminate the best offshore renewables experiences and provide policy makers with project case studies, business cases and facts on the technology;

• Facilitate international co-operation by identifying decarbonisation synergies among marine sectors;

• Give guidance on understanding the right supply chain for offshore technologies;

• Create an offshore renewables portfolio for SIDS, by understanding their energy needs and recommending technologies that can address the issues identified;

• Include financiers in the offshore renewables discussion;

• Determine offshore renewables contributions to Nationally Determined Contributions (NDCs) and support countries in drafting their NDCs;

• Assist countries in harnessing the socio-economic benefits of renewable energy, particularly in terms of new job creation and local economic value.

To facilitate ocean energy uptake, IRENA could:

• Make available to policy makers the frameworks and information on viable electricity prices for ocean energy and the creation of other market indicators that go beyond LCOE;

• Facilitate access to decision makers and underline the need for revenue support through feed-in tariffs or renewable energy certificates.

Key recent initiatives

SIDS LIGHTHOUSES INITIATIVE

Launched by IRENA in 2014, the SIDS Lighthouses Initiative supports small islands in scaling up renewable energy through partnerships between public institutions, the private sector, inter-governmental and non-governmental organisations. After the initiative’s initial targets for 2020 were met ahead of schedule and even considerably exceeded, a new even more ambitious phase of the initiative was launched in 2018. The action areas for this second phase include promoting all renewable sources, including ocean energy, as well as reinforcing links between renewables and non-energy sectors – including the water sector. In this context, IRENA could play a key role in establishing a platform to share experiences and technical knowledge on water desalination to support building capacities among SIDS.

SHIPPING: GETTING TO ZERO COALITION

IRENA has joined the Getting to Zero Coalition, an alliance of more than 90 companies within the maritime, energy, infrastructure and finance sectors – supported by key governments and international organisations – that was launched at the 2019 Climate Action Summit. The Alliance is committed to getting commercially viable deep-sea zero-emission vessels into operation by 2030. With the status of knowledge partner, IRENA is supporting Workstream #1 – Fuels, Technologies & Pathways. In October 2019, IRENA participated in the Global Maritime Forum Annual Summit in Singapore where the Agency launched its report Navigating the way to a renewable future: Solutions to decarbonise shipping (IRENA, 2019c). This report explores the impact of maritime shipping on CO₂ emissions, characterises the shipping sector and identifies various clean energy solutions with the potential to reduce the sector’s carbon footprint.

References

Antonyan, M. (2019), Energy footprint of water desalination, Master’s thesis, University of Twente, Enschede, https://essay.utwente.nl/78100/1/Antonyan%2C%20M.%201817078%20_openbaar.pdf.

Bellini, E. (12 December 2019), “Offshore PV system goes online in North Sea, pv magazine”, www.pv-magazine.com/2019/12/12/offshore-pv-system-goes-online-in-north-sea.

Efstathiou, J., Jr. (16 January 2019), “Global clean energy funding dips 8% as China cools solar boom”, Bloomberg News, www.bloomberg.com/news/articles/2019-01-16/global-clean-energy-funding-dips-8-as-china-cools-solar-boom.

Ember (2020), Global electricity review 2020, Ember, London, https://ember-climate.org/wp-content/uploads/2020/03/Ember-2020GlobalElectricityReview-Web.pdf.

EMEC (n.d.a), “Tidal devices”, European Marine Energy Centre, Orkney, www.emec.org.uk/marine-energy/tidal-devices (accessed 3 March 2020).

EMEC (n.d.b), “Wave devices”, European Marine Energy Centre, Orkney, www.emec.org.uk/marine-energy/wave-devices (accessed 3 March 2020).

Equasis (2017), The world merchant fleet in 2017, European Maritime Safety Agency, Lisbon, http://emsa.europa.eu/publications/technical-reports-studies-and-plans/download/5459/472/23.xhtml.

Froese, M. (3 October 2018), “Ports trying to keep pace with offshore wind development”, Windpower Engineering & Development, www.windpowerengineering.com/ports-trying-to-keep-pace-with-offshore-wind-development.

Ganora, D., C. Dorati,T.A. Huld, A. Udias and A. Pistocchi (2019), “An assessment of energy storage options for large-scale pV-Ro desalination in the extended Mediterranean region”, Scientific Reports, Vol. 9, Springer Nature, London, www.nature.com/articles/s41598-019-52582-y.

GCWDA (2015), H₂0 minus CO₂, Concept paper, Global Clean Water Desalination Alliance, http://clca.columbia.edu/Global-Water.pdf.

GlobalData (2018), Solar PV module, Update 2018 – Global market size, competitive landscape and key country analysis to 2022, GlobalData, London.

Hirtenstein, A. (18 October 2017), “World’s first floating wind farm begins operating in Scotland”, BloombergNEF, https://about.bnef.com/blog/worlds-first-floating-wind-farm-begins-operating.

Huang, L. et al. (2019), “Enhanced water yield of solar desalination by thermal concentrated multistage distiller”, Desalination, Vol. 477, Elsevier, Amsterdam, p. 114260, https://doi.org/10.1016/j.desal.2019.114260.

IMF (2020), World economic outlook, International Monetary Fund, Washington, D.C., www.imf.org/en/Publications/WEO/Issues/2020/01/20/weo-update-january2020.

IMO (2015), Third IMO GHG study 2014 - Executive summary and final report, International Maritime Organization, Suffolk.

IRENA INSPIRE (n.d.), International Standards and Patents in Renewable Energy (INSPIRE platform), http://inspire.irena.org.

IRENA (2020), Unlocking the potential of ocean energy around the globe, IRENA, Abu Dhabi.

IRENA (2019a), Future of wind, IRENA, Abu Dhabi.

IRENA (2019b), Future of solar photovoltaic, IRENA, Abu Dhabi.

IRENA (2019c), Navigating the way to a renewable future: Solutions to decarbonise shipping, IRENA, Abu Dhabi.

IRENA (2019d), Hydrogen: A renewable energy perspective, IRENA, Abu Dhabi.

IRENA (2019e), Renewable energy and jobs – Annual review, IRENA, Abu Dhabi.

IRENA (2019f), Innovation landscape for a renewable-powered future: Solutions to integrate variable renewables, IRENA, Abu Dhabi.

IRENA (2018a), Opportunities to accelerate national energy transitions through enhanced deployment of renewables, IRENA, Abu Dhabi.

IRENA (2018b), Renewable energy benefits: Leveraging local capacity for offshore wind, IRENA, Abu Dhabi.

IRENA (2017), Electricity storage and renewables: Costs and markets to 2030, IRENA, Abu Dhabi.

IRENA (2014), Wave energy: Technology brief, IRENA, Abu Dhabi.

IRENA and IEA-ETSAP (2012), Water desalination using renewable energy: Technology brief, IRENA and International Energy Agency Energy Technology Systems Analysis Programme, Abu Dhabi and Paris.

Jia, X. et al. (2019), “Analyzing the energy consumption, GHG emission, and cost of seawater desalination in China”, Energies, Vol. 12/3, MDPI, Basel, p. 463, www.mdpi.com/1996-1073/12/3/463.

Jones, E., M. Qadir, M.T.H. van Vliet, V. Smakhtin and S-m. Kang (2019), “The state of desalination and brine production: A global outlook, Science of the Total Environment”, Vol. 657 (March), Elsevier, Amsterdam, pp. 1343-1356.

MHI Vestas Offshore Wind (20 November 2018), “New blade mould arrives at MHI Vestas factory on Isle of Wight, substantial economic boost coming to the Solent Region”, www.mhivestasoffshore.com/new-blade-mould-arrives-at-mhi-vestas-factory.

Mint Selection (14 February 2019), “Excipio Energy launches hybrid floating offshore wind system”, www.mintselection.com/excipio-energy-launches-hybrid-floating-offshore-wind-system.

Mørk, G., S. Barstow, A. Kabuth and M. Pontes (2010), “Assessing the global wave energy potential, Proceedings of the 29th International Conference on Ocean, Offshore Mechanics and Arctic Engineering”, Shanghai, China, www.researchgate.net/publication/274069267_Assessing_the_Global_Wave_Energy_Potential.

Muntean, M. et al. (2018), Fossil CO₂ emissions of all world countries – 2018 report, European Commission, Joint Research Centre, Publications Office of the European Union, Luxembourg, http://publications.jrc.ec.europa.eu/repository/bitstream/JRC113738/kjna29433enn.pdf.

Neptune Energy (2020), “The world’s first offshore green hydrogen plant”, www.neptuneenergy.com/esg/climate-change-and-environment/poshydon-hydrogen-pilot (accessed 21 October 2020).

Nihous, G.C. (2007), “A preliminary assessment of ocean thermal energy conversion resources”, Journal of Energy Resources Technology, Vol. 129/1, American Society of Mechanical Engineers, pp. 10-16, https://doi.org/10.1115/1.2424965.

North Sea Energy (2020), “About us”, https://north-sea-energy.eu/en/home (accessed 21 October 2020).

O’Connell, J. (28 August 2018), “Can offshore wind save the workboat industry?”, Maritime Executive, www.maritime-executive.com/magazine/can-offshore-wind-save-the-workboat-industry.

OES (2020), Annual report: An overview of ocean energy activities in 2019, Ocean Energy Systems, Lisbon.

OES (2017), An international vision for ocean energy, Ocean Energy Systems, Lisbon.

Offshore Service Facilities (2020), “Background: IJVER”, https://offshoreservicefacilities.nl/ijmuiden-ver (accessed 21 October 2020).

Power Technology (13 June 2019), “Floating foundations are the future of deeper offshore wind”, www.power-technology.com/comment/floating-offshore-wind-2019.

Publicover, B. (2 April 2020), “Seychelles to host 5.8 MW of floating PV”, pv magazine, www.pv-magazine.com/2020/04/02/seychelles-to-host-5-8-mw-of-floating-pv.

Radowitz, B. (6 December 2019), “South Korea plans world’s largest floating solar plant in Yellow Sea”, Recharge, www.rechargenews.com/transition/south-korea-plans-world-s-largest-floating-solar-plant-in-yellow-sea/2-1-719765.

Renews (6 November 2020), “Canada backs Nova Scotia tidal array”, https://renews.biz/64279/canada-backs-nova-sco-tia-tidal-array.

Skråmestø, Ø.S., S.E. Skilha-gen and W.K. Nielsen (2009), Power production based on osmotic pres-sure, Spokane, Washington.

UN DESA (2019), World population prospects 2019, online edition. rev. 1., United Nations, Department of Economic and Social Affairs, Population Division, New York, https://population.un.org/wpp/Download/Standard/Population.

WEC (2016), World energy resources: 2016, World Energy Council, London, www.worldenergy.org/assets/images/imported/2016/10/World-Energy-Resources-Full-report-2016.10.03.pdf.

Whitmarsh, M. (2019), The UK offshore wind industry: Supply chain review, Offshore Wind Industry Council, https://cdn.ymaws.com/www.renewableuk.com/resource/resmgr/publications/supply_chain_review_31.01.20.pdf.

World Bank (2018), Where sun meets water: Floating solar market report, Washington, D.C., http://documents.worldbank.org/curated/en/579941540407455831/pdf/Floating-Solar-Market-Report-Executive-Summary.pdf.

Zheng,Y. and K.B. Hatzell (2019), “Technoeconomic analysis of solar thermal desalination”, Desalination, Vol. 474, Elsevier, Amsterdam, p. 114168, www.sciencedirect.com/science/article/abs/pii/S0011916419313542.

1 https://undocs.org/en/a/74/630

2 The UN conference was cancelled amid the COVID-19 pandemic.

3 Based on Ocean energy: Technology readiness (IRENA, 2014) and Innovation outlook: Ocean energy technologies (IRENA, 2020).

4 Global electricity demand was 25 814 TWh in 2019 (Ember, 2020).

5 Based on Future of wind (IRENA, 2019c).

6 Based on Future of solar photovoltaic (IRENA, 2019d).

7 Based on Future of wind (IRENA, 2019c).

8 Based on Future of solar photovoltaic (IRENA, 2019d).