Assessment of the Potential of Floating Offshore Wind Turbines in the Red Sea

Introduction

Global renewable energy targets often include solar photovoltaic and wind power as two major components for achieving green energy targets. According to the Global Electricity Review 2022, wind and solar power accounted for more than 80% of new electricity generation installations worldwide in 2021(Ember 2022). This level is driven by policy support, technological advances and decreasing costs. Wind power has achieved record low prices in many countries, and it is often considered the least expensive form of power generation, along with solar photovoltaics (IRENA 2022). Additionally, wind tends to be strongest at night, while solar tends to be strongest during the day.Thus, combining wind and solar power diversifies the energy mix and delivers amore consistent supply of clean energy than each individual resource.

The Emergence of Floating Wind Turbines

Floating offshore wind turbines (FOWTs) have recently gained traction and are being installed in several regions of Europe and Asia. This new technology eliminates depth constraints and enables the large-scale renewable power generation beyond Europe — the traditional location of seabed-anchored offshore wind facilities. FOWTs use the same technology as typical offshore wind turbines, except that FOWTs are not anchored to the seabed directly. Instead, they are tethered to the seabed with mooring lines and can float freely in the water, allowing for development opportunities in areas with a water depth greater than 60 meters (the limit of current seabed-anchored offshorewind turbines).

The deployment of wind turbines further offshore allows for the capture of wind power in areas with higher and more constant wind speeds. Different types of floating platform exist for wind turbines, such as spar buoys, tension-leg platforms and semisubmersibles (see next Figure). The choice of one type over another depends on various factors, such as sea and seabed conditions, wind speed and direction, turbine size and costs.

In 2009

FOWT technology deployment started in 2009 with a pilot 2-megawatt turbine installed offshore in Karmøy, Norway.

+8 years later

Eight years later, the technology passed the research and development stage and the first commercial FOWT was installed off the northeast coast of Scotland. The Hywind project consists of five 6-megawatt Siemens turbines installed on floating structures at sea depths of 95-120 meters (WindEurope 2017).

Installed capacity

According to the National Renewable Energy Laboratory’s offshore wind market report, as of the end of 2021, Only 10 FOWT projects were operating globally, totaling 123.4 megawatts (Musial et al. 2022). Seven of those 10 projects (112.9 megawatts) were in Europe, and three (10.5 megawatts) were in Asia. However, the pipeline of this technology is growing rapidly and is forecast to grow to more than 64 gigawatts by 2035

Scotland

The Scottish government has continued to exploit the potential of offshore wind resources by leasing seabeds, as identified by the Scottish Government’s Sectoral Marine Plan for commercial-scale offshore wind projects. Twenty ScotWind projects have seabed option agreements for up to 10 years.
‍
Construction of ScotWind projects is expected to begin in the late 2020s, and 14 of the 20 projects are floating rather than fixed turbine projects, with a total expected FOWT capacity of 17.4 gigawatts (Crown Estate Scotland 2022).

European countries

In April 2023, nine European countries signed the Ostend Declaration of Energy Ministers on the North Sea as Europe’s Green Power Plant. This declaration set a political commitment to deploying 120 gigawatts of offshore wind capacity in the North Sea by 2030 and 300 gigawatts by 2050. Within this declaration, Norway has pledged a floating wind target of 1.5 gigawatts, while the U.K. aims to deliver 5 gigawatts of innovative FOWTs by 2030 (Ostend 2023). In Ireland, EDF Renewables entered a partnership with Simply Blue Group to develop two floating offshore wind projects off the coast of Ireland, which will help the country achieve its 2-gigawatts target by 2030 (Enerdata 2023).

Southern Europe

In Italy, FOWT production is being accelerated. Three FOWT projects will be developed in Lazio (540 megawatts), and two other wind farms will be developed off Olbia (500 and 1,000 megawatts). The three projects will produce approximately five terawatt-hours/year and will operate between 2028 and 2031 (Enerdata 2023).
‍
On the Iberian Peninsula, IberBlue Wind has three other projects under development: the 990-megawatt Botafogo floating offshore wind project off the coast of Figueira da Foz in Central Portugal and two cross-border floating offshore wind projects totaling 1.96 gigawatts on the North Atlantic coast, located on the maritime border between Spain and Portugal (Enerdata 2023).

China

China has been leading the world in terms of renewable energy capacity. Regarding FOWTs, China has started constructing the world’s largest FOWT project offshore of Hainan. The project’s first phase will see the deployment of 200 megawatts by 2025, and the second phase will add 800 megawatts by 2027 (Enerdata 2023).

In Australia, the Philippines, Canada, the U.S. and Europe, several companies have announced plans to participate in future auctions to develop FOWT projects, exemplifying the ambitions of a growing number of countries to expand offshore wind development.

LCOE

Accelerating the scalability of FOWT requires a swift and substantial reduction in the LCOE.

80%

reduction in the LCOE for FOWTs is anticipated by 2050, according to DNV's Energy Transition Outlook 2022.

This projection hinges on several factors including:

  • The overall installed capacity forecasted to reach 300 GW in the DNV scenario.
    ‍
  • Benefits from economies of scale.
    ‍
  • Advancements in serial manufacturing.
    ‍

Part of the challenge in cost reduction lies in the operational costs of FOWT, primarily attributed to novel components such as mooring systems and dynamic cables.

Resource assessment in the Red Sea

There are only a few studies that assess the potential of offshore wind power in the Red Sea. One key study by Bahaj et al. (2020) looked at offshore wind energy in the Arabian Peninsula and focused on seabed-anchored turbines. For FOWT, the Ocean Renewable Energy Action Coalition created maps showing potential within 200 km of the shoreline worldwide, estimating 78 GW potential for Saudi Arabia (GWEC 2021). This study aims to be the first to conduct an in-depth analysis specifically on the Red Sea's suitability for FOWT deployment.

Methodology

This paper presents a FOWT in the Red Sea. Using spatial analysis, it identifies areas that are suitable for FOWT installations based on factors like wind resources, water depths, maritime routes, and geographic borders. The study employs GIS for spatial modeling and analysis, along with multi-criteria decision support frameworks (MCDA), to consider local conditions and technical factors. This approach gives an accurate estimate of the potential FOWT capacity. The technical potential is then evaluated through power density calculations. This research lays the foundation for future studies and policy discussions on utilizing the Red Sea's renewable energy resources.

Method Steps

Red Sea characteristics

The Red Sea plays a crucial role in global trade as part of the East-West Shipping Lane, making it a region with heavy marine traffic. It stretches from Bab El-Mandeb in the south, connecting to the Gulf of Aden, to the Gulf of Suez in Egypt and the Gulf of Aqaba in Jordan. The Red Sea covers an area of approximately 450,000 km² and spans about 1,930 km in length. The Gulf of Aqaba is around 180 km long with an average width of 20 km (Batayneh et al. 2014), while the Gulf of Suez is about 300 km long with a maximum width of 50 km.

Water depth

Deeper water could mean higher installation and maintenance costs, but also more flexibility in choosing locations. The Red Sea generally has water depths of 60 meters or more, with the deepest point reaching approximately 3,040 meters. The Gulf of Aqaba has a narrow coastal plain, a maximum depth of about 1,676.40 meters, and an average depth of 800 meters. The rest of the Red Sea coastline, from the convergence of the Gulf of Suez and the Gulf of Aqaba to Bab Al-Mandeb in the south, has a maximum depth of around 1,219 meters (Ryan et al. 2022)    .

Wind speed

Higher wind speeds lead to higher power output and lower energy costs. In the Red Sea, wind speeds are generally favorable for wind energy harvesting. On the northern west coast of Saudi Arabia, wind speeds range from 4.11 to 11.83 meters per second (m/s), typically between 7.17 and 8.75 m/s. In the central-west coast region, between the coastlines of Makkah and Madinah provinces, average wind speeds range from 6.11 to 7.83 m/s. On the southern west coast, in Jazan Province, average wind speeds range from 5.11 to 6.17 m/s (Windy 2023).

KSA Maritime Boundaries

To understand the potential areas for FOWT development, it is essential also to understand maritime boundaries, which are set under the provisions of the Law of the Sea Convention (LOSC). These boundaries are divided into six zones: Internal Waters, Territorial Sea, Contiguous Zone, Exclusive Economic Zone (EEZ), Continental Shelf, and High Seas and Deep Ocean Floor.

  • Territorial Sea: Extends 12 nautical miles (22.24 kilometers) from a country's baseline into the sea.
    ‍
  • Contiguous Zone: Starts from the edge of the Territorial Sea and extends an additional 12 nautical miles, reaching up to 24 nautical miles (44.45 kilometers) from the baseline.
    ‍
  • EEZ: Extends up to 200 nautical miles (370.40 kilometers) from the baseline or up to 176 nautical miles (325.95 kilometers) beyond the Contiguous Zone. (NOAA 2023).

Red Sea ports

Installation of large structures is always a challenge, especially when it is in the middle of the sea. However, unlike fixed offshore wind turbines, part of the FOWT installation is done onshore on a floating structure before it is moored to the desired location and tethered to the seabed. The sheer size of the wind turbine components means they need a dedicated large area in the port for installations. On its Red Sea coast, Saudi Arabia has six of its 11 ports. Saudi Arabia is endowed with a strategic geographic location along the East-West shipping lane, where around 13% of international trade passes through the Suez Canal.

Spatial assessment

Using maps and interactive geo-visualizations, GIS can effectively communicate complex findings and conclusions, making it a valuable tool for policy and decision makers. GIS is widely used for spatial modeling and analysis across various fields. When combined with decision support frameworks like multi-criteria decision analysis (MCDA), GIS can enhance situational awareness studies and suitability assessments. In this study, we use a simplified approach with binary analysis. By overlaying layers of favorable conditions, we identify areas where all these conditions are met.
‍
Our key assumptions include:

  • Wind speeds between 7-9 m/s.
    ‍
  • Locations within the contiguous zone.
    ‍
  • Water depths between 60-1000 meters.

Identified areas

The GIS suitability analysis identified the potential area for the development of FOWT. The highlighted areas indicate two promising regions for the development of FOWT projects. The first region is located off the northwest coast of Saudi Arabia and covers an area of 4593 km2. The second region is situated offshore of Yanbu and covers an area of 3862 km2. Both areas present an untapped potential for the development of FOWT. The technical potential for capacity deployment is estimated with the assumption that the whole area is available for development without any constraints. This is to give an initial read on the opportunities for this technology.

Capacity density

It is important to understand the concept of power (or capacity) density, which refers to the potential power output achievable from an offshore wind farm relative to its spatial footprint. Typically, the capacity density is calculated in megawatts per square kilometer (MW/km2). This metric is influenced by several variables including the specifications of the wind turbines, the quality of the wind resource, and inherent array losses. A practical strategy to optimize power production is adjusting the spacing between turbines. This is needed to address the wake effect, whereby the wind leaving the turbine will have lower energy (i.e., speed) than the wind arriving at the turbine. Although increased spacing minimizes turbine interactions and subsequent interferences (i.e., the wake effect), it also diminishes the overall capacity density. Often, the distance between turbines is gauged using the rotor diameter, which gives a good proxy for the area of the wake that is created by the turbine.

Red Sea characteristics

The Red Sea plays a crucial role in global trade as part of the East-West Shipping Lane, making it a region with heavy marine traffic. It stretches from Bab El-Mandeb in the south, connecting to the Gulf of Aden, to the Gulf of Suez in Egypt and the Gulf of Aqaba in Jordan. The Red Sea covers an area of approximately 450,000 km² and spans about 1,930 km in length. The Gulf of Aqaba is around 180 km long with an average width of 20 km (Batayneh et al. 2014), while the Gulf of Suez is about 300 km long with a maximum width of 50 km.

Water depth

Deeper water could mean higher installation and maintenance costs, but also more flexibility in choosing locations. The Red Sea generally has water depths of 60 meters or more, with the deepest point reaching approximately 3,040 meters. The Gulf of Aqaba has a narrow coastal plain, a maximum depth of about 1,676.40 meters, and an average depth of 800 meters. The rest of the Red Sea coastline, from the convergence of the Gulf of Suez and the Gulf of Aqaba to Bab Al-Mandeb in the south, has a maximum depth of around 1,219 meters (Ryan et al. 2022)    .

Wind speed

Higher wind speeds lead to higher power output and lower energy costs. In the Red Sea, wind speeds are generally favorable for wind energy harvesting. On the northern west coast of Saudi Arabia, wind speeds range from 4.11 to 11.83 meters per second (m/s), typically between 7.17 and 8.75 m/s. In the central-west coast region, between the coastlines of Makkah and Madinah provinces, average wind speeds range from 6.11 to 7.83 m/s. On the southern west coast, in Jazan Province, average wind speeds range from 5.11 to 6.17 m/s (Windy 2023).

KSA Maritime Boundaries

Installation of large structures is always a challenge, especially when it is in the middle of the sea. However, unlike fixed offshore wind turbines, part of the FOWT installation is done onshore on a floating structure before it is moored to the desired location and tethered to the seabed. The sheer size of the wind turbine components means they need a dedicated large area in the port for installations. On its Red Sea coast, Saudi Arabia has six of its 11 ports. Saudi Arabia is endowed with a strategic geographic location along the East-West shipping lane, where around 13% of international trade passes through the Suez Canal.

Red Sea ports

Installation of large structures is always a challenge, especially when it is in the middle of the sea. However, unlike fixed offshore wind turbines, part of the FOWT installation is done onshore on a floating structure before it is moored to the desired location and tethered to the seabed. The sheer size of the wind turbine components means they need a dedicated large area in the port for installations. On its Red Sea coast, Saudi Arabia has six of its 11 ports. Saudi Arabia is endowed with a strategic geographic location along the East-West shipping lane, where around 13% of international trade passes through the Suez Canal.

Spatial assessment

Using maps and interactive geo-visualizations, GIS can effectively communicate complex findings and conclusions, making it a valuable tool for policy and decision makers. GIS is widely used for spatial modeling and analysis across various fields. When combined with decision support frameworks like multi-criteria decision analysis (MCDA), GIS can enhance situational awareness studies and suitability assessments. In this study, we use a simplified approach with binary analysis. By overlaying layers of favorable conditions, we identify areas where all these conditions are met.
‍
Our key assumptions include:

  • Wind speeds between 7-9 m/s.
    ‍
  • Locations within the contiguous zone.
    ‍
  • Water depths between 50-1000 meters.

Identified areas

The GIS suitability analysis identified the potential area for the development of FOWT. The highlighted areas indicate two promising regions for the development of FOWT projects. The first region is located off the northwest coast of Saudi Arabia and covers an area of 4593 km2. The second region is situated offshore of Yanbu and covers an area of 3862 km2. Both areas present an untapped potential for the development of FOWT. The technical potential for capacity deployment is estimated with the assumption that the whole area is available for development without any constraints. This is to give an initial read on the opportunities for this technology.

Capacity density

It is important to understand the concept of power (or capacity) density, which refers to the potential power output achievable from an offshore wind farm relative to its spatial footprint. Typically, the capacity density is calculated in megawatts per square kilometer (MW/km2). This metric is influenced by several variables including the specifications of the wind turbines, the quality of the wind resource, and inherent array losses. A practical strategy to optimize power production is adjusting the spacing between turbines. This is needed to address the wake effect, whereby the wind leaving the turbine will have lower energy (i.e., speed) than the wind arriving at the turbine. Although increased spacing minimizes turbine interactions and subsequent interferences (i.e., the wake effect), it also diminishes the overall capacity density. Often, the distance between turbines is gauged using the rotor diameter, which gives a good proxy for the area of the wake that is created by the turbine.

Technical potential

The capacity density (CD) can be estimated by the equation adapted from (IRENA 2015):                                                               

Our analysis is based on NREL’s Annual Technology Baseline model turbine, which has a rated capacity of 15 MW and a rotor diameter of 240 meters. Typical turbine spacing is 6-8 rotor diameters. Applying the 6-rotor diameter spacing in primary and secondary wind direction, the capacity density would be 7.23 MW/km2. While applying an 8-rotor diameter spacing would yield 4.06 MW/km2.
‍
Multiplying CD by the available area for development, a range of technical potential for FOWT has been estimated.

  • The first region has an area of 4,593 km2 and shows a potential of 18.6-33.2 GW.
    ‍
  • The second region covers 3,862 km2 and has an estimated potential of 15.6-27.9 GW.
    ‍
  • The total technical potential for large-scale FOWT development across both regions is approximately 34-60 GW.

Conclusions

As the Kingdom advances in its energy and environmental aspirations, floating offshore wind resources can become a competing option in the long run. Although FOWT is an emerging technology, it is already at the commercial deployment stage. It offers the potential to substantially increase the amount of offshore wind that can be developed since FOWT can operate in water depths much greater than conventional offshore wind. This study conducts the first technical potential of FOWT for Saudi Arabia and finds that this potential ranges between 34-60 GW. The findings of this study highlight the considerable, yet untapped, potential of FOWT for Saudi Arabia, suggesting significant opportunities for large-scale deployment. The study highlights that Incorporating GIS methodologies alongside technical analyses can provide essential insights to inform energy policies. Further studies are needed to further refine the analysis and to analyze cost-effective deployment strategies. Successful deployment will also require extensive governmental policy support for its deployment infrastructure to garner the full economic and environmental benefits.

While challenges remain in the offshore wind sector—including high initial project costs, the need for new infrastructure, and the integration of wind farms into the existing power grid—this study highlights the critical role of government support, policy frameworks, and multi-sector collaboration in fostering the development of FOWT. The specific needs for port development are also highlighted. The capability of the ports is strongly linked to the technical capacity deployable into the wind farms which in turn inform the requirements from industry and supply chain. Additionally, navigating the challenges posed by competing interests on the Red Sea, including tourism, marine life conservation, and security concerns, necessitates careful planning and stakeholder collaboration. The successful integration of FOWT could help diversify the clean energy mix for the local demand, but also open opportunities for energy export, whether through direct electricity connections to neighboring countries or in the form of ammonia produced on site and shipped to demand centers. This development would also contribute to global efforts to curb carbon emissions, aligning with international climate change objectives to achieve net-zero emissions.

Publication

Researchers

Ahmed Al-Balawi

Nora Nezamuddin

Frank Felder

Abdelrahman Muhsen

Amro Elshurafa

Productization

Abeer AlGhamdi

Khawlah Alharbi

Quick Links

Our Products KAPSARC

Get In Touch

Email Our Team
© 2023, KAPSARC. All Rights Reserved