Deploy high wave-resilient offshore floating solar

This case study has been developed in partnership with the Solar Impulse Foundation, which is promoting – through assessing, certifying and facilitating access to finance - the multitude of clean and profitable solutions currently available worldwide. Discover more of Solar Impulse Foundation’s labelled solutions here.

The Port of Sète is owned by the Occitanie / Pyrénées-Méditerranée Region, which established a Regional Public Establishment named Port Sud de France in 2008, to manage its three port concessions: the commercial port, the fishing port, and the marina. The commercial port of Sète is the second deep-water port in the French Mediterranean. It is a versatile port offering multimodal infrastructures, serving as an essential link in France's logistics chain and a gateway to Europe.

Since 2015, the strategic plan for the Port of Sète has included measures to balance port activities with its urban proximity, reducing environmental impact while enhancing economic benefits. This commitment, consolidated under the Smart & Green Port initiative, has become a priority for the 2021–2025 period.

In 2023, the hosting of the Sun'Sète project aligned perfectly with the port's renewable energy development strategy, initiated in 2014. This included the installation of over 46,000 m² of photovoltaic panels, with a second phase planned for 2025, featuring 16,000 m² of photovoltaic canopies for self-consumption.

SolarinBlue has developed robust floating solar technology for extreme offshore conditions, including waves exceeding 10 meters and winds up to 200 km/h, with minimal ecological impact and a lifespan of over 30 years. In Sète, the highest wave height faced by the technology was 8.7m in 14m water depth, and the floating structures remained functional in these conditions.

Such technology is helpful to address the following challenges:

Port decarbonization: Close to port and coastal industries, decarbonized electricity contributes to achieving carbon neutrality and self-consumption as opposed to electricity from the national grid.

Limited land availability: Where land is at a premium and minimal visual impact is required, SolarinBlue’s technology provides a way to reduce electricity costs and CO2 emissions.

Offshore wind colocation: Combining solar and wind generation generates synergies and cost savings on cables and substations, facilitating integration into the grid, boosting production by up to 30%, and reducing renewables intermittency.

SolarinBlue implemented the Sun'Sète project, to prove the relevance of offshore solar PV technology.

The company followed a structured approach:

1. Site identification: find a potential site where to deploy such solution, at almost 2km from the shore of the Port of Sète, under the administrative area of the harbour, beyond the breakwater.

Figure 1: Site location

2. Permitting: Collaborated with regulatory bodies for approvals, involving impact studies

3. Technical studies: Focused on anchorage, installation, and PV setup, considering site conditions.

4. Construction: Coordinated assembly with internal quality control, ensuring thorough oversight.

Figure 2: Assembly phase

5. Installation: Executed mooring, towing, and connecting to anchorages.

Figure 3: Two Floating Solar Units installed

6. Marine Behavior Study and PV production setup: Monitored offshore conditions to evaluate the impact on PV performance.

Sustainability impact

Climate

The project targets Scope 1 and Scope 2 emissions by producing green electricity and directly reducing dependency on fossil fuels.

The project demonstrated a GHG reduction through a 6% increase in electricity production compared to the closest rooftop solar installations (all correction factors taken into account), significantly contributing to the port’s decarbonization goals.

Nature

Offshore solar farms avoid land use and reduce land-use competition onshore.

The project’s design minimizes interference with marine life: the truss structure and the height of the panels allow water oxygenation, and 30% of light passes through.

Moreover, the solution promotes bio-fueling reproduction on floaters.

Social

The project provides clean energy, contributing to public health by reducing air pollution.

It also offers employment opportunities in the renewable energy sector, fostering economic growth.

Regarding the visual impact of the installations, it is completely invisible from 5km from the coast.

Business impact

Benefits

Beyond sustainability, the project enhances operational efficiency and reduces energy costs with a target Levelized Cost of Energy (LCOE) of EUR 50/MWh (megawatt hour) in optimal conditions. The project’s success demonstrates the viability of offshore solar, attracting potential investors and partners.

This solution provides a comparatively new form of renewable energy by leveraging the marine environment for solar power, addressing energy needs while conserving land ecosystems.

Costs

The project required significant initial investment, influenced by local conditions such as sun exposure (i.e. irradiance) and the marine environment (water depth and oceanic data).

Project’s Capital Expenditures (CAPEX) distribution is estimated as follows:

Operational costs are minimized through efficient design and maintenance strategies.

Planned and unplanned maintenance tend to overlap thanks to components redundancy and the fact that the peak of production happens during favorable meteorological conditions, differently from offshore wind where unplanned maintenance is an urgent issue during winter and it implies significant costs.

Subsidies and partnerships helped offset costs, making the initiative financially viable during early-stage Technology Readiness Levels (TRL).

Impact beyond sustainability and business

Co-benefits

The project promotes technological innovation in the renewable energy sector. It also raises awareness about the potential of offshore solar energy, encouraging similar projects worldwide.

Potential side-effects

Potential risks include challenges in maintenance. The solution addresses these by continuous monitoring and adopting adaptive management practices.

Typical business profile

This initiative is most relevant for:

• Energy companies

• Coastal industries

• Companies in regions with limited land for solar farms such as islands

It suits businesses at an advanced stage in their Net Zero journey, especially those exploring innovative renewable energy solutions. As mentioned above, ports, islands authorities and offshore wind developers are among the actors that showed the most interest so far.

Approach

Apart from the technical steps outlined in the Solution section, this initiative can be implemented by:

1. Conducting feasibility studies and securing necessary permits

2. Collaborating with technical experts for design and installation

3. Ensuring continuous monitoring and maintenance for optimal performance

Adapting these steps to local conditions and regulatory frameworks is crucial for success.

Stakeholders involved

Key stakeholders involved:

• Project leads: SolarinBlue management

• Company functions: Engineering, Project Development, Procurement, Construction Operations and Maintenance Teams

• Others: Regulatory bodies, local communities, and the Port’s Authority

Key parameters to consider

• The solution is today a proven technology with ongoing innovations, that will be fully implemented in the project’s next upgrade, Méga Sète, planning for 1MW capacity, at the same location

• The average lifetime of offshore solar PV is estimated operational life of 25 years

• A robust mooring system is necessary to face specific marine conditions (oceanic data such as waves and winds are needed already at the engineering phase)

• In regard to geographical relevance the solution is suitable for coastal regions with ample sunlight

• Availability of financial incentives and subsidies linked to the development of renewable energy projects must be considered, as it can significantly impact feasibility and economic return

Implementation and operations tips

• Address regulatory requirements early to avoid delays

• Engage with all local stakeholders to ensure community support at early stage

• Invest in high-quality materials and regular maintenance to enhance longevity

• Monitor environmental impact continuously and adapt practices as needed