Iberdrola considering two-turbine floating installation at Baltic Eagle

Iberdrola floating offshore wind department manager Ignacio Pantojo Titos told an 8 December 2020 webinar on the floating wind market organised by the Asia Wind Energy Association that the company believes floating wind turbines may be better suited to some parts of the Baltic than bottom-fixed turbines.

Mr Pantojo Titos said this is because of the complex and variable nature of the seabed in some parts of the Baltic, which can make punch-through of the legs of a jack-up vessel a potential issue, and because the variable nature of the seabed could mean that, in some locations, piling a bottom-fixed foundation could be problematic.

In the Shallow Float project, Iberdrola wants to determine whether floating wind projects are potentially applicable in the Baltic – and other areas.

Mr Pantojo Titos said the project “could open the gate” to the use of floating wind in shallow water. “Certain areas in the Baltic are not suitable for bottom-fixed offshore wind, so we are evaluating the feasibility of installing two floating turbines that would be connected to the windfarm,” he explained.

Iberdrola’s floating wind manager defined shallow water as water depth of less than 50 m, although in the area under consideration for the Shallow Float project the water is approximately 45 m deep. He described the metocean conditions at the sites it is considering as ‘mild’ but the seabed conditions are very challenging, with a 10-20 m layer of unconsolidated mud with no bearing capacity.

“We want to prove that floating solutions are feasible in shallow water, “ he concluded. “If we can, it will reduce installation costs and reduce risk.”

The company hopes to secure an ‘innovation tariff’ for the Shallow Float project, which would be approximately 50% higher than the commercial tariff.

The 476-MW Baltic Eagle project is due to be commissioned in 2023. Iberdrola selected MHI Vestas Offshore Wind as supplier of turbines for the offshore windfarm. The contract awarded to the OEM includes the supply of a maximum of 52 of the company’s V174-9.5 MW wind turbines for delivery in 2022 and 2023.

Mr Pantojo Titos did not indicate which turbine and what kind of foundation would be installed if it decides to go ahead with Shallow Float.

Iberdrola was awarded the project in April 2018 in the second call for offshore tenders launched by the Federal Network Agency.