Floating solar systems to use recyclable materials in EU-backed project

Through its Construction Technology Center, Spanish company ACCIONA has unveiled a new circular, eco-friendly breakwater concept for floating solar systems as part of the EU-funded SUREWAVE project.  

This breakwater is designed to shield offshore floating photovoltaic (FPV) systems from harsh sea conditions, enhancing their energy output and lifespan. The project aims to develop sustainable marine infrastructure for renewable energy projects while promoting the use of recycled and circular materials.

The SUREWAVE project, supported by Horizon Europe, brings together a consortium of seven partners from six EU nations to develop a durable solution for FPV installations. ACCIONA is spearheading the work package focused on developing circular materials for the breakwater’s construction, with a particular focus on cutting the environmental footprint.

To achieve this, the company said that it has created two types of sustainable concrete. First, a high-performance concrete with a compressive strength of 120 MPa, which incorporates slag and fly ash to cut clinker, a major pollutant in cement production, by 20%, noted ACCIONA. This concrete’s strength allows for a 40% reduction in materials used.

The second material is lightweight concrete, developed with recycled glass and construction and demolition waste (CDW) aggregates, reducing its density to under 1900 kg/m³. 

This mixture also uses a cement containing blast-furnace slag, cutting clinker content by 35%. For the core of the breakwater, ACCIONA introduced a cellular concrete with a density of 365 kg/m³, further reducing the environmental footprint by using minimal cement and recycled glass.

These materials have been validated through a prototype, which is expected to be installed at the Port of Gijón in the near future, marking what is seen as a critical step toward sustainable marine infrastructure for renewable energy projects.

In November 2023, the SUREWAVE consortium carried out wave tank tests of the floating solar concept at the Maritime Research Institute Netherlands (MARIN).