ACORN poised to extend lifespan of tidal and wave devices

Coated specimens tested at the Marine Corrosion Test Site (Photo: CTC)

EU-funded ACORN project has developed an innovative aluminium-based coating said to extend the lifetime of marine structures, including tidal and wave energy devices.

The coatings, developed under the ACORN project which lasted for three years, can work on an array of offshore steel structures used for the production of renewable energy, including wind turbine foundations and wave or tidal energy devices, as well as conventional offshore infrastructures, according to the European Commission (EC).

Henry Begg, a researcher at the ACORN project, said: “As global energy demands shift, renewable energies will likely see the construction of more offshore energy installations over the next decades. Having these installations protected with the coatings developed by the ACORN project helps ensure that the production of sustainable energy is itself sustainable.”

When the new coating is used, not only do these structures enjoy an extended and virtually maintenance-free lifespan of over 20 years, the need for supplementary (and costly) cathodic protection is also reduced – or even avoided, EC said.

As a result, the project is boosting the competitiveness of the industry and helping to facilitate widespread roll-out of additional offshore technologies.

The ACORN project solution, now in it the commercialization phase, bases its technology on thermally sprayed aluminium (TSA).

In addition to providing long-term resistance to corrosion in offshore environments, according to EC, the TSA coating is also enhanced with a range of environmentally friendly, active anti-fouling substances that do not need to be released into the water.

“Steel structures in marine environments are subject to many forms of degradation, two of the most problematic being corrosion and biofouling. Although coatings to protect against such conditions exist within the shipping industry, where ships can be periodically dry-docked for maintenance, offshore structures are required to be moored in the water for extended periods of time and without ongoing preventative maintenance,” Begg said.

A series of specimens of different materials coated with the ACORN solutions were tested since 2013 at the Marine Corrosion Test Site (MCTS) El Bocal, close to Santander, Spain.

The project involved collaboration of the Technological Centre of Components Foundation (CTC), together with the Cantabrian company DEGIMA and other European partners including TWI Institute, the University of Göteborg, and the European industrial companies Wave Dragon, Tocardo Tidal Powr and Alphatek Hyperformance Coatings Limited.