Until recently fossil fuel electricity was much cheaper than renewable electricity, this is changing, renewable energy is growing fast in various parts of the world, and it is now less expensive than coal and gas.
Wind power has been the most widely used renewable energy, through onshore, inshore and offshore infrastructures.
A wind turbine is a device that turns kinetic energy into electricity, as the the winds rotates the turbines blades, which turn a shaft and the gearbox to create electricity.
The electricity from the generator goes via cables to an offshore transformer jacket platform, and then to offshore substations, where it is converted to the right voltage. Underwater cables carry electricity to an onshore main substation, which will convert electricity again for the grid or local network.
Generally an offshore wind farm consists of Offshore turbines, accommodation platforms, substations platforms. The installation of the infrastructures includes the foundations construction (pales) for turbines and platforms support, protection structures (scour), stabilization (mattress), etc. Then the laydown cable tasks begin.
The Offshore and Inshore wind farms sector have created lots of work for commercial divers, constantly engaged in several situations. Work activities that require diver intervention include the installation of concrete mattresses used to protect subsea cables and as scour protection around underwater facilities (pales, jacket platforms), sand or grout bags placed under a span as a cable support, cable or bend protection system installation to protect the exposed cable from fatigue and abrasion, post works surveys, anode replacements (Al-based galvanic anodes), Nondestructive Testing (NDT), subsea cable installations and repairs, Unexploded Ordnance (UXO) Surveys, etc.
As the demand for renewable energy continues to grow, there is a growing and urgent need for specific skills to support the energy transition. Commercial diving plays an important role in the various stages of installation or decommissioning tasks.
Read more in the digital JP Mag – JPmag – October 2021
Paolo Mazzone
SubEng – HSE Adviser
They are bags filled with cement or grout and used to correct free spans conditions.
Concrete mattress or Articulated Concrete Block Mattresses (ACBM) consist of a prefabricated concrete blocks connected by polypropylene rope.
Cable free span occurs when a cable part is not supported by the seabed. In other words cable extends between the highest points of seabed.
Cover: Navy divers assigned to the Chilean Buzo Salvatoaja, walk along the ocean floor during diving operations, by U.S. Navy photo by Mass Communication Specialist 1st Class Jayme Pastoric, from flickr.
