By Andy Martin, Chief Commercial Officer, Verlume

Underwater inspection has seen huge advances over the last four decades, with the sector becoming continually more autonomous with technology advancements, including establishing docking systems for remotely operated vehicles (ROVs) and autonomous systems for long-distance surveying.

Now, as the importance of underwater infrastructure becomes more prevalent amongst national security concerns, the oil and gas industry is migrating towards two options for the future advancement of these systems: mothership deployed vehicles or subsea resident vehicles.

A recent example of this continued innovation is the operator TAQA who announced a pilot project with offshore survey company Fugro, where an uncrewed surface vessel is being used in conjunction with an electric ROV to inspect two platforms in the Dutch North Sea. This is said to be the first project of its kind in the world.

A New Approach to Infrastructure Design

Verlume is currently developing its own concept to create in-field resident AUV charging and communications stations for prolonged underwater inspection or survey missions.

As part of the Renewables for Subsea Power (RSP) project, where a Verlume Halo battery energy storage system is currently connected to a Mocean Energy Blue X wave energy convertor offshore Orkney, a Transmark Subsea autonomous underwater vehicle (AUV) charging dock is integrated onto the Verlume unit for remote recharging from a renewable source (image below).

Further building on the integration as demonstrated in the RSP project, Verlume’s new concept will demonstrate that AUVs can dock, recharge batteries, upload data and receive new mission data without requiring offshore intervention.

The concept will look to utilise Halo as the seabed recharging unit which is capable of recharging a fully functional AUV multiple times. The Halo is connected to the surface by a tether leading to a communications buoy that transmits mission data back to shore, receiving new mission parameters via return over-the-horizon communications.

New Concept, New Benefits

A key benefit of the system is that it has lower operational emissions than existing methods that involve topside crewed vessels, as the system has the capability to be powered in-situ through a range of renewable energy sources such as wave, wind, tidal or solar.

In addition, by reducing the reliance on topside vessels the number of vessel days required significantly decreases as well as the number of launch and recoveries to a host vessel, the area where most incidents with AUVs and ROVs occur offshore. As well as this, by providing launch from shore, the cost and safety implications associated with sending personnel offshore also decreases. Safety and reliability can therefore be improved, as complex offshore handling systems are removed.

There is commercial value in using this concept over several sectors of the blue economy, including offshore wind, and especially floating wind, where a significant amount of new subsea infrastructure will be required as the industry grows at pace to meet international climate targets. Other sectors where this concept will be valuable are oil and gas, carbon capture and storage, defence and security.

As specialists in intelligent energy management and renewable energy integration, we are working hard to create innovative solutions such as the resident AUV charging station in the charge towards further autonomy in this space.

Article published in OGV Renewables Magazine: