Batteries have been used to drive thrusters on a drilling vessel for the first time, marking a further step in the deployment of hybrid technology in the offshore sector.
The 5.6-MW hybrid power and energy storage solution has been tested on the first of eight thrusters on Transocean’s vessel Spitsbergen. Hybrid power for the remaining thrusters is now being commissioned by Canadian engineering firm Aspin Kemp and Associates.
The thrusters will be able to operate independently of the main engines and power distribution system, allowing the engines to run at an optimised load. The separation of thruster power also reduces risk when station keeping in dynamic positioning mode.
AKA’s scope of supply includes the conversion to DP3 closed-bus operation and the addition of the hybrid power and energy storage system. The retrofit is underway in Norway while the drilling rig is in operation.
“The energy storage system at the thrusters is a new way of making the vessels safer by keeping them in position even during a potential failure of the power plant,” said AKA chief executive Jason Aspin. “This prevents them from drifting off the drilling location, which endangers the people who work on these rigs and our environment.”
Spitsbergen has eight fixed-pitch, azimuthing Rolls-Royce Aquamaster thrusters providing nearly 4.5 MW of propulsive power each. The semi-submersible rig is powered by eight Bergen engines rated at 5.27 MW, each driving an Alconza generator.
Transocean is not the only drilling vessel owner to deploy battery power. The diesel-electric generators on Northern Drilling’s vessel West Mira will be supplemented by Siemens’ BlueVault lithium-ion system when it enters service in the North Sea this year.
The solution consists of four converter and battery systems with a total maximum power of 6 MW. The batteries are expected to cut running time of the platform’s diesel engines by around 42%. That will cut CO2 emissions by 15% and NOx emissions by 12%.
Siemens has installed batteries on around 60 ships and has earmarked the offshore sector for further growth. It has opened an automated plant in Norway that will develop and manufacture energy storage technologies for both marine and offshore oil and gas applications.