When one of the world’s largest wind farm operators requested a hybrid-powered crew transfer vessel, they looked to Volvo Penta for propulsion options. The end result utilizes electric Inboard Performance Systems, five variable-speed Volvo D8 gensets and two D13 diesel engines.
A battery pack will complement the power to support peak-shaving and allow the vessel to operate in full electric mode at low speeds.
Set to launch in the summer of 2021, the 112-foot vessels will feature eight cabins and carry up to 24 crew. They will run workers out to wind farms located 56 and 65 nautical miles off of England’s Yorkshire Coast.
Efficiency was the paramount objective, and the engineers at Volvo worked with Danfoss Editron — which specializes in electric and hybrid propulsion — to come up with the hybrid power plants.
“One of the best ways to advance our technology is to take on these bold projects and work collaboratively with other technology leaders,” said Volvo Penta chief technology officer Peter Granqvist in a statement. “This project is teaching us a lot about experimental technical solutions, and we are excited to see the outcomes and learn more.”
The vessels will use quad drives for propulsion: two electric and two diesel. The main source of power for the electric propulsion will come from five Volvo D8 gensets. These smaller gensets offer variable speeds combined with a selectable option to run one or all of the gensets to lower downtime and increase efficiency.
Additionally, the gensets can be replaced by fuel cells or similar technology as it becomes available. Perhaps the most exciting part of the system are the electric IPS drives themselves, which will be powered by electric motors supplied by Danfoss Editron.
Once proven in the waters of the North Sea, it wouldn’t be a surprise to see similar electric options filter down to recreational boats.
The crew vessels will be capable of operating fully electric or in a hybrid mode. When cruising to the wind farms all four Volvo Penta IPS can be used. When transiting the harbor at idle speeds or at the wind farm, the operator can make a switch and run the vessels with the battery pack powering the electrical Volvo Penta IPS legs or any combination of one to all five gensets, depending on weather conditions.
Volvo estimates the hybrid option will save about 127 metric tons of CO2 compared to traditional, diesel-powered vessels.