Imagine you and your spouse or partner gently navigating near Gothenburg at night on a restaurant cruise, but with almost no noise or vibration, and knowing that your beautiful moment is pollution-free.
If you live in or visit Gothenburg, you will soon be able to experience such a moment, as our Metstech team in Gothenburg is ready with the commissioning of a parallel hybrid propulsion system aboard the M/S Lyrön.
The owner of this lovely vessel is Börjessons Charterbåtar and our customer, the shipyard where the work is being carried out, is Ö-VARVET AB, a company for whom we have carried out other projects.
A parallel hybrid propulsion system is a propulsion system where the diesel engine and the electric motor (in this case, 50 kW) can operate simultaneously or independently to propel the vessel. It includes complete electric propulsion, HMI, automation, drives, charging and EMS.
Reduced emissions and noise are not the only benefits. Hybrid propulsion improves fuel efficiency by allowing the engine to run at its optimum load and switch between electric and diesel operation. Another benefit is improved manoeuvrability and performance, as the electric drive offers precise control and instant torque response. Maintenance and running costs are also reduced as the electric drives have fewer moving parts and, if that were not enough, the vessel has redundancy by having two independent power sources.
You may be wondering what the main challenges are in adding such a parallel hybrid powertrain. Before we get to the electrical work, let’s talk about two issues that may seem mundane but are critical: weight and space.
Retrofitting a ship with new hybrid propulsion systems means adding significant new components such as batteries, motors, power electronics and wiring, with each component adding weight that wasn’t considered in the original ship design. On the other hand, ships rarely have space for additional equipment as the original design rarely allows for additional electric propulsion systems or extensive battery storage.
As far as the electrical features of the system are concerned, M/S Lyrön has:
1) Software systems that control the operating mode between harbour, electric or diesel;
2) Power electronics that convert DC battery power to AC engine power (drives);
3) Onboard equipment for recharging batteries from shore, generators, or renewable sources (charging system);
4) Software/hardware solution that manages the energy flow between engines, batteries, electric motors, and loads(EMS).