Cruise completely silent and emissions-free in an eco-tender with MG batteries

Imagine you’re the very happy owner of a 50m Perini Navi sailing yacht, but over the years your needs have evolved. It’s not so much that you want a bigger boat, you’re longing for flexible cabin space for your guests and something more than a conventional RIB (rigid inflatable boat) to explore closer inshore to pursue your hobby of nature photography.

You purchase a vessel with the same graceful looks, quality feel and luxurious comfort as the mother ship, that provides additional accommodation and can operate independently as a 25m extension of your sailing yacht. It’s no ordinary tender, it’s an eco-tender, designed and built with a super yacht mentality with amenities and technologies to match.

For one, it comes with a sophisticated hybrid propulsion system developed by Siemens, which provides four operational modes:

  • Diesel mode: twin MAN diesel engines (2 x 1213 kW) power two Hamilton waterjets for a maximum speed in excess of 30 knots.
  • Hybrid mode: one engine drives its neighbouring waterjet and also serves as a generator for an e-motor to power the other waterjet.
  • Diesel-electric mode: a 130 kW generator supplies electricity for two e-motors to drive the waterjets.
  • Zero-emission mode: a 2 x 70 kWh MG RS Series battery bank powers both waterjets via the e-motors at around 8 knots for up to an hour.

Although close attention has been paid to minimising noise in all propulsion modes and keep contractual sound levels below 55dB throughout, it’s the last mode that allows you to cruise at low speed in marine parks or other environmentally sensitive areas, completely silent and emissions-free. Honestly, what more could you possible want?


Components used

  • 2 x MAN 1213 kW diesel engines
  • 2 x Siemens 150kW electric motor
  • 1 x Siemens Custom 135 kW generator
  • 2 x Hamilton HM531 waterjet
  • 2 x 10 RS Series battery modules (2 x 70 kWh)
  • 1 x MG Master HV




Preserving Venice by boarding a hybrid vaporetto with MG’s batteries

When visiting the beautiful city of Venice there are to ways to get around: on foot or by water. In case the former is no option, a vaporetto is the way to go. It’s Italian for water bus and a large fleet makes up a public transport network for the city and province, transferring hundreds and thousands of passengers each day, from the mainland across the lagoon, through the canals and to the nearby islands.

The increase of tourists and therefor transportation has a dangerous impact on the delicate environment of the lagoon in general and the canals in particular, with many precious historic buildings on their banks. The constant navigation and frequent manoeuvring generates a lot of waves and washing water, which in turn leads to progressive erosion of their foundations, draining them of sand and clay.

Operating conditions of a vaporetto are very particular. Due to the many stops, congested traffic, varying speed limits and timetable optimisation their navigation pattern show high acceleration and deceleration performances. The heavy sequence of stop-an-go transitions requires a very irregular power supply. When supplied directly by a generator, this would lead to high diesel consumption and high exhaust emissions.

Enter Liuto: an acronym for Low Impact Urban Transport water Omnibus. It’s a vaporetto with a low resistance hull and a hybrid energy solution, designed around two decades ago. The 300kW Siemens propulsion system used to be powered by lead-acid battery pack, which in turn was charged by a diesel generator running at constant speed. This way the engine could operate at its optimum efficiency level, minimising fuel consumption, pollutant emissions, vibrations and noise.

At the time the hydrodynamic impact was reduced by the optimised hull and propeller, while the hybrid energy solution was a good compromise between technical, economic and environmental requirements. Recently its lead-acid battery bank has been upgraded to MG’s RS batteries, two strings of eight modules each, controlled by a HV Master. Together they operate as peak power supply and energy buffer, under very high but short charge/discharge power levels.

This is what our RS Series excel at. Compared to traditional lead-acid batteries these lithium-ion modules can take in and push out a large amount of power in a short time. Liquid thermal management keeps the battery cells on temperature, to improve performance and extend cycle life. A redundant BMS, a unique cell-to-cell propagation protection and a built-in fire suppression mechanism take safety to the next level. As an added advantage they’re compact and lightweight.

Compared to steel or aluminium vessels with traditional propulsion systems Liuto is a beautiful example of a more efficient, more economic and more ecological solution even in a challenging application such as urban water transport. It generates less wave motion pollution, less air pollution and increases comfort for all passengers. Now it’s ready to serve another decade while protecting the delicate and valuable context of Venice and its lagoon, for both tourist and inhabitants alike.

Components used

MG’s safe and powerful solutions at the Electric & Hybrid Marine World Expo 2019

From June 25-27 we’re at the Electric & Hybrid Marine World Expo 2019, with a range of safe and powerful solutions we’re very excited to present to you.