When the Sunreef 50 Eco-Electric catamaran was introduced last year it also launched awareness of EPTechnologies, the Swedish company that worked with them on the luxury yacht’s electric drive system.
Eco-electric catamaran has twin 35kW saildrives
The team decided on twin saildrives from EPT that are driven by 35kW IPM (Interior Permanent Magnet) motors. Behind them are 77kw batteries with lithium NCM chemistry (Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2).
To be clear, the Sunreef is not an all-electric catamaran, it also has a diesel generator onboard. So while it can’t promise to eliminate burning fossil fuel entirely, the goal is to run the generator only 2-3 hours per day rather than the 24 hours per day which is not uncommon on similar luxury boats.
That amount of usage would mean diesel consumption in the range 200-300L per week (50-80 GalUS) rather than 800-900L (210-250 GalUS).
We wrote about EPTechnologies during BOOT Düsseldorf because they were exhibiting a drop in sterndrive-inboard/outboard unit that makes it easy to bolt an EPT 145kW electric motor onto an existing Mercruiser setup. You can see it (but not hear it, it is incredibly quiet!) in action in this video of the production testing.
In addition to working with Sunreef and supplying both the motors and batteries, EPT has worked with other large companies in different roles, as they did with a Danish ferry project led by Danfoss.
Battery solution reduced diesel operation by 60 to 1
Danfoss was asked to address the situation of the country’s shortest ferry route. The ferry is quite busy, making about 6,000 trips per year and providing a lifeline for residents of Venø island in the remote Jutland. While its journey only takes two minutes, the diesel version of the vessel was burning through an astonishing 90,000 litres (24,000 gallons) of fuel each year!
Danfoss put together a team of experts, including EPT, who consulted on and provided the batteries for the refit. Because of stringent fire safety criteria, they decided on two LiFePo4 88kWh packages designed to ensure that even if there were a fire in one cell (highly unlikely with LiFePo4), it would not spread to the other cells.
The ferry still required a diesel back-up, but with the new electric system the use of the diesel generator was used only about 1/60th of what it had been running for previously: from 19 hours per day to only 20 minutes.
Electric motors for all types of boats
EPTechnologies was founded in 2014 by Kaspar Falkenburg, who has been involved in electric marine propulsion for almost two decades. While their work on the Sunreef Eco-Electric catamaran raised their public profile, they have been working with other major companies such as Danfoss since the beginning.
Those projects have largely been in the industrial sector, though, on vessels like ferries and tour boats. What is changingfor them now is that the general public is becoming more interested in their electric motors for use in both sail and power boats.
Their saildrives and inboards are suitable for monohulls and catamarans up to 30 metres (100 feet) and they are also working with companies like Phillippi for real time operating data and Raymarine for integration with standard navigations screens. This is the future of electric boats – making it easy for companies and consumers to switch to electric and reduce fossil fuel use by the amounts EPT has so powerfully demonstrated.