Pioneers in Electric Propulsion have been around for a while but none have really taken off. Electric propulsion is still in the development stage and is not a mainstream product. One Company however the Finnish Oceanvolt has been pursuing this for 8 plus years. With their determination they have refined many aspects of the electric drive and we can see many examples on the water (see below).
Oceanvolts system includes the saildrive unit and special motor which is constructed and built to withstand the marine environment.
One of the great things about electric is you wont have to go to the fuel dock anymore. However Batteries and battery management will be the new issue. Instead of a dedicate battery for engine start you may have the opposite.
If you are considering an electric drive there a few major points to look at.
The weight of system; below in the Class 40 example you will see the motor and batteries have a total weight of 206 KG (453 Lbs) This is close to the weight of a 15HP engine and 200 lbs. of batteries. So with such a light motor the large battery bank keeps the system within acceptable range from a standard diesel.
Another question with electric is renewing energy in the battery bank. You cannot run forever or even a long time without replenishing the batteries. There are several ways to do this. Oceanvolts sail drive acts as a Hydrogenerator. When you are sailing the prop can spin when left out of gear and the spinning charges the batteries. Another source of energy on a long trip is solar or wind. You could also add another hydro generator like the Watt and Sea. For short trips you may get away with just shore power at the Dock. If you typically just use the engine for short periods in and out of the slip battery drain may be minimal.
While looking at an Electric system you need to make a full inventory of loads on the battery
Oceanvolt electric drives
Oceanvolt electric drives for new boats and retrofit. The system comprises the Display and throttle levers, the Oceanvolt AX Synchronous permanent magnet electric motor and the sail drive.
The Oceanvolt electric motor system is the result of over eight years of product development and testing. Tests have been conducted both in laboratory conditions and at sea. The sail drive is purposely made in marine grade cast aluminum coated with durable epoxy, including a sacrificial anode.
X Yacht installation
Show is the Oceanvolt SD8.6
Technology used in X-Yachts X-302: Name: s/y Sarastus Owner: Timo Gröhn Boat length: 9,1 m Beam: 3 m LWL: 8.05m Displacement: 3600kg Old diesel engine: Yanmar Company in charge of refitting: Leevene Electric motor system: Oceanvolt SD8.6 Electric motor system weight: 47kg Batteries: 2 x Torqeedo Power26/104 Lithium Battery capacity: 5.4 kWh Battery weight: 48.4 kg.
Electric motor system: Oceanvolt SD15 Electric motor system nominal power: 15kW Electric motor system voltage: 48 V Electric motor system weight: 50 kg Batteries: 8 x Valence U27-12XP Lithium Batteries Battery capacity: 14 kWh Battery weight: 156 kg
Oceanvolt SEA – Perfect match for multihulls
The SEA in Oceanvolt SEA® stands for Silent Electric Autonomy. Oceanvolt SEA® is a complete electric motor system for catamarans and sailboats between 20-60 ft. It provides everything from motors, batteries and chargers to charging with solar panels, wind turbines and generators, not to forget the powerful regeneration (average 2 kW @ 8-17 knots) by the motor itself. Oceanvolt SEA® also enables running the air conditioning system overnight without the generator.
Features of the Oceanvolt SEA: Silent and lightweight Easy manoeuvering with the sleek dual throttle lever Instant power when switched on Possibility to recharge batteries while sailing Minimal maintenance compared to diesel motors Ability to run your AC and other appliances without a generator
Oceanvolt electric drives
Pros & Cons
- Pros No more fuel Silent Hydro generator
- Cons Initial cost Charging
Oceanvolt Ltd is a European company focusing 100 % on electric propulsion for boats. Electric propulsion has many benefits in favor of traditional combustion engines when considering noise, simplicity and reliability. Oceanvolt strives to make the best use of the opportunities that a compact electric motor offers by starting R&D efforts from a clean table.