E-propulsion I-Series (inboard)

[DangerousPirate]

Something I just found out about, that is very, very little known about. E-propulsion is best known for their electric outboards but apparently, since very recently, they also offer inboard engines! Wow!

Sounds really cool if I am honest. But I am not sure if it is really worth buying as it is, or if someone should stick to a regular diesel engine.

For me, the biggest issue seems to be the battery. The capacity, how long you can run the engine with the power you have, and how long it will take to charge.

There is no real question here, because I have my engine and I don't plan on replacing it any time soon. Just wanted to share and hear what you people think. Might be an interesting topic.

 

[dunedin]

There are an increasing number of electric inboard engines becoming available. OceanVolt also expanded their range, and the huge Brunswick Corp (make Mercury outboards amongst loads of other things) are launching new options.
But electric motors are the easy and cheap bit. Been around on boats for hundred years or more.

It is the batteries that are the more complex and costly bit of need any decent range (though many usage cases don’t)

In 30 years most yacht auxiliary motors will be electric. As for now, really depends on how you want to use your boat.

PS. a lots of YouTube watchers who can’t do maths quote Sailing Uma as proving it is viable - but in a recent report they claimed they never motor for more than 30 minutes, and never do more than 4knots. So their battery range is a bit higher (circa 40 miles I think at 4 knots), but they claim never to use an engine list most other yachts

 

[DangerousPirate]

There are an increasing number of electric inboard engines becoming available. OceanVolt also expanded their range, and the huge Brunswick Corp (make Mercury outboards amongst loads of other things) are launching new options.
But electric motors are the easy and cheap bit. Been around on boats for hundred years or more.

It is the batteries that are the more complex and costly bit of need any decent range (though many usage cases don’t)

In 30 years most yacht auxiliary motors will be electric. As for now, really depends on how you want to use your boat.

PS. a lots of YouTube watchers who can’t do maths quote Sailing Uma as proving it is viable - but in a recent report they claimed they never motor for more than 30 minutes, and never do more than 4knots. So their battery range is a bit higher (circa 40 miles I think at 4 knots), but they claim never to use an engine list most other yachts

Exactly my concern. What use is the engine, if it depletes my batterbank in 2 hours? That is enough to get in and out of the harbour, but what if there is foul weather? Then I am screwed. Uma has an eletric engine? Do you know which one they opted for? I'll go and have a look now and try to find a video about their engine.

Brunswick Corp is an interesting name, I was born in the name giving city. Glad to see it makes its rounds

 

[Kelpie]

Depends entirely on your needs.
Here in the Caribbean I think it could work well- lots of solar potential, short passages, and generally sailable angles. And unless you're on a charter, your generally don't have deadlines to meet.

Unfortunately a large proportion of new boats are built for the charter market, who need or want to cover quite a few miles in a short period, regardless of conditions. It's not a great match for them, so ex charter boats will continue to arrive on the market with diesel inboards.

 

[lustyd]

That is enough to get in and out of the harbour, but what if there is foul weather?

They're aimed at sailing boats

 

[dunedin]

Exactly my concern. What use is the engine, if it depletes my batterbank in 2 hours? That is enough to get in and out of the harbour, but what if there is foul weather? Then I am screwed. Uma has an eletric engine? Do you know which one they opted for? I'll go and have a look now and try to find a video about their engine.

Brunswick Corp is an interesting name, I was born in the name giving city. Glad to see it makes its rounds

Don’t bother with looking up Uma - they don’t use as a normal engine, and very low range.
To save you looking they have had three engines in about 5 years - a simple electric motor on the existing shaft drive, then a cast off OceanVolt saildrive (donated by one of their supporters?), replaced within a year by a sophisticated OveanVolt 15kW pod drive with natty variable geometry prop to give better recharging.

 

[DangerousPirate]

They're aimed at sailing boats

And sailboats don't get into rough conditions?

 

[DangerousPirate]

OveanVolt 15kW pod drive with natty variable geometry prop to give better

Sounds nice? I wonder how many amps the engine eats up. Difficult to find any information on that. Even on epropulsion. With that one could calculate the required power.

 

[lustyd]

And sailboats don't get into rough conditions?

Yes, but they use their sails in those conditions even with a diesel engine.

 

[Tranona]

Sounds nice? I wonder how many amps the engine eats up. Difficult to find any information on that. Even on epropulsion. With that one could calculate the required power.

Plenty of information available, particularly if you do a search on here as there have been regular threads on the subject.

Just as a taster spend some time on this site
oceanvolt.com/solutions/systems/sail-drive/
and you will get a good flavour of the current state of play with the sort of costs involved and what you can expect in terms of performance and range - plus of course the eye watering sums these systems cost.

The shaft drive motors as already noted have been around for 130 years and successfully used where range and speed are not critical. New entrants like the ones you link to are relying on battery technology developments to widen the market, but are still a long way from being a viable alternative for cruising yachts.

Just as an example a basic electric package for a boat like yours cost about 50% more than a diesel and will give you a range of about 60 miles at 4 knots. Some people can live with that.

 

[dunedin]

Sounds nice? I wonder how many amps the engine eats up. Difficult to find any information on that. Even on epropulsion. With that one could calculate the required power.

The Uma OceanVolt system runs at 48V. So simple maths 15000W / 48V = 312A. Needs BIG cables.

It’s why most of their units to date have been 15kW or less.

Now going bigger voltages to allow bigger drives. But in some markets that means no DIY allowed needs qualified professionals.

 

[lustyd]

15000W / 48V = 312A. Needs BIG cables

50mm cable is standard on most yachts and would cope with this. 70mm isn't a huge stretch and does 485A. Many AWBs have 95mm cables from the factory

 

[Alan S]

Sounds nice? I wonder how many amps the engine eats up. Difficult to find any information on that. Even on epropulsion. With that one could calculate the required power.

Required power is 15kW.
Required energy as many kWh as you can carry or afford.

 

[lustyd]

Required power is 15kW.
Required energy as many kWh as you can carry or afford.

incorrect. Max power is 15kW. Required power depends very much on your use of the throttle and sails. Motor sailing makes it more efficient as Uma demonstrated recently heading to Majorca

 

[boomerangben]

If I was in the market (I’m not) for a new yacht, I would seriously look at going all electric (including cooking). To discard x kilos of engine, fuel and tank, gas bottle and spare would give a substantial mass of battery and therefore kWh storage capacity. Of course issues such as engine maintenance , over wintering, fuel bug issues, cooling issues, gas leaks etc all disappear too. Agreed, there are new set of maintenance challenges and skills to learn but it has to be simpler than looking after a vibrating mass of moving parts requiring oil, grease, seawater and protection from any excuse to corrode. If you had a boat that sailed well (and a crew happy to go to windward) with a decent regenerative prop system and supplementary solar and wind together with occasional marina mains top up, we must be close to if not already at technological viability. OK many might want to compromise of performance, personal polar graphs, and time constraints for whom diesel is more optimum, but otherwise it’s just the cost that’s a hurdle. And it’s a big one. But with more players entering the market, it won’t be long before cost start to come down.

 

[fredrussell]

^^^ Agreed. My boat has a 30 year old Yanmar that’s chugging away happily with no sign of giving up any time soon. But when it does I’ll stick an electric motor in there.

 

[AntarcticPilot]

Sounds nice? I wonder how many amps the engine eats up. Difficult to find any information on that. Even on epropulsion. With that one could calculate the required power.

15kW at (say) 12 volts requires 1250 amps, assuming no losses. Of course, that's flat out and would flatten any reasonable-sized battery PDQ. Basically, to use one of these requires factoring in battery storage from the design stage. Also, lead-acid batteries probably aren't a good choice as only about half the nominal capacity is actually usable. If you could incorporate the Battery and BMS from an EV you might get somewhere.

 

[Pete7]

Don’t bother with looking up Uma - they don’t use as a normal engine, and very low range.
To save you looking they have had three engines in about 5 years - a simple electric motor on the existing shaft drive, then a cast off OceanVolt saildrive (donated by one of their supporters?), replaced within a year by a sophisticated OveanVolt 15kW pod drive with natty variable geometry prop to give better recharging.

In the past 5 years they have sailed from the Caribbean up the Eastern US seaboard, across the Atlantic, into the EU, up to Norway, across to Svalbard and back down to the med. Not too shabby. Ocean Volt use AC voltages for the electric motor and I think PWM to control the speed. There are DC motors like Lynch made in Devon which powered the late Queen's barge in 2012.

This graph is some numbers from a Cal 34 fin keeled yacht, but likely to be similar for 31-35ft yachts, hence my interest.

 

[lustyd]

15kW at (say) 12 volts requires 1250 amps,

Pretty none of the inboard ones are 12V. 48V is common and I believe they are increasing that too.

 

[dunedin]

In the past 5 years they have sailed from the Caribbean up the Eastern US seaboard, across the Atlantic, into the EU, up to Norway, across to Svalbard and back down to the med. Not too shabby. Ocean Volt use AC voltages for the electric motor and I think PWM to control the speed. There are DC motors like Lynch made in Devon which powered the late Queen's barge in 2012.

This graph is some numbers from a Cal 34 fin keeled yacht, but likely to be similar for 31-35ft yachts, hence my interest.

Lots of people have sailed the world with no engine at all.
But in a recent article in our host’s magazine YM, Uma claim never to have motored for more than 30 minutes. If that is your requirement for an auxiliary engine fine (though probably not worth spending all the money on an OceanVolt saildrive unless you get it FoC for publicity purposes).
But most people want to be able to make more progress than that when the wind has dropped, need to do a crossing ahead of bad weather, or just get home for work.