ePropulsion Spirit 1 EVO hydrogenerator in YM

[Neeves]

Could work well with a trimaran....

With things in our favour we can average 10 knots over 100nm. The generation ability looks very interesting.

I wonder how you secure it to your transom - it will need some hefty fixtures. In seas we can take water through our transoms and over the cockpit sole (good for cleaning the aft decks). Our cockpit clearance above sea level is 1 metre. For a conventional outboard this would mean the outboard would be alternatively swamped and/or then the prop lifted completely out of the water . It merits note that to average 10 knots you will be making 6 -16 knots - and I note the unit cuts out over 10 knots.....? At 16-20 knots we take a lot of the sea belting the underside of the bridge deck -takes some getting used to - but those same seas are going to hit anything hanging beneath (or at a level below) the bridgedeck......?

A WattnSea, from memory (and I did not look in too much detail as they are expensive) has a major bracket and the shaft is quite long (keeping the head high out of the water).

Its a great idea but hardly innovative - to me its obvious - there needs to be a bit more detail (which might be in the article ).

I've now read the Nestaway post which answers some of my comments - but I'd worry about swamping and the prop running above the water which (if nothing else) will reduce output. I would agree that at 10 knots our Aquagen 4 generates so much power you, almost, don't know what to do with it. Desalinators make a good use of power, run the bread maker . My worry would be swamping the head and belting it with big seas (when making 10 knots (average).

But its very interesting

Jonathan

 

[[2574]]

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[PeterWright]

Battery capacity is normally measured in Amp hours or Watt hours - it is a measure if energy, not power. Power is the derivative of energy, measured in Watts or, in archaic societies, in horsepower.

There is no way a battery can have a capacity of 1 kW.

To deliver power of 3.3hp, the motor must have an output power of 2.46 kW, hence my confusion over the description. It's nothing subjective, just a scientific fact, like a 40 foot yacht must be 12.192 metres long.

Peter.

 

[Pete7]

There is a German alternative to the Watt and Sea but its still E1750 so the epropulsion looks the better option:

SailnSea

 

[lustyd]

To deliver power of 3.3hp, the motor must have an output power of 2.46 kW, hence my confusion over the description. It's nothing subjective, just a scientific fact, like a 40 foot yacht must be 12.192 metres long.

Sort of true, but in this case also sort of not true. The maximum power of the motor vs engine probably would be directly comparable, but that's not what they're saying. The comparable power is the ability of the outboard unit in its entirety to push a boat forwards. This is not the same thing, since electric motors can drive different props which may stall a petrol unit at low revs. As such, it is a bit subjective because you have to add some caveats around what you deem to be comparable propulsion.

 

[Ningaloo]

you have to add some caveats around what you deem to be comparable propulsion.

Subjectively it feels like the ePropulsion gets going quickly at low power, but reaches a point at about 50% power after which the speed increase is slight. There is no gps in the ePropulsion control unit so I don't know actual speeds (but they may be available on their website) but it feels like I reach (maybe) 4kts at 50% power which gives a battery life of 3+ hours, then 5kts at full power but only 1.5 hours battery life.

 

[PeterWright]

I accept that an elecric motor will produce massive torque at low revs compared to an internal combustion engine which generally needs 90% of max rpm to get to peak power. However, when you open the throttle of a petrol outboard, it reaches peak power in a very short period (?2 seconds). Such a sort period waiting for full power is hardly significant in the performance of a yacht tender that is unlikely ever to exceed 5 knots.

I still fail to see how a power quoted in one system of units can be described as the equivalent of around double that power quoted in a different set of units. Would you find a statement "1 kW equivalent to 2.238 kW" to make sense? because that is the exact meaning of "1kW equivalent to 3 hp"

Peter.

 

[lustyd]

I feel like you're missing the important thing here. If a petrol unit with a given prop can accelerate a boat and achieve a given speed, then ANY device which can accelerate and achieve that same speed in the same time is equivelant regardless of the actual power output of the power unit. Petrol devices cannot use their full power effectively because they stall if a prop is installed which might take advantage of their ultimate power, so top end is compromised. Acceleration is compromised because the engine needs to ramp up slowly. I can absolutely see a scenario where an electric unit with half the capacity will beat the petrol one.

If you accelerate sub optimally for 2 seconds, and achieve a lower top speed due to the suboptimal prop, then why is ultimate power important?

 

[KompetentKrew]

I don't think there's much point in arguing about the power-equivalence of electric vs petrol outboards - everyone who's considering buying one knows that there are a bunch of reasons why comparisons are inexact.

Nestaway say on their site:

We have often heard of people being told the (now discontinued) 1003 is equal to a 3hp petrol outboard (and the 503 to 1.5hp). We consider that to be slightly misleading if you take it literally, as a 3hp petrol motor will get many small, lightly loaded craft of the right hull form “on the plane”, and a Torqeedo 1003 won’t. The propeller supplied is not even designed for that sort of speed (it’s rated 9kmph at 790W, or about 5.5 knots flat out). Where the Torqeedos excel is pushing surprisingly heavy loads (when the 3hp petrol wouldn’t get you on the plane anyway) at up-to-displacement speeds. They’re more than happy pushing a 9ft inflatable dinghy with 4 people in it at about 5 knots, for example.​

So we’d happily say the Torqeedo 1003 and 1103 are equivalent to a 3hp petrol outboard, for the way most people use them most of the time, but not equal. The new 603 is more akin to a 2hp petrol outboard motor.​

The acceleration up to those displacement speeds is also impressive, as electric motors (unlike petrol ones) generate full torque from very low revs. So the Torqeedo outboards have lots of low to mid-range push, but not the whizzy top end of a petrol. Unlike “trolling motors” they will be genuinely useful as a main propulsion unit – just not for anything much over 5 knots (10kmph).​

Further down the page, they discuss range:

BUT, in most typical small boat applications, half-power or 500W on the 1103 isn’t much slower than full power – and then it should last approx 1hr 50mins. 500W on a typical 9ft dinghy is somewhere around 4.5 knots. Whilst that is not enough for everybody it is enough for a lot of users, if you think about how you actually use it.​

Most users therefore find the Torqeedo 1103 has a realistic range of 8-10 nautical miles, if they’re happy with 4 to 4.5 knots. Slow down to 3.5 knots and the range skyrockets, as power used increases/decreases by the cube of speed. At 2 knots the range is meant to be huge, but we’ve never had the patience to find out!​

On another page they say:

Torqeedo claim 35 miles at 2 knots (for their 915Wh battery); we don’t want to sit in a boat going at 2 knots for 17 hours to prove or disprove it!​

Being able to push along a loaded dinghy, carrying 2 or 3 people, luggage and provisions, not very fast and being able to reliably go a mile or two and back - several miles at a push - seems to me like a very fair equivalence with how most people use 3HP petrol outboards. I've never owned a 3HP motor, but their claim about "happy pushing a 9ft inflatable dinghy with 4 people in it at about 5 knots" seems very good indeed to me.

The above is quoted from the Torqeedo page on Nestaway's site - you have to scroll quite a way down to find it and if Nestaway are reading, can I suggest you break the power comparison: electric vs petrol section out into a separate page of its own? They also share informative opinions on their ePropulsion page.

I have a 9.8 two-stoke, the well-known Tohatsu, that I love - with it, the dinghy gets immediately on the plane and goes fast. However it is a bit heavy to handle alone, between boat and tender at anchor, and was considering a 3HP two-stroke as spare and for short trips. It would probably only cost me a couple of hundred quid, and I wouldn't consider an electric outboard were it not for this promise of regenerative battery charging.

 

[Neeves]

As a regenerative unit forget the maths. As I've said the shaft length for an outboard on a dinghy is, commonly, shorter (for a variety of reasons) than that needed for a hydro-generator. Don't get sucked into the concept unless the shaft is, much, longer. It is simply too expensive unless you are only going to generate power in flat water. As there is no, or a very limited, market for a long shaft electric outboard and a short shaft regeneration unit will either constantly break the water surface or be swamped (or both) they need to introduce some means to extend the shaft - not difficult, but not yet offered. If you attach a unit to your transom, think expensive bracket, you will only generate power worthy of the cost of the unit in decent wind, when you will be well healed and seas are choppy. Alternatively the head needs to be offered with sufficient water proof guarantees (which I suspect is more difficult/expensive than extending the shaft). I note that all electric outboards I see are used in flat water - where flooding of the head would simply not occur.

The environment in which a regenerative unit is to be used is totally alien to the environment in which an electric outboard is used.

The bearings necessary for the 'outboard' function are unlikely to be the same bearings needed to generate power, say crossing the Atlantic (so long term regeneration usage) at 10 knots.

Currently, based on our experience - as a regen unit - its an expensive lemon

I notice that Nestaway are not responding to my comments (and I am sure they are following this thread - of if not their marketing is appalling). But if they sell the device as an outboard for the tender of a yacht (fine) but when used as a regen unit (in the way implied) they are going to have a flood of complaints - which will stick with the concept and Nestaway for years to come.

I'm waiting for Nestaway to come back and tell me my comments are all rubbish and they have engineered the device to answer all my doubts (and no they do not pay me to provide a vehicle for them to extend their marketing efforts .

Keep your wallets tightly closed.

Jonathan

 

[KompetentKrew]

I notice that Nestaway are not responding to my comments (and I am sure they are following this thread - of if not their marketing is appalling). …

I'm waiting for Nestaway to come back and tell me my comments are all rubbish and they have engineered the device to answer all my doubts (and no they do not pay me to provide a vehicle for them to extend their marketing efforts .

Mate, it's Christmas. Some people have lives and families - I don't, but many people do, and those running their own business deserve themselves a break at times of year when the public will tolerate a closed shoppe.

I deliberately didn't ping Nestaway by using their @ when I replied to this thread, but sent them an email asking their opinion so they could respond at their leisure. I was appreciative of your comment of this morning (last night, I guess your time) and have been cogitating on it (I'm inclined to think you're right, and I'll have to spring for an expensive Watt & Sea or DuoGen), but I think you're being a bit unreasonable thinking that a tradesman should reply to you within a few hours on a bank holiday.

Also, Nestaway are not the manufacturers of this unit - they are "main dealers" for both Torqeedo and ePropulsion.

I believe shaft length is a bit longer than a petrol outboard due to the larger diameter prop, but probably not significantly enough to overcome your concerns.

 

[Neeves]

When we ran our own business we worked, effectively 24/7 - we lived in HK and supplied into China from sources in the UK and US. If we did not work 24/7 how else are you going to speak to suppliers and customers in their time zone. Its the problem of running a small business. Maxwell (a significantly bigger business), the windlass people, have a man on stand-by 24/7, they have a rota, this includes Xmas Day - because they sell leisure products and people use their products, primarily at weekends and holidays. Responding to queries 24/7 is how to engender customer loyalty and a decent reputation when you sell to the leisure industry.

I don't expect anyone to answer any of my queries, ever. Its a forum and I'm not a customer. BUT - I'd be happier buying from a supplied that does react - especially during holidays - as it shows a commitment and maybe if I have an issue on a Sunday I can expect a response. I had an issue with our windlass (and some one I know had a different problem with their windlass) - both were owner's installations and both operator error. I had a manual overnight, which I already had (which was also our night) by email, and (importantly) a list of things to check - problem solved. Do I recommend Maxwell - of course I do.

So if Nestaway do not react till after the holidays - is this an indication of the support they offer to customers who invest STG2,000 in a bit of kit, say on a Boxing Day.

Nestaway have chosen to have a forum presence, as Nestaway - so I have to assume they have made these decisions as a mechanism to improve their marketing. Their choice. Other companies do not become members of this forum and I would not expect (Lewmar, North Sails et al to respond - but I bet they monitor. They can set up an alert to be notified of any new posts and they can set up a Google alert based on keywords such as Nestaway. They do not need to monitor every post - but just check their emails. Its not difficult and to me - professional. But maybe I am wrong and people selling leisure products should be able to ignore marketing opportunities that develop during times of leisure.

If someone in deepest China rang on a Sunday asking about one of our products - should we have told them to ring back between 9-5 on a weekday? Though it was difficult to respond from a 10m racing yacht in the middle of a race .

Its tough - but that's the business they chose to work in (and we chose to run our business 24/7 - no complaints - every customer had our home phone number - that was our choice. But don't blame me if my ideas are alien to others . If you have the answer at your finger tips - 10 minutes on a keyboard, or an apology - please wait till I can ask the manufacturer. To me seems simple.

I've pointed out what I consider is the harsh reality and from your post is seems the message has got through - maybe I should have not bothered (and spent the time with the grandchildren) and let you waste your money. If I'm right - just be grateful some of us bother, even though we too have holidays, children and grandchildren. If I'm wrong then Nestaway could be replying with an educated response, countering my post - and I'd be impressed - as I am sure, so might others. I'm providing Nestaway with a legitimate opportunity to air the superiority of the unit and its design - which normally would be frowned upon on YBW - the chance is theirs.

Take care, stay safe - and I hope you all have a better 2022 than 2021.

Jonathan

 

[Kelpie]

I don't know how big an outfit you think Nestaway boats are, but I think it's perfectly reasonable for Ian to take a day or two to respond to a query, especially over Christmas.

 

[Neeves]

I don't know how big an outfit you think Nestaway boats are, but I think it's perfectly reasonable for Ian to take a day or two to respond to a query, especially over Christmas.

I'm assuming Nestaway is a smallish business, I'm not being derogatory - our business in HK was small, and is the passion of one man, Ian, I assume, with some support from a few employees, maybe only 2 or 3.

Of course its reasonable. I prefer and note the exceptional. Its a pleasure to hear you are so supportive - its just not how I would do it - b ut then I'd be hungry to develop that positive images, engender (potential) customer support etc etc - each to their own. It would not do if we were all the same, and a pleasure we can express different views amicably.




I have a friend who is a small business management consultant. He described to me one of his clients.

The client was a very keen fisherman and set up a tackle business in Sydney. His business did not prosper and he called in my friend (but he might have been selected by some support initiative on behalf of Government). He checked the books of the business and asked what the owner did at the weekends. The owners advised that this was when his kids were not a school and they tried to get out fishing every Saturday and Sunday. He wanted to ensure his kids had the same passion he did.

Jonathan

 

[dunedin]

……….
Nestaway have chosen to have a forum presence, as Nestaway - so I have to assume they have made these decisions as a mechanism to improve their marketing. Their choice.
……….

Actually I think you have this wrong and you would do well to offer Nestaway an apology.

If I recall correctly they did not come on as a marketing exercise, but rather joined to post very informative and balanced technical information about electronic outboards, onto a thread that was asking for help.
I personally thought their comments were very helpful and informative - very much not sales oriented. Many others on here expressed the same view.

Personally I tend to agree with the point that what makes a good electric outboard for a tender does not necessarily make a good regeneration device for a yacht. And unless a yacht can regularly do 6-8 knots without the regeneration propellor being lifted clear of the water or in such disturbed wake, then regeneration will i suspect be pretty ineffective.

But people should not criticise a small and helpful UK dealer for the design choices of a major Chinese manufacturer over which they probably have minimal to no influence.

PS. I have no connection to Nestaway Boats, just benefitted from their technical postings on here.

 

[Neeves]

Actually I think you have this wrong and you would do well to offer Nestaway an apology.

If I recall correctly they did not come on as a marketing exercise, but rather joined to post very informative and balanced technical information about electronic outboards, onto a thread that was asking for help.
I personally thought their comments were very helpful and informative - very much not sales oriented. Many others on here expressed the same view.

Personally I tend to agree with the point that what makes a good electric outboard for a tender does not necessarily make a good regeneration device for a yacht. And unless a yacht can regularly do 6-8 knots without the regeneration propellor being lifted clear of the water or in such disturbed wake, then regeneration will i suspect be pretty ineffective.

But people should not criticise a small and helpful UK dealer for the design choices of a major Chinese manufacturer over which they probably have minimal to no influence.

PS. I have no connection to Nestaway Boats, just benefitted from their technical postings on here.

There was no criticism of Nestaway not an iota. I was not suggesting they replied in the past as a marketing exercise - they simply replied with an educated and informative comment based on a comment on YBW. I am uncomfortable when suppliers jump to supporting one bit of kit and are less enthusiastic to supporting other bits of kit. Don't blame the messenger for timing - that's the fault of today's immediate media. If you run a small business - you need to be jack of all trades and holidays and weekends are secondary - at least to me. If you don't want the be part of YBW, don't be a member,. If you don't want to be associated with a business - choose another name - simple stuff.

I don't think I need to make an apology - they did what is (I think) allowed within the rules of YBW - and I hope their actions are supported. I live in the 21st century and the immediacy of electronic media needs to be accepted - you cannot chose the nice bits.

A point I made was that in the absence of critical comment - they are restricted in what they can post - so critical comment gives them an opportunity. If one should apologise for being critical - because it gives the opportunity to reply - then there is something fundamentally wrong.

If you want to adopt usage of 21st century facilities, this forum, then it comes with price. Ignore posts at you cost.

Being small and helpful business does not make the equipment better, or worse. I have made critical comment - about the equipment (not about the distributor) of which the distributor hopes to make sales. If my comments are wrong the distributor has opportunity to counter my comments. Its a significantly expensive bit of kit and (to me) my comment might merit a reply. If the kit is not important I'd not expect much of a response and if my comments are wrong - I'd expect to be damned (not criticised for airing them).

Interestingly the 2 replies so support what I have said - though these two supportive replies, your post and one by Kelpie, might not have been posted had I held fire.

So one person, in the wilderness, has not been sold on the idea - and out of the blue 2 other people have suggested similar conclusions - but been critical of the message..... strange world.

Take care, stay safe

Jonathan

 

[dunedin]

......... I'm a bit mystified by the "1 kW, and 3 hp equivalent" statement in the article. When I was at school, 1 hp was 746 W and I don't think it's changed since then so 1 kW is 1.34 hp......

You are right to be sceptical about some of the hp equivalence claims. Undoubtedly electric outboards are a great convenience, and they deliver efficient torque at low revs. But (unlike most yacht diesels and car engines), many of us run tiny 2 stroke outboards regularly at full throttle, and I don't believe these marketing comparisons apply.

Our hosts Yachting Monthly ran a SUPERB article comparing 8 electric outboards in the October 2021 issue. Very worthwhile getting a copy if thinking of investing.
One thing they did was speed tests in a RIB tender (as well as a skiff dinghy). None of the electric outboards got the tender planing and the max speeds were:
- ePropulsion 1.0 EVO - max 4.5 MPH - ie 3.9 knots
- Torqeedo 1103 - max 4.4 MPH - ie 3.8 knots

Having read that, I did a little comparison in my 2.7m inflatable floor tender with an ancient (and completely neglected) Mariner 2.5hp 2-stroke outboard - this maxed out planing happily at 5.7 knots (measured by GPS in still water with no tide flow, still accelerating when I ran out of room). I suspect many others on here might have similar experience with little 2.5hp outboards.
So I would suggest the "3hp equivalence" is inaccurate for full power / speed use, and perhaps well under 2hp mould be more accurate.

Not an issue for pottering, particularly if full load and not going to be planing anyway. But a consideration if expected use includes solo trips and wanting to get on the plane to beat a tide or go a longer distance.

 

[Ningaloo]

Alternatively the head needs to be offered with sufficient water proof guarantees (which I suspect is more difficult/expensive than extending the shaft). I note that all electric outboards I see are used in flat water - where flooding of the head would simply not occur.

My main concern to date has been the fact that the tiller does not fully fold so it makes attaching the shaft to a 1m+ high transom impractical.
Fortunately (according to Nestaway) the tiller can be removed when in regen mode so waterproofing isn't an issue. I am yet to be convinced that this really is the case as the tiller contains the switch to engage the regen mode. I'll try it out by towing the tender before drilling holes in the transom!
The battery is waterproof, or at least the marketing materials make a great deal of its flotation abilities with pictures if it in the briney!

The Spirit XS shaft, which is the same length as a petrol short shaft isn't available on the EVO. The ePropulsion short shaft is about 10cm longer than this which might help in getting the prop into the water for regen.
I have calculated that I need to be able to lower/raise the motor about 50cm to get it deep enough into the water for effective regen and high enough out to have the prop clear of waves when regen isn't required.
Osculati make an attractive aluminium sliding outboard mount with 40cm travel. Wondering if this is enough? Probably not as the prop itself is 30cm.

 

[PeterWright]

I feel like you're missing the important thing here. If a petrol unit with a given prop can accelerate a boat and achieve a given speed, then ANY device which can accelerate and achieve that same speed in the same time is equivelant regardless of the actual power output of the power unit. Petrol devices cannot use their full power effectively because they stall if a prop is installed which might take advantage of their ultimate power, so top end is compromised. Acceleration is compromised because the engine needs to ramp up slowly. I can absolutely see a scenario where an electric unit with half the capacity will beat the petrol one.

If you accelerate sub optimally for 2 seconds, and achieve a lower top speed due to the suboptimal prop, then why is ultimate power important?

Acceleration is of no consequence in a yacht tender, speed through the water when the revs have got up to max is. If you have a 15 minute trog out to the mooring, that is determined by the boats top speed, not whether it gats to maximum revs in 2 seconds or half a second. Once the petrol outboard is at max revs, a 3 hp motor will push it through the water faster than a 1 kW motor and hence shorten the time taken to get to the mooring - a real advantage. Who cares about the first 2 seconds of the trog?

 

[Neeves]

My main concern to date has been the fact that the tiller does not fully fold so it makes attaching the shaft to a 1m+ high transom impractical.
Fortunately (according to Nestaway) the tiller can be removed when in regen mode so waterproofing isn't an issue. I am yet to be convinced that this really is the case as the tiller contains the switch to engage the regen mode. I'll try it out by towing the tender before drilling holes in the transom!
The battery is waterproof, or at least the marketing materials make a great deal of its flotation abilities with pictures if it in the briney!

The Spirit XS shaft, which is the same length as a petrol short shaft isn't available on the EVO. The ePropulsion short shaft is about 10cm longer than this which might help in getting the prop into the water for regen.
I have calculated that I need to be able to lower/raise the motor about 50cm to get it deep enough into the water for effective regen and high enough out to have the prop clear of waves when regen isn't required.
Osculati make an attractive aluminium sliding outboard mount with 40cm travel. Wondering if this is enough? Probably not as the prop itself is 30cm.

I might've thought removing the battery completely would be the answer for integrity of the battery - simply provide a cable to allow the battery to be charged, but remotely from the unit. The battery would not need to be much distance to ensure it is kept dry. Unfortunately the rest of the unit also needs to be waterproof - and that's the issue, rather than the battery. Having the head high enough to ensure the device is not constantly but intermittently submerged will be the issue.

It is being advertised suggesting it will operate upto 10 knots of boat speed, this implies a decent amount of wind 25-35 knots, which will result in big seas. Achieving 8-10 knots in big seas is a perfect combination as the auto-pilot will be working hard. The trouble being you will be surfing down waves , being buried by following seas and the transom coming right out of the water every time you go over a crest. Our transoms come out of the water - almost to the sail drives - at speeds in seas.

The LVM trailing rope with prop on the end had a similar but different problem. At speed the prop would leap out of the water as it broke through following wave crests - and then proceed to hockle the rope. The prop came with 2 sets of blades and I made an even smaller set from stainless plate to reduce the problem. The WattnSea has been ocean tested and apart from a few issues, some of which WattnSea have suggested are caused by owner modification of which they did not approve, seem to be reliable - and does what is says on the box (at a price).

Jonathan