Charging Up to Hybrid

  • 13 Dec 2019 02:35
    Reply # 8260650 on 8133077

    Going by the data from the calculations in sheet the electric motor seller provided Jim (the OP) on page 3, that hypothetical battery bank of 1917 Ah would be ~400 Ah at 48 volts, which would/should give around 35 NM at 4 knots speed and 50 NM with "reduced speed" (3.3 knots). On par with dinosaur juice. This with 9500 lbs displacement which is considerably more than you (Arne) and David are working with.

    There are solar panel and electric motor efficiency numbers available on the internet, the former being I think around 20% and the latter at 85-95%?

    No arguments here that the issue with electric motors is energy storage, that's the downside, albeit one of the only ones. By combining solar, wind and regeneration from the prop it's not that crazy anymore, given that after the initial investment (and future upkeep) of mainly batteries, those are free.

    And let me also say that yes, if your intent is to motor for 12+ hours for whatever reason then forget about electric motors, I'm talking about sailors here. With a 2 hour range you already have a lot of flexibility. Pretty much the same as with a yuloh or sculling oar, except it's faster and you won't be out of breath when you run out of juice.

    All of this said I'm still leaning towards keeping my diesel engine, because the electric alternative is quite expensive upfront and I'm also somewhat lazy and not that zealous about saving the planet... With any boat designed from scratch the largest combustion engine I'd like to have would be an outboard, something like the 6 hp Tohatsu often mentioned here. But now I have what I have, so...

  • 12 Dec 2019 23:28
    Reply # 8259370 on 8133077

    That kind of thinking is also why most of the world still runs on petrol...

    Edit: Before a flame war is started, yes, pleasure sailors have quite a small impact in the grand scheme, was referring to the world at large seeing the planet go to shit before their eyes but not doing anything because of stock prices and cost calculations.

    Last modified: 12 Dec 2019 23:33 | Anonymous member
  • 12 Dec 2019 20:13
    Reply # 8257987 on 8133077
    Anonymous member (Administrator)

    A 4-stroke petrol engine runs with around 25% efficiency (..give or take quite a bit...). That means that a litre of petrol should produce around 2.3kWh mechanical energy. A single ten-litre can therefore stores about 23kWh. In 12V battery parlance that means 1917 Ah  -  and that is with loss-free batteries (which don’t exist...)

    In plain English; ten litres of fuel fed to David’s or my Tohatsu 6, will move our boats somewhere between 30 and 50 Nautical miles, with a bit reduced speed.

    David is right that for only motoring in and out of harbour, the electric engine would be great, with access to plug-in power at the berth. However, it doesn’t pay back the extra cost of replacing the existing petrol engine with an electric one.

    The only place where I think using electric propulsion would be a practical and economical advantage, is on short-distance shuttle ferries. All other use will be based on idealism, ‘electric enthusiasm’ or special needs, such as quietness (birdwatching etc.).

    Arne


  • 12 Dec 2019 11:37
    Reply # 8254078 on 8249113
    Arne wroteWhat we need today, even if we are die-hard sailors, is an engine, which safely gets us in and out of tight harbours.

    But that's precisely where electric drive would be better! No warm-up time, reliable power when needed, a short period of use, and then plug in to shore power to recharge.

    Today’s 4-stroke engines are great. They almost never let you down by coughing and dying in a tight manoeuvre. The fuel consumption for Ingeborg’s Tohatsu 6 has been about five litres a year.
    Arne


    fuel consumption is not a major issue - I used about 15 litres this summer in four months and 1850 miles of cruising. That says to me that overall and on average, a cruising boat can generate enough power, with solar panels. The problem comes in not being able to store enough power, for that common-enough scenario when I'm 5 miles from harbour, sunset is coming on, the ebb is about to start - and the wind dies.
  • 11 Dec 2019 23:59
    Reply # 8249322 on 8248342

    They also come with less parts. The big one is the transmission and coupling. The quiet torque also has pretty much everything mounted to a motor shaped single unit that has motor mounts made to fit in most diesel replacement scenarios. The control parts also look less ready to install or at least less water proof than in the quiet torque. So the one is a quick easy replacement while the other is very much a DIY start of a kit that requires the buyer to search for more parts and study what ratios should be used etc. Very much getting what one pays for.
    I think you summed up the reason for the difference in prices very well. I'm not knowledgeable enough in electrical matters to presume I could assemble a system by myself, like the owner of Suma. See the blog, "Sailing Suma"
  • 11 Dec 2019 23:26
    Reply # 8249113 on 8247504
    Anonymous member (Administrator)
    Annie wrote:


    I love the idea of an electric motor, for all sorts of reasons and I am less likely than many to fire up an engine on a whim, but I still don't think that it's a genuine option.  I should have to add 2 very large solar panels (on my beautiful teak decks!) and fill my bilges with heavy batteries instead of water.  This is before I even buy the expensive electric motor (which would look a lot neater on my boat).  Sadly I have concluded that my 6hp, high-thrust Nissan/Tohatsu (yes, David, they do make one!) is the only really cost-effective and practical solution.


    Annie, I think your choice of motor is OK.
    What we need today, even if we are die-hard sailors, is an engine, which safely gets us in and out of tight harbours. Today’s 4-stroke engines are great. They never let you down by coughing and dying in a tight manoeuvre. The fuel consumption for Ingeborg’s Tohatsu 6 has been about five litres a year. I am thinking of reviving my former yuloh idea, as I think I have found a way of fitting it to Ingeborg, and making it in two pieces. Just for fun, of course. Since yulohs are no good in tight marinas, the Tohatsu will have monopoly there - except when the wind lets me sail back into the berth.

    Arne


    Last modified: 12 Dec 2019 08:11 | Anonymous member (Administrator)
  • 11 Dec 2019 21:47
    Reply # 8248342 on 8239009
    Anonymous wrote:

    I've been eyeballing these:

    https://www.thunderstruck-ev.com/sevcon-brushless-sailboat-kit-5kw.html

    https://www.thunderstruck-ev.com/sevcon-brushless-sailboat-kit-10.5kw.html

    Not sure how they compare with the QuietTorque but price is way lower and they're also 48 VDC brushless motors.


    They also come with less parts. The big one is the transmission and coupling. The quiet torque also has pretty much everything mounted to a motor shaped single unit that has motor mounts made to fit in most diesel replacement scenarios. The control parts also look less ready to install or at least less water proof than in the quiet torque. So the one is a quick easy replacement while the other is very much a DIY start of a kit that requires the buyer to search for more parts and study what ratios should be used etc. Very much getting what one pays for.
  • 11 Dec 2019 19:46
    Reply # 8247504 on 8133077

    My feeling is that even if you change your boat's primary function from being a sailing vessel to being a generating plant, at this stage of their evolution, electric motors are only at the very best, a pure auxiliary and not an alternative form of propulsion, which is how most people view their diesel engines.  Nor, considering the resource-intensive infrastructure that is required to power them, are they necessarily a particularly 'green' choice, particularly if you intend to keep the batteries charged from shore power (possibly produced from coal), when the boat isn't in use.  I think the amount of time you generally spend under power needs to be factored in when making the decision.

    A lot of people like the idea of an engine as 'safety' gear.  However, when you are reliant on solar to power the batteries, it has been overcast for some time and you want to make a safe haven which is directly to windward, will you have the power and range required?  What about in fog, when all your electronic gizmos are working flat out and competing with the engine for battery power? 

    I love the idea of an electric motor, for all sorts of reasons and I am less likely than many to fire up an engine on a whim, but I still don't think that it's a genuine option.  I should have to add 2 very large solar panels (on my beautiful teak decks!) and fill my bilges with heavy batteries instead of water.  This is before I even buy the expensive electric motor (which would look a lot neater on my boat).  Sadly I have concluded that my 6hp, high-thrust Nissan/Tohatsu (yes, David, they do make one!) is the only really cost-effective and practical solution.

    Kurt has a very effective electric auxiliary motor on mehitabel, but in spite of having a wind generator, heaps of solar and generous batteries, as far as I can gather, it is definitely simply an auxiliary engine and not an alternative form of propulsion.

    PS Oscar - converting your boat to junk will probably not reduce its value; indeed it could well make her easier to sell, ready-made junk-rigged boats being in short supply!

  • 11 Dec 2019 06:51
    Reply # 8241996 on 8239009
    Oscar Froberg wrote:

    3. Replace with outboard engine
    Pros:
    - Inexpensive
    - Easy maintenance
    - Easy to replace anywhere anytime
    - Combined with 2 (removing the footwell) would gain lots of space inside
    - Get rid of prop+shaft (no leaking & improve sailing performance)
    Cons:
    - Horrible in a seaway with prop coming out of the water
    - Aesthetically non-pleasing

    At this point I'm torn between 1 and 2. Due to the hull shape (double-ender) an outboard well isn't really an option, otherwise 3 would be almost a no-brainer.

    Well, based on my experiences of an outboard as an auxiliary motor that would be my choice every time. I had an outboard on my 9 meter Newick trimaran, and as you will know on the 10 meter 'Footprints' I have nothing but positive comments to make about a good outboard, and this is based on both coastal and ocean cruising. I think the only choice would be the 9.9hp high thrust Yamaha with remotes and self raising. I understand Tohatsu also make a 6hp high thrust motor which would suit smaller boats. The motor on Footprints was in a well but it was right at the transom. I don't recall that the prop coming out of the water in rough seas was ever a problem, but I would motorsail in those type of conditions anyway. I can see though that fitting an ouboard to a double ended vessel could have it's challenges, but not impossible I think to come up with a workable solution.

    If you have an old, difficult to access diesel engine then I think that electric drive will seem very appealing, so it really comes down to cost and practicality.

    it will be interesting to follow Jim's installation of electric drive, which is what this thread is all about, and I am sure he will share the details with us. It will great to know how the challenge of sufficient battery charging, hence range, is dealt with on a smaller vessel size. Jim's will be a real world experience which will ultimately allow all of us to better weigh up the pros and cons of the three main drive options. Maybe Alan on Zebedee has got us all beat with only a yuloh?!

    Last modified: 11 Dec 2019 07:06 | Anonymous member
  • 10 Dec 2019 23:56
    Reply # 8239181 on 8133077

    And Jim, sorry if I hijacked your thread but figured it was relevant to point out some (to me) valid reasons for throwing out a perfectly good diesel engine.

    Very much looking forward to seeing your progress!

       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

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