Solomon Technologies - "Electric Wheel" electric motor propulsion systems

"True. Agree. `Cept the general public buys into all sorts of stuff that makes no sense whatsoever, so it's worth a try"

OK, maybe I should have said in mass. In my mind the "green" movement isn't successful until it captures a significant percentage of the market.

"I see some gorgeous little ferryboats out there, real shippy- looking little vessels (electric, of course). Gotta be an easier sell to the Yacht Club, than a modern multihulled craft. "

So true. In addition a long and slender monohull will achieve 6 knots and carry the weight of passengers and batteries better than a multi-hull. Multi-hulls greatest advantage is light weight, but electric vehicle are intrinsically heavy. So how do these fit together? : confused:

At 6 knots all boats are in displacement mode, so maximizing your displacement speed will improve your efficiency at 6 knots. I would look at displacement hulls with a length of >=36' so that your operating speed is <= to the square root of the length in feet.

The Compromise 47 is a beautiful boat and Beckmann has a lot more at http://www.steamboating.net/eboats.html

Cheers;
Mike Schooley

 

I'm prepared to start somewhere Mike.

Hmmmm... so Mike. For a given displacement, a well formed set of multi-hulls wouldn't be any more efficient (require less energy to propel) than a single-hulled displacement vessel?

Apart from which may be the more efficient configuration at 6 knots, the "two legs" provides a more stable platform no? Our harbour is choppy with all the boat traffic in the height of the summer. I just find the mono's so "tippy" now - we do have some fairly "chunky" powerboats and ferrys in this harbour, which make the rest of us tend to bounce around a bit.

Also, if you've stepped aboard the bridgedeck of a larger cat, with it's wide open,airy salon, etc., and almost 360° views around the boat, it's a different feeling for me, than stepping down into the belly of a displacement craft. I like the pontoon boat thinking as much because it can be reconfigured easily. With a full canvas enclosure over the whole deck, it can be zipped off in stages, opening the boat up for fair weather. We're sailors -we're used to canvas biminis etc around the cockpit <smile>

And I believe the power multihull won't need the same broad beam that the sailing multi's use. Can't have this sucker too beamy, `cause the Club hauls all our boats out in the winter, up a marine railway and down a fairly narrow row of ways loaded with cradles (and boats).

All along, I've been assuming that the lighter the craft is, the more this would translate into energy savings over the life of the craft. You were the first person BTW to mention calculating
maximum and average loads and researching hull forms. Odd when I think about this - most of what I've read (on electric propulsion) hasn't dwelt on this much... They talk xxxxxx lbs displacement, but do these figure assume the boat is fully crewed and provisioned? Not sure...

The ferry gets "interesting" perhaps, because its all up weight does vary greatly on the trips, from empty (just the driver) to full (driver plus 39 bodies plus buggies of gear and groceries, dogs, etc)...

I'm don't know what the standard allowance for passenger weights are, but if I use 170lbs per passenger including gear that's a swing of over 6500lbs from empty to full. Because the craft is otherwise "stripped out" (no galley, no head, no bar <sigh>), the lighter the craft (when empty), the greater this swing from min. to max. weight will effect the performance - for better or for worse?

In other words, I'm trying to design a craft that'll take 40 people fully loaded, but the truth is, for most of it's runs it is less than 1/2 full. Gets back to the idea of maybe having three motors (one for each pontoon), with the option to not employ the middle motor much of the time.

Yeah. I grabbed a pic of the 47 for my site. But when I look at her, all I see is a heavy wooden(looking) superstructure. More weight, more energy required to push her?

Lock

 

"Because the craft is otherwise "stripped out" (no galley, no head, "

A boat for hire, 39 passengers, with no head? In the US I think the law would require you to have many things you might not think nessasary.

Gary

 

Honest Gary - she does a 10 minute trip, one way. The Coasties don't require a head
Lock

 

Re: Solomon Technologies

Dear David
I wanted to say thank you for your posts here.

I have a serious question for you, please.

I would like to try and promote electric propulsion in the sailing community. I have one application which, I think, may be extremely suitable to present battery and electric motor options. And I wonder about many of the other tenders I see working and playing in the waters around the Club and in the harbour.

Today, in Ontario, a working committee of our provincial legislature made recommendations to our Premier that Ontario get a lot greener. Very specific recommendations shutting down gas/coal, and promoting non FF development. In Ontario right now, this means electric. Fuel cell and wind development.

http://www.eye.net/eye/issue/issue_06.27.02/news/enviro.html

I don't know if anything will ever come of this report.

This last week in Southern Ontario, we suffered (?) through three days of SMOG alert warnings.

There is a rebate for the 8% Provincial Sales Tax here. For alternate-fueled vehicles licenced under our Highways traffic act. A new alt-fuel bus gets 100% of the tax paid, rebated. I have written the Premier to ask if he would kindly amend the regulation so it'll read vehicle or VESSEL (licenced by our Transport Canada.) I believe this would be in the spirit of the regulation!

Anyway, I digress.

My Yacht Club recently decided to go ahead with a "classic" displacement craft, diesel powered, as a private 40-passenger ferry to operate across one mile of Toronto harbour for the summers. There is a six knot speed limit in the harbour.
This purchase decision took two years of hard work and anguish for many club members and execs, working through the options. (ever belonged to a club, David? <smile>)

I may have been asleep at the switch. I'm not a Senior (voting) member there, just a Drysailor. But I've been a member there for maybe 8 years, and I sorta care anyway.

While I may not be able to sway my fellow club members to re-open this, I know there are other Clubs that use club boats (if not their own boats) in applications that may also be appropriate for electric. But I think I may be able to come up with a reasonable proposal. If I can show a (much) lower purchase cost, and significantly lower operating costs - for the little ferry service we run.

If our Club did make the switch. If they did sell off the oil burner, and recommission an electric craft, she would be the first all-electric vessel that has operated in Toronto harbour for some time. This under the nose of a 5-million metropolitan area, and many, many other yachtsmen.

Anyway David. I know nothing about boat design, electrics or electronics, or diesel or gas engines. I know a little bit about small boat sailing, and I'm pretty good with knots.
I am trying to educate myself just a bit, so that I can, I hope, ask intelligent questions!

I realize your time is valuable. I, for one, would like to assure you that your posts here are very much appreciated, and I personally, hope in some way to make this effort on your part worthwhile for Solomon Technologies, or at least, the electric boating industry as a whole.

My serious question?

Would my 40-passenger ferry project make economic and engineering sense, when compared to a displacement diesel powered craft?

I think that's not a fair question - it's a thousand questions rolled into one. But if I am fortunate, and get one or two answered by you, well, that'll be a couple of question less to go!

Thank you
Fair winds, and leave a clean wake.

Laughlin Hughes

http://groups.yahoo.com/group/QCYCTender/

 

Monohulll versus multihull

There are many on this forum that know much more about hull forms and efficiently powering them than I do. I will differ to their experience, after I finish putting my foot in my mouth.

To improve performance you want to minimize weight, reduce wetted surface area, reduce form or shape drag and increase length.

Weight: The heaviest part of a monohull is the ballast that is required for stability. Since you will have a load of batteries and you can mount them very low, I do not think you will need additional ballast. The monohull is actually a more efficient structure than a multi-hull. It does not need a platform to tie the two hulls together and one large tube (hull) of a given volume will always weigh less than to smaller tubes with the same combined volume and the same length.

Wetted surface area: This should be obvious.

Form drag: I know that the monohull will need to be wider than the multi-hulls for stability, but many people overlook the interference effects of multi-hulls. According to my Naval Engineering book, at some speeds the bow wave coming off one hull can cause increased drag on the other. You need to make sure that the hulls are spaced wide enough to avoid this at 6 knots. This might be hard since you said that you can't accommodate too much beam.

Cheers;
Mike Schooley

 

Mike - (if we can leave that mono-multi option alone for now...<smile> )
You worked all this out, but doesn't this change a lot, knowing that the max. speed permitted is 6kts? And you don't reference any displacement? Won't the size/weight of the craft affect this also? And, why 144 volts?

Lock

 

Electric Ferry

Yes, and now that I know you want to carry 40 passengers that changes it a lot also. I question the assumption that you could do 6 kts with a 6 HP motor.

Yes the exhaustive approach would be to do a conceptual design of each option.

Because that is what Solomon Technologies use in their system. I note that they run some boats on 120 VDC instead of 144 VIC. Maybe Dave could explain why this is?

Cheers;
Mike Schooley

 

I would like to see a marriage between the Solomon Technologies Electric Wheel and the WhisperGen generator/heater for use in a monohull sailing cruiser.

The WhisperGen (http://www.whispertech.co.nz) is a Stirling Engine .75KW DC generator that also provides 5 KW of available hot water for heating using about 16 litres of diesel per day at maximum output.

I'm on the Upper Left Coast and a warm boat is a happy boat

So, the WhisperGen produces 18 KW per day, which should provide enough for lights, stove, electronics, and A/C while anchored. With a battery bank large enough to motor out of harbor, the regen should cover most of my needs. As long as I have a large battery bank for one, why not use it for both.

The only (!) drawback is cost. It costs about $10K. Of course you get some reliability and longevity with it. Every 2000 hours, check the burner and overhaul every 50,000.

 

Sounds like a good application of the WisperGen. I have been trying to figure out a way to use it efficiently. The biggest problem with WisperGen is, if you don't need heat it is a mighty inefficient generator. The second biggest problem is cost.

Cheers;
Mike Schooley

 

Yeah, the WhisperGen is really an efficient heater that produces 18 KW on the side. But like I mentioned, I'm in the Northwest and I can get frozen not 50 miles from here, so heating capability is a big plus.

If you factor in the cost of a large heater with the cost of a small, but very reliable genset, it only looks twice as expensive as it should be

 

Exhaust Heat Exchanger

Check this out.

http://www.polarpowerinc.com/products/heat_exchanger/heat_exchanger.htm

It is a heat exchanger that goes on your generators exhaust. It will recover a lot of waste heat from you exhaust. The efficiency of the engine is about 34% and the efficiency of the heat exchanger is ~33%. So you will be using almost 67% of the energy produced by the engine. In addition about 12-15% of the heat goes into the water jacket of the engine. If you are recovering that you are up to 80%.

While your are Polar Power checkout their "Marine Micro-Cogen" systems http://www.polarpowerinc.com/products/generators/marien_micro_cogen_lomb.htm

Stay warm.

Cheers;
Mike Schooley

 

Two quick coments:

I'm adverse to an engine mounted heat exchanger becuase of the engine. I am willing to pay a premium for a quieter solution, when not sailing. It is primarily an aesthetics issue for me. Plus, the WhisperTech has an 85-90 percent efficiency as a heater alone, so that is a bonus.

Why does Solomon spec a 144 volt sytem for some and a 120 volt for others? Because some people don't want the weight/cost of 12 12-volt batteries and are willing to accept the reduced performance provided by the less-expensive/lighter package of 10 batteries.

 

Well, two batteries saved = approx. 140lbs. weight, and about one cubic foot of space. That's pretty easy.

It's the $$$ cost I have trouble with, and "reduced performance".
Looks like the batteries (that Solomon specs) are about $212US a pop. So say $450 saved with 10 batteries insteada 12.

But wouldn't the additional 2 batteries (20% more than 10) mean smaller DoD's for the battery bank? ie, more cycles before the batteries need to be replaced?

Lifeline publishes one graph
http://www.lifelinebatteries.com/lifecycleper.htm

which appears to show that the diff. between 40% and 50% DoD translates as the diff. between 1,000 and 1,500 cycles before replacement... But I don't know how significant the additional two batteries would be, in terms of DoD...

Lock

 

Gentlemen....Solomon Technologies 120/144 questions....our motors are voltage dependent(the higher the voltage the more RPM's it is capable of) and when we do a diesel electric hybrid where the generator keeps that voltage above 120 then we can go with only 10 batteries. When we sell a system that is using only batteries we go to 144 so that there is a larger spread in voltage (full charge 162vdc to 80% discharge at 120vdc). We are presently thinking about sticking to 144vdc for all boats. Now, having said this....DO NOT GET HUNG UP ON the Batteries and weight...if you have 10 group 31's ...it weighs that same as 12 group 27's...it is entirely adjustable to mission profile. And as a diesel electric hybrid (see Ted Turners 40ft Condor Trimaran) the batteries can be adjusted to only last 20min.(UU1 Deep Cycle Wheel Chair batteries) becuse when the generator comes on it will motor you as long as the fuel lasts like any other boat. He has just enough batteries to take care of his "normal mission profile and cycle of use". He TYPICALLY only needs the motor for 5 to 10 minutes to get out of the slip and 5 to 10 minutes to get it back.....under normal conditions he has all the power he needs with 10 20LB batteries....when every thing goes wrong he turns generator on and uses fossil fuel.
Dave Tether