Electric drive conversion

[TropicalPengy]

no offense taken Moody, my power usage was somewhere between 30 and 90 amp hours a day while sailing, plus maybey 5 to ten minutes running the small generator every other day for microwave while at anchor. while cruising i hardly ever ran the gen.
I lived aboard full time,and used about 1pound of lp gas about every 3 days for meals or had samwiches or cold food. I fished alot underway and like staying out of sight of land. yet this example was for only one boat of many,there were boats with power deficits that tookrunning the motor more often, and one that i think i ran the motor for 20minutes in 3 months. Im a relativley young guy and in my teen years sailing florida and the coast of carolinas, carribean and bermuda i was into the no power lifestyle, before cell phones an such. I have only owned1 radar in my some15 boats, gps is a luxury i got a few years ago, handheld... i like my sextant and oil lamps, compasses are neat and paper charts dont die when the batteries do. Again i view all these modern things as a bonus, not toatlly neccisary, and my ruising style is very different from most peoples, if im a week or 2 behind schedule oh well, pick up a dive service job for a week or 2 get more food and be4 weeks behind...the types of questions im asking aremore how people like electric power if they have tried it, and what they would do to streamline it, if you cant sail into a dock your not a sailor...or into an anchorage and drop hook then sail off the hook...imagine if they had deisels 200years ago?

 

[TropicalPengy]

I totally agree kloudy,im not after a solar motorboat,and again its not going to be free, just free me..its ok the tripis worth more than the destination,thats cruising,and if i can garnish a decent power allowance,boost range and hull speed, for little or no fuel sacrifice thats just sweet!

 

[COOL]

gps is a luxury i got a few years ago, handheld... i like my sextant and oil lamps, compasses are neat and paper charts dont die when the batteries do.
my cruising style is very different from most peoples, if im a week or 2 behind schedule oh well,
if you cant sail into a dock your not a sailor...or into an anchorage and drop hook then sail off the hook...

Sounds like you are a good candidate for electric propulsion.

 

[Moody Buccaneer]

no offense taken Moody, my power usage was somewhere between 30 and 90 amp hours a day while sailing, plus maybey 5 to ten minutes running the small generator every other day for microwave while at anchor. while cruising i hardly ever ran the gen.
I lived aboard full time,and used about 1pound of lp gas about every 3 days for meals or had samwiches or cold food. I fished alot underway and like staying out of sight of land. yet this example was for only one boat of many,there were boats with power deficits that tookrunning the motor more often, and one that i think i ran the motor for 20minutes in 3 months. Im a relativley young guy and in my teen years sailing florida and the coast of carolinas, carribean and bermuda i was into the no power lifestyle, before cell phones an such. I have only owned1 radar in my some15 boats, gps is a luxury i got a few years ago, handheld... i like my sextant and oil lamps, compasses are neat and paper charts dont die when the batteries do. Again i view all these modern things as a bonus, not toatlly neccisary, and my ruising style is very different from most peoples, if im a week or 2 behind schedule oh well, pick up a dive service job for a week or 2 get more food and be4 weeks behind...the types of questions im asking aremore how people like electric power if they have tried it, and what they would do to streamline it, if you cant sail into a dock your not a sailor...or into an anchorage and drop hook then sail off the hook...imagine if they had deisels 200years ago?

Thanks for sharing that.

I almost failed a sailing instructors proficiency when I had trouble docking a boat. After I thought about it it hit me ... I was taught never approach a dock under power in a way that could not be done under sail. No one would sail past a slip, stop, then back into it under sail when it would have been easy to just sail the boat into the slip, then warp it around if it had to pointed the other way for some reason.

It sounds like you might indeed have a handle on low power requirement cruising. I think that is great.

It will be interesting for you to evaluate the pros and cons of power recovery from the prop. Have fun!

Randy

 

[sailingdog]

While the boat I showed a photo of is not a sailboat, I seriously doubt that you'll be able to get away with anything reasonable in terms of solar panel array size to charge the batteries for your electric drive boat. For instance... let us assume you have a 25 hp engine or the electrical equivalent of it.... 1 HP = 745.7 Watts... so the motor is equal to 18.6 kW or so in power consumption. Run it for an hour at half load...that's 9.3 kWh...

Say you have 1040 watts of panels... consisting of eight 130 watt panels. Each panel is about 2' x 5' in size. Total surface area required for mounting these is an area 5' x 16' or 8' x 10' or two areas 8' x 5' or 10' x 4'.... Assuming that you get the equivalent of 100% efficiency from the panels for five hours per day, which is about the standard used for solar panel efficiency calculations. That means you're getting 5200 watt-hours or 5.2 kWh... which is less than half of what your motor used in just 30 minutes at half-power... This means, that if you had 100% charging efficiency from your 1040 watt solar panel array, you could motor for roughly 15 minutes per day and still have the batteries recharged by the array...

Even if you could find the space to mount that many panels, I seriously doubt that you'd get 100% efficiency from all of them as some of them would probably be shaded on a 35' boat. Also, there are losses incurred in the charging process. If you've ever felt a battery being charged, you'd feel how warm they get....that is energy being lost as waste heat in the charging process...

So exactly how are you going to run anything other than your motor off of this battery bank, unless you can see motoring only 15 minutes per day.... I don't see that as happening. It isn't like you can save up the energy from the days you don't motor to use on the days that you do, without having a truly massive battery bank. As you add weight to the boat, the boat requires more energy to move it... and IMHO you can't scale the batteries such that the stored energy goes up faster than the increased energy costs, without going to very expensive batteries.

 

[sailingdog]

I'd also point out that there are a lot of marinas where getting a slip that you can sail into is almost impossible. And some of them do not have mooring fields.

 

[TropicalPengy]

Thanks Randy, it will prove interestin indeed, I intent to start out with little more than say 4 batteries aboard and only one panel, maybey 80watt, a removable wind turbine, cause again i hate that noise! and my trysty lil 3kw genny. those items will total about the same as the new deisel(actually just a little less) and initially i will loose weight, again the goal is to increase weight in the lower areas to help with the ride a little even if i loose a few points of a knot. so i will add 2 to 4 more batteries and a second panel later, that will be it for the adding, again i really dont think sailingdog gets quite what type of sailor i am, lol we dock catalina capri 30's parralellparking and reverse into 35 and 40 ft fairways here in rainbow harbor side by side in cat slips without bumping with a little less than 2 ft of manuvering room, under sail alone, our race boats dont even have motors, outboard or anything, we sail out of slips and back into them, in very tight quarters.often with only a helmsman and a line handler. as for the cruising bit the concept of ever operating my power plant above even 45% for more than an hour a day continuous run would just be silly, besides even the free spinning prop alone would recover that much power in about 5 hours on the water at 60%hull speed... one interesting idea a freind on another thread suggested was a manually variable prop, to trip power output at vavious hull speeds, something like a digital controll on a VW conversion kit for carborated air cooled cars in mountainous roads, Ive seen my buddy pull 65mpg on his VWbus by tweaking the mixture, logged on the laptop in real time! imagine having that kind of tweaking power albeit loosing considerable speed and inducing drag, but the juice you could get in the peak parts of the day, then trickle it in decent parts, and go zero hull friction apparent at less than 5%output for that apparent wind at night, if your range was 50nm on batteries at 90% that would give you some 20 hours of 5%thrust with some to spare on a 35 ft boat, ive never seen a night last 20 hours or no wind or no sun for that long, and when it was that dead with wind who cared about wind, it was a lake flat as glass, then the solar would be a real bonus, or just let em charge an bust out the fishin poles an a bottle of rum

 

[TropicalPengy]

think i rather like this one...for the speed i usually motor at 60% this would be nice with a bank of 8D-8 gel or standard batteries, or more lighter ones, though im still a sucker for the traditional batteries resistance to life near water, they just dont discharge as quickly and an old trick of poppin off caps with a knife effectivley un sealing them and adding electrolyte is as good as any gas can...
http://www.propulsionmarine.com/5_kw_e-drive.htm

i would go with 2 80watt panels
http://www.abovethewaterline.net/grebe.htm

cool but why waste power on all those gadgets?
http://www.abovethewaterline.net/kapowai.htm

my kinda bimini
http://www.abovethewaterline.net/vesper_1.htm

There are so many options out there, but im pretty sure this sealed type drive is what im after or the direct drive, yet its regenerative power is not as efficient, and almost certainly would need a dedicated generator to keep up with demand. the removable wind turbine is key so that it is stored below decks when not in use, in case those panels and the sail rig decide they want to do some deep sea diving :S

 

[Shooter II]

I'm curious if anyone is developing a generator based on "self-winding" technology. Boats typically move around a lot.