Switching my 1976, Hunter 30 diesel to electric
- Thread starter Filmstress
- Start date
How pray tell? How does the propellor know that it is being turned by an electric motor instead of a diesel? This is the sort of magic claimed by electric advocates that makes me nervous.If you go to an Oceanvolt saildrive system, goodbye prop walk.
I think this is in reference to the fact that the Oceanvolt system is a saildrive, and the prop isn't mounted on a shaft per se.
Saildrives don't have prop walk? Or just less prop walk. because the sail drive is further from the rudder than the typical prop there may be less prop wash on the rudder, which is different from prop walk.
More to do with the angle of the prop to the water surface. Most sailboats prop are not perpendicular to the waterline cause p factor due to blade incidence of down going blade vs up moving blade. Like a prop driven airplane in a climb. Plus due to no angle with a sail drive the water flow does not work it's way up, as readily, to one side of the hull helping to causing a turn in reverse. I've loved the sail drives I've had in the past. Have you ever noted a properly trimmed (prop perpendicular to water), outboard doesn't have prop walk?
Thanks. Its been too many years since I drove an outboard. As I recall the boat only had 2 speeds, at the dock and wide open.
Not so sure about a business with broken links in their web site.
The unit looks like it would fit into the existing motor compartment on my hunter 280. That is cool.
It comes with a prop size that is similar in size to my current prop. I am not sure what the impact is on rudder response is when you move the prop 6 to 8 feet forward of the one currently installed. That might be a question to ask.
From the cut sheet.
Regeneration:
When under sail, place the throttle in neutral with the keyswitch “on” when the dragging propeller rotates this will regenerate a power charge to the batteries . Hull Speed and Prop Shaft RPM dictate charging amperage.
So while using sail power I have to sacrifice speed and time to charge the battery? The max speed on my 280 is 6 to 7 knots at best. using this method, now I am doing 4 to 5 knots?
Solar/Wind Power:
Solar panels or a wind generator can be added to supplement regeneration and shore power charging. This is especially useful for moored boats. Solar, wind and/or regenerative charging can allow the boat owner to be completely free of the power grid and fossil fuel power.
In this statement (words have meaning) using words like "supplement regeneration" and "Solar, wind and/or regenerative charging can allow the boat owner to be completely free of the power grid and fossil fuel power" does not assure me that I "will be" free of the power grid.
Also
Hull Speed and Prop Shaft RPM dictate charging amperage. Does that mean on a light wind cruising day I am just out of luck on regeneration?
Not sure if $15k is worth "if, buts and maybe" regeneration will work when it comes to regeneration. Weighing the balance of being of being clean and green and me getting into my slip is worth it.
One last thought. As I look at upgrading to off the solar on my Hunter 280, the question continues to be is there enough room for mounting the necessary solar panels to accomplish of the grid solar.
It's all about power management. Yes, you won't have regen on a light wind day, so plan accordingly. As sailors, we have always had to consider plan B, or plan C while sailing. Any modern electric propulsion system will have a computer to tell you your power usage and remaining charge, so there should be no surprises. Even the Torqeedo on my dingy tells me the state of charge, and how far I could motor at my present rate of speed.
If you are looking to break even or make a profit on electric propulsion, then forget about it. When we built our house on Maui, we installed solar panels and water catchment at considerable expense, knowing we are too old to ever see the break even point. The fact that we are not paying any utility bills at all is satisfaction enough.
On your Hunter 280, you might have enough room on the bimini (if you have one) to install one or two flex panels. These can be mounted with snaps and easily removed, giving you up to 200 watts of power, enough power if it is managed.
Please explain these terms. Are we talking only after you get the system installed and before you have to dump the system?
As I learn from reading about the manufacture of Solar panels, LiFePO batteries, and other parts of an electrical system, the discussion revolves around:
- raping the forests and land of 3rd world countries to extract the raw rare earth minerals.
- large amounts of energy to refine these minerals
- a manufacturing process in 3rd world countries that have little regard for human life
- Waste from these processes.
You enjoy the "FREE ENERGY" and great feeling of "BEING GREEN".
Then when the system needs to be replaced, the storage system and panels have little or no recycling value so they are dumped. There half life is something like 5K years in a disposal site. The site of course if like the Bangladesh dumps for used up ocean vessels...
GREEN SAIL BOAT ADVENTURES>
in my experience, the angle of the prop shaft doesn't have much (if anything) to do with prop walk. My old boat, a C&C 27, had a fairly "normal" angle on the prop shaft and very little prop walk. My current boat, an Islander Freeport 36 has an almost horizontal prop shaft and, when I first launched the boat, had a LOT of prop walk. After switching from an over-propped 3 blade to a proper sized 2 blade propeller the prop walk reduced but is still more than the C&C27.
Years ago I heard a theory that prop walk was due to reduced flow at the top of the prop compared to the bottom due to the proximity of the hull. That would explain why an outboard has little (or no) prop walk compared to an inboard.
I slightly helped a couple that were doing this on the really cheap. They bought their batteries, motor and control system from an automotive junkyard that had an electric car that had been totaled but the engine, batteries and computer control systems were not destroyed.
All I can say, it's not for the feint of heart and the wife was an electrical engineer and really knew her stuff!!! The boat was a 30 footer and between the two of them, they completely disassembled the car components and built the system into their boat.
I feel you'll want approximately an 18 to 20 KW electric engine for a 30 foot boat.
After that, you'll need to know where and how you'll want to use the boat to decide on both stored energy and amount of regeneration power you'll need.
Most folk cruising are more likely to want a diesel at this stage of the development cycle, but going all electric is very interesting....
dj
let me explain "clean and green". It is a fairy tale, fallacy, a freaking big lie and nightmare.
wind turbines you will never harvest green energy that is equal to or exceeds the amount of carbon energy that it takes build them, install them and remove and dispose of them at the end of their life cycle.
solar panels and batteries the earth destruction for rare elements and the current inability to recycle puts them high on the earth unfriendly scale than nuclear.
Sailboats wind and a little diesel to get in and out. That's the real deal
I‘m no nuclear scientist, but I did sleep at a Holiday Inn Express once.
I don't really follow this argument. We should continue to do what we have always done? And continue to to create shipyard gavesites?
Solar and wind technology is relatively new, and getting better at a very fast pace. And the world stage has had its eye on the ecological damage of mining precious metals. The "raping" you cite is 10 - 12 year old stories.
IMHO, one can not justify replacing an existing diesel engine, that is functional, in a boat that's maybe worth $15K with an electric system that will cost at least $15K or more. There is no justification financially and certainly not on fuel savings. Now, if you are building a custom yacht, maybe you want to consider electric vs diesel, especially if cost is no concern; however, retrofitting an old boat doesn't compute.
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That is true.
I do understand people do not always do such ideas based on financial computations. As comparison, building a dragster in your garage and then taking it out on to a track and racing it is not financially rewarding, but it can produce a lot of fun.
How one chooses to spend money that they worked for is fine with me.
I just resist the notion that "solar is free or green" or what ever "good for the environment". At this time it is not factual. Is it an alternative? Yes. There is a cost that is not discussed.
The discussion of raw mineral acquisition is current reporting from the Wall Street Journal.
My friend put an electric drive system in his 1990 Hunter 30. He also added batteries to simulate the weight of his removed Yanmar 2GM20F. He was limited to about 25 miles. After that, he carried a small generator. On generator power, he said he could make about 3 knots. Shore power was his friend.