Electric or Diesel, That is the question

[Hyprdrv]

Ok, I've tried to search the archives as well as the internet on the Hybrid on a sailboat question to no avail. My wife and I are interested in a 2004 Lagoon 410 with electric drives. We plan on staying close to shore for a few years, up and down the East coast. The thing that is bothering me is the lack of true full disclosure as to the effectiveness of the systems over the last few years. Improvements have been made, Lagoon is now in G2 mode (second generation) but no mention as to what that entails. I truly believe that this is the way of the future but I'm not happy with the info available. This isn't a good sign. I've read the posts on the 420's but not sure if they apply to the 410. The boat we're looking at has the Solomom drives and very clean. I would appreciate any input or direction to a site that could help my knowledge base.

Thanks,
Steve

[westsail42]

Last update I heard from Nigel Calder on electric drives (January 09) is that a number of those D/E Lagoons were converted BACK into straight diesel propulsion at the request of the owners.

According to Calder, nearly ALL of the D/E propulsion systems on the market now (Lagoon or otherwise) are LESS efficient than straight diesels. There is still some work to be done on the generator side of things.

Chances are that Lagoon you are looking at is less "green" than a traditional diesel setup.

His articles explaining all of this should be appearing in Professional Boatbuilder in the next few months.

[Pblais]

According to Calder, nearly ALL of the D/E propulsion systems on the market now (Lagoon or otherwise) are LESS efficient than straight diesels.

When you consider the skyrocketing costs of batteries a real electric system is too far from reality. They seem to be working well if you don't cruise, but having a huge bank of batteries that might last a few years seems expensive. There is no way to generate enough power real time to recharge them without a serious generator. Everything works well enough but the energy deficient comes back to get you.

Wind is still the best solar power going.

[LtBrett]

I chartered a Lagoon 410 S2 and a 420, both electric. Here's my review of the 410:
http://www.cruisersforum.com/forums/...&postcount=202
Take a look at the full thread and you'll have a ton of opinions to sift through.
There's a vibrant community of Lagoon 420 owners who I'm sure can chime in here. But the 410's are completely different from the 420's. I enjoyed both, but would not consider owning either unless it is within the factory warranty period. There seems to be a continual flow of replacements and uprades from Lagoon for the 420. That reflects two problems. First, the 410 represents abandoned technology. Second, the latest and greatest, the 420, isn't perfected yet. Then again, if the price is right and you'll always be close to tech support...

Brett

[Hyprdrv]

Thanks guys for the input, maybe it's the expectations, might be the hopes of a new technology. Brett the link was great to read as was the rest of the posts in the link to "420 owners" but as you probably know, 90% of the posts there were either owners waiting for their boats and complaining, people who new little of the tech and complaining, bashers just bashing, and then the 10% who had hopes that this may be an improvement to their sailing experience.
I won't by a hybrid car because my feelings are the manufactures are building something to fill a gap. I don't have expectations that the 100% electric car is in the near future however a commuter car for lets say 100 miles on a charge is possible and a car I could use.
I don't have any hopes (or desire at this time)of sailing around the world on zero dino fuel. I want to feel comfortable on a week or 2 sail knowing I have a system that is dependable and low maintenance. So lets look at it from this perspective.
Brett, you mentioned sailing a 410. You seemed to have enjoyed the sailing and I'm wondering how the boat felt compared to a non E cat of similar size. I'm not concerned about a 1/2 knot difference but the balance and "feel" of the boat just under sail. I would hope I would be sailing 80% of the time and the use of the genset would be limited to the entry/exit of the slip. If under power and the genset is running for 800 nm I would think that the "green" effect would still be high compared to 3 diesels running but even if it was the same I'd be ok at this time with that.
It seems that the big maintenance replacement item on electrics are the batteries. The AGM 4D batteries run about $400 a piece and you got 12= $4,800 about every 5 years or a budget of $1k a year. From what I read here the maintenance costs of diesels is much higher than that. In 5 years the technology of batteries will be improved drastically. The Engines will still be the same ones in 5 years (I would hope) so the cost of maintenance will stay the same or increase. Yes this doesn't take into consideration maintenance on the other controllers or the genset but these will improve as well so upgrading is still a factor.
Redundancy of the diesel engines, the ability to run still on 1 motor is a huge plus but there are still a lot of ways you can loose both engines.

If you take out the factor that you aren't going to generate the full replacement energy with no genset you use at this point is the Ecat still better than a couple of diesels dollar for dollar?
No where do I see a list of the negatives of an Ecat spelled out compared to the typical cat if you take the hype out of the technology. Yes there was a lot of things said about the wave of the future but what if you look at the positives compared to the existing systems? Are they that bad?

Again thanks,
Steve

[Pblais]

The AGM 4D batteries run about $400 a piece and you got 12= $4,800 about every 5 years or a budget of $1k a year.

I think you are quite low on 4D AGM batteries. Locally the best I can do is a bit over $700.

I don't have any hopes (or desire at this time)of sailing around the world on zero dino fuel. I want to feel comfortable on a week or 2 sail knowing I have a system that is dependable and low maintenance.

Once you are talking more than a few days the reality falls away. The ability to make and store electric power is not currently capable. Just the idea of 12 - 4D batteries does not solve the math issue. Bigger batteries that cost less don't solve the issue of generating the electric power to recharge the system. The batteries run on deficit go dead sooner or later.

One horse power is 745 watts of electric power assuming the perfection of 100% efficiency. There is no technology possible to exceed that efficiency let alone equal it. There isn't a magic technology possible to beat that conversion rate.

Using generous conversion rates of 90% efficiency you need to make 909 watts to generate, store, and deliver 1 horsepower on the prop shaft. In 12 volt terms that is 75 amps / horsepower. With that rate you need to run a generator longer to recharge the batteries than to operate the electric drive.

With solar and wind generated power you will be doing exceptionally well meeting the refrigeration and other electric needs aboard. The electric drive has no charging source unless you plug in the shore charger regularly or run a generator.

[David M]

I am waiting for the technology to mature and to prove itself for long distance. If I were to buy a boat tomorrow I would buy the diesel because everything about it is already known and proven. It comes down to choosing between the proven and the somewhat unknown.

[Hyprdrv]

Great Paul, I think we can talk reality here.
I'm not up on the electrics to generate the power needed but let me ask a few novice questions. Lets toss the regeneration of power from the props out the window. No generation from anything other than the Genset.
You state that "With that rate you need to run a generator longer to recharge the batteries than to operate the electric drive." The question is will the generator have a capacity to run 2 electric motors and charge the batteries? What about 1 electric motor and charge the batteries?
Lets assume a 15kw generator and 2 12hp electric motors.
Paul, will the generator power the 2 motors all day and a gps? I guess this is were I get lost. I can't imagine the manufactures of the system not providing a means to generate enough power to operate the boat on its prime system. The Genset and the electric drives. Storage capacity (batteries) at this time couldn't be made large enough to handle the load or a means to regenerate power to charge. I can except that and expect the 2 hours on batteries until the Generator kicks in however with all the other loads, frig, a/c and what not, I would expect the generator to be way over sized for this application.

[Pblais]

2 - 12 HP motors requires @90% efficiency 19,668 watts off the genset. The genset can't maintain the motors at this 2 X 12 HP rating. In a perfect world it takes 17,880 watts. You can't even dream of that. In one sense you could claim that one genset powering 2 motors might do better than two motors. The conversion of torque off the engine to electricity then back to torque has to have energy lost. The cost is hard to deal with easily. You still ned 24 HP of power at the prop. You need to back track to find the ideal genset size to make the loading work effciently.

For the electric drive to run long term you have to be sailing almost all the time plus have decent wind /solar generators to charge the batteries beyond the consumption of normal use with no engine propulsion so there are amps left over that can be replaced from motoring.

You'll be burning 62 amps @ 12 volts X 24 HP motoring or about 1 - 4D battery total working capacity every ten minutes. Now you see why you need 12 batteries. I'm also dealing in a perfect electrical universe so no new technolgy can beat 745 watts per HP.

[LtBrett]

With the Solomon system, you can't get 24 hp at the prop. Your max power is 50A per shaft, or just under 20hp. In practice, the amperage jumps around as waves surge, so you have to throttle back. Remember you blow a breaker if you exceed 100A. Cruising at 6 kts draws 40A per shaft, or 5.8kw or just under 8 hp. IIRC, the genny on Waypoint was 17kw, more than enough to recharge and drive the props. This is not the case on the 420's, where you can cruise and recharge but you cannot run the props at full power without draining the batteries.

As for sailing feel, the 410's electric propulsion takes some getting used to. You are never a pure sail boat. You must have the electric motors energized at all times underway. This means you will have fan noise, only noticeable when the wind is light. You also have to choose whether to put the throttles in N or bump them forward. Bumping them forward actually gives you the potential for more charging, but it also means that the genny may kick on unexpectedly if you are net discharging the batteries. If you keep the throttle in N, you get a feeling that the boat isn't "in the groove". Likewise, with the throttles bumped, the groove can be hard to find because prop thrust masks slightly sub-optimal trim. If you don't have a racer's feel for sail trim, you may never notice. Tacking with the throttles bumped is child's play. You also gain a safety margin for man overboard.

Functionally, I really like electric propulsion. I just don't want to maintain the system. Your criteria of "dependable" and "low maintenance" seem to exclude an electric propulsion system. BTW, the battery technology you'll be looking at in 5 years is here today--Lion. It will be cheaper. The next technology, whatever that may be, won't be priced attractively yet.

Brett