Diesel vs Electric Engine

[MoxieGirl]

Would you ever consider an Electric Engine for your boat?

As I read people's sailing stories, blogs and books, I read about how they are always having to refill the tanks for their diesel engines. With battery motors becoming better and more reliable technology, would you ever (assuming money wasn't an issue) swap to electric?

Maybe you have an electric engine. What do you think of it?

MG

[a64pilot]

I think if you can live with a range of 20 miles or so, then electric is OK, I cannot, so at this time I'm not interested

There are many threads on this if you search.

I think anyone who could live with an electric motor, would probably not burn a whole tank of Diesel in a year, but my draw to electric would be the lack of noise and smell, not the lack of fuel consumption. Of course other opinions differ.

[skipmac]

What A64 said. Frequent discussions on this question. The most recent is 13 pages here. http://www.cruisersforum.com/forums/...on-138755.html

My take on it as an electrical engineer and someone that would like to go electric if and when it makes sense for me is also the same as A64.

1. For basic electric drive and batteries you will get very, very limited range unless you install a few thousand dollars and a few thousand pounds of batteries. Even then you will have only a few hours run time.

2. If you want motoring range similar to a diesel powered boat you will need to install a generator.

3. If you have a larger boat the cost of an electric motor with similar performance to an existing diesel it could be $10,000 or more.

4. Considering points 2 and 3 it will probably cost you about three times what a new diesel AND transmission would run.

[skipmac]

Originally Posted by MoxieGirl

As I read people's sailing stories, blogs and books, I read about how they are always having to refill the tanks for their diesel engines. With battery motors becoming better and more reliable technology, would you ever (assuming money wasn't an issue) swap to electric?

I didn't mention this specifically in my previous reply but look at it this way. You can refill your tanks with diesel or refill your batteries with charge.

So where do you get the charge? If you never motor further than the dock to the channel then it's easy. If you motor more than that then it isn't.

Solar? Would have to cover your entire boat with panels and have them hanging off all sides to have enough to go far.

Dock power. Great but unless you have a huge battery bank you won't go far.

Generator. Great but now you're back to filling your tank with diesel.

[Adelie]

Originally Posted by MoxieGirl

Would you ever consider an Electric Engine for your boat?



As I read people's sailing stories, blogs and books, I read about how they are always having to refill the tanks for their diesel engines. With battery motors becoming better and more reliable technology, would you ever (assuming money wasn't an issue) swap to electric?



Maybe you have an electric engine. What do you think of it?



MG

No I wouldn't, there's no such thing as an electric engine.

An electric motor, yeah I'd consider that.


Adelie

[valhalla360]

Electric motors have been a great option for decades. Nothing new that changes that.


Storing electricity...that's the problem.

[roverhi]

Ditto what all the others said. With the state of current batteries ability to store energy and slow recharge, electric power is great if you aren't going anywhere.

[europaflyer]

To my mind, electric motors are for - and only for - people who are 'nearly engineless' already, but aren't ready to totally abandon those nice sheltered harbours or tricky coves quite yet, so need, say, 15 minutes of slow speed running no more than once a day. For these people, a few standard AGM batteries in the bilge and a couple of solar panels will cater for their propulsion needs perfectly, and the advantages of a setup like this are very appealing! There are some very, very happy sailors on CF who have gone down this route.

It's the people who try to replicate the performance of a diesel with an electric rig who are the problem - they need a huge weight of extremely expensive lithium batteries, and are either constantly hooking up to shore power or running a petrol generator. They end up paying much more than for a replacement diesel, with a boat then is heavier, and more reliant on 'fuel' (be it petrol or shore power) than they were before. If you're the motoring type, electric just isn't for you!

[libramax]

Originally Posted by skipmac

Solar? Would have to cover your entire boat with panels and have them hanging off all sides to have enough to go far.

Dock power. Great but unless you have a huge battery bank you won't go far.

Generator. Great but now you're back to filling your tank with diesel.

You forgot regeneration. Seems to me a cruiser (weekender or long-term, coastal or blue water) can keep batteries charged and topped off with regeneration through the free-spinning prop. At least as long as they have wind and are sailing. At anchor, they have to rely on solar or windmills.

I've been following all the electric propultion threads, and it seems like the major limitations of electric for cruisers are:
- No motoring when becalmed to get somewhere faster. Take extra food.
- No motoring through adverse currents to get somewhere. Need to change course.
- Very limited motoring if in danger (such as currents in a pass or in trouble off a lee shore).

So it's a question of schedules, destinations, and to an extent safety. There are other issues but I think they are manageable:

- Lights need to be LEDs, but otherwise use as much as you want.
- Basic electronics should be covered, but something like a radar would need some extra battery reserve.
- Cooking needs to be propane or alcohol, so you don't eliminate flammables/fumes. Induction cooking might be possible if you beef up the batteries (and are willing to eat cold sometimes).
- Refrigeration (fridge/freezer) might be possible again with bigger batteries (and assuming you can charge them reliably through regen, solar, or wind). You'll definitely need an energy-saving design (efficient compressor, lots of insulation, perfectly sealed, top-loading).
- Hot water: not likely without any engine or generator. I do wonder if an inline induction heater exists just so you don't take freezing showers. Has anyone ever installed a permanent solar water heater (with black pipe panels) on a sailboat? A small electric heated tank could also be a dump load for when your batteries are charged.
- Cabin heating for higher lattitudes probably propane, especially if already used for cooking. But wood might be a substitute. This could also solve the hot water issue (have an integrated hot water tank to use residual heat--do those even exist?).

To me seems possible to cruise with an electric-powered sailboat (and reasonable batteries, say 30 minutes of full power) as long as you take those issues into account. Of course, I'm not out there proving it can be done, but I'd like to try someday. There are 2 open questions in my mind:

- It seems you can run a small sailboat's electric loads (lights and electronics) with regen, solar, or wind--essentially what "frugal" sailors are doing now in cheap 30' boats. But what about a larger boat with refrigeration, hot water, etc. How many loads can you add, and can you meet those loads most days with your generation/storage capacity?

- Has anyone circumnavigated with an electric aux sailboat? Seems like it might be still possible to do it as a "first." Though I guess those that circumnavigate without engine at all prove it's possible.

[Finnigan]

I an on my 3rd liveaboard boat in 10 years 1 gas 1 diesel and now electric
I will not be going back to ether. As has been stated EP has its limitations as dose everything and there is no such thing as a free lunch I do have a gen set if I need it but have not yet need it. We did run it just to make sure it worked and that I could go hybred if ness. I built my own using a DIY setup and have about 35-40 mile range under power depending on conditions and that works for me. It dose take a while for it to charge but I just waste that time eating and sleeping. It was nowhere near the cost of a new diesel with every thing and its a lot easer to maintain no noise no vibration no smell great for a bay boat but that's just my opinion

[barnakiel]

Originally Posted by MoxieGirl

Would you ever consider an Electric Engine for your boat?

(...)

MG

Yes.

a) on a weekend sailor that is always close to the socket AND only needs to get out of / into the marina,

b) on an offshore boat, if you allowed me to carry a generator (then this is called hybrid drive, I think), BUT why use a hybrid drive if you can get the same result (the propulsion part) with a diesel inboard?

c) on an offshore boat, if you delivered juice when juice were required. NO I do not trust you.

energy density energy density ...

b.

[haiqu]

On a lake, as a backup to the primary engine on a very small boat, maybe. Otherwise no.

[Fog Bank]

We have an electric drive aboard our boat, and like it. That being said, limitations exist. As long as you understamd what those limitations are, and can plan around them, an electric drive is great.

[skipmac]

Originally Posted by libramax

You forgot regeneration. Seems to me a cruiser (weekender or long-term, coastal or blue water) can keep batteries charged and topped off with regeneration through the free-spinning prop. At least as long as they have wind and are sailing. At anchor, they have to rely on solar or windmills.

I've been following all the electric propultion threads, and it seems like the major limitations of electric for cruisers are:
- No motoring when becalmed to get somewhere faster. Take extra food.
- No motoring through adverse currents to get somewhere. Need to change course.
- Very limited motoring if in danger (such as currents in a pass or in trouble off a lee shore).

So it's a question of schedules, destinations, and to an extent safety. There are other issues but I think they are manageable:

- Lights need to be LEDs, but otherwise use as much as you want.
- Basic electronics should be covered, but something like a radar would need some extra battery reserve.
- Cooking needs to be propane or alcohol, so you don't eliminate flammables/fumes. Induction cooking might be possible if you beef up the batteries (and are willing to eat cold sometimes).
- Refrigeration (fridge/freezer) might be possible again with bigger batteries (and assuming you can charge them reliably through regen, solar, or wind). You'll definitely need an energy-saving design (efficient compressor, lots of insulation, perfectly sealed, top-loading).
- Hot water: not likely without any engine or generator. I do wonder if an inline induction heater exists just so you don't take freezing showers. Has anyone ever installed a permanent solar water heater (with black pipe panels) on a sailboat? A small electric heated tank could also be a dump load for when your batteries are charged.
- Cabin heating for higher lattitudes probably propane, especially if already used for cooking. But wood might be a substitute. This could also solve the hot water issue (have an integrated hot water tank to use residual heat--do those even exist?).

To me seems possible to cruise with an electric-powered sailboat (and reasonable batteries, say 30 minutes of full power) as long as you take those issues into account. Of course, I'm not out there proving it can be done, but I'd like to try someday. There are 2 open questions in my mind:

- It seems you can run a small sailboat's electric loads (lights and electronics) with regen, solar, or wind--essentially what "frugal" sailors are doing now in cheap 30' boats. But what about a larger boat with refrigeration, hot water, etc. How many loads can you add, and can you meet those loads most days with your generation/storage capacity?

- Has anyone circumnavigated with an electric aux sailboat? Seems like it might be still possible to do it as a "first." Though I guess those that circumnavigate without engine at all prove it's possible.

Yes you can charge your batteries by other methods than the couple I mentioned; regen, fuel cells and probably a few more. But no matter how you recharge you will still have to deal with how many batteries you can carry and how quickly you run them down.

As far as circumnavigating, there are people that circumnavigate with no engine or electric at all so one could certainly circumnavigate with electric drive. You would just have to deal with the limitations of the system, mainly only enough power to get into port or down a narrow channel.

[hamburking]

YES, totally, go electric propulsion with diesel generator. Great system. Imagine coming up to the dock in total silence and actually hearing what the guy on the dock (or bow) is trying to tell you. Imagine an engine that never fails to start, because an electric engine is neither on or off, it just works. Imagine zero maintenance on your propulsion engine.

Yes, go electric. Definitely.