Thoughts on a viable and MARKETABLE Electric Drive Train

[valhalla360]

Originally Posted by John DeLong

I'm interested in how you're calculating CO2 reductions?

The electricity is generated somewhere.
Is this all wind/solar power generation?


The eco-cred calc seems suspect...

I consider the eco-street cred a joke personally. But there is no doubt, it sells.

I do agree, electric production is certainly not zero emissions (hate that term) but if you look at it objectively, even coal powered electricity is usually quite a bit lower in emissions compared to ICE. I'll leave it to you to run the actual calculations. I'm just saying if the goal is to move towards electric power with no fuel burnt on the boat, this is at least a viable option without major reductions in capability.

[misfits]

Originally Posted by Adelie

40kWhr battery is about 600lb plus about 100lb for motor, cabling, shore charger and controller. 700lb total.
If you boat is currently propelled by an outboard that’s a 100lb motor and maybe another 100lb fuel.
If you have an inboard you are probably looking at 150-200lb motor plus 100lb fuel.

Adding 400lb to the dry weight would be tough and you might have to sacrifice significant storage space to do so. I bet you could get 25kWhr on board though in the existing engine compartment. Would drop battery weight to about 375 saving about 225lb.

Recharging would be plug-in overnight; wait a long time using installed solar and maybe some wind turbine or wait a somewhat less long time using installed solar, wind and extra panels that are pulled out when becalmed or at anchor. Extra panels could use a tracking mount.

My boat had a MD7A along with a 20 gallon fuel tank. I presently have 4-12v Trojan T1275's for the propulsion bank at 80# each. They fit perfectly where the fuel tank was. Weight wise with the drive, drop pan, etc., I'm real close keeping the boat balanced.

Lithium is coming down in price. I can purchase the cells to construct a 100 amp 48v battery bank from china for what it would cost me to replace the present FLA batteries. It's all the other stuff you have to purchase to make this happen. I'm retired now so I'm careful about how I spend money.

[Adelie]

Originally Posted by valhalla360

Already went thru this in the original post:

- 25hp 4 stroke outboard is 160lb.

- 2 - 18 gal fuel tanks full about 300lb

- 2 - BBQ size propane tanks 80lb

- 4 - 6V Golf Cart Batteries 260lb.



That's about 800lb eliminated but close enough to call it a wash if not a slight decrease.



Recharging is assumed to be shore power during the week most of the time with occasional generator use if trying to cover a lot of miles on multiple days.



A small solar array (maybe 750w) could supplement but really isn't a primary source for propulsion power unless you are only using the boat once every couple weeks. It would mostly be useful if at anchor for multiple days to cover house loads.

I was addressing Misfit’s actual situation on his boat as outlined in his post not your proposal.

[StuM]

Originally Posted by misfits

A 40 KW, 48 volt lithium bank discharged to 10% DOD, I could run my 28' boat 36 hours @ 4 knots, maybe 7 hours at 6 knots.
I have no idea how I'd recharge the bank truth be told. I don't have that kind of real estate for panels.

That would be 40KWh.



So that's what, 400+ Kg of batteries on your 28' boat?

[hamburking]

Why put the batteries in place of the fuel tanks and propane tanks? You stated you are building from scratch, not a retrofit...so do it right!

Put the batteries down low. If possible, replace some of the ballast with batteries. Ideally, the batteries would go deep inside the keel. Combine the need for weight in the keel with the need to carry heavy batteries. This could greatly increase the amount of batteries carried without adding overall weight to the boat...wouldn't that be nice?

Outboard electric is good. 2 reasons. 1) electric engines need cooling to run efficiently, so outboards have cooling water available without needing through hull fittings and plumbing. 2) MODULAR. You can option bigger or smaller electric outboards, no problem....when something better comes along, the boat is ready to mount it easily.

Actually, a MODULAR system is the key. Each component can be sized easily for the intended use. Make a place to mount the outboards, a place for the batteries, a place for the generator. The should be wired so changing, removing, or replacing these items is easy by the end user.

Think about PCs (computers)...they never really took off until they became modular. ATI made great video cards, Western Digital made hard drives, Sony made monitors....smaller companies could increase the performance of their "module" in a competitive free enterprise market. Mega successful companies like DELL didn't manufacture computers, they just assembled good components built by other small companies and stuck their name on it. Companies like IBM built the entire computer from the ground up, and quickly became obsolete (and overpriced). Cars are moving in the direction now...basic chassis that can accept a variety of configurations (truck, van, sedan) on top.

Make the boat the chassis that takes modular components easily. You'll get better batteries, better outboards, better generators. Soon enough the generator could be replaced with a hydrogen fuel cell. Provided it fits in the "hole" on the boat, this is no problem....replace the module, not the boat.

[Yihang]

Originally Posted by hamburking

Why put the batteries in place of the fuel tanks and propane tanks? You stated you are building from scratch, not a retrofit...so do it right!

Put the batteries down low. If possible, replace some of the ballast with batteries. Ideally, the batteries would go deep inside the keel. Combine the need for weight in the keel with the need to carry heavy batteries. This could greatly increase the amount of batteries carried without adding overall weight to the boat...wouldn't that be nice?

Outboard electric is good. 2 reasons. 1) electric engines need cooling to run efficiently, so outboards have cooling water available without needing through hull fittings and plumbing. 2) MODULAR. You can option bigger or smaller electric outboards, no problem....when something better comes along, the boat is ready to mount it easily.

Actually, a MODULAR system is the key. Each component can be sized easily for the intended use. Make a place to mount the outboards, a place for the batteries, a place for the generator. The should be wired so changing, removing, or replacing these items is easy by the end user.

Think about PCs (computers)...they never really took off until they became modular. ATI made great video cards, Western Digital made hard drives, Sony made monitors....smaller companies could increase the performance of their "module" in a competitive free enterprise market. Mega successful companies like DELL didn't manufacture computers, they just assembled good components built by other small companies and stuck their name on it. Companies like IBM built the entire computer from the ground up, and quickly became obsolete (and overpriced). Cars are moving in the direction now...basic chassis that can accept a variety of configurations (truck, van, sedan) on top.

Make the boat the chassis that takes modular components easily. You'll get better batteries, better outboards, better generators. Soon enough the generator could be replaced with a hydrogen fuel cell. Provided it fits in the "hole" on the boat, this is no problem....replace the module, not the boat.

Batteries in the keel present some problems. They heat up, and some have off gassing safety valves, Having them down in the keel is asking for trouble. Atleast with current technology. A typical modern keel also doesn't have the real-estate. Battery density is also much much lesser than lead.

Best implementation i've seen is in a trimaran, everything centralised and down as low as possible without going into the keels.

[Woodland Hills]

This sounds like a sure-fire way to make a small fortune.......... out of a large one.

If you look at the current crop of marine engines, they are all marinized automotive or industrial engines. Until there are similar electric motors, charger/controllers and batteries in widespread use to repurpose for marine use, the cost will be prohibitive. We are at least a decade away from that point, wait until at least 1/2 of all delivery trucks on the road are electric. Then you might have a chance at getting the price low enough and the range high enough. Until then it’s just a fantasy.

[valhalla360]

Originally Posted by StuM

That would be 40KWh.

So that's what, 400+ Kg of batteries on your 28' boat?

I was estimating around 600lb based on a tesla 80kwh battery being 1200lb. Might be a little more but certainly within reason for a 34ft boat based on what you can omit.

[valhalla360]

Originally Posted by hamburking

Why put the batteries in place of the fuel tanks and propane tanks? You stated you are building from scratch, not a retrofit...so do it right!

Put the batteries down low. If possible, replace some of the ballast with batteries. Ideally, the batteries would go deep inside the keel. Combine the need for weight in the keel with the need to carry heavy batteries. This could greatly increase the amount of batteries carried without adding overall weight to the boat...wouldn't that be nice?

Outboard electric is good. 2 reasons. 1) electric engines need cooling to run efficiently, so outboards have cooling water available without needing through hull fittings and plumbing. 2) MODULAR. You can option bigger or smaller electric outboards, no problem....when something better comes along, the boat is ready to mount it easily.

Actually, a MODULAR system is the key. Each component can be sized easily for the intended use. Make a place to mount the outboards, a place for the batteries, a place for the generator. The should be wired so changing, removing, or replacing these items is easy by the end user.

Think about PCs (computers)...they never really took off until they became modular. ATI made great video cards, Western Digital made hard drives, Sony made monitors....smaller companies could increase the performance of their "module" in a competitive free enterprise market. Mega successful companies like DELL didn't manufacture computers, they just assembled good components built by other small companies and stuck their name on it. Companies like IBM built the entire computer from the ground up, and quickly became obsolete (and overpriced). Cars are moving in the direction now...basic chassis that can accept a variety of configurations (truck, van, sedan) on top.

Make the boat the chassis that takes modular components easily. You'll get better batteries, better outboards, better generators. Soon enough the generator could be replaced with a hydrogen fuel cell. Provided it fits in the "hole" on the boat, this is no problem....replace the module, not the boat.

No need to keep the fuel or propane tanks because they are no longer needed. Just a small tank to accommodate the generator on rare longer motoring trips.

It's a catamaran, so no ballast needed. I'm simply putting the weight back in the same place we removed weight.

Yes, I greatly prefer outboard. Not only is it easy to swap out but with the Gemini you can fully retract it resulting in zero drag under sail and you can use a prop optimized for propulsion rather than a folding/feathering/etc compromise prop.

[valhalla360]

Originally Posted by Woodland Hills

This sounds like a sure-fire way to make a small fortune.......... out of a large one.

If you look at the current crop of marine engines, they are all marinized automotive or industrial engines. Until there are similar electric motors, charger/controllers and batteries in widespread use to repurpose for marine use, the cost will be prohibitive. We are at least a decade away from that point, wait until at least 1/2 of all delivery trucks on the road are electric. Then you might have a chance at getting the price low enough and the range high enough. Until then it’s just a fantasy.

Electric motors are common place already and plenty of appropriately sized ones are available for an inboard design. (For outboard: Elco has a 20kw motor advertised for $8k...fully marinized. You are probably looking at $6k for a 25hp gas outboard), so it's really the battery bank that's a price increase but on a new $250-300k boat, a $10k option isn't unrealistic.

Commercial truck motors would be way too big & expensive for a displacement sailboat. Even a commuter car motor is too big unless you are getting up into something like a 50-60ft monohull.

[AKA-None]

I think the original thought is a likely direction. Match the use case to the current capability not trying to make electric replace ice in all situations .
The one primary advantage of solar and electric drive is that you can recharge the batteries just by waiting. Will it work for all use cases? No but it could work for some at this point.

[valhalla360]

Originally Posted by AKA-None

The one primary advantage of solar and electric drive is that you can recharge the batteries just by waiting. Will it work for all use cases? No but it could work for some at this point.

Unless you go extreme on the solar installation, you generally aren't going to recharge by waiting. Technically you can but not from a realistic and marketable point of view. 3000w on a Gemini with no mast would be pretty well maxed out and that would take 3 days to replace 40kwh for around 26miles. Nice bonus but not really something I would try to market because it will quickly be proven silly.

As far as working for all use cases...that's my point. Most of these systems from the commercial side seem to be focused on long range ocean passages. but probably 95% of new cruising boats are sold to people who mostly weekend. As long as you have a way to accommodate the occasional long day's motoring, you have their needs covered. Honestly, with a decent solar array, you have ocean passages covered as it's not really a use that demands any mechanized propulsion. The solar would be mostly for autopilot and house loads. If you are at the upper limit of battery charge, you could boost a bit with the electric motors but purely a bonus, not a need.

[Montanan]

The discussion of electric marine, becomes rather simple.

The motors are very efficient and capable, but the power supply to run the motors is the issue and really the only significant factor to evaluate.

A hybrid wherein a combustion engine powers a generator becomes a redundancy to the traditional ICE powered vessel.

The on-board battery power supply is limited and thus the speed and distance of travel why under battery power. Define your desired speed and distance of travel. In the eMobility sector we call that the defined Drive Cycle, called in the marine sector, Your Planned Voyage.

The power density measured in terms of weight and volume for batteries is adverse compared to fuel and conversion of combustion as to vessels which have constraints as to volume contained within a hull and the according displacement associated with the weight. That is the hole in the water one has to invoke to carry the weight and the hole in the water that one has to cause to be invoked every inch that the boat desires to travel.

As to marketabliity, I only see severe downsides because of the limitation of the Drive Cycle / Voyage / volume and weight displacements.

As to expense, such a system will cost more than a traditional ICE powered vessel.

For boats that have short transit routes and easy access to high powered shore based recharging stations, electric propulsion is very viable and has many advantages, for more distant voyages and to places without high powered charging stations electrification is not yet advantageous.

I have been working developing exceptionally efficient electric propulsion drive systems for eBuses and eTrucks for six years, terrrestrial EVs are definitely ready and preferrable. Not so much for marine EVs and Eviation. The power density just is not there for anything but short distances.

[valhalla360]

Originally Posted by Montanan

As to marketabliity, I only see severe downsides because of the limitation of the Drive Cycle / Voyage / volume and weight displacements.

As to expense, such a system will cost more than a traditional ICE powered vessel.

The point is there is an underlying demand for what I will jokingly call eco-street cred. As long as we can keep the cost differential low while allowing for normal operational expectations, I think it's marketable and that's what I tried to lay out. It's very much like electric cars that cost more but as long as the meet the need, people will pay a premium for them.

Not many weekend cruisers need a 500 mile range at 6.5kt. Likewise, not many will accept 100mile range at 3kt. By looking at real usage patterns, you can build a viable alternative that can sell while keeping it reasonable.

Kind of like local delivery vans...they are fine with 150-200mile range and can recharge at the home base every night. They don't need top of the line cutting edge technology to be viable. You just need to understand the use case.

[Yihang]

Originally Posted by valhalla360

The point is there is an underlying demand for what I will jokingly call eco-street cred. As long as we can keep the cost differential low while allowing for normal operational expectations, I think it's marketable and that's what I tried to lay out. It's very much like electric cars that cost more but as long as the meet the need, people will pay a premium for them.

Not many weekend cruisers need a 500 mile range at 6.5kt. Likewise, not many will accept 100mile range at 3kt. By looking at real usage patterns, you can build a viable alternative that can sell while keeping it reasonable.

Kind of like local delivery vans...they are fine with 150-200mile range and can recharge at the home base every night. They don't need top of the line cutting edge technology to be viable. You just need to understand the use case.

Within 5 years Electric Cars are going to have the same range as most ICE cars AND be cheaper.

https://www.theguardian.com/environm...models-by-2024

For marine the main barrier for charter market is probably cost right now? Once battery cost halves again we might start to see something like the lagoon 420 electric again.