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Reducing pollution from boats by switching to electric motors

purewatercraft.com

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Re: Reducing pollution from boats by switching to electric motors

#61

Post by sokoloff »

driverdan wrote: post #33
Accujack wrote: post #20

Earlier quoted context omitted.

Only for tiny boats, though, and they're quite expensive. My boat needs two 150kW plus engines to move at speed. I might be able to get by at displacement speed with two 50kW engines, but something that like isn't available, and neither is the needed battery pack (Li-Ion, lead is too heavy to work).

If you can afford a boat with twin 200HP motors you can afford to retrofit it with electric.

They can also much more cheaply afford to not retrofit it, despite having some amount of inclination/willingness to do so.

(They literally can't afford to retrofit it right now as nothing is commercially available in that power output range.)

Re: Reducing pollution from boats by switching to electric motors

#62

Post by Robotbeat »

personjerry wrote: post #6

My bicycle is infinite times better than an electric car but it doesn't really serve the same purpose does it?

A bicycle is not infinitely better. In fact, due to emissions from agriculture and livestock and inefficiency of conversion of food to mechanical work, if you have a heavily meat-based or fresh-fruit-Based diet (neither of which are common, I admit), the extra calories spent biking can actually have worse CO2 emissions than an electric car per mile.

Re: Reducing pollution from boats by switching to electric motors

#63

Post by kwhitefoot »

sephamorr wrote: post #39
arthurbrown wrote: post #27

Electric cars don't reduce emissions from tyre and brake wear. These particles make up a huge amount of air pollution at a size small enough to cause health issues. Once they settle, they are swept into waterways and form the majority of our microplastic problem. https://www.sciencedirect.com/science/article/pii/S135223101... https://www.theguardian.com/environment/2018/nov/22/tyres-an...

Regenerative braking certainly is reduced by EV's; a Tesla may never replace its brakes during its lifetime. Reading the paper, the dominant source of PM2.5/PM10 is resuspension of dust already on the road, rather than tires or brakes.

> a Tesla may never replace its brakes during its lifetime.

If you live in a northern area where they salt the roads you will need to reduce regen or perhaps occasionally do an emergency stop to grind the corrosion off the brake disks in the winter.

I had to have two brake disks replaced at the last service on my 2015 S 70D because they were too rusty.

But generally speaking you are correct.

Re: Reducing pollution from boats by switching to electric motors

#64

Post by jmpman »

TylerE wrote: post #54
jmpman wrote: post #43

Earlier quoted context omitted.

Isn’t the purpose of traction control to keep the tires in contact with the ground in a static coefficient of friction, and thus not slipping?

If there was zero slippage there would be zero acceleration.

My understanding is that tires, even when accelerating, can operate in the static coefficient of friction range. And, you want them to operate in the range, because it provides the greatest acceleration. But, maybe my mental model is wrong. The following video is from someone who has considered it much more in depth.

https://youtu.be/iyeLXkacocA

Re: Reducing pollution from boats by switching to electric motors

#65

Post by mehrdadn »

Robotbeat wrote: post #62
personjerry wrote: post #6

My bicycle is infinite times better than an electric car but it doesn't really serve the same purpose does it?

A bicycle is not infinitely better. In fact, due to emissions from agriculture and livestock and inefficiency of conversion of food to mechanical work, if you have a heavily meat-based or fresh-fruit-Based diet (neither of which are common, I admit), the extra calories spent biking can actually have worse CO2 emissions than an electric car per mile.

Source for this?

Re: Reducing pollution from boats by switching to electric motors

#66

Post by semi-extrinsic »

liability wrote: post #47
jimmaswell wrote: post #38

Earlier quoted context omitted.

Is 2 stroke really that common for personal-use boats? I've only heard of them running on 93 gas, which is all I see sold at marinas, no oil to mix in.

I've seen tiny outriggers used for fishing,etc that are two-stroke. Maybe some jet skis too? I'm not sure. Certainly anything substantial won't be two-stroke.

Evinrude's E-Tec line is two-stroke and goes up to 150 horsepower in the G1 series, and to 300 horsepower in the recent G2. That's pretty substantial.

OTOH, they have done a lot of engineering to meet emissions requirements, so they are a far cry from grandpa's old outboard that left trails of blue smoke.

Re: Reducing pollution from boats by switching to electric motors

#67

Post by sokoloff »

adrianN wrote: post #60
TylerE wrote: post #54

Earlier quoted context omitted.

If there was zero slippage there would be zero acceleration.

That's not very intuitive. Can you provide a longer explanation for this?

Here's a pretty decent, graspable explanation: https://physics.stackexchange.com/questions/142463/does-a-ti...

Tires that are not slipping are not creating any force against the road surface (so they don't have to slip when coasting, but will slip while accelerating longitudinally [braking or accelerating fore/aft] or laterally [cornering]).

Re: Reducing pollution from boats by switching to electric motors

#68

Post by sokoloff »

jmpman wrote: post #64
TylerE wrote: post #54

Earlier quoted context omitted.

If there was zero slippage there would be zero acceleration.

My understanding is that tires, even when accelerating, can operate in the static coefficient of friction range. And, you want them to operate in the range, because it provides the greatest acceleration. But, maybe my mental model is wrong. The following video is from someone who has considered it much more in depth. https://youtu.be/iyeLXkacocA

That is a "driver's view" of tire slip (for best results, don't spin or slide the tires too much) rather than a chassis or tire engineer's view of tire slip (if you don't slip the tires, you can't generate any force).

Re: Reducing pollution from boats by switching to electric motors

#69

Post by swayvil »

softgrow wrote: post #14

Its not just boats going electric with positive results. Electric chainsaws starting to appear on trial near me for emergency services dealing with fallen trees. Much less noise, no smell (two stroke) and recharges itself on the truck. Just need someone to invent a self cleaning and sharpening one :)

I've got an electric chainsaw (Kobalt 40v).

Pros : quiet, clean, light, ultra-reliable

Cons : weak. Not good for cutting up medium-to-large trees. Only good for softwood under 9", hardwood under 4"

I don't do much serious treefelling these days so I prefer it. And if I need a Husqvarna 350 or whatever I borrow it.

Re: Reducing pollution from boats by switching to electric motors

#70

Post by cle »

crazygringo wrote: post #17

I've always loved being on the water, but had a kind of instinctual revulsion at the gas usage, the fumes, the oil that leaks into the water, and the sheer noise from the engine -- like boating is about being with nature, but the gasoline aspect just ruins it for me. I tried sailing, but even then you need a backup motor and to get in/out of the oil-soaked harbor. (And sailing is a lot of work.) The idea of electric…

I actually rode on a boat with one of their motors, and it was a very positive experience, having grown up with gas-powered boats. It felt much less invasive and more like I was enjoying nature and the water, rather than just enjoying the boat. Like being on a sailboat. And you look down and don’t see the rainbow swirls of gas/oil in the water. I don’t know how much oil they actually leak, probably very low/none.
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