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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

#101

Post by sokoloff »

jmpman wrote: post #81
jmpman wrote: post #76

Earlier quoted context omitted.

Would you say that a rubber belt on a pulley is slipping? I’m sure at a microscopic level there are some places where the belt isn’t making perfect contact and the rubber is slipping across the pulley, but at a macro level, the belt remains in contact with the pulley in the same place from when it initially contacts until it disconnects.

https://youtu.be/ZVW9uMeFXK8 Yet another video about static coefficient of friction on tires that aren’t slipping. Electric cars are more easily able to keep their tires in this maximum static coefficient of friction range, maximizing acceleration.

At a micro level, I would say that a rubber V-belt on a pulley which is transferring significant force is slipping as an unavoidable element of delivering that force.

What traction control/ABS does is keep the the tire slip ratio in the right range to optimize acceleration. https://www.researchgate.net/figure/Typical-tire-longitudina...

What we intuit about whether or not we're slipping our tires every time we brake for and then drive away from a traffic light "without slipping them" is not actually correct at a micro level. With respect to this thread, it is the micro level that is relevant to tire wear and resulting particulate emissions from that slippage.

Re: Reducing pollution from boats by switching to electric motors

#102

Post by cmcaine »

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.

This is hardly a full lifecycle assessment.

The assertion is true only for cyclists eating a mad diet and only if:

1. Motorists really do eat less food than cyclists, controlling for other factors.

2. You only count transit-energy emissions (not construction or recycling or road maintenance or healthcare etc).

To my knowledge, there is no evidence that active travel modes are associated with greater calorie consumption. There is plenty of evidence that all kinds of important externalities are worse for any kind of car-travel versus cycling.

You can perhaps make an argument based on average lifespan that motoring is better for the environment because it costs more life years per km, but advocating for shorter lives in the name of carbon emissions is not going to be popular (and if so, there are less polluting ways to do it).

Re: Reducing pollution from boats by switching to electric motors

#103

Post by andyrebele »

ElKrist wrote: post #92
andyrebele wrote: post #77

Earlier quoted context omitted.

There are 15.7 million recreational power boats in the US alone (1 for every 10 households), 70% of those in the installed base are powered by outboard motors. This is not the car market, but it is not tiny.

If you have numbers about how often these recreational boats are used I'd be interested

There are all sorts of surveys, but the best source I've found for real data on how much these boats are used is this official report on fuel usage (2013):

https://www.fhwa.dot.gov/policyinformation/pubs/pl17012.pdf

Basically, it indicates that recreational boats use 1% of the fuel of all passenger cars.

Re: Reducing pollution from boats by switching to electric motors

#104

Post by sunstone »

ajross wrote: post #25

What this article is really saying is "Two stroke engines are outrageously nasty". Which we knew. They really are dozens of times worse for immediate pollutants (soot/particulates, hydrocarbons, NOx) than a routine car engine and catalytic converter. And they're significantly less efficient, so even their CO2 output is quite a bit higher than a gas engine of the same power. But they're a tiny market and no one has bo…

My understanding is that things are a little more complex than they appear. Take a look at the Tohatsu offerings [1]

They offer both 4 stroke and "TLDI" versions of many of their outboards. The TLDI is a two stroke but with updated tech that meets pollution standards and the oil is not mixed with the gas before hand, the oil is mixed with the gas in real time from it's own separate tank with in the motor.

Tohatsu is pretty careful not to mention "two stroke" on their site because of its bad connotations from the past.

[1]https://www.tohatsu.com/outboards/all.html

Re: Reducing pollution from boats by switching to electric motors

#106

Post by andyrebele »

matt-attack wrote: post #90
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 grew up in the 80s & 90s running a 150HP 2-stroke Mercury outboard. Fed it oil on each fill-up. Amazing sounding engine, but in hindsight, horribly polluting.

With that outboard at wide-open-throttle, you were emitting ~ 4 gallons of unburned gasoline per hour out the exhaust, not to mention the oil you cited.

Re: Reducing pollution from boats by switching to electric motors

#107

Post by Accujack »

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.

Common misconception. I purchased my boat for $3000, and have spent around $12000 on it in four years making it safe and cleaning it up.

I don't have the money to pay for a $20,000 retrofit to electric power. I can't afford a Tesla, either.

Re: Reducing pollution from boats by switching to electric motors

#108

Post by Accujack »

jessaustin wrote: post #29
Accujack wrote: post #22

Earlier quoted context omitted.

They're selling a 25-40 hp equivalent. My boat needs something like two 75 HP motors to run safely at displacement speeds, and much more to get on plane. In case you're curious, it's about 10M long. You have to have a larger boat to travel away from shore with any safety... small boats have to stick to the coast. My boat isn't actually very big, and doesn't have the range or stability to travel between continents awa…

It's understandable that the first useful motors would be smaller than you seem to require. Big boats are fun and useful, but so are small boats. Someone will eventually make motors big enough for your needs. In the meantime, other boaters will enjoy the motors described in TFA. If you want to "travel between continents", get a sailboat. No powerboat is practical for that. If you're just talking about a fishing trip,…

>If you want to "travel between continents", get a sailboat. No powerboat is practical for that

Not true. Lots of power cruisers are out there, and all commercial traffic (cargo, people shipping, etc) happens via motor vessels.

Re: Reducing pollution from boats by switching to electric motors

#109

Post by gmiller123456 »

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…

Try kayaking. I've been doing it for 15 years, you get all the joy of being on the water, and can go more remote places than the bigger boats can.

Re: Reducing pollution from boats by switching to electric motors

#110

Post by uoaei »

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.

What's the dominant source of dust on the road? Would expect a large amount of that to be tire/brake wear.
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